Comparative simulation and measurement of the deformation features of the soil-rock deep foundation pit with a positive corner
WANG Hong-de1,2,QIN Yu-bin1,MA Yun-dong2,ZHANG Li-man2(1 School of Civil & Safety Engineering,Dalian Jiaotong University,Dalian 116028,Liaoning,China;2 Tunnel & Underground Structure Engineering Center of Liaoning Province,Dalian Jiaotong University,Dalian 116028,China)
The present paper is inclined to introduce our research into the causes of the specially shaped foundation pit degeneration features and their effects on the construction process,for the purpose to provide a safe and reliable guidance to the design and construction of such pits.As a matter of fact,deep excavation engineering projects not only represent the trend of the features of maximization and profundity,but also reveal the actual need to do so,because,if not,the design would fail to meet the safe construction demand.Taking the metro station of Line Two in Dalian for example,we feel it necessary to analyze the simulation and the actual measurement results comparatively in the deformation of the soil-rock deep foundation pit with a positive corner.The reason to do such comparative studies comes from the fact that,first of all,the designers demand to set up the finite element simulation models of the deep foundation pit with positive corner,among which,the soil structure is to be modeled with Mohr-Coulomb model whereas the rock structure is modeled with a synthetic material structure.And,in contrast,the anchors,the soil nailing and the concrete structures are to be modeled with the linear elastic model.Secondly,the simulation models should be verified on the basis of the actual measurement data.The contrast and analysis results show that the actual measured value of the maximum settlement should be between 4 mm to 5 mm,the maximum vertical displacement at the foundation pit positive corner is less than 2.5 mm,and the maximum horizontal displacement here is only 1.1 mm,well with those of the calculated with the finite element method.And,finally,we have made a discussion on the deformation characteristics of the soil-rock deep foundation pit with positive corner based on the finite element simulation system,whose relative curve stands between the soil-rock foundation pit deformation and its covering soil thickness.And,last of all,we have analyzed the effects of the positive corner and the negative corner,and found the horizontal and vertical displacement trends of the deep foundation pit covering soils in the different positive corners.Thus,it can be seen that the simulation and measurement can serve as a security guarantee for the same sort of engineering excavation and timbering,which can make the foundation excavation construction more rational,economic,safe and effective.
【Fund】： 国家自然科学基金项目(51050003);; 辽宁省自然科学基金项目(201202022);; 大连市科技计划项目(2011E15SF118)
【CateGory Index】： TU433
【CateGory Index】： TU433