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Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong长石Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong云母Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong蒙脱石Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong高岭石Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong碎石土Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong砂土Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong粉土Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong粘性土Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong云母Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(一)推土机施工(一)推土机施工Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong水工程施工水工程施工Shui Gong Cheng Shi GongShui Gong Cheng Shi Gong第一章第一章 土石方工程与地基处理土石方工程与地基处理Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2 2、反铲挖土机、反铲挖土机l 反铲挖土机工作特点:反铲挖土机工作特点:l 是开挖停机面以下的土壤,不需设置进出口通道。适用于开挖管沟和基槽,也可开挖小型基坑。尤其适用于开挖地下水位较高或泥泞的土壤。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong反反铲铲挖挖土土机机传传动动方方式式:有液压传动和机械传动两种。表1-15为机械传动反铲挖土机的主要技术性能及工作尺寸。常用反铲主要技术性能表1-15技术参数符号单位数据土斗容量支杆长度斗柄长度支杆倾角最大挖掘深度最大挖掘半径卸土开始时半径卸土终止时半径卸土开始时高度卸土终止时高度qLL1xHRR1R2H1H2m3mm度mmmmmm0.55.52.8455.569.204.668.102.205.26605.569.203.537.003.106.14Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 沟端开挖:挖土机停在沟槽一端,向后倒退挖土,汽车可在两旁装土,此法采用较广。其工作面宽度较大,单面装土时为1.3R,双面装土时为1.7R,深度可达最大挖土深度H。l 沟侧开挖:挖土机沿沟槽一侧直线移动挖土。此法能将土弃于距沟边较远处,可供回填使用。由于挖土机移动方向与挖土方向相垂直所以稳定性较差,而且开挖深度和宽度(一般为0.8R)也较小,也不能很好控制边坡 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3 3、拉铲、拉铲挖土机挖土机l 拉铲挖土机的工作装置简单,可由起重机改装。拉铲的开挖方式,基本上与反铲挖土机相似拉铲的开挖方式,基本上与反铲挖土机相似,也可分为沟端开挖和沟侧开挖 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong常用拉铲挖土机的主要技术性能,见表1-16。技术参数单位W-501W-1001铲斗容量铲臂长度铲臂倾斜角度最大卸土高度最大卸土半径最大挖掘半径侧面挖掘深度正面挖掘深度m3m度mmmmm0.51.010131316303.510.011.14.47.3455.58.310.23.85.6305.312.514.36.610.0458.010.413.25.97.8304.212.814.45.88.5456.910.813.24.97.4305.715.417.58.012.2459.012.916.27.19.6Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl4 4、抓铲挖土机、抓铲挖土机l 抓铲挖土机一般由正、反铲液压挖土机更换铲土斗换上合瓣式抓斗而成,也可由履带式起重机改装。可用以挖掘面可用以挖掘面积较小,深度较大的沟槽沉井或独立柱积较小,深度较大的沟槽沉井或独立柱基的基坑,最适宜于进行水下挖土,基的基坑,最适宜于进行水下挖土,如放置在驳船上,开挖地面水取水构筑物基础水下土石方。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl图1-38为合瓣铲挖土机示意图,图1-39为拉铲产用三角形挖土方法。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong单斗挖土机生产率计算:单斗挖土机纯工作小时生产率Ph可按下列公式计算:(m3/h)(1-43)式中:q土斗容量(m3)n每分钟挖土次数;Tp挖土机每次循环延续时间(s)K系数,一般为0.60.87Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong单斗挖土机台班生产率Pd按下式计算:(1-44)式中:KB工作时间利用系数:在向汽车装土时,KB为0.680.72在侧向堆土时,KB为0.780.88挖爆破后的岩石时,KB为0.60;土斗容量愈小,KB值愈低。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)多斗挖土机(二)多斗挖土机施工施工l1、多斗挖土机的性能及其开挖方式l 多斗挖土机又称挖沟机、纵向多斗挖土机。与单斗挖土机比较,它有下下列列优优点点:挖土作业是连续的,在同样条件下生产率较高;开挖每单位土方量所需的能量消耗较低;开挖沟槽的底和壁较整齐;在连续挖土的同时,能将土自动卸在沟槽一侧。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl挖沟机不宜开挖坚硬的土和含水量较大的土。它宜于开挖黄土,粉质粘土等。l挖沟机由工作装置、行走装置和动力、操纵及传动装置等部分组成。挖沟机的类型,按工作装置分为链斗式和轮斗式两种。按卸土方法分为装有卸土皮带运输器的和未装卸土皮带运输器的两种。通常挖沟机大多装有皮带运输器。行走装置有履带式、轮胎式和履带轮胎式三种。动力一般为内燃机。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl链斗式挖沟机的构造如图1-40 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl挖沟机土斗装设有围绕斗架的无极斗链上。土斗前端用铰链连接于斗链,后端自由地悬挂。斗架位于机械后部,前端有钢索连接于升降斗架的卷筒,并有滚子嵌在凹槽形的导轨内。开动卷筒,通过钢索使斗架沿导轨升降,改变沟槽开挖深度。l动力装置通过传动机构使主动链轮转动,带动斗链转动,于是没入土中的土斗切土。当土斗上升至主动链轮处,其后端即与斗链分开而卸土,土沿堆土板滑下,由装设在堆土板下方的皮带运输器卸至机器一侧。皮带运输器由一马达带动,其运行的方向与挖沟机的开行方向垂直。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl沟槽开挖宽度与土斗宽度相同。为加大开挖宽度,可在土斗两旁各装设一铸造钢制的括耳,使开挖宽度由0.8m加大至1.1m。如要增加挖深,可更换较长的斗架。l挖沟机开挖的沟槽断面一行贿受贿为直槽,但更换工作装置(图1-41)后,也可挖成梯形槽。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl轮斗式与链斗式挖沟机的主要区别,在于前者的土斗是固定在圆形的斗轮上,斗轮旋转使土斗连续挖土。当土斗旋升到斗轮顶点时,土即卸至皮带运输器上被运出卸在沟槽一侧。斗轮通过钢索升降改变挖土深度。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 当地面具有较大横向坡度时,采用可调节轮轴的挖沟机(图1-42) Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong2、挖沟机的生产率计算挖沟机生产率Ph可按下式计算:( m3/h) ( 1-45)式中:n土斗每分钟挖掘次数;q土斗容量(L);Kc斗的充盈系数;KP土的最初可松性系数;K土的开挖难易程度系数;KB时间利用系数。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong第四节 土方施工发生塌方与流砂的处理 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl在土石方开挖施工中,由于处理不当,常会发生边坡塌方和产生流砂现象。l(一)边坡塌方(一)边坡塌方l沟槽、基坑边坡的稳定,主要是由土体的内摩阻力和粘结力来保持平衡的。当土体失去平衡,边坡就会塌方。边坡塌方会引起人身事故,同时也妨碍施工正常进行,严重塌方还会危及附近建筑物的安全 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl发生边坡塌方的原因发生边坡塌方的原因有以下几点:l1、基坑、沟槽边坡放坡不足,边坡过陡,使土体本身的稳定性不够。在土质较差开挖深度较大时,常遇到这种情况;l2、降雨、地下水或施工用水渗入边坡,使土体抗剪能力降低,这是千万塌方的主要原因;l3、基坑、沟槽上边缘附近大量堆土或停放机具;或因不合理的开挖坡脚及受地表水、地下水冲蚀等,增加了土体负担,降低了土体的抗剪强度而引起滑坡和塌方等。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl针对上述分析,为了防治滑坡和塌方,应采取如下措施:注意地表水、地下水的排除;严格按不同土质放坡规定,放足边坡;当开挖深度大,施工时间长、边坡有机具或堆置材料等情况,边坡应平缓;当因受场地限制,或因放皮增加土方量过大,则应采用设置支撑的施工方法。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)流砂的防治(二)流砂的防治l 流砂现象流砂现象:在沟槽、基坑开挖低于地下水位,且采用坑(槽)内抽水时,有时发生坑底下面的土形成流动状态,随地下水涌进坑内而产生流砂。