海积软粘土的单剪试验研究  

Study on simple shear tests for marine soft clay

作　　者：丁金伟[1] 胡黎明[2] 郑文棠[1] 

机构地区：[1]广东省电力设计研究院,广州510663 [2]清华大学水利水电工程系水科学与水力水电工程国家重点实验室,北京100084

出　　处：《工程勘察》2012年第10期22-26,共5页Geotechnical Investigation & Surveying

基　　金：广东省电力设计研究院院级科标项目(EV00711W)

摘　　要：开展了天津新港海积软粘土的一系列基于应变控制的单剪试验,研究了动剪切的频率、土样超固结比和剪切应变幅值对该土的等效动剪切模量影响,以及等效动剪切模量和阻尼比与动荷载作用时间的变化关系。试验结果表明:剪切频率越高或者土样的固结比越大,相同应变幅值对应的应力幅值和等效剪切模量越大,但是存在一个动荷载频率的阈值,低于此阈值,荷载频率对等效剪切模量的影响可以忽略;等效剪切模量随着循环振次增加而衰减,这种衰化主要发生在循环的初始阶段,超过一定的循环周次后,振动周次的影响逐渐减小;阻尼比受循环振次的影响较小。A series of cyclic simple shear tests based on the strain control for the marine soft clay at Tianjin New Harbor are carried out. The effects of the consolidation, shear frequency, OCR and the number of cyclic cycles on the dynamic shear modulus and damping ratio are studied. The test results indicate： The equivalent dynamic shear modulus increases with the increase of the dynamic shear load frequency and OCR. There is a threshold of dynamic load frequency, under which the effect of the frequency on the dynamic shear modulus is negligible. The equivalent shear modulus decreases with the increase of the cyclic number, but after certain number of the cycles, the effect will reduce. The cyclic loading cycles have little effect on the damping ratio.

关 键 词：海积软粘土 循环单剪试验 动剪切模量 

分 类 号：TU41[建筑科学—岩土工程]