Deep Foundation Pit Supporting Design And Numerical Simulation About Changchun Trade Union Mansion

Deep foundation pit engineering is a very comprehensive geotechnicalengineering technical problem which is related to soil mechanics, rock mechanics,structural mechanics, mechanics of materials, hydrology, and so on. Not only strengthand deformation of general geotechnical engineering need considering but alsodeformation compatibility between supporting structure and soil have to be taken careof. Therefore, deep foundation pit is a complex geotechnical engineering problem.Along with the rapid economic development, city construction gradually speedsup, a large number of deep foundation pits well up. These pits mostly are located inurban centers, diversified in engineering geological conditions, complex surroundingenvironment conditions, no matter project scale or technical difficulty are gettinglarger and larger. There are higher and higher demands in reasonableness and safety offoundation pit supporting structure design.There are lots of types of deep foundation pit supporting structure, and each hasits own characteristics and application. Reasonable selection is not just related to theproject investment, but also related to the safety of foundation pit. According tovariety conditions of foundation pit and supporting structure types, the computationaltheory and design method are also different, and each of them has its ownapplicability and limitations. Because of soil, rock, groundwater, supporting structureand many other factors involved, the design of foundation pit supporting is verycomplex. Parentally at home, due to the complexity of foundation pit, together withunreasonable design, incorrect construction method and improper order, monitoringnot on position and other reasons, there are a lot of pit accidents. These accidentsdelayed the projects, brought a huge loss to the country and the people, and producedserious consequences. So, it must be careful when we choose the type of foundation supporting structure and computational theory and methods. Thus, we can design thebest reasonable supporting plan and ensure the safety and economic of foundation pit.This shows that the research of foundation pit supporting design has a strongtheoretical and practical significance.This paper takes Changchun Trade Union Mansion deep foundation pit forexample, analyzes the merits and faults and applications of the common types offoundation pit supporting structure, combined with actual project. This design willchoose pile anchors support program. On the analysis the advantages and weaknessesof foundation pit supporting theories and calculations, this paper determines to adoptthe equivalent beam method based on limit equilibrium theory to support design andcalculation. Then, the calculation is to be optimized by elastic footing beam method.The final result is to design the foundation pit supporting program.The results of the foundation pit design and calculation proved to be correct bystability analysis, and the actual project results also show it is safe and correct. In theprocess of construction, there are some problems. After analyzing the causes andtaking appropriate engineering measures, it is guaranteed that the foundation pitcompleted on time successfully.This paper introduces the principles and characteristics of finite differenceprogram FLAC3D which is commonly used in the field of geotechnical engineering.It uses the numerical simulation method to simulate the step-by-step support andexcavation of deep foundation pit about Changchun Trade Union Mansion, and getsstress and displacements of the soil and supporting structure. According to thesimulation results, it finds that with the increase of excavation, soil and supportingstructure will have internal force and displacement change. On the basis of analysis ofthe results, it points out the possible weakness and proposes some means to optimizethe supporting program. According to the analysis of the simulation results and thecomparison with field test results, the numerical simulation shows to be acceptable. Italso shows that it is feasible for FLAC3D to be used in foundation excavating.Besides, it provides the foundation pit design and analysis a new kind ofsupplementary means.