流砂严重时会引起沟槽、基坑边坡塌方、滑坡,如附近有建筑物,会因地基被掏空而使建筑物下沉、倾斜,甚至倒塌。因此,在土方施工时必须消除地下水的影响。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)流砂的防治(二)流砂的防治l 流砂现象流砂现象:在沟槽、基坑开挖低于地下水位,且采用坑(槽)内抽水时,有时发生坑底下面的土形成流动状态,随地下水涌进坑内而产生流砂。流砂严重时会引起沟槽、基坑边坡塌方、滑坡,如附近有建筑物,会因地基被掏空而使建筑物下沉、倾斜,甚至倒塌。因此,在土方施工时必须消除地下水的影响。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 流砂防治的措施流砂防治的措施:水下挖土法(此法在沉井不排水挖土下沉施工中常用)、打钢板桩法、地下连续墙法(施工工艺复杂,成本高,多用于高层建筑、工业建筑地下工程及水利工程)等,而采用较广并较可靠的方法是人工降低地下水法。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)滑坡体施工中的作业(三)滑坡体施工中的作业方法方法l首先应对滑坡区的地质资料作好调查研究。据此正确选择施工程序,并拟定合理的施工方法,确定保持滑坡体稳定的边坡坡度,预防滑坡发生。在进行开挖和填方时,应注意以下几点: Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、在靠近滑坡边沿处开挖土方l一般不应切割滑坡体的坡脚,当必须切割坡脚时,应按切割深度,将坡脚随原自然坡度由上向下削坡,逐渐挖至要求的坡脚深度,如图1-43所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 2、在滑坡体上挖填土方l (1)当需在滑坡内挖方时,应遵守由上至下的开挖程序,如滑坡土方量不大,所有滑坡体应全部挖除;l (2)在滑坡体上进行填方时,应遵守由下至上的施工顺序。此外,尚须在滑坡体的坡脚处,填筑能抵抗滑坡体下滑的土体。如图1-43(b)所示的土体I,图中土体II为填土区域,施工程序是由下向上填筑 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong第五节第五节 沟槽及基坑支撑沟槽及基坑支撑l支撑是防止沟槽土壁坍塌的一种临时性挡土结构,由木材或钢材做成。l支撑的荷载就是原土和地面荷载所产生的侧土压力。l沟槽支撑与否应根据土质、地下水情况、槽深、槽宽、开挖方法、排水方法、地面荷载等因素确定。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl支撑结构应满足下列要求支撑结构应满足下列要求:l1、牢固可靠,进行强度和稳定性计算和校核。支撑材料要求质地和尺寸合格,保证施工安全。l2、在保证安全的前提下,节纸用料,宜采用工具式钢支撑。l3、便于支设和拆除及后续工序的操作。l 为了做到上述要求,支撑材料的选用、支设和使用过程,应严格遵守施工操作规程 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl一、支撑种类及其适用条件一、支撑种类及其适用条件 l 沟槽支撑形式:沟槽支撑形式:有横撑、竖撑和板桩撑,开挖较大基坑时还采用锚碇式支撑等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 1、横撑和竖撑:l横撑和竖撑板(挡土板)、立柱和撑杠组成。横撑式支撑,根据挡土板放置方式的不同,可分成:水平挡土板断续式和连续式两种。断续式横撑是撑板之间有间距;连续式横撑是各撑板间密接铺设。竖撑为挡土板垂直连续放置。l断续式横撑适用于开挖湿度小的粘性土及挖土深度小于3m时。连续式横撑用于较潮湿的或散粒土及挖深不大于5m的沟槽。竖撑用于松散的和湿度高的土,挖土深度可以不限 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl撑板(挡土板)分木制和金属制两种。木撑板不应有纹裂等缺陷;金属撑板由钢板焊接于槽钢上拼成,槽钢间用型钢连系加固。金属撑板每块长度分2、4、6m几种类型 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl立柱和横杠通常采用槽钢。l撑杠由撑头号和圆套管组成,如图1-46所示。撑头为一丝杠,以球铰连接于撑头板,带柄螺母套于丝杠。应用时,将撑头丝杠插入圆套管内,旋转带柄螺母,柄把止于套管端,而丝杠伸长,则撑头板就紧压立柱,使撑板固定。丝杠在套管内的最短长度应为20cm ,以保证安全。这种工具式撑杠的优点是支设方便,而且可更换圆套管长度,适用于各种不同的槽宽 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、锚碇式支撑:在开挖较大基坑或使用机械挖土,而不能安装撑杠时,可改用锚碇式支撑。 锚桩必须设置在土的破坏范围以外,挡土板水平钉在柱桩的内侧,柱桩一端打入土内,上端用拉杆4与锚桩拉紧,挡土板内侧回填土。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl在开挖较大基坑,当有部分地段下部放坡不足时,可以采用短桩横隔板支撑或临时挡土墙支撑,以加固土壁。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 3、钢板桩撑l在开挖深度较大的沟槽和基坑,当地下水很多且有带走土粒的危险时,如未采用降低地下水位法,可采用打设钢板桩撑法。使板桩打入坑底以下一定深度,增加地下水从坑外流入坑内的渗流路线,减少水力坡度,降低动水压力,以防止流砂发生 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl施工中常用的钢板桩多是槽钢或工字钢组成,或用特制的钢桩板 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl桩板与桩板之间均采用啮口连接,以便提高板桩撑的整体性和水密性。特殊断面桩板惯性矩大且桩板间啮合作用高,故常在重要工程上采用。l桩板在沟槽或基坑开挖前用打桩机打入土中,在开挖及其后续工序作业中,始终起保证安全作用。板桩撑一般可不设横板和撑杠,便当桩板入土深度不足时,仍应辅以横板与撑杠 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 二二 、支撑的计算、支撑的计算l 支撑计算包括确定撑板、立柱(或横木)和撑杠的尺寸。通常,支撑构件的尺寸取决于现场已有材料的规格,因此,支撑计算只是对已有构件进行校核,根据校核适当调整立柱和横撑的间距,以确定支撑的形式 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl支撑承受的土压,根据产测资料表明,在排除地下水的情况下,作用在支撑上的土压力分布如图1-51所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong其侧土压力P:对砂取对软粘土取H-4c。式中Ea为主动土压力系数,为土的内摩擦角Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(一)撑板的计算l撑板按简支梁计算,如图1-52所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong计算跨度等于立柱或横木的间距l1,每块撑板的宽度为b,厚度为d,所承受的均布荷载等于Pb(kN/m)。撑板的最大弯矩:撑板的抵抗矩:因此,撑板的最大弯曲应力为:式中w材料容许弯曲应力。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)立柱计算l立柱所受的荷载q等于撑板所传递的侧土压力,支点反力R,如图1-53所示。计算时,假设在支座(横撑)处为简支梁,求其最大弯矩,较核最大弯曲应力。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)撑杠计算l撑杠为承受以柱或横木支点反力的压杆,计算时应考虑纵向弯曲,即将抗压强度乘以轴心受压构件稳定系数值(查手册可得)。l施工现场常采用的支撑构件尺寸为:l 木撑板一般长26m,宽度2030m,厚50m。横木的截面尺寸一般为10cm15cm20cm20cm(视槽宽而定)。立柱的截面尺寸为10cm10cm20cm20cm(视槽深而定)。槽深在4m以内时,立柱间距为1.5m左右;槽深46m,立柱间距在断续式横撑中为1.2m,连续式支撑为1.5m;槽深610m,立柱间距1.5m1.2m。撑杠垂直间距一般为1.21.0m Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl三、支撑的设置和三、支撑的设置和拆除拆除l 逐层开挖逐层支设,支设程序一般为:首先支设撑板并要求紧贴槽壁,而后安设立柱(或横木)和撑杠,必须横平竖直,以设牢固。l 竖撑支设过程为:将撑板密排立贴在槽壁,再将横木在撑板上下两端支设并加撑杠固定。然后随着挖土,撑板底端高于槽底,再逐块将撑板锤打到槽底。根据土质,每次挖深5060cm,将撑板下锤一次。撑板锤至槽底排水沟底为止。下锤撑板每到1.21.5cm,再加撑杠一道。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 施工过程中,更换立柱和撑杠位置,称倒撑。当原支撑妨碍下一工序进行;原支撑不稳定;一次拆撑有危险;或因其他原因必须重新安设支撑时,均应倒撑。l 在施工期间,应经常检查槽壁和支撑的情况,如发现槽壁有塌方预兆,应加设支撑,而不应倒拆支撑。l 沟槽内工作全部完成后,才可将支撑拆除。拆撑与沟槽回填同时进行,边填边拆。拆撑时必须注意安全继续排除地下水,避免材料损耗。遇撑板和立木较长时,可在还土后或倒撑后拆除 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong第六节第六节 土方回填土方回填 l l 回填的施工过程包括回填的施工过程包括:l 还土、摊平、夯实、检查等工序。l 沟槽回填应在管道验收后进行,基坑要在构筑物达到足够强度再进行回填土方。但回填也应及早开始,避免槽(坑)壁坍塌,保护已建管道的正常位置,而且尽早恢复地面平整。其中关键工序是夯实,应符合设计所规定的密实度(回填土的密实度要求和质量指标通常以压实系数c表示)要求。 l Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 埋设在沟槽内的管道,承受管道上方及两侧土压和 面上的静荷载或动荷载。