越江地铁荷载作用下软黏土孔压试验研究  

Experimental study of pore pressure model of soft clay under cross-river subway loading

作　　者：丁智 庄家煌 魏新江 孔勃文 马少俊[4] DING Zhi;ZHUANG Jiahuang;WEI Xinjiang;KONG Bowen;MA Shaojun(Department of Civil Engineering,Zhejiang University City College,Hangzhou,Zhejiang 310015,China;Guangzhou Metro Design and Research Institute Co.,Ltd.,Guangzhou,Guangdong 510030,China;College of Civil Engineering and Architecture,Zhejiang University,Hangzhou,Zhejiang 310058,China;Zhejiang Province Institute of Architectural Design and Research,Hangzhou,Zhejiang 310006,China)

机构地区：[1]浙大城市学院土木工程系,浙江杭州310015 [2]广州地铁设计研究院股份有限公司,广东广州510030 [3]浙江大学建筑工程学院,浙江杭州310058 [4]浙江省建筑设计研究院,浙江杭州310006

出　　处：《岩石力学与工程学报》2020年第S01期3178-3187,共10页Chinese Journal of Rock Mechanics and Engineering

基　　金：浙江省自然科学基金资助项目(LQ16E080008,LHZ20E080001);浙江省重点研发计划项目(2020C01102)。

摘　　要：杭州湾区域越江地铁往往穿越江底深厚软土层,同时上覆冲淤以及水位的变化会对地铁变形造成不利的影响,从而对地铁安全运营造成隐患。基于双向动三轴试验,首次模拟了越江地铁循环荷载对软黏土地基的作用,得到软黏土孔压发展曲线,并建立越江地铁作用下软黏土的孔压模型。研究结果表明:越江地铁循环荷载作用下,软黏土的孔压发展呈现出"急剧上升→增速减缓→趋于稳定"的变化规律;增大循环加载过程中的有效围压,孔隙水压力会上升;增大径向循环应力比孔隙水压力的稳定值会随之增大;采用二次对数模型能够较好地模拟越江地铁荷载作用下软黏土的孔压发展,且综合考虑了越江地铁荷载径向循环应力比和有效围压的影响,能够为越江地铁工后沉降的控制及预测提供相应的参考。Many cross-river subways are often constructed in deep soft soil layers,and the frequent changes of the warp soil above and the water level is a disadvantage to the control of the post-construction settlement.Therefore,the safety of cross-river subway is a challenge to control the post-construction settlement.Therefore,the safety of cross-river subway is undermined when it starts running.In this paper,the bidirectional dynamic triaxial test was operated by trial and error to stimulate the loading of cross-river subway on soft clay sample.The changing curve of pore pressure through dynamic test could be plotted,and a pore pressure model of soft clay under cross-river subway loading can be built.The study shows that:Under cross-river subway loading,the growing of pore pressure is firstly rapid,then slows down and stable.Increasing the effective confining pressure during cyclic loading make the pore water pressure rise,the stability value of pore water pressure will increase with the increase of radial cyclic stress ratio.The quadratic logarithmic model can be used to simulate the pore pressure development of soft clay under cyclic loading.The model takes the effects of radial cyclic stress ratio and effective confining pressure into consideration,which can provide as a reference for post-construction settlement prediction of cross-river subway.

关 键 词：土力学 越江地铁 循环荷载 孔压 围压 径向循环应力比 

分 类 号：TU43[建筑科学—岩土工程]