Design & Realization of CAD Software System Design & Realization of CAD Software System for Railway Roadbedfor Railway Roadbed( ( ( (铁路路基铁路路基铁路路基铁路路基CADCADCADCAD软件系统的设计与实现软件系统的设计与实现软件系统的设计与实现软件系统的设计与实现) ) ) )200412110020200412110020Xie BaiyiXie Baiyi18th Apr. 0518th Apr. 05 Outline1.Instruction2.technical contents3.Software applications4.Future Work: the study of Expert system for Roadbed CADRoadbed Roadbed is is an an important important part part of of railway railway infrastructure. infrastructure. It It has has a a function function to to bear bear the the traintrain s s load load and and resist resist the the damage damage from from environment environment and and other other sources. sources. Roadbed Roadbed design design includes includes three three main main parts, parts, i.e. i.e. the the design design of of slope slope reinforcement reinforcement and and protection, protection, the the design design of of soft soft clay clay ground ground treatment, treatment, and and the the design design of of drain drain system. system. The The roadbed roadbed design design has has a a close close relationship relationship with with the the conditions conditions of of terrain terrain and and geology. geology. For For the the conditions conditions of of terrain terrain and and geological geological are are various various and and changeable, changeable, the the design design for for roadbed roadbed is is various various and and difficult. difficult. This This paper paper introduces introduces a a model model to to simulate simulate the the design design of of roadbed roadbed and and discusses discusses how how to to realize realize it it by by using using Object Object Oriented Programming technology and ObjectARX.Oriented Programming technology and ObjectARX.1. 1. InstructionInstruction2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design model2.22.2Input data treatmentInput data treatment2.32.3CAD treatmentCAD treatment2.42.4Quantity calculationQuantity calculation2. technical contents2. technical contents2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design modelTo build an overall roadbed CAD model, there are two key To build an overall roadbed CAD model, there are two key considerations. considerations. The first is the problem reduction principle, i.e. for roadbed The first is the problem reduction principle, i.e. for roadbed design is very difficult in a whole, so I separate it into some design is very difficult in a whole, so I separate it into some components. Each component can be computerized and components. Each component can be computerized and must be relatively functional independent. So we can use must be relatively functional independent. So we can use Object Oriented Programming technology to formalize them. Object Oriented Programming technology to formalize them. And we build a big class of roadbed with aggregating the all And we build a big class of roadbed with aggregating the all component classes. It contains all component classes as its component classes. It contains all component classes as its component basecomponent base. The function of the aggregating class of . The function of the aggregating class of roadbed is to form different performance, i.e. different roadbed is to form different performance, i.e. different roadbed design scheme, by choosing one or more different roadbed design scheme, by choosing one or more different component classes from component base.component classes from component base.2. technical contents2. technical contents2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design modelThe second is multiple level parameterized controls. The The second is multiple level parameterized controls. The railroad is a strip structure. And itrailroad is a strip structure. And it s changeable in roadbed s changeable in roadbed design conditions. design conditions. The roadbed design has some common features, so we can The roadbed design has some common features, so we can abstract some overall parameters from it. abstract some overall parameters from it. 2. technical contents2. technical contents2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design modelSecondly the components keep relatively stability in a scope. Secondly the components keep relatively stability in a scope. Moreover, we introduce some control parameters in Moreover, we introduce some control parameters in components according to unification principle, so they can components according to unification principle, so they can have same parameterized control but perform differently have same parameterized control but perform differently according to different roadbed design conditions. according to different roadbed design conditions. We make every component have a property of subsections and We make every component have a property of subsections and every subsection has subsection parameters. every subsection has subsection parameters. So it forms the second level of parameterized control. So it forms the second level of parameterized control. 2. technical contents2. technical contents2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design modelFinally, in every subsection of a component, there still exist Finally, in every subsection of a component, there still exist some special features that cannot be completely expressed some special features that cannot be completely expressed by subsection parameterized control, especially in a situation by subsection parameterized control, especially in a situation that some users are unwilling to have the component to that some users are unwilling to have the component to divide into more subsections. So we take the cross-section divide into more subsections. So we take the cross-section parameterized control into model. The cross-sections are parameterized control into model. The cross-sections are contained by the component subsection. They can have contained by the component subsection. They can have same or different parameters with subsection they belong to same or different parameters with subsection they belong to according to real design condition.according to real design condition.2. technical contents2. technical contents2. technical contents2. technical contents2.12.1Roadbed design modelRoadbed design modelThe software system structure can be expressed as following The software system structure can be expressed as following diagram.diagram.OutputInput data treatmentCAD treatmentSoft clay ground treatmentDrain systemQuantity calculationSlope reinforcement and protection2. technical contents2. technical contents2. technical contents2. technical contents2.22.2Input data treatmentInput data treatmentThey are the roadbed designThey are the roadbed design s input part. The key s input part. The key consideration is how they will be obtained more efficiently consideration is how they will be obtained more efficiently and what way they will be stored. and what way they will be stored. 