摘要
在中国沿海地区,预压法已经成为一种处理软基的常用方法。结合真空预压和堆载预压加固软土的现场试验,通过三维有限元分析进行加固过程中软土的性能评价。在数值模拟中,地基土采用莫尔-库伦强度破坏准则。塑料排水板采用实体单元进行单独建模,并保证与实际的塑料排水板有相等的截面积。通过数值分析获得的沉降、分层沉降、水平位移和超孔隙水压力与现场数据进行对比,研究了两种预压方式下地基土的性能特点。结果表明,真空预压可以有效地减少地基上的不均匀沉降。在真空预压的影响下,加固区外土体的土压力系数在主动土压力系数K_a与静止土压力系数K_0之间;而在堆载预压的影响下,加固区外土体的土压力系数在被动土压力系数K_p与静止土压力系数K_0之间。
Preloading method has been a widely-used alternative to improve soft soil in coastal areas in China.A field test of soft soil with vacuum preloading and surcharge preloading was introduced.Based on the field test,threedimensional(3-D)finite-element analyses were conducted to evaluate the performance of the soft soil during consolidation.In the simulation,the subsoil was simulated as the material with Mohr-Coulomb failure criteria.The PVDs were modeled individually as solid elements with the equivalent cross section of the real PVD.The settlements,layered settlements,lateral displacements and excess pore-water pressure obtained by numerical analysis were compared with the field data to study the performance characteristics of two kinds of preloading methods.The results show that the differential settlement on the ground can be minimized in the vacuum preloading.The stress state in the subsoil outside the treated area was between K_aand K_0 in the vacuum preloading while the stress state in the subsoil outside the treated area was between K_0 and K_p in the surcharge preloading.
出处
《地下空间与工程学报》
CSCD
北大核心
2018年第S1期315-321,共7页
Chinese Journal of Underground Space and Engineering
基金
国家自然科学基金(51508408，51078271)
上海市浦江人才计划(15PJ1408800).
关键词
软土
真空预压
堆载预压
孔隙水压力
有限元分析
soft soil
vacuum preloading
surcharge preloading
pore water pressure
finite-element analysis
