考虑真空加载过程及堆载随时间变化下砂井地基的普遍固结解析解  

General analytical solution for consolidation of sand-drained foundation considering the vacuum loading process and the time-dependent surcharge loading

作　　者：林伟岸[1] 江文豪 詹良通[1] LIN Wei-an;JIANG Wen-hao;ZHAN Liang-tong(MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou,Zhejiang 310058,China)

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

出　　处：《岩土力学》2021年第7期1828-1838,共11页Rock and Soil Mechanics

基　　金：浙江省重点研发计划项目(No.2019C03107)。

摘　　要：基于Barron砂井地基等应变固结理论,考虑了真空加载过程及堆载随时间变化,同时还考虑了真空压力沿深度及径向的衰减、砂井的涂抹效应及竖向渗流等因素,推导建立了真空联合堆载预压下砂井地基的固结控制方程,并求解得到了一个较为普遍的固结解析解。通过将退化解析解与已有的解析解及文中解析解与有限差分解分别进行对比,验证了解答的正确性。基于解析解,分析了砂井地基的固结性状。分析表明:砂井地基的固结速率随真空加载因子η的增大而增大,但当η增大到一定程度时,真空加载过程对砂井地基固结速率的影响可以忽略;随着负压衰减系数k_(1)和k_(2)的增大,砂井地基的固结速率发生减小;砂井地基的固结速率随真空压力p0的增大而减小,随最终堆载qu的增大而增大;随着加载时间Th1的增大,砂井地基的固结速率逐渐减小,堆载为瞬时加载下的固结速率最快。Based on Barron’s equal strain consolidation theory,the consolidation governing equation of sand-drained foundation under vacuum combined surcharge preloading is derived and a general analytical solution is obtained,which considers the vacuum loading process,the time-dependent surcharge loading,the characteristics of the vacuum pressure decreasing along the depth and radial direction,and the well resistance of vertical drains and the vertical flow.The correctness of the analytical solution proposed in this paper is verified by comparing the degenerate analytical solution with the existing analytical solution and the finite difference solution.Based on the analytical solution,the consolidation behaviors of sand-drained foundation are analyzed.The analysis shows that the consolidation rate of sand-drained foundation is accelerated with the increase of vacuum loading factorη.However,whenηincreases to a certain extent,the influence of vacuum loading process on the consolidation rate of sand-drained foundation can be ignored.The consolidation rate of sand-drained foundation decreases with the increase of vacuum pressure attenuation coefficient k_(1) and k_(2).The consolidation rate of sand-drained foundation decreases with the increase of vacuum pressure p0 and increases with the increase of final surcharge loading qu.With the increase of loading time Th1,the consolidation rate of sand-drained foundation decreases gradually,and the consolidation rate is the largest under instantaneous surcharge loading.

关 键 词：真空加载过程 堆载 真空联合堆载预压 砂井地基 普遍解析解 

分 类 号：TU472[建筑科学—结构工程]