Internal Force Analysis And Study On Structural Optimization Of Conduit Buried In Fill

ABSTRACTWith national economy developing by leaps and bounds, conduit buried in fill has been applied extensively in fields such as transportation, water conservancy, municipal engineering and energy sources. In this dissertation, the distinguishing feature of earth pressure and optimum structural design on conduit buried in fill are studied and discussed in detail, some valuable results are obtained. The main contents are as follows:Firstly, the distinguishing feature of earth pressure in different lying way and the main calculation methods of the vertical earth pressure are analyzed and compared, the defect and applying limitation of earth calculation formula are pointed out. Based on the elastic theory, formula to calculate vertical earth pressure on general trenching conduit is derived. Besides, the dissertation introduces the general formula to calculation horizontal earth pressure on projecting conduit and trenching conduit.Secondly, the dissertation summarizes the fundamental principle of finite element analysis on conduit subway, introduces the main calculation formula for finite element analysis, and then it develops reinforced concrete finite element calculation computer program which includes quadrilateral 8 nodes isoparametric element and one-dimensional 3 nodes isoparametric element. According to calculation samples, and the analysis on the results of stress and displace in detail, it obtains some valuable conclusions.Thirdly, the fundamental principle on optimal design of structures is treated. Based on the characters of RCCP (reinforced concrete culvert pipe) optimal design, it imports the design theory of discrete optimum design of structures, and more analysis has been taken on samples on this design theory. The mathematical model of discrete optimal design of structures of RCCP is established, and introduced a binary algorithm on the (0,1) program. The calculation program of discrete optimal design of structures is developed.Finally, in order to upgrade the efficiency of calculation and design, a set of program on finite element graphic pre-processing and post-processing is developed.By this program, finite element mesh automatic dissection, finite element calculation, optimum design of structures, finite element mesh drawing, displace of finite element mesh drawing are integrated, which makes structural analysis easier.