2. technical contents2. technical contents2. technical contents2. technical contents2.22.2Input data treatmentInput data treatmentAmong these, how to get the geological data efficiently and Among these, how to get the geological data efficiently and precisely is a key problem. So we build an precisely is a key problem. So we build an engineering engineering geological automatic stratum connecting modelgeological automatic stratum connecting model, which , which contains a simple intelligence reasoning to form an contains a simple intelligence reasoning to form an automatic stratum connecting, to give facilities for getting automatic stratum connecting, to give facilities for getting the roadbedthe roadbed s geological data automatically.s geological data automatically.2. technical contents2. technical contents2. technical contents2. technical contents2.32.3CAD treatmentCAD treatmentthe design of slope reinforcement and protectionthe design of slope reinforcement and protectionIt contains It contains cross-section designcross-section design, and , and elevation designelevation design, i.e. the , i.e. the slope plane design to show exactly the slope design, which slope plane design to show exactly the slope design, which shows slope design in detail but ignores other part. There shows slope design in detail but ignores other part. There are many are many slope treatmentsslope treatments, so the software must deal with , so the software must deal with all these treatments. The cross-section design is the root all these treatments. The cross-section design is the root design. After having finished treatment of cross-section design. After having finished treatment of cross-section design, the elevation design data are automatically acquired, design, the elevation design data are automatically acquired, which can be used to do the elevation design. So the which can be used to do the elevation design. So the elevation design can be automatically fulfilled in this system. elevation design can be automatically fulfilled in this system. For elevation design is a more detail design for slope, so we For elevation design is a more detail design for slope, so we require that its design result can be used to optimize the require that its design result can be used to optimize the cross-section design. The software has a method to deal cross-section design. The software has a method to deal with it, by modifying the component parameters according with it, by modifying the component parameters according to elevation result. It is not tough, for all cross section and to elevation result. It is not tough, for all cross section and elevation design result data are all in the same subsection.elevation design result data are all in the same subsection.2. technical contents2. technical contents2. technical contents2. technical contents2.32.3CAD treatmentCAD treatmentthe design of soft clay ground treatmentthe design of soft clay ground treatmentThere are many kinds of There are many kinds of ground treatment ground treatment methods. We have methods. We have analyzed them and draw out some components from it. In analyzed them and draw out some components from it. In soft clay ground design, it contains not only cross-section soft clay ground design, it contains not only cross-section design, but also soft clay ground treatment design, but also soft clay ground treatment horizontal plane horizontal plane design and engineering geological vertical section design design and engineering geological vertical section design of of soft clay ground treatment. (We merge the soft clay ground soft clay ground treatment. (We merge the soft clay ground horizontal plane parameterized control data into cross-horizontal plane parameterized control data into cross-section design data, so we can ensure their consistence). section design data, so we can ensure their consistence). In order to treat engineering geological vertical section design, In order to treat engineering geological vertical section design, we build an we build an engineering geological automatic stratum engineering geological automatic stratum connecting modelconnecting model, which has been mentioned in the data , which has been mentioned in the data treatment part.treatment part.2. technical contents2. technical contents2. technical contents2. technical contents2.32.3CAD treatmentCAD treatmentthe design for drain systemthe design for drain systemRoadbed Roadbed drain system design drain system design is a very important aspect, for is a very important aspect, for most damages of roadbed are caused by water, directly or most damages of roadbed are caused by water, directly or indirectly. This software builds a procedure which has some indirectly. This software builds a procedure which has some kind of intelligent treatment for drain system, which can kind of intelligent treatment for drain system, which can automatically locate the horizontal and vertical position, automatically locate the horizontal and vertical position, make the water flow along a smooth drain gradient. After make the water flow along a smooth drain gradient. After being treated automatically, if users want to change design being treated automatically, if users want to change design to their own desire, they can do it freely.to their own desire, they can do it freely.2. technical contents2. technical contents2. technical contents2. technical contents2.42.4Quantity calculationQuantity calculationThe calculation for quantity of the materials that used in The calculation for quantity of the materials that used in roadbed is very import, for we must use it to evaluate the roadbed is very import, for we must use it to evaluate the economical invest and prepare the materials when economical invest and prepare the materials when constructing the railroad. The software automatically constructing the railroad. The software automatically calculates the quantity in componentscalculates the quantity in components CAD process with CAD process with some intelligence. some intelligence. 