含塑性细粒砂的液化强度与变形特性分析  

Analysis of Liquefaction Strength and Deformation Characteristics of Plastic Fine-grained Sand

作　　者：邸勇 刘利[2] DI Yong;LIU li(College of Geological Engineering and Survey,Chang’an University,Xi’an 710054,China;China Railway Eighteenth Bureau Group Co.,Ltd.,Tianjin 300222,China)

机构地区：[1]长安大学地质工程与测绘学院,陕西西安710054 [2]中铁十八局集团有限公司,天津300222

出　　处：《粉煤灰综合利用》2021年第6期18-23,共6页Fly Ash Comprehensive Utilization

基　　金：国家自然科学基金重大项目(41790443);长安大学中央高校基本科研业务费专项资金(300102260105);中国地质调查局地质调查项目(DD20190647)。

摘　　要：砂土液化易产生严重危害,威胁到生命安全及公共财产。为详细分析具有不同塑性指标、细粒含量比和孔隙比的砂土液化强度和变形特性,本研究进行了循环加载试验和静力加载试验分析,试验中采用湿装夯实和水下沉积两种方式制备试件,研究使用了ALID二维数值计算程序模拟地震期间变形进行对比验证。结果表明:(1)一定条件下,混合试件的液化强度随着相对密度的减小而减小;(2)当CC=10%时,试件的超静孔隙水压力比并没有达到1.0,剪切应变增幅超过20%,这种现象源于“循环软化”,不同于“液化”;(3)剪切模量比与液化安全系数的关系的试验数据总体与前人经验公式一致。本研究可为相关砂土液化问题提供一定参考。Liquefaction of sandy soil is likely to cause serious harm,threatening life safety and public property.In order to analyze in detail the strength and deformation characteristics of sand with various plasticity indexes,fine particle content ratio and void ratio.In this study,a cyclic loading test and a static loading test were carried out.The test used two methods of water-pluviated and moist-tampedto prepare samples.Then,the study used a two-dimensional numerical calculation program called ALID to simulate the deformation of the river embankment during the earthquakeand it has been compared and verified with previous classic calculations.The research results show that:(1)Under certain conditions,the liquefaction strength of the mixed specimens decreases with the decrease of the relative density;(2)when CC=10%,the excess pore water pressure ratio of the specimen does not reach 1.0,and the shear strain increases by more than 20%.This phenomenon originates from“cyclic softening”,which is different from“liquefaction”;(3)the relationship between the shear modulus ratio and the safety factor of liquefaction is consistent with the previous empirical formula in the overall test data,but some research results show an underestimated state.This study can provide a reference for related sand liquefaction issues.

关 键 词：细粒砂土 液化强度 可塑性 剪切模量 

分 类 号：TU441[建筑科学—岩土工程]