真空–堆载联合预压加固吹填土地基有限元分析法的研究  

Finite element analysis of reclaimed soil foundation consolidated by surcharge preloading combined with vacuum preloading

作　　者：孙立强[1] 闫澍旺[1] 李伟[2] 

机构地区：[1]天津大学建工学院岩土工程研究所,天津300072 [2]天津港集团有限公司,天津300072

出　　处：《岩土工程学报》2010年第4期592-599,共8页Chinese Journal of Geotechnical Engineering

基　　金：天津市科技创新专项资金项目(07fdzdsf02100-03)

摘　　要：吹填土地基作为欠固结土,其真空预压加固过程比较复杂,初始条件和边界条件也比较复杂。通过对吹填土地基的形成和真空预压加固过程的分析,对其初始孔隙水压力和真空度在排水板中的传递规律进行了研究;在砂垫层和排水板中施加负的真空压力;根据真空预压加固机理,将非线性本构关系(Duncan-Chang模型)引入Biot固结理论,综合考虑不同工程的荷载形式、初始条件和边界条件编制了通用的有限元程序,对真空预压法地基加固进行平面应变有限元分析;该程序实现了堆载的施加,既能用于计算单纯的真空预压也能用于真空–堆载联合预压的有限元计算。利用提出的有限元程序分别对吹填土地基整个加固过程和正常固结土地基的真空–堆载联合预压进行了有限元分析,计算结果与实测结果对比表明,该方法较好地反映了实际工程沉降及孔隙水压力的发展趋势。The reclaimed soil foundation is consolidated,and its vacuum preloading consolidation process is very complex,so are the boundary and initial conditions.Through the analysis of the formation of the reclaimed soil foundation and its consolidation process,the initial pore water pressure and the delivery of negative vacuum pressure in the PVDs are studied.The negative vacuum pressure is applied in the sand layer and the PVDs elements.The nonlinearity constitutive relation（Duncan-Chang’s model） is incorporated into the Biot’s consolidation theory program.Considering different load conditions,initial conditions and boundary conditions,a general-purpose program is compiled to analyze the behavior of the soft clay consolidation by use of the plain strain FEM.The program can both calculate the vacuum preloading and the surcharge preloading combined with the vacuum preloading.Two actual projects are calculated using this program.Comparison with the field measurements indicates that the proposed method reflects the developing trend of settlement and pore water pressure of the projects.

关 键 词：真空预压 平面有限元 非线性弹性 负压 堆载 孔隙水压力 吹填土地基 

分 类 号：TU43[建筑科学—岩土工程]