如果提高管道两侧(胸腔)和管顶的回填土密实度,可以减少管顶垂直土压力。根据经验,沟槽各部位的回填土密实度,如图1-54所示。胸腔、管顶及管顶以上50cm范围内填土的密实度不小于95%(压实系数c不小于0.95)。l 基坑回填的密实度要求应由设计根据工程结构性质,使用要求以及土的性质确定。一般压实系数c为0.9或0.9以上 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl一、回填土方的压实方法一、回填土方的压实方法l 沟槽和基坑回填压实方法有夯实和振动。振动不是将重锤放在土层表面或内部,借助振动设备使重锤振动,土壤颗粒即发生相对位移达到紧密状态。此法用于振实非粘性土壤 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl夯实法l 是利用夯锤自由下落的冲力来夯实土壤,是沟槽、基坑回填常用的方法。l 夯实法使用的机具类型较多,常采用的机具有:蛙式打夯机、内燃打夯机、履带式打夯机以及压路机等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(一)蛙式夯(一)蛙式夯l 由夯头架、拖盘、电动机和传动减速机构组成(图1-56)。蛙式夯构造简单、轻便,在施工中广泛使用 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 夯土时,电动机经皮带轮二级减速,使偏心块转动,摇相绕拖盘上的连接铰转动,使拖盘上下起落。夯头架也产生惯性力,使夯板作上下运动,夯实土方。同时蛙式夯利用惯性作用自动向前移动。l 夯土前,应根据密实度要求及土的含水量,由试验确定夯土制度。施工实践表明,采用功率2.8kw蛙式夯,在最佳含水量条件下,铺土厚20cm,夯击34遍,可达到回填土密实度要求的压实系数c=0.95左右 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl( (二)内燃二)内燃打夯机打夯机l 又称“火力夯”,由燃料供给系统、点火系统、配气机构、夯身夯足、操纵机构等部分组成 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 打夯机启动时,需将机身抬起,使缸内吸入空气,雾化的燃油和空气在缸内混合,然后关闭气阀,靠夯身下落将混合气压缩,并经磁电机打火将其点燃。混合气在缸内燃烧所产生的能量失去活塞,使夯轴和夯足作用于地面。在冲击地面后,夯足跳起,整个打夯机也离开地面,夯足的上升动能消尽后,又以自由落体下降,夯击地面。l 火力夯可用以夯实沟槽、基坑、墙边墙角还土较为方便 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)履带式打夯机(三)履带式打夯机 履带式打夯机(图1-58),可利用挖土机或履带式起重机改装重锤后而成。打夯机的锤形有梨形、方型,锤重14t,夯击土层厚度可达11.5m。适用于沟槽上部夯实或大面积回填土方夯实。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl二、土方回填的施工要点二、土方回填的施工要点l1、还土一般用沟槽或基坑原土。l 在土中不应含有粒径大于30mm的砖块;粒径较小的石子含量不应超过10%。l 回填土土质应保证回填密实。不能采用淤泥土、液化状粉砂、细砂、粘土等回填。当原土属于上类土时,应换土回填。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、回填土应具有最佳含水量。l 高含水量原土可采用晾晒,或加白灰掺拌使其达到最佳含水量。l 低含水量原土则应洒水。当采取各种措施降低或提高含水量的费用较换土费用高时,则应换土回填。有时,在市区繁华地段,交通要道、交通枢纽处回填,或为了保护附近建筑物安全,或为了当年修路,可将道路结构以下部分由砂石、矿渣等换土回填 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 还土时沟槽或基坑应继续排水,防止槽壁坍塌和管道或构筑物漂浮事故。采用明沟排水,还土从两相邻集水井的分水处开始和集水井延伸。不应带水回填。雨季施工时,必须及时回填。为了防止产生浮管事故,回填时也可在管内灌水。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 回填前,应建立回填制度。回填制度是为了保证回填质量而制定的回填操作规程。例如根据构筑物或管道特点和回填密实度要求,确定压实工具、还土土质、还土含水量、还土铺土厚度,压实后厚度、夯实工具的夯击次、走夯形式等。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 沟槽回填,应在管座混凝土强度达到5Mpa后进行。回填时,两侧胸腔应同时分层还土摊平,夯实也应同时同一速度前进。管子上方土的回填,从纵断面上看,在厚土层与薄土层之间,已夯实土与未夯实土之间,均应有一较长的过渡地段,以免管子肥压不匀发生开裂。相邻两层回填土的分段位置应错开 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 胸腔和管顶上50cm内范围夯实时,夯击力过大,将会使管子壁或管沟壁开裂。因此,应根据管子和管沟的强度确定回填方法。管顶以上100150cm还土方可使用碾压机械压实。基坑回填时,也应使构筑物两侧回填土高度一致,并同时夯实。l 每层土夯实后,应检测密实度。测定的方法有环刀法和贯入法两种。采用环刀法时,应确定取样的数目和地点。由于表面土常易夯碎,每个土样应在每层夯实土的中间部分切取。土样切取后,根据自然密度、含水量、干密度等数值,即可算出密实度。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 胸腔和管顶上50cm内范围夯实时,夯击力过大,将会使管子壁或管沟壁开裂。因此,应根据管子和管沟的强度确定回填方法。管顶以上100150cm还土方可使用碾压机械压实。基坑回填时,也应使构筑物两侧回填土高度一致,并同时夯实。l 每层土夯实后,应检测密实度。测定的方法有环刀法和贯入法两种。采用环刀法时,应确定取样的数目和地点。由于表面土常易夯碎,每个土样应在每层夯实土的中间部分切取。土样切取后,根据自然密度、含水量、干密度等数值,即可算出密实度。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3、回填应使槽上土面略呈拱形,以免日久因土沉陷而造成地面下凹。拱高,亦称余填高,一般为槽宽的1/20,常取15cm 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl第七节第七节 地基处理地基处理 地基处理使用条件:在工程实际中,常遇到一些软弱土层如:土质疏松、压缩性高、抗剪强度低的软土,松散砂土和未经处理的填土。当在这种软弱地在上直接修建建筑物不可能时,往往需要对地基进行加固或处理。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl地基处理的目的是地基处理的目的是:l1、改善土的剪切性能,提高抗剪强度。l2、降低软弱土的压缩性,减少基础的沉降 l 或不均匀沉降。l3、改善土的透水性,起着截水、防渗的作用。l4、改善土的动力特性,防止砂土液化。l5、改善特殊土的不良地基特性l(主要是指消除或减少湿陷性黄土的湿陷性和膨胀土的胀缩性等) Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl地基处理的方法地基处理的方法:l有有换土垫层、挤密与振密、碾压与夯换土垫层、挤密与振密、碾压与夯实、排水固结和浆液加固等五类。实、排水固结和浆液加固等五类。l地基处理技术方面发展很快,各种方法的具体采用,应从当地地基条件、目的要求、工程费用、施工进度,材料来源、可能达到的效果以及环境影响等方面进行综合考虑。并通过试验和比较,采用合理、有效和经济的处理方案,必要时还需要在构筑物整体性方面采用相应的措施。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl一、换土垫层一、换土垫层l 换土垫层是一种直接置换地基持力层软弱土的处理方法。施工时将基底下一定深度的软弱土层挖除,分层填回砂、石、灰土等材料,并加以夯实振密。换土垫层是一种较简易的浅层地基处理方法,在各地得到广泛应用。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(一)砂垫层(一)砂垫层地基处理方法分类表1-17分类处理方法原理及作用适用范围换土垫层素土垫层砂垫层碎石垫层挖除浅层软土,用砂、石等强度较高的土料代替,以提高持力层土的承载力,减少部分沉降量;消除或部分消除土的湿陷性、胀缩性及防止土的冻胀作用;改善土的抗液化性能适用于处理浅层软弱土地基、湿陷性黄土地基(只能用灰土垫层)、膨胀土地基、季节性冻土地基挤密振实砂桩挤密法灰土桩挤密法石灰桩挤密法振冲法通过挤密或振动使深层土密实,并在振动挤压过程中,回填砂、砾石等材料,形成砂桩或碎石桩,与桩周土一起组成复合地基,从而提高地基承载力,减少沉降量适用于处理砂土粉土或部分粘土颗粒含量不高的粘性土碾压夯实机械碾压法振动压实法重锤夯实法强夯法通过机械碾压或夯击压实土的表层,强夯法则利用强大的夯击,能迫使深层土液化和动力固结而密实,从而提高地基土的强度,减少部分沉降量,消除或部分消除黄土的湿陷性,改善土的抗液化性能。一般适用于砂土、含水量不高的粘性土及填土地基。强夯法应注意其振动对附近(约30m内)建筑物的影响Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong排水固结堆载预压法砂并堆载预压法排水纸板法井点降水预压法通过改善地基的排水条件和施加预压荷载,加速地基的固结和强度增长,提高地基的强度和稳定性,并使基础沉降提前完成适用于处理厚度较大的饱和软土层,但需要具有预压的荷载和时间,对于厚的泥炭层则要慎重对待浆液加固硅化法旋喷法碱液加固法水泥灌浆法深层搅拌法通过注入水泥、化学浆液、将土粒粘结;或通过化学作用机械拌和等方法,改善土的性质,提高地基承载力适用于处理砂土、粘性土、粉土、湿陷性黄土等地基,特别适用于对已建成的工程地基事故处理Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl砂垫层适用于处理软土地基,见图Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、其材料必须具有良好的振密加密性能。宜采用砾砂、中砂和粗砂。若只用细砂时,宜同时均匀掺入一定数量的碎石或卵石(粒径不宜大于50mm)。l2、砂和砂石垫层材料的含泥量不应超过5%。