夯扩挤密碎石桩加固液化砂土地基的动力数值分析

发布时间：2018-02-27 20:50

本文关键词： 夯扩挤密碎石桩液化砂土动力数值分析超静孔隙水压力孔压比　出处：《岩土力学》2014年S2期 　论文类型：期刊论文

【摘要】：砂土液化问题一直是土动力学与岩土地震工程研究领域的重要课题之一。基于南水北调中线某工程,通过现场和室内试验获取土体的物理力学参数,利用岩土数值分析软件FLAC3D对夯扩挤密碎石桩加固干渠液化砂土地基进行了动力数值分析。结果表明,由于夯扩挤密碎石桩的排水作用,干渠底部饱和砂土地基中的超静孔隙水压力和孔压比与加固前相比明显减小;干渠渠道底部饱和砂土中的监测曲线表明,随着地震荷载持续时间的增加,饱和砂土地基中超静孔隙水压力和孔压比峰值较加固前大幅值降低,且时程曲线达到峰值之后也由加固前的基本保持不变改为迅速消减降低;由于夯扩挤密碎石桩的排水和挤密作用,有效消除了干渠渠道底部以及渠堤坡面外侧平台至坡脚底部砂土层的液化现象,加固后干渠底部饱和砂土地基中没有液化现象产生。
[Abstract]:Sand liquefaction is always one of the most important topics in the field of soil dynamics and geotechnical seismic engineering. Based on a project in the middle route of South-to-North Water transfer Project, the physical and mechanical parameters of soil are obtained through field and laboratory tests. The dynamic numerical analysis of consolidation of liquefaction sand soil foundation of trunk canal by compaction compaction gravel pile with FLAC3D software is carried out. The results show that, because of the drainage function of compacted compacted crushed stone pile, The excess pore water pressure and pore pressure ratio in saturated sand foundation at the bottom of the trunk canal are obviously reduced compared with those before reinforcement, and the monitoring curves in saturated sand soil at the bottom of the trunk canal show that the seismic load duration increases with the increase of seismic load duration. The peak value of excess pore water pressure and pore pressure ratio in saturated sand foundation is lower than that before reinforcement, and the time history curve has changed from the basic unchanged before reinforcement to the rapid reduction after the peak value of time history curve is reached. Because of the draining and compacting effect of rammed compacted gravel pile, the liquefaction phenomenon of sand layer at the bottom of the canal and the outside platform of the slope surface of the canal embankment to the bottom of the slope is effectively eliminated, and there is no liquefaction in the saturated sand soil foundation at the bottom of the trunk canal after reinforcement.
【作者单位】：华北水利水电大学资源与环境学院;河北省水利水电第二勘测设计研究院;
【基金】：国家自然科学基金青年基金资助项目(No.41102203) 水利部公益性行业科研专项经费项目(No.201301034) 郑州市创新型科技人才培育计划领军人才项目(No.10LJRC185) 河南省基础与前沿技术研究项目(No.122300410146) 华北水利水电学院高层次人才引进项目(No.201105)
【分类号】：TU472;TU441.8

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