摘要
针对黄河下游冲积流域分布的大量粉质黏土,利用动、静三轴仪,研究了试样在振动荷载作用、不同围压、超固结比下的静抗剪强度变化。研究表明:振动荷载作用后,试样呈现出类似超固结土的现象,对比振动前的静抗剪强度发现,当似超固结比小于1.25时,振动对试样的抗剪强度影响较小;当似超固结比大于1.25时,抗剪强度迅速衰化,而破坏孔压比呈现出先减小而后增大的特征。在不同超固结比作用下,对比卸载后相同围压的静抗剪强度可得,超固结比与抗剪强度呈指数增长关系,而似超固结比对抗剪强度的提高要强于超固结比;随着似超固结比、超固结比的增大,试样的抗剪强度比均有所增加,当工程中缺乏动力试验条件时,采用超固结比评价经过动荷载作用的地基强度变化是偏安全的。
Based on the large-distributed silty clay in the impact basin of the lower Yellow River,the dynamic triaxial apparatus and the strain controlled triaxial apparatus were conducted to investigate the undrained shear strength of the silty clay after vibration under different confining pressures and over-consolidated ratios.It is shown that the shear behavior of the sample after vibration is similar to that under over-consolidated state.Compared with the shear behavior before vibration,it can be found that the vibration has little influence on the shear strength when the similar over-consolidated ratio(SOCR)is less than 1.25;while SOCR is larger than 1.25,the shear strength of the sample decreases rapidly and the failure pore pressure ratio decreases firstly and then increases.By comparing the shear strength after unloading under the different SOCR and the same confining pressures,it can be concluded that the shear strength increases with the over-consolidated ratio(OCR)by exponential relation.And the increase of the shear strength caused by SOCR is more obvious than OCR.In addition,the shear strength ratio also increases with the increase of the SOCR and the OCR.Therefore,the OCR can be adopted to evaluate the foundation strength after dynamic load if it is difficult to carry out dynamic test in practice.
作