吹填土地基真空预压加固过程分析及有限元研究  

CONSOLIDATION PROCESS ANALYSIS OF RECLAIMED SOIL FOUNDATION BY VACUUM PRELOADING AND FINITE ELEMENTS STUDY

作　　者：孙立强[1] 闫澍旺[1] 何洪娟[2] 李伟[3] 

机构地区：[1]天津大学建筑工程学院,天津300072 [2]天津城市道路管网配套建设投资有限公司,天津300384 [3]天津港(集团)有限公司,天津300461

出　　处：《岩石力学与工程学报》2010年第A02期3878-3884,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：天津市科技创新专项资金项目(07fdzdsf02100–03)

摘　　要：通过对吹填土地基的形成和真空预压加固吹填土过程的分析,得出吹填土地基在真空预压前为欠固结土,土体中存在由吹填土有效自重产生的超孔压,在插板期间会产生固结沉降。现场检测的插板期间(插板期为15～20d)产生的固结沉降达到真空预压总沉降的1/3～1/2,不能按照正常固结土的方法进行计算,应考虑插板后超孔压消散引起的固结沉降。提出在进行有限元分析时,荷载由真空荷载和吹填土有效自重2部分组成,并提出荷载的施加方法。同时对真空度在排水板中的传递规律进行研究,采用非线性本构关系,编制适合于吹填土地基的有限元程序,对真空预压法加固吹填土地基整个过程进行有限元分析,对比计算结果与实测结果表明,该方法较好地反映实际工程沉降及孔隙水压力的发展趋势。Through the analysis of the formation of the reclaimed soil foundation and its consolidation process,it was proposed that the reclaimed soil foundation was unconsolidated;and there was initial excess pore water pressure in it. Settlement would be generated during the plastic vertical drains（PVDs） installation,and the field data showed that it reached 1/3–1/2 of the total settlements. So it could′t be considered as the consolidated soil. It was suggested that in the finite element analysis the load included vacuum loading and effective self weigh of the reclaimed soil. The delivery of negative vacuum pressure in the PVDs was studied. Nonlinearity constitutive relation was adopted and a program was compiled to analyze the behavior of the reclaimed soil foundation consolidation with plane strain finite element method（FEM）. An actual project was calculated using this program, and comparing to the field measurements data,it is found that the method reflected very well the developing trend of settlement and pore water pressure for the projects.

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

分 类 号：TU472[建筑科学—结构工程]