Safety management in tunnel construction: Case study of Wuhan metro construction in China,Author： MiroslawJ. Skibniewski Lieyun Ding, et al Reporter: Wu Tong-gang Central South University,New words,Shaft: 通风井 Grouting: 灌浆，给灌浆 High-pressure jet grouting piles(HJGP): 高压喷射灌浆柱 Silty clay: 粉质黏土 Tunnel boring machine(TBM): 隧道掘进机 Gush: 涌出 Double-spool: 双轴,Outline,PART 1 Introduction,PART 2 Method,PART 3 Results,PART 4 Conclusion,Introduction,1,1.1 Background,Shield tunneling technology,1.2 Objective,1.3 Project profile,Wuhan Yangtze Metro Tunnel (WYMT),Characteristics: Double-spool tunnel connecting two large cities Two sets of ventilation shafts A curve radius of 350m and an extremely close distance away from Yangtze River 4. Fine sandstone and silty clay,Method,2,Waterproofing,Ground freezing,Lowering of water level method,Reinforcing,1. The cement paste tends to be washed away by the flowing water, resulting in poor reinforcement.,A high-pressure jet grouting,2.1 Safety system design,2. No significant waterproofing results would be achieved due to the close proximity to the Yangtze River.,2.1 Safety system design,Ground heterog-eneity,Constru-ction methods,Soil structure interact-ion,Non-linear behavior of soils,2.2 Safety analysis,Systemic safety,Economic requirements,Numerical simulation,ANSYS,2.3 Safety control process,2.3.1 Reinforcement control,2.3 Safety control process,2.3.2 Freezing control,Layout of freezing holes,Workers are examining the freezing effect.,2.3 Safety control process,2.3.3 UCW removing control,Workers are cutting down the steel within UCW.,Workers are pasting quilts onto the workface of the tunnel portal.,Results,3,3 Results,3 Results,a,b,c,a: Distribution of compressive stress b: Distribution of tensile stress c: Distribution of shear stress,Conclusion,4,Conclusion,Combine freezing method and HJGP,Include the preliminary deviation ahead of the drilling process,Apply numerical simulation by ANSYS,Question-inviting,5,LOGO HERE,THANK YOU!,PRESENTED BY WuTong-gang,