l3、 砂垫层施工的关键是将砂石材料振密加密到设计要求的密实度(如达到中密)。目前,砂垫层的施工方法有振密法、水撼法、夯实法、碾压法等多种,可根据砂石材料、地质条件、施工设备等条件选用,参见表1-18。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong砂和砂石垫层的施工方法及每层铺筑厚度、最佳含水量表1-18项次捣实铺筑厚度(mm)每层铺筑厚度(mm)施工时的最佳含水量(%)施工说明备注1平振法2002501520用平板式振捣器往复振捣(宜用功率较大者)不宜使用于细砂或含泥量较大的砂2插振法振捣器插入深度饱和1、用插入式振捣器2、插入间距可根据机械振幅大小决定3、不应插至下卧粘性土层4、插入振捣完毕后,所留的孔洞,应用砂填实不宜使用于细砂或含泥量较大的砂Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong3水撼法250饱和1、注水高度应超过每次铺筑面层2、用钢叉摇撼捣实,插入点间距为100m3、钢叉分四齿,齿的间距8cm,长300mm,木柄长900mm湿陷性黄土、膨胀土地区不得使用4夯实法1502008121、用木夯或机械夯2、木夯重量40kg,落距0.40.5m3、一夯压半夯,全面夯实5碾压法250350812重量610t压路机往复碾压1、适用于大面积砂垫层2、不宜用于地下水位以下的砂垫层Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(二)灰土垫层(二)灰土垫层适用条件:湿陷性黄土适用条件:湿陷性黄土Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl二、挤密桩与振冲法二、挤密桩与振冲法l(一)挤密桩(一)挤密桩l 挤密桩可采用类似沉管灌注桩的机具和工艺,通过振动或锤击沉管等方式成孔、在管内灌料(砂、石灰、灰土或其它材料)、加以振实加密等过程而形成的。图系砂桩施工的机械设备。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1 1、挤密砂石桩、挤密砂石桩l(1)使用条件:挤密砂桩用于处理松散砂土、填土以及塑性指数不高的粘性土。l(2)布置方式:砂石桩宜采用等边三角形或正方形布置,直径可采用300800mm。对饱和粘土地基宜选用较大的直径。砂石桩的间距应通过现场试验确定,但不宜大于砂石桩直径的4倍 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong砂石桩孔内的填砂石量可按下式计算:式中:S填砂石量(以重量计);Ap砂石桩的截面积;L桩长;ds砂石料的相对密度;e1桩孔中砂捣实后的孔隙比;w砂石料的含水量。桩孔内的填料宜用砾砂、粗砂、中砂、圆砾、角砾、卵石、碎石等。填料中含泥量不得大于5%,并不宜含有大于50mm的颗粒Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2 2、生石灰桩、生石灰桩l 在下沉钢管成孔后,灌入生石灰碎块或在生石灰中掺加适量的水硬性掺合料(如粉煤灰、火山灰等,约占30%),经密实后便形成了桩体。生石灰桩之所以能改善土的性质,是由于生石灰的水化膨发挤密、放热、离子交换、胶凝反应等作用和成孔挤密、置换作用 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 生石灰桩直径采用300400mm,桩距33.5倍桩径,超过4倍桩径的效果常不理想。l 生石灰桩适用于处理地下水位以下的饱和粘性土、粉土、松散粉细砂、杂填土以及饱和黄土等地基。l 湿陷性黄土则应采用土桩、灰土桩 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)振冲法(二)振冲法l 在砂土中,利用加水和振动可以使地基密实。振冲法就是根据这个原理而发展起来的一种方法 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl振冲法施工的主要设备是振冲器,它类似于插入式混凝土振捣器,由潜水电动机,偏心块和通水管三部分组成。振冲器由吊机就位后,同时启动电动机和射水泵,在高频振动和高压水充的联合作用下,振冲器下沉到预定深度,周围土体在压力水和振动作用下变密,此时地面出现一个陷口,往口内填砂一边喷水振动,一边填砂密实,逐段填料振密,逐段提升振冲器,直到地面,从而在地基中形成一根较大直径的密实的碎石桩体,一般称为振冲碎石桩。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 从振冲法所起的作用来看,振冲法分为振冲置换和振冲密实两类。振冲置换法适用于处理不排水抗剪强度不小于20kPa的粘性土、粉土、饱和黄土和人工填土等地基。它是在地基土中制造一群以石块、砂砾等材料组成的桩体,这些桩体与原地基土一起构成复合地基。而振动密实法适用于处理砂土、粉土等,它是利用振动和压力水使砂层发生液化,砂颗粒重新排列,孔隙减少,从而提高砂层的承载力和抗液化能力 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl三、碾压与夯实三、碾压与夯实l(一)机械碾压(一)机械碾压l 机械碾压法采用压路机、推土机、羊足碾或其它压实机械来压实松散土,常用于大面积填土的压实和杂填土地基的处理。l 处理杂填土地基时,应首先将建筑物范围内一定深度的杂填土挖除,然后先在基坑底部碾压,再将原土分层回填碾压,还可在原土中掺入部分砂和碎石等粗粒料。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 碾压的效果主要取决于压实机械的压实能量和被压实土的含水量。应根据具体的碾压机械的压实能量,控制碾压土的含水量,选择合适的铺土厚度和碾压遍数。最好是通过现场试验确定,在不具备试验的场合,可参照表选用。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong垫层的每层铺填厚度及压实遍数施工设备每层铺填厚度(cm)每层压实遍数平碾(812t)203068羊足碾(516t)2035816蛙式夯(200kg)202534振动碾(815t)6013068振动压实机(2t,振动力98kN)12015010插入式振动器2050平板式振动器1525Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)振动压实法(二)振动压实法l 振动压实法是利用振动机振动压实浅层地基的一种方法。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 适用于处理砂土地基和粘性土含量较少,透水性较好的松散杂填土地基。l 振动压实机的工作原理是由电动机带动两个偏心块以相同速度相反方向转动而产生很大的垂直振动力。这种振动机的频率为11601180r/min,振幅为3.5mm,自重20kN,振动力可达50100kN,并能通过操纵机使它能前后移动或转弯。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 振动压实效果与填土成分、振动时间等因素有关,一般地说振动时间越长效果越好,但超过一定时间后,振动引起的下沉已基本稳定,再振也不能起到进一步的压实效果。因此,需要在施工前进行试振,以测出振动稳定下沉量与时间的关系。对于主要是由炉渣、碎砧、瓦块等组成的建筑垃圾,其振动时间约在1min以上。对于含炉灰等细颗粒填土,振动时间约为35mm,有效振实深度为1.21.5m。l 注意振动对周围建筑物的影响。一般情况下振源离建筑物的距离不应小于3m 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)重锤夯实法(三)重锤夯实法l l重锤夯实法是利用起重机械将夯锤提到一定高度,然后使锤自由下落,重复夯击以加固地基。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl适用:稍湿的一般粘性土和粉土(地下水位应在夯击面下方1.5m以上)、砂土、湿陷性黄土以及杂填土等。l夯锤:一般采用钢筋混凝土圆锥体(截去锥尖),其底面直径为11.5m,质量为1.53.0t,落距2.54.5m。经若干遍夯击后,其加固影响深度可达1.01.5m,均等于夯锤直径。当最后二遍的平均击沉量不超过1020mm(一般粘性土和湿陷性黄土)或510mm(砂土)时,即可停止夯击 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(四)强夯法(四)强夯法l 强夯法亦称动力固结法,是法国梅那技术公司于1969年首创的一种地基加固方法。这种方法是将很重的锤(一般为100400kN)从高处自由下落(落距一般为1040m),给地基土施以很大的冲击力,在地基中所出现的冲击波和动应力,可提高土的强度,降低土的压缩性,改善土的振动液化条件和消除湿陷性等作用。同时还能提高土的均匀程度,减少将来可能出现的差异沉降 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 强夯法适用于碎石土、砂土、粘性土、湿陷性黄土、填土等地基的加固。应用强夯法处理的工程范围极为广泛,有建筑、水池、公路和铁路路基、飞机跑道及码头等 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong强夯施工参数的确定1、强夯法的有效加固深度既是选择地基处理方法的重要依据,又是反映处理效果的重要参数。强夯法创始人梅那提出了用下列公式来估算影响深度H:(1-50)式中:M锤的质量(t);h落距(m)。根据国内外实践证明,有效加固深度H应按下式估算:(1-51)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl式中:K深度影响系数,其数值可参考表1-20 a作者K值Leonards(美国)0.5福冈正已(日本)0.40.7建筑科学研究院0.45(砂土、粉土为0.6)上海石油化工总厂设计院0.5太原工业大学饱和砂土(0.50.6)填土(0.60.8)湿陷性黄土(0.340.4)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、强夯点一般按正方形或梅花形布置,间距410m,夯点间距不宜过密否则将在浅层形成硬层,不利于夯击能向深度传递。l3、夯击次数应通过现场试夯确定,以夯坑的压缩量最大,夯坑周围隆起量最小为原则。可从现场试夯得到的锤击数和夯沉量关系曲线确定。但要满足最后两击的平均夯沉量不大于50mm,当夯击能量较大时不大于10mm,且夯坑周围地面不发生过大隆起。l 4、单位夯击能指单位面积上所施加的总夯击能。