海堤荷载下海积软土沉降的现场测试和数值模拟  

FIELD MEASUREMENT AND NUMERICAL SIMULATION OF ESTUARINE DEPOSIT SETTLEMENTS UNDER EMBANKMENT LOADS

作　　者：姜民[1,2] 边学成[1,2] 吴建国[3] 黄建武[3] 陈云敏[1,2] 陈仁朋[1,2] 

机构地区：[1]浙江大学软弱土与环境土工教育部重点实验室,浙江杭州310058 [2]浙江大学岩土工程研究所,浙江杭州310058 [3]浙江省电力设计院,浙江杭州310014

出　　处：《岩石力学与工程学报》2010年第5期1060-1067,共8页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家重点基础研究发展计划(973)项目(2007CB714001);国家自然科学基金资助项目(50629802;10702063)

摘　　要：海积软土在海堤荷载作用下的沉降变形往往是堤防建造和围海造地等重大工程中的关键环节,为研究海积软土的变形特性,在室内单元体试验的基础上,由修正Cam-clay模型改进来的软土模型中加入海积软土固有的结构性特征。结合实际的工程项目,建立相应的数值分析模型,并研究大面积均匀堆载和新建海堤不均匀荷载作用下海积软土的长期沉降和超静孔隙水压力消散特性,分析中考虑竖井地基处理和海堤填筑进程的影响。通过与原位监测数据的对比发现,该模型能够很好地反映海堤下方处和厂区大面积回填处的地基沉降和侧向变形,同时能较好地考虑填筑过程中地基不同深度处超静孔隙水压力的累积和消散过程。Settlement deformations of soft estuarine deposit under applied loads are essential to embankment construction and land reclamation in coastal areas. Based on the laboratory tests,a soft soil model derived from the modified Cam-clay model is proposed to considering the inherent structure characteristics of soft estuarine soil. Using this soil model,a finite element numerical model with realistic geometric sizes and physical properties from an embankment engineering is established to investigate ground settlement and excess pore water pressure dissipation procedure of soft estuarine deposit. Two load conditions are taken into account in the same analysis model,one is large area uniform surcharge loads,and the other is newly-built sea embankment. The numerical model incorporates both effect of the prefabricated vertical drains（PVDs） installed in the underlying soil deposit and the stage construction process of the embankment in the analysis. Good resemblances are found for the in-situ monitoring data and the simulation results,both for vertical and lateral ground deformations. At the same time,the accumulation and dissipation processes of excess pore water pressure at different depths beneath embankment and backfill area are accurately simulated by the proposed numerical model.

关 键 词：土力学 海积软土 结构性软土 沉降 超静孔隙水压力 原位监测 

分 类 号：TU433[建筑科学—岩土工程]