软土灰砂桩加固后加载引起的超静孔隙水压力  

Excess Pore Water Pressure Changes as Step Loading in the Reinforced Soft Soil by Lime-sand Pile

作　　者：马文国[1,2] 王兰民[1,3] 李学丰[2] 

机构地区：[1]兰州大学土木工程与力学学院,兰州730000 [2]宁夏大学物理电气信息学院固体力学研究所,银川750021 [3]中国地震局黄土地震工程重点实验室,兰州730000

出　　处：《科学技术与工程》2015年第23期189-192,197,共5页Science Technology and Engineering

基　　金：国家自然科学基金(51368050);宁夏区科技支撑计划项目(201301)资助

摘　　要：研究了湖相沉积软土在灰砂桩加固后随着上部结构的分级加载及后期地基中超静孔隙水压力的变化情况。以银川地区广泛分布的湖相沉积软土的地质条件为背景,利用灰砂桩加固软土地基,其原理是基于生石灰吸水膨胀发热吸收土中的水来对桩周土起挤密作用。模拟中使用了改进的Mohr-Coulomb强度准则,计算了软土灰砂桩加固后随着上部结构施工过程及施工完成后超孔隙水压力的增长与消散过程。计算显示超静孔隙水压力变化引起基础中的有效应力能够承受上部荷载,说明湖相沉积软土采用灰砂桩加固在实践和理论上是可行的。In order to research the excess hydrostatic pore water pressure with the change of the step loading of superstructure in lime-sand pile compound foundation for the soft soils of lacustrine deposit. To the soft soils of the Yinchuan lacustrine deposit as the background, application of lime-sand pile in soft soil to reinforced foundation, the mechanism of lime-sand pile in soft soil as practical experience. A modify Mohr-Coulomb strength criterion was used in simulation, the excess hydrostatic pore water pressure with change of step loading and time on lime-sand pile compound foundation was analyzed by the finite element method. The results showed that the change of excess hydrostatic pore water pressure in lime-sand pile compound foundation can also bearing superstructure loads, using lime-sand pile to reinforce soft soils of lacustrine deposit is feasible in practice and theoretically.

关 键 词：软土 灰砂桩 超孔隙水压力 改进Mohr-Coulomb强度准则 有限元 

分 类 号：TU432[建筑科学—岩土工程]