单位夯击能大小与地基土的类别有关,根据我国工程实践的经验,粗颗粒土单位夯击能可取10003000kNm/m2,细颗粒土为15004000 kNm/m2 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl四、预压法四、预压法l 在软土地基上建造建筑物时常因地基强度低、变形大,或易于发生滑动,而需预先加固。l 堆载预压法是在软土地区常用的方法之一。在预压堆载的过程中,饱和粘性土体孔隙水逐渐排出,地基土的强度得到了提高;而且由于预先使地基土排水固结,减少了建筑物的沉降,改善地基条件。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 土中孔隙水的排出与其渗透距离有关,当软土层很厚,单纯依靠堆载预压来排水需要很长时间,如果在土体中设置排水井,再加上堆载,就可加快排水,用排水井加堆载的方法就称为砂井堆载预压法 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl砂井堆载预压是由排水系统和加压系统两部分共同组合而成的。l(一)排水系统l设置排水系统主要在于改变地基原有的排水条件,增加孔隙水排出的途径,缩短排水距离。该系统由水平排水垫层和竖向排水体构成。竖向排水体常用的是砂井,它是先在地基中成孔,而后灌砂而成的。l近年来砂井施工技术和工艺有新的发展,出现了袋装砂井(直径小至70mm,间距1.52.0m)、塑料排水板(表层为土工织物滤水膜,中间为塑料芯板,截面尺寸一般为4mm100mm),使井孔尺寸和间距大为减小。而细而密的井孔有利于加快土的固结。目前,已研制了相应的埋设机械,使工效成倍增加 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)加压系统l1 1、堆堆载载法法:加载材料常用的有砂、石料、土料等。对于油罐、水池等构筑物常利用其本身的容积进行充水预压。l2 2、真空预压法、真空预压法:在地基中设置砂井等竖向排水体,其顶部采用砂垫层连通之后,在地表铺一层不透气的塑料膜,周边均埋在起封闭作用的粘土层中。砂垫层中埋置吸水滤管网,用真空泵抽气,使膜内气压低于大气压,形成负压,砂井中的孔隙水压力降低,被加固软土中的孔隙水流入砂井。目前实际工程的真空度可达80kP以上。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl图165表示真空预压加固的一般布置 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl 它由袋装砂井或塑料排水板、排水管线、汇水垫层、复盖不透气的塑料薄膜以及长期抽水保持膜下真空度(负压力)等整套设备组成。l 真空预压法通过抽气、降低孔隙水压力以达到固结排水的目的。这是一种实用的软土地基加固新技术。与常规堆载预压相比,可降低造价1/3,加固时间缩短1/3 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl五、浆液加固五、浆液加固l l 浆液加固法是指利用水泥浆液、粘土浆液或其它化学浆液,采用压力灌入、高压喷射或深层搅拌,使浆液与土颗粒胶结起来,以改善地基土的物理力学性质的地基处理方法。l Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(一)灌浆法(一)灌浆法l灌浆材料常可分为粒状浆液和化学浆液。l1、粒状浆液l 是指由水泥、粘土、沥青等以及它们的混合物制成的浆液。常用的是纯水泥浆、水泥粘土浆和水泥砂浆,以上称为水泥基浆液。水泥基浆液是以水泥为主的浆液,在地下水无侵蚀性条件下,一般都采用普通硅酸盐水泥砂浆,其水灰比一般为1.1。这种浆液能形成强度较高,渗透性较小的结石体。它取材容易,配方简单,价格便宜,不污染环境,故成为国内外所常用的浆液 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、化学浆液l是采用一些化学真溶液为注浆材料,目前常用的是水玻璃、其次是聚氨脂、丙烯酰胺类等。l(1)水玻璃是最古老的一种注浆材料,它具有价格低廉、渗入性较高和无毒性等优点。而一般水玻璃是碱性的,由于碱性水玻璃的耐久性较差,对地下水有碱性污染,因而目前先后出现了酸性中性水玻璃 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(2)聚氨脂注浆是70年代之后发展起来的,分水溶性聚氨脂和非水溶性聚氨脂二类。注浆工程一般使用非水溶性聚氨脂,其粘度低,可灌性好,浆液遇水即反应成含水凝胶,故而可用于动水堵漏,其操作简便,不污染环境,耐久性亦好。非水溶性聚氨脂一般把主剂合成聚氨脂的低聚物(预聚体),使用前把预聚体和外掺剂按配方配成浆液。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(3)丙烯酰胺类浆液亦称MG646化学浆液,它是以有机化合物丙烯酰胺为主剂,配合其它外加剂,以水溶液状态灌入地层中,发生聚合反应,形成具有弹性的,不溶于水的聚合体,这是一种性能优良和用途广泛的注浆材料。但该浆液具有一定毒性,它对神经系统有毒,且对空气和地下水有污染作用。l水玻璃水泥浆也是一种用途广泛、使用效果良好的注浆材料。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl灌浆方法分类:l(1)渗透灌浆l 在不改变土体颗粒间结构的前提下,浆液在灌浆压力作用下渗入土体孔隙,呈符合达西定律的层流运动。这种注浆所使用的压力一般较小,要求土层可灌性良好 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(2)劈裂灌浆l 采用增大注浆压力的方法使土体产生剪切破坏,浆液进入剪切裂缝之后在注浆压力的作用下裂缝不断被劈开,使注浆范围不断扩大,注浆量不断增加。这种注浆所需的压力较高,常适用于粘性土层的加固。l(3)压密灌浆l 使用很稠的水泥砂浆作为注浆材料,采用高压泵浆浆液压入周围土层,通过上提注浆管,形成连续的灌浆体,对土层起挤密和置换的作用。这种方法对浆材和注浆泵都有较高的要求 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl劈裂灌浆劈裂灌浆Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)高压喷射注浆法(二)高压喷射注浆法l旋喷法的施工程序见图1-66 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl先用射水、锤击或振动等方式将旋喷管置入要求的深度处,或用钻孔机钻出直径为100200mm的孔,再将旋喷管插至孔底。然后由下而上进行边旋转边喷射。旋喷法的主要设备是高压脉冲泵和特制的带喷嘴的钻头。从喷嘴喷出的高速喷流,把周围的土体破坏,并强制与浆液混合,待胶结硬化后便成为桩体,这种桩称为旋喷桩 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl高压喷射注浆法的种类有:单管法、二重管法、三重管法等多种。它们各有特点可根据工程需要和土质条件等选用。l单管旋喷法虽然加固质量好,施工速度快和成本低,但固结体(桩)直径较小 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl二重管旋喷法使用双通道的二重注浆管。在管底部侧面有一个同轴双重喷嘴,高压浆液以20Mpa左右的压力从内喷嘴中高速喷出,压缩空气以0.7Mpa左右的压力从外喷嘴中喷出。在高压浆液射流和它外圈环绕气流的共同作用下,破坏土体能量显著增大,固结体直径明显增大。l三重管旋喷法使用分别输送水、气、浆三种介质的三重注浆管。高压水射流和外圈环绕的气流同轴喷射冲切土体,形成较大空隙,再由泥浆泵注入浆液填充,喷嘴作旋转和提升,最后便在土中形成直径较大的圆桩状固结体 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl旋喷法施工的主要机具和参数见表1-21l旋喷法适用于砂土、粘性土、人工填土和湿陷性黄土等土层。其作用有:旋喷桩与桩间土组成复合地基,作为连续防渗墙,防止贮水池、板桩体或地下室渗漏;制止流砂以及用于地基事后补强等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong旋喷法施工的主要机具和参数表1-21项目单管法二重管法三重管法参数喷嘴孔径(mm)喷嘴个数(n)旋转速度(r/min)提升速度(mm/min)23220200250231210100231251550150机具性能高压泵压力(Mpa)流量(L/min)2.004.00(浆液)601202.004.00(浆液)601202.004.00(浆液)60120空压机压力(Mpa)流量(L/min)7001370013泥浆泵压力(Mpa)流量(L/min)3.05.0100150Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl使用的固化剂状态不同,施工方法亦不同,把粉状物质(水泥粉、磨细的干生石灰粉)用压缩空气经喷嘴与土混合,称为干法;把液状物质(一定水灰比的水泥浆液、水玻璃等)经专用压力泵或注浆设备与土混合,称为湿法。其中干法对于含水量高的饱和软粘土地基最为适合。l我国自1977年开始研究试验,生产出了心用和定型的SJB1型双搅拌轴、中心管输浆的深层搅拌机及其配套机械,并在很多工程中应用,取得了良好的技术经验效果。图1-67和图1-68为深层后搅拌法施工程序图SJB1型深层搅拌机构造图 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl第八节第八节 土石方爆破施工土石方爆破施工 在土石方工程施工中,爆破技术常用于地下和水下工程、基坑(槽)、管沟开挖、坚石土层或岩石的破除。此外,在场地平整、清除施工现场的障碍物及开掘冻土等,也常需要采用爆破方法施工。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl一、爆破的作用圈及爆破漏斗l 爆破,是指炸药经引爆借助其化学分解释放出的大量气体和巨大能量,使周围的介质受到各种不同程度的破坏。l(一)爆破作用圈l炸药在岩石的炮眼中爆炸,在装药内部产生爆轰波,爆轰波以20007000m/s或40006000m/s的速度沿炮眼传播。越靠近药包中心,受到的破坏就越大 。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl通常可按爆破影响的范围分为不同的爆破作用圈 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(1)破碎圈。