2. technical contents2. technical contents2. technical contents2. technical contents2.42.4Quantity calculationQuantity calculationBeside automatic quantity calculation, the name of quantity Beside automatic quantity calculation, the name of quantity can be modified flexibly, which is necessary when the can be modified flexibly, which is necessary when the materials have changed. This software has a database to materials have changed. This software has a database to manage the quantity names, which produces a quantity code manage the quantity names, which produces a quantity code for every quantity item. In the software, all quantity items for every quantity item. In the software, all quantity items are identified as a code. are identified as a code. We still can add some new quantity items to the design We still can add some new quantity items to the design automatically by giving the new name and a formula of automatically by giving the new name and a formula of added quantity item. added quantity item. 2. technical contents2. technical contents2. technical contents2. technical contents2.42.4Quantity calculationQuantity calculationThe quantities must be The quantities must be summed up summed up and, furthermore, it is and, furthermore, it is required that the quantities and their sum steps must be required that the quantities and their sum steps must be output in report forms. We can write code to deal with it. But output in report forms. We can write code to deal with it. But we have an easier way to do it by means of putting them we have an easier way to do it by means of putting them to to EXCEL worksheetsEXCEL worksheets. We know that EXCEL software has a . We know that EXCEL software has a function to provide a service for automation. We can use this function to provide a service for automation. We can use this feature to fill all reports to EXCEL.feature to fill all reports to EXCEL.3 3 Software applicationsSoftware applicationsFrom 1998, the software has been applied in almost all railway From 1998, the software has been applied in almost all railway lineline s roadbed design we took charge in, from primary s roadbed design we took charge in, from primary design stage to detail-drawing design stage. It had a usage design stage to detail-drawing design stage. It had a usage rate from 66% when beginning to over 95% latterly. The rate from 66% when beginning to over 95% latterly. The famous Beijing-Shanghai High-speed railway line and all famous Beijing-Shanghai High-speed railway line and all other railway lines used it to fulfill the design. Corresponded other railway lines used it to fulfill the design. Corresponded with practicewith practice s needs, it has made three times version s needs, it has made three times version conversion and upgrade, and now it still in the process of conversion and upgrade, and now it still in the process of improving. In Apr. 7th 2001, the software system passed the improving. In Apr. 7th 2001, the software system passed the provincial authentication and we were grad to know an provincial authentication and we were grad to know an authoritative evaluation that this software system had authoritative evaluation that this software system had reached the countryreached the country s highest level in its field.s highest level in its field.4 4 Discussion for expert systemDiscussion for expert systemThis railway roadbed CAD software system implements the This railway roadbed CAD software system implements the railway roadbedrailway roadbed s automatic design by producing a model to s automatic design by producing a model to simulate the process of real world design. It used the Object simulate the process of real world design. It used the Object Oriented and CAD Programming technology, and other Oriented and CAD Programming technology, and other technologies. It has been used in the highway roadbed technologies. It has been used in the highway roadbed design. By doing some conversion, it can be applied to other design. By doing some conversion, it can be applied to other relevant fields of rock and soil engineering. It has improved relevant fields of rock and soil engineering. It has improved the productive efficiency greatly and gained a great profit to the productive efficiency greatly and gained a great profit to its application field.its application field.4 4 Discussion for expert systemDiscussion for expert systemBut if we want to do better, we must have some more ideas. But if we want to do better, we must have some more ideas. We know that CAD software must be combined with MIS, We know that CAD software must be combined with MIS, and we have been doing this work and make MIS be the and we have been doing this work and make MIS be the base of the system and CAD the core. But it is not enough. base of the system and CAD the core. But it is not enough. To have a fundamentally changing, we must have an expert To have a fundamentally changing, we must have an expert system, which provide expert quality advice, diagnoses and system, which provide expert quality advice, diagnoses and recommendations given real world problems.recommendations given real world problems.4 4 Discussion for expert systemDiscussion for expert systemAs to the roadbed design field, for there are numerous As to the roadbed design field, for there are numerous commercial expert system shells. We must find a way to commercial expert system shells. We must find a way to separate domain specific knowledge from more general separate domain specific knowledge from more general purpose reasoning and representation techniques. purpose reasoning and representation techniques. To cultivate this expert system, we have so much to learn, To cultivate this expert system, we have so much to learn, especially the knowledge of knowledge engineering. But it especially the knowledge of knowledge engineering. But it has encouraged us that expert systems have been used to has encouraged us that expert systems have been used to solve a wide range of problems in engineering domains solve a wide range of problems in engineering domains which involve design. I have confident to realize it in a not which involve design. I have confident to realize it in a not far future.far future.Thank youEnd