砂质粉土冲击液化微观机理研究  

TEST STUDY ON MICRO-MECHANISM OF IMPACT LIQUEFACTION OF SANDY SILT

作　　者：段钊[1,2,3] 董晨曦 郑文杰 马建全 李晓军[1,2] DUAN Zhao;DONG Chenxi;ZHENG Wenjie;MA Jianquan;LI Xiaojun(College of Geology and Environment,Xi'an University of Science and Technology,Xi'an 710054,China;Shaanxi Provincial Key Laboratory of Geological Support for Coal Green Exploitation,Xi'an 710054,China;Shaanxi Key Laboratory of Geotechnical and Underground Space Engineering,School of Civil Engineering,Xi'an University of Architecture and Technology,Xi'an 710055,China)

机构地区：[1]西安科技大学地质与环境学院,中国西安710054 [2]陕西省煤炭绿色开发地质保障重点实验室,中国西安710054 [3]西安建筑科技大学土木工程学院,中国西安710055

出　　处：《工程地质学报》2022年第4期1087-1097,共11页Journal of Engineering Geology

基　　金：国家自然科学基金(资助号:41702298,41602359);陕西省自然科学基础研究计划(资助号:2017JQ4020);地质灾害防治与地质环境保护国家重点实验室开放基金(资助号:SKLGP2017K010).

摘　　要：近年来,土体冲击液化引起的工程地质问题已经广泛地出现在人们的视野中,但目前对于土体冲击液化机理的研究尚不够完善。本文通过冲击液化试验及相关微观试验,揭示了不同冲击能下砂质粉土的孔压发育与微观结构变化情况,在此基础上,从微观角度对砂质粉土冲击液化机理进行了讨论。结果表明:砂质粉土受冲击液化会出现明显的孔压激增现象,且单位冲击能下激发的孔压随落距增大而减小,并伴随明显的微结构变化;冲击液化作用主要从土体颗粒接触关系、颗粒形态,孔隙大小、形态及方向等方面改变了土体的微观结构;颗粒骨架破坏与孔隙收缩是土体冲击液化的主要微观机理,不同冲击能下土体的液化机理也由于骨架破损和孔隙收缩程度不同而产生出相应的差异。Engineering geology issues raised by earthquake-induced soil liquefaction have been drawn particular public attention.Studies focused on the formation mechanism of impact load-induced liquefaction and associated influencing factors are remarkably limited.This study conducts a series of impact load liquefaction tests on the sandy silt and its micro structure analyses towards revealing the development of pore pressure and the change in micro structure.The results indicate that impact load aggravates the development of pore pressure and its magnitude decreases with increase of impact energy.The micro structure analyses showed that impact load also causes a change in interparticle contact,particle morphology,and pore structure.Soil skeleton damages and pore shrinkage are deemed as the main cause to lead to soil liquefaction when subjected to impact load.The formation mechanism varies depending on the level of soil skeleton damage and pore shrinkage.

关 键 词：滑坡运动 砂质粉土 冲击液化 微观试验 应力路径 

分 类 号：TU435[建筑科学—岩土工程]