处于药包周围的岩石直接承受巨大的冲击波压力作用而粉碎。如果是可塑性的泥土,便会遇到压缩而形成孔穴。所以破碎圈也叫压缩圈。l(2)抛掷圈。当压缩波到达临空面(即自由面)时,由自由面反射变成拉伸波。被破碎的岩石朝自由面方向扩张,脱离岩体而产生抛掷现象,并形成爆破漏斗。l(3)破坏圈。在这个范围内,虽然不产生抛掷运动,但岩石结构将受到不同程度的破坏,有的成为碎块,部分形成裂缝,相互间仍连成整体。l (4)振动圈。在这个范围内,爆破作用已减弱到不能使岩石结构产生破坏,只是发生振动。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)爆破漏斗 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl爆破漏斗是由于冲击波的作用,使部分岩石沿自由面被抛掷而形成的。它由下列参数确定:l(1)爆破漏斗半径r:即漏斗上口的圆周半径;l(2)最大可见深度h:从附落在坑内的岩石碎块表面到自由面的最大距离;l(3)最小抵抗线W:即从药包中心到自由面的最短距离;l(4)爆破作用半径R:即从药包中心到爆破漏斗上口边沿的距离。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong爆破漏斗的形状和大小,依据岩石的性质、炸药性能和药包大小、药包埋置深度等而不同。通常以爆破作用指数(n)表示,并用以区分不同的爆破类型,即式中:n爆破作用指数;r漏斗半径(m);W最小抵抗线(m)。当n=1时,即r=W,为标准抛掷爆破类型,称标准抛掷爆破漏斗。特点是部分岩石被抛出;当n1时,即rW,为加强抛掷爆破型,称为加强抛掷爆破漏斗。特点是爆后绝大部分岩石被抛出;当n1时,即rW,为减弱抛掷爆破型,称为减弱抛掷爆破漏斗。特点是爆后大部分岩石不能从漏斗中抛出Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl在爆破工作中,自由面(即岩石的临空面)愈多,爆破效果愈好。此外,炮眼设置的方向不同,爆破效果差异也很大。据实验表明炮眼垂直自由面的爆破效果仅为炮眼平行自由面的爆破效果的1/10左右 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl二、药包量计算l药包量是指炸药包的重量。药包按爆破作用分为内部作用药包、松动药包、抛掷药包(包括标准抛掷药包和加强抛掷药包)和裸露药包,如图1-71所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl内部作用药包是当药包爆炸时,破坏作用仅限于地层内部压缩,不显露到临空面。松动药包只使岩石内部破坏到临空面,但不产生抛掷运动。抛掷药包的作用是形成爆破漏斗。裸露药包是指放在被爆破体或岩石表面上的药包,爆炸后可使被爆体或岩石破碎或飞移 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl药包量的计算,除与炸药的性能和品种有关外,还要根据岩石物理力学性质、岩石构造及层理、爆破方法、临空面多少、预计爆破的石方体积,以及以往的施工经验等来确定。其计算的基本原理,是假定药包量的大小与被爆破的岩石体积和岩石的坚实程度成正比 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong1、标准抛掷药包量Q的计算在标准抛掷药包爆破的情况下,所爆除的岩石体积,即为标准爆破漏斗的体积,即:(1-53)所以Q=eqW3式中:Q所需药包重量(kg);W最小抵抗线(m)q岩石单位体积炸药消耗量(kg/m3),见表1-22e炸药换算系数,见表1-23Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong标准抛掷药包的炸药单位消耗量q值表1-22土的类别一二三四五六七八q( kg/m3)0.951.101.251.51.61.92.002.20Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong炸药换算系数e值表1-23炸药名称型号e炸药名称型号e煤矿铵梯煤矿铵梯1号2号0.971.1262%胶质炸药62%胶质炸药普通耐冻0.780.78煤矿铵梯岩石铵梯3号1号2.160.8035%胶质炸药混合胶质炸药普通普通0.930.88岩石铵梯露天铵梯2号1号、2号0.881.00黑火药梯恩梯1.001.250.921.00胶质硝铵硝酸铵1号、2号0.781.35铵油炸药1.001.20Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl表1-22以1号露天铵梯炸药为标准计算,当用其它炸药时,需乘以换算系数e值。表中所列q值,系指一个自由面的情况,如两个自由面,应乘以0.83;三个自由面乘以0.67。l表中q值是在药孔填塞良好,即堵塞系数(实际堵塞长度与计算堵塞长度之比)为1的情况下定出,如堵塞不良,应视具体情况乘以12的堵塞系数 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong2、加强抛掷药包量Q的计算当W25m时为:(1-55)式中n爆破作用指数Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong3、松动药包量Q的计算(1-56)4、内部作用药包量Q的计算(1-57)式中符号意义同式(1-53)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong由于影响爆破、破碎效果的因素很多,在实际爆破工作中,应根据下述各种条件并结合实践经验合理选择计算中的各项爆破参数确定药包量,以便获得预期的爆破效果。(1)地质条件。应了解岩石的岩性、坚硬、强度、破碎和风化程度,以及地质构造、岩层层理、节理、裂隙和断层等,这些都会影响单位体积耗药量和爆破范围、形状及破碎状态。对于坚硬、强度高且地质构造完整的岩石,需要的药包量多;节理、裂隙多和有断层的岩石,由于会引起漏气,降低爆破威力,也会影响爆破效果。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(2)地形条件。指地面的形状。如地形只有一个临空面时,炸药消耗量就大,爆破方数少;地形临空面多,爆破时受约束面小,炸药消耗量少,爆破方数也多。其相互关系可参见表1-24。药包重量、爆破体积与临空面的关系表1-24临空面数(个)药包重量系数(Kq)爆破体积系数(Ku)临 空 面 数(个)药包重量系数(Kq)爆破体积系数(Ku)1231.00.830.671.02.33.74560.500.330.175.75.58.0Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(3)施工条件。诸如装药数量和密度,有水部位的水、防潮,堵塞材料和堵塞密实程度,以及爆破技术等都会影响爆破效果Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl三、炸药和起爆器材l(一)炸药l炸药是一种由可燃元素(碳和氢)及含氧元素组成的化合物或混合物。它能在热能(加热、火花)、机械能(撞击、摩擦)或爆炸能的外界条件爱莫能作用下而产生爆炸 .l按照在爆破过程中所起的作用不同,炸药可分为主要炸药和引爆药物;根据猛烈程度,可分为缓性炸药和猛性炸药 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、主要炸药l常用的主要炸药有以下几种:l(1)砂铵炸药又称岩石炸药。它的组成成分是砂酸铵(NH4NO3)、梯恩梯(即TNT、三砂基甲苯)和水粉或煤粉等。运输及使用较为安全,但易受潮结块,以致爆炸不完全,甚至拒爆。l(2)铵油炸药l这种炸药是低敏感性炸药,由砂酸铵与少量液体燃料(轻、重柴油、煤油等)混合而成。其原料来源广,加工方法简单,使用、运输安全,成本低廉,在爆破石方中大量使用。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(3)硝化甘油胶质炸药l主要成分为硝化甘油。这种炸药威力较大,爆发反应迅速,适用于坚硬岩石的爆破。它属于猛性炸药,因此在运输和使用时要注意安全。具有防水性,可用于水下或较潮湿处的爆破工程。l(4)黑色炸药l由硝酸钾、硫黄及木炭按一定比例混合后湿磨而成的粉末状物质,为缓性炸药,爆破力较小,爆发反应迟缓,适用于中等硬度以下的岩石或开采料石。这种炸药制备简易,成本低,使用安全 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、引爆炸药l主要炸药需要有敏感度更高的引爆炸药引爆。引爆炸药有雷汞、迭氮铅、黑索金、泰安等,威力较大,一般放置在雷管中 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)起爆器材l1、导火线l导火线在爆破工程中传递火焰引燃普通雷管或药包之用。内部为黑火药芯,依次包缠有棉线,黄麻(或亚麻),四号石油沥青,牛皮纸,外面再用棉线缠紧,敷以涂料,使织物纤维不致松散。其燃烧速度约为10mm/s .l2、传爆线l外形与导火线相似,但线芯是采用猛度大爆速高的引爆炸药,如泰安、黑索金等制成,一般用于药包间的连接,以达全部药包同时爆炸的目的 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3、雷管l雷管在爆破工程中引爆炸药,是装有引爆炸药的铜、铝等金属或纸板制成的管状制品。雷管分为普通雷管和电雷管两种。l(1)普通雷管l构造如图1-72。导火线火花通过金属帽的孔口使正起爆药首先爆炸,而后副起爆药爆炸继而引起主要炸药爆炸 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(2)电雷管l构造如图1-73所示。与普通雷管相似,只是以电阴丝通电后点燃缓燃剂,从而引起炸药爆炸 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl4、电源l电气起爆的电源,有干电池、蓄电池、放炮器、照明电力线路及动力电力线等。l放炮器的规格有10发(每次能起爆串联10个电雷管)、30发、50发和100发等。干电池和蓄电池用于规模较小的爆破作业。照明或动力电力线路,在药包多、准爆电流需要大的情况下,是最可靠的起爆电源 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl5、电气起爆测量仪表l如小型欧姆计、爆破电桥、伏特计和安培计、万能电表等。l小型欧姆计适用于检查电雷管和电爆线路的导电性,以及电路是否接通或近似的电阻数值,爆破电桥用以测量电雷管的电阻和全部的电爆网路上的电阻。