不排水循环荷载下纤维加固砂土的超孔压及流动液化特性研究

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国家科技期刊平台
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中文摘要：通过对纤维加固超疏松和疏松饱和砂土开展不排水动三轴试验,分析了其超孔压发展规律和流动液化特性.结果表明,未加固超疏松和疏松饱和砂土具有较高的液化势,其在不排水循环荷载下均发生流动液化.离散纤维向砂土骨架提供加密效应和约束效应,从而提高其抗流动液化特性,然而,纤维的约束效应受到加载路径和试样应变发展模式的显著影响.纤维加固改变了饱和砂土残余孔压的发展规律,当纤维向砂土骨架施加较强的约束效应时,试样的残余孔压发展呈倒L型,明显不同于未加固砂土的S型发展.在双向非对称和单向循环荷载下,纤维应力贡献较大,砂土骨架的有效应力在超孔压上升100％后远大于0,加固试样的强度损失低于11％,纤维阻止了液化的发生.

外文标题：Evolution of excess pore pressure and flow liquefaction responses of fibre reinforced sand under undrained cyclic loading

外文摘要：By conducting undrained cyclic triaxial tests on fibre-reinforced very loose and loose saturated sand,we investigated the build-up of excess pore pressure and the flow liquefaction responses.The test results show that unreinforced very loose and loose saturated sand has a high potential for liquefaction,with flow liquefaction occurring in all unreinforced samples under undrained cyclic loading.The presence of fibre reinforcement has a positive impact on the resistance to flow liquefaction of sand.Fibres provide both a densifying effect and a confining effect to the sand skeleton.However,the confining effect of fibres depends on the loading path imposed on the samples and the deformation mode of the samples.The presence of fibres alters the evolution law of the residual excess pore pressure in saturated sand.When fibres impose a strong confining effect on the sand skeleton,the evolution of residual excess pore pressure along with the normalized loading cycles follows a curve with an'inverted L'shape,being significantly different from an'S'shape curve which is followed by the unreinforced sand.Under the two-way symmetrical and one-way cyclic loading,the significant fibre stress contribution is mobilized,leading to the effective stress of the sand skeleton being much greater than 0 after the 100％build-up of excess pore pressure.As a result,the strength loss of the reinforced sample remains below 11％and thus the fibres prevent liquefaction from developing.

外文关键词：

fibre-reinforcementsandflow liquefactionresidual excess pore pressurestrength losseffective stress

作者：

张希栋、董晓强、段伟、胡顺磊、张豪儒

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作者单位：

太原理工大学土木工程学院,山西太原 030024

太原理工大学山西省土木工程防灾与控制重点实验室,山西太原 030024

关键词：

纤维加固砂土流动液化超孔压强度损失有效应力

基金：

山西省科技厅基础研究计划青年科学研究项目中国博士后科学基金国家自然科学基金国家自然科学基金国家自然科学基金国家自然科学基金

项目编号：

202103021241102022M71233852208362521083325197843852281340410

出版年：

2024

DOI：

10.16285/j.rsm.2023.0475

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

年,卷(期)：2024.45(2)

参考文献量25