不同剪切速率下吸力基础-黏土界面剪切特性研究

Shear Behavior of Suction Foundation-Clay Interface under Different Shear Rates

采用GDS界面剪切仪,开展不同剪切速率下吸力基础-黏土界面剪切试验,研究了沉贯过程中基础沉贯速率对吸力基础-黏土界面剪切特性的影响,分析了不同剪切速率、不同沉贯深度下的界面剪切特性。试验结果表明,吸力基础-黏土界面的抗剪强度随着法向应力的增加而增大,但随着剪切速率的增加而减小;界面峰值强度对应的剪切位移均在1 mm以内,且随着法向应力的增加而增大;界面凝聚力与剪切速率呈正相关,界面摩擦角则相反。在沉贯速率1.0~1.2 cm/min范围内,界面凝聚力增加幅度最大。摩擦系数在0.27~0.34变化,且随着沉贯速率的减小而增大,随沉贯深度的增加呈现减小趋势。

Shear tests of suction foundation-clay interface at different shear rates were carried out by using a GDS interface shear tester to explore the installation process.This study is focused on the effect of foundation penetration rate on shear characteristics of suction foundation-clay interface during the penetration process,and the shear characteristics of interface at different shear rates and penetration depths.Test results show that the shear strength of the suction foundation-clay interface increases with the increase in normal stress,but decreases with the increase in shear rate.Moreover,the shear displacement corresponding to the peak strength of the interface is within 1mm and increases with the increase in the normal stress.The interface cohesion increases with the increase in shear rate,while the interface friction angle is opposite.Furthermore,in the shear rate range of 1.0-1.2 cm/min,the increase in interface cohesion becomes the largest.The friction coefficient varies from 0.27 to 0.34,and increases with the decrease in shear rate and decreases with the increase in penetration depth.