使用前,须先用万能电表或安培计检测其两接线柱上输出电源数值,为了使用安全,最大电流不得超过50mA。伏特计和安培计分别用于测定电源线路中的电压和电流。万能电表主要用于检查爆破电桥,或作为伏特计和安培计使用,但不能用以测量电雷管的电流 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl四、起爆方法l如前所述,药包的爆炸,必须给予一定的热能和机械能等外界条件,才能使炸药爆炸,这就是起爆(引爆)。在工程中常用的起爆方法有:火花起爆法、电力起爆法、传爆线起爆法和习爆管起爆法等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(一)火花起爆法l起爆药卷的构造如图1-74所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl起爆药卷只能在爆破地点或装药前制作该次所需量,不得先制成成品备用。导火线使用前,应将浸有防潮剂的线端剪去将剪平整的一端插入火雷管最底部,使药芯正对传火孔结合牢固,另端剪成椭圆面,并将头部捏松,以便点火。导火线在爆破中所取长度,应根据燃烧速度试验和在点火后能避入安全地点的时间确定,但最短不得小于1.2m。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)电力起爆法l电力起爆,是利用电雷管中电力引火剂的通电发热燃烧使雷管爆炸,然后使药包爆炸。使用的器材有电雷管、电线、电源及测量仪等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl电力起爆网路布置如图1-75所示,其中电线用来联结电雷管,组成电爆网路。电线按其在网路中作用的不同,又分为脚线、端线、联接线、区域线和主线。由电雷管引出的导线称为脚线,通常采用直径0.50.7m的纱包线或塑料绝缘线。联结电雷管脚线和联结线的称为端线;联结各炮眼间的导线称为联结线,一般是采用直径1.131.37mm的胶皮绝缘线或塑料绝缘线。联结主线与联结线的导线称为区域线;由电源开关器引至联结线的导线称为主线。区域线和主线,一般采用七股1.62.11mm绝缘线 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl电爆网路的形式有多种,常用的有单发电雷管串联网路、成对并联电雷管的串联网路和三发并联电雷管的串联网路。其接线方式如图1-76 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl网路型式应根据爆破方法,一次爆破规模,工程性质,电流和爆破材料等因素确定。l单发串联网路的优点是操作简便,易于检查导线,所需导线少且准爆电流较小。但网路联结的可靠性差,若网路中某一雷管出现故障,将使整个网路拒爆。这种网路适用于装药分散,并相距较远,电源、电流不大的小规模爆破。l双发成对并联的串联网路和三发并联网路可靠性较串联大,导线和电源消耗较大。适用于每次爆破的炮眼、药包组多,且距离较远的爆破作业 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)传爆线起爆法l传爆线起爆,是利用传爆线直接引起药包爆炸。由于传爆线的爆炸速度快,可以同时起爆多个药包。使用材料主要有传爆线和点燃传爆线的雷管。l传爆线起爆线路的联结类型,如图1-77所示 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl串联联结法,线路简单,联结方便且接头少,但联结可靠性差。在整个线路中,如有一个药包拒爆时,将会影响到后面所有药包拒爆。目前很少采用。l分段并联法,是将联结每个药包的每段传爆线与一根传爆线主线相联结。各药包爆破互不干扰,一个药包拒爆不影响整个起爆,准爆有可靠保证。传爆线消耗量少但联结较复杂,检查不便,因联结不好,个别也会产生拒爆。这种方式在爆破工程中应用很广 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(四)导爆管起爆法l导爆管是一种半透明具有一定强度、韧性、耐湿、不透火,内涂一薄层高燃混合炸药的塑料软管起爆材料。起爆时,以1700m/s左右的速度通过软管引爆大雷管,但软管不会破坏。这种材料具有抗火、抗电、抗冲击、抗水及传爆安全等性能,是一种安全导爆材料。在运输保管过程中,可作非危险品处理。它与雷管、传爆线、导火线相比,具有作业简单、安全、抗杂散电流、起爆可靠、成本低、运输保管方便和效率高等独特优点。l导爆管起爆,是利用导爆管传爆起爆药的能量,引爆雷管,然后使药包爆炸。主要器材有导爆管、普通雷管和起爆器。导爆管网路的联结与电力起爆相似,可采用串联、并联及簇联等方式 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl五、爆破施工l在土木建筑工程中,常用到的爆破方法有炮眼爆破、药壶爆破、深孔爆破、小洞室爆破、二次爆破、定向爆破及微差爆破等方法。选择爆破方法,应根据工程性质和要求、地质条件、工程量大小及施工机具等确定。在给水排水工程中,通常为小面积爆破,一般多采用炮眼爆破法施工 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(一)炮眼爆破法l炮眼爆破,是在岩石内钻凿直径2546mm、深度15m的炮眼,然后装入长药包进行爆破。具有操作简便、炸药消耗量较少,岩石破碎均匀,飞石距离近,不易损坏附近建筑物等优点。广泛用于各种地形或场地狭窄的工作面上作业,如岩层厚度不大的一般场地平整,开挖管沟、基坑(槽)、平整边坡、冻土松动及大块岩石的二次爆破等 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、炮眼的布置。l布置炮眼位置时,应尽量利用临空面较大、较多的地形,或有计划地改造地形,使前一次爆破为后次爆破创造更多的临空面,以利提高爆破效果。炮眼方向应避免与临空面垂直,否则,会因炮眼轴线与最小抵抗线的方向一致,易造成“冲天炮”;炮眼方向应尽量与临空面平行,或与水平临空面成45角,与垂直临空面成30角。炮眼布置应避免穿过岩石裂隙,孔底与裂隙应保持2030cm距离,以避免爆炸时发生漏气现象,影响爆破效果 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、炮眼深度L与最小抵抗线W的确定。炮眼深度视岩石硬度、梯段高度和抵抗线而定(图1-78) Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong在坚硬岩石中:(1-58)式中:H岩石梯段高度。对中硬岩石:L=H(1-59)在松软岩石中:(1-60)最小抵抗线W,也是随岩石硬度和梯段高度而定,一般取为:(1-61)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3、炮眼间距的确定。炮眼布置一般为梅花形,如图1-79。炮眼间距a是依岩石特性、爆炸要求、炸药种类和起爆方法等确定 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong对于火花起爆:(1-62)对于电力起爆:(1-63)炮眼的行距,可采用第一行炮眼的计算最小抵抗线W;若第一行各炮眼的W不相同时,则取其平均值。炮眼爆破时,行距b计算一般采用:(1-64)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong4、药包量计算。炮眼法的药包量可按前述药包量计算式确定。如需布置多行炮眼时,则每一炮眼药包量可按下式计算:用抛掷爆破时Q=qabl(1-65)采用松动爆破时Q=0.33qabL(1-66)式中:a炮眼间距;b行距;L炮眼深度。在实际工作中,通常炮眼较多,一般不采用公式计算,而是根据炮眼深度和岩石情况,结合经验,装药量一般控制在炮眼深度的1/31/2左右Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl5、钻眼、装药及堵塞方法l(1)钻眼:钻眼可有人工和机械两种方法。l人工钻眼,仅当炮眼深度在3m以内,炮眼数量不大或受施工场地条件限制的情况下采用。钻眼工具为钢钎,有冲钎法和锤击法,前者适用于松软岩石,后者可用于中等硬度以下的岩石。由于岩石的力学性能,其抗切与抗拉强度远比抗压强度低,因此,无论采用冲钎法或锤击法,在钻眼过程中都应不断使钢钎转动冲击,以利提高钻眼效率 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl机械钻眼,常用电动凿岩机或风动凿岩机。l电 动 凿 岩 机 使 用 较 轻 便 , 冲 击 频 率 为2002200次/min,冲击功4.5kg.m,钻眼深度4m。但电钻易磨损,可用于松软岩土钻眼。l风动凿岩机,在工程中常采用手持式O130型、气腿式YT25型及YT23型风动凿岩机,操作简便。钻眼深度45m,冲击频率17002100次/min,耗气量2.43.6m3/min,使用气压0.5Mpa。适用于大量浅眼爆破和任何硬度的岩石凿眼。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(2)装药和堵塞。钻眼后,在装药前应将炮眼内石粉、碎屑和泥浆除净。为防止炸药受潮,可在炮眼底部放置油纸或使用经过防潮处理的炸药。炮眼中可装药粉或药卷,应分几次装入,并用木棍轻轻压紧。起爆药卷(雷管)应置于装药全工的1/31/2处,应注意不能撞击或挤压,以防触及雷管而发生爆炸事故。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl装药后,炮眼的堵塞一般均可就地取材,使用砂、粘土等易于充填密实、不漏气的材料,其配合比最好为1份粘土和2份或3份砂混合而成。堵塞应轻轻捣实保证长度,并须注意保护起爆导火线或雷管脚线。对于水平或斜炮眼可用粘土做成比炮孔略小、长100150mm的圆柱土条,土料要有塑性但不过湿,分节填塞。l堵塞完毕,应对爆破网路作最后检查,并按爆破安全操作的有关规定进行爆破。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(二)管沟、基坑(槽)和隧道的爆破开挖l1、管沟、基坑(槽)的爆破开挖 l爆破开挖管沟、坑、槽时,炮眼深度不得超过沟(槽、坑)宽度的0.5倍。如需超过时,则应采用分层爆破 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(1)基坑爆破开挖 一般分两次进行,第一次用斜孔爆破增加临空面,然后用垂直孔爆破成所需形状Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(2)沟槽爆破开挖为满足沟槽宽度和堆土地点的要求,爆破可分为 多列纵药包爆破时,需分两次进行,先爆破靠边部分,后爆破中间部分。