岩土力学2024,Vol.45Issue(4) :1081-1091,1120.DOI:10.16285/j.rsm.2023.0531

冲击荷载下含夹层饱和砂土孔压变化规律分析

Analysis of pore pressure variation pattern of saturated sandy soil containing interlayer under impact loading

金丹丹 鲁先东 王炳辉 施展 张雷
岩土力学2024,Vol.45Issue(4) :1081-1091,1120.DOI:10.16285/j.rsm.2023.0531

冲击荷载下含夹层饱和砂土孔压变化规律分析

Analysis of pore pressure variation pattern of saturated sandy soil containing interlayer under impact loading

金丹丹 1鲁先东 2王炳辉 3施展 2张雷3
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作者信息

  • 1. 江苏大学土木工程与力学学院,江苏镇江 212013;中国地震局工程力学研究所中国地震局地震工程与工程振动重点实验室,黑龙江哈尔滨 150000
  • 2. 江苏大学土木工程与力学学院,江苏镇江 212013
  • 3. 江苏科技大学土木工程与建筑学院,江苏镇江 212100
  • 折叠

摘要

砂土中夹层的性状会影响饱和砂土孔压发展,从而影响砂土层变形.为研究夹层位置、厚度和种类等不同夹层状态下砂土液化过程中的孔压变化规律,设计了冲击荷载作用下层状砂液化试验,建立了含夹层饱和砂土理论模型,并将试验结果与理论分析进行对比.结果表明:含夹层饱和砂土的孔压发展呈现3个阶段,即快速上升、快速消散、缓慢消散阶段.高渗透性夹层高度越高,其下方土层孔压快速消散时长越短,越快趋于稳定值,但消散总时长无明显影响;低渗透性夹层高度或厚度的增大,均会使夹层上方孔压快速消散阶段速率加快,孔压消散稳定阶段延长,孔压消散总时长随之线性增长;同时,孔隙水会在低渗透性夹层下方形成水膜,夹层高度或厚度的增加均会使水膜持续时间增长,但水膜形态主要受夹层厚度影响.试验结果与理论分析较为一致,说明了试验的可靠性.

Abstract

The existence of intercalation in sandy soil affect the pore pressure development in saturated sandy soil,thereby impacting the deformation of sandy soil layer.In order to study the pore pressure change during the liquefaction of sandy soil under different intercalation conditions such as location,thickness and type,a liquefaction test of laminated sand under impact load was conducted.This study involved establishing a theoretical model of saturated sandy soil with intercalations and comparing the test results with the theoretical analysis.The findings reveal that the development of pore pressure of saturated sandy soil containing intercalated layers exhibits three stages:rapid rise,rapid dissipation,and slow dissipation.In cases involving high-permeability intercalations,a higher location of the intercalation results in a shorter rapid dissipation time of pore pressure below it,leading to a faster convergence to a stable value.However,the total dissipation time shows no significant change.Conversely,for low-permeability intercalations,an increase in the height or thickness of the intercalation accelerates the rate of rapid dissipation phase of pore pressure above the intercalation,prolongs the stable phase of pore pressure dissipation,and linearly increases the total dissipation time of pore pressure.Additionally,a water film forms below the low-permeability intercalation,and increasing the intercalation height or thickness extends the duration of the water film,with the water film formation primarily affected by the intercalation thickness..The test results are more consistent with the theoretical analysis,indicating the reliability of the test.The test results align more closely with the theoretical analysis,indicating the reliability of the test.

关键词

层状砂土/冲击荷载/超孔隙水压力/夹层高度/夹层厚度/水膜

Key words

stratified sandy soil/impact load/excess pore water pressure/intercalation height/intercalation thickness/water film

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基金项目

中国地震局工程力学研究所实验室开放基金(2021D19)

国家自然科学基金面上项目(51978317)

出版年

2024
岩土力学
中国科学院武汉岩土力学研究所

岩土力学

CSTPCD北大核心
影响因子:1.614
ISSN:1000-7598
参考文献量20
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