Rate-Dependent Weakening of the Shear Force for the Submerged Granular Medium Based on the Experimental Study

查看全文 作　　者：Hu [1,2]Zheng;Guowei [1]Dai;Wuwei [1,2]Mao;Yu [1,2]Huang 机构地区：[1]Department of Geotechnical Engineering,College of Civil Engineering,Tongji University,Shanghai 200092,China;[2]Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China 出　　处：《Journal of Earth Science》索引2023年第34卷第2期,共7页 基　　金：financially supported by the National Natural Science Foundation of China(Nos.42120104008,41831291,42002273);the Fundamental Research Funds for the Central Universities(No.22120210143)。 摘　　要：An experimental study is conducted to describe rate-dependent shear strength in a submerged granular medium to understand the mystery of submarine landslides with extremely small slide angles and long run-out distances.The experimental apparatus allows a long-span shear strain rate,■,for five orders of magnitude from 10^(-4)to 10^(1)s^(-1).It is observed that(a)submerged sand under higher shear tend to have bigger yield strength;this positive response of rate effect is significantly affected by the magnitudes of shear strain rates.(b)the residual strength of soil is clearly affected negatively by shear strain rate,decreasing as shear strain rate increases;even small variations under lower rate cause notable differences in residual strength,indicating a novel weaking rate-dependent.The yield strength and residual strength are corresponding to the shear state of soil.Hence,it is enough experimentally to explain that as long as the submarine mass flow speeds up,the slope sliding can be kept by only a small amount of force along the slide direction,which can be calculated as the gravity component even with a small slide angle. 关 键 词：rate dependent granular medium submarine landslides yield strength residual strength engineering geology