一侧堆土也需分二次进行,第二次爆破在第一次爆破所抛起的土刚回落到地面时进行Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(3)开挖渠道爆破:炮眼宜采用沟槽式布置 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl先先沿沿渠渠道道中中心心爆爆破破成成沟沟槽槽,创创造造出出临临空空面面,再再沿沿沟沟槽槽布布置置斜斜孔孔进进行行爆爆破破(图图1-83(a),或或用用两两个个标标准准抛抛掷掷药药包包,其其间间距距a=W,使使爆爆破破后后形形成成一一条条整整齐齐的的沟沟槽槽(图图1-83(b)。当当渠渠道道底底宽宽还还需需加加大大时时,可可再再沿沿沟沟槽槽布布置置斜孔进行爆破。斜孔进行爆破。l在同时需要在同时需要起爆多个炮眼时,应采用电力起多个炮眼时,应采用电力起爆或传爆线起爆方法爆或传爆线起爆方法 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、隧道爆破开挖l通常采用炮眼法分次进行,先爆破遂道中心部分,再爆破其余部分。隧道炮眼的钻进方向应根据岩层性质及裂隙等情况确定,同时还要考虑到钻凿方法。钻凿炮眼应尽量采用斜插于临空面的斜孔,则爆破效果要好 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(三)水下爆破l给水排水工程中,水下爆破常用于开挖水下管沟、构筑物基坑及除去障碍物等。l水下爆破应使用防水炸药,如常用的胶质猛炸药。如用其他炸药应采取密封防水措施。l水下爆破方法有裸露爆破和钻眼爆破两种。须依水深、流速、河床地质构造、岩石硬度及沟槽(基坑)宽度、深度等选择爆破方法 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、裸露爆破l裸露爆破一般在水深较大,但要求爆破深度较浅,或爆破量较小时采用。l裸露爆破的药包连接,根据被爆破物的大小、形状、位置而定。药包绑在绳上。长串接结的药包多用于开挖沟槽、基坑或爆破礁石时,可将药包用绳网连接成平面 裸露药包用小船投放或由潜水员投放Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、钻孔爆破l采用回转式或冲击式钻眼机,在水中直接钻眼。水下常用套管钻眼,以防覆盖层孔壁坍塌。l风钻适用于浅水下(0.51.0m)岩石钻眼,如需深层爆破,可分层进行,即一层爆破后清渣,再进行下一层。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl炮眼的深度,根据地质、水深、计划挖深等确定。炮眼布置分为稀孔密距及密孔稀距两种,见图1-86 前者炮眼布置均匀,岩石破碎均匀,易于清除;后者眼较少但集中,可少钻眼,少放炸药,并能扩大开挖方量。爆破后,水中清渣最大时,可用空气吸泥导管、斗式或吸扬式挖泥船进行Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl(四)拆除水池、罐体结构的水压控制爆破l水压控制爆破,是指在完全封闭或开口的中空容器结构物中,进行全部或部分灌水,然后在水中悬挂一定位置和深度的药包进行起爆,充分利用水的不可压缩性,传递爆炸荷载,以达到均匀破碎四周壁体的爆破方法。在给排水工程中,水压控制爆破方法适用于封闭式开口的水池、罐体、地下室、钢铁容器等结构的破碎拆除施工,具有安全简便、破碎均匀,比钻眼爆破法工效高且费用低,可控制飞石和粉尘等特点。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、水压控制爆破的药包布置l药包的布置应根据结构形式和尺寸而定 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl对于均匀圆筒形或长宽比a/b1.2的矩形罐体和水池,一般采用中心药包(图1-87a)。若罐体高度大于或近似于3倍布药距离RW时,可设置上、下层中心群药包。若矩形结构的长宽比a/b1.5时,可设置群布药包。药包入水深度H0与布药距离RW之比应为H0(0.70.5)RW,药包距罐底H1=(0.350.5)RW,水深应充满结构。群布药包(图1-87(b))中各药包间距a=(1.01.5)Rw,如结构外壁设有加强柱时,应在加强柱根部增设辅助药包 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、装药量计算l水压控制爆破装药量经验公式:l Q=KdR2W (1-67)l式中Q药包总重量(kg);l d结构物壁厚(m);l RW取内直径或内短边长(m);l K与容积结构特性、爆破方式 、配筋情况、材质、环境条件等有关的系数,一般取0.52.5;直径10m,壁厚0.2m,常取K=0.51.25 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3、爆破注意事项l水压控制爆破的药包应有防水措施,宜用瓶装密封,以防受潮失效;当拟爆结构有孔洞时,应预先堵塞或用钢板补焊闭封,以提高爆破效果;位于地上的容器结构,应在四周设排水设施,以便爆破后水的排队;应在爆破壁面上覆盖轻型覆盖物(如荆笆、草席),以缓冲碎块抛速,但不宜用挡板等较重物体覆盖,防止爆炸时将挡板冲跨,冲向邻近建筑物造成损害 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl六、爆破安全措施l爆破施工,应严格贯彻执行爆破安全堆积和有关安全规定。切实作好爆破作业各项施工工序的操作检查处理,力求做到安全施工 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl1、爆破器材储存和运送的安全措施l爆破器材仓库必须干燥、通风、温度保持在1830之间,其周围5m范围内,须清除一切树木和干草。仓库内须有消防设备。仓库必须离开工厂和住宅区800m以上。炸药和雷管须分开存放,不同性质的炸药也不要放在一起,尤其是硝化甘油类炸药必须单独储存。仓库要有专人保卫,严防发生事故。l雷管和炸药必须分开运送,搬运人员须彼此相距10m以上,严禁把雷管放在口袋内,中途不得在非规定的地点休息或逗留。如为汽车运输时,相距不小于50m。中途停车地点须离开民房、桥梁、铁路200m以上 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl2、爆破施工的安全措施l(1)装药必须用木棒把炸药轻轻压入炮眼,严禁冲捣和使用金属棒;堵塞炮泥时,切不可击动雷管。l(2)炮眼深度超过4m时,须用两个雷管起爆;如深度超过10m,则不得用火花起爆。l(3)在闪电鸣雷时,禁止装药、安装电雷管和联接电线等操作,应迅速将雷管的脚线和电线的主线两端连成短路。此时,所有工作人员应即离开装药地点,隐蔽于安全区。l(4)放炮前必须划出警戒范围,立好标志,并有专人警戒。裸露药包、深眼法、洞室法的安全距离不小于400m;炮眼法、药壶法不小于200m。 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl3、爆破作业的安全距离l爆破前,应结合工程和施工现场的具体条件确定爆破作业的安全距离,避免因爆破飞石、爆破地震、冲击波以及爆破互气对人身、生产设备及建筑物、构筑物的危害 Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(1)爆破飞石的安全距离,可按下式计算:(1-68)式中:R飞石安全距离(m);K与岩石性质、地形有关的系数,一般取1.01.5;n最大一个药包的爆破作用指数;W最大一个药包的最小抵抗线(m)。为保证绝对安全,一般按上式计算结果再乘以系数34;同时参照现行爆破安全规程加以确定。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(2)爆破震动对建筑物影响的安全距离,可按下式计算:(1-69)式中:Rc爆破地点至建筑物的安全距离(m);Kc根据场地土壤而定的系数(表1-25);X依爆破作用指数而定的系数表1-26);Q爆破装药量(kg)。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongKc值表1-25被保护建筑物地区的土壤Kc备注坚硬密实岩石坚硬密实岩石夹有砾石、碎石的土壤砂土粘土回填土流砂、泥煤层3.05.07.08.09.015.020.0药包在水中和含水土壤时,系数值应增加0.51.0倍Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongX值表1-26爆破条件X扩炸药壶n0.5n=1n=2n31.21.00.80.7Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(3)空气冲击波的安全距离,可按下式计算:(1-70)式中:RK空气冲击波的安全距离(m);KB与装药条件和破坏程度有关的系数,见表1-27Q爆破装药总量(kg)Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong在计算空气冲击波对人身危害的安全距离时,KB采用15,一般最少用510。KB值表表1-27破坏程度安全级别KB值裸露药包全埋入药包安全无损坏偶然破坏玻璃玻璃全坏,门窗偶坏隔墙、门窗、天棚破坏砖石结构破坏全部破坏123456501501050510251.521.5105051025120.51.0Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gong(4)爆破毒气的安全距离,按下式计算:(1-71)式中:RE爆破毒气的安全距离(m);KE系数,平均值取160;Q爆破装药总量(t)对于下风向的安全距离应增加一倍。Shui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi GongShui Gong Cheng Shi Gongl4、瞎炮处理措施l(1)如果炮眼外的电线、导火线或传爆线经检查完好,可以重新起爆。l(2)可用木制或竹制工具将堵塞物轻轻掏出,另装入雷管或起爆药卷重新起爆。绝对禁止拉动导火线或雷管脚线,以及掏动炸药内的雷管。l(3)如系硝铵炸药,可以清除部分堵塞物后,向炮眼内灌水,使炸药溶解,或用压力水冲洗,重新装药爆破。l(4)距炮眼近旁600mm处打一平行于原炮眼的炮眼,装药爆破。如果不知道原炮眼的位置,或附近可能有其他瞎炮时,此法不得采用。l采用那种方法处理瞎炮,需根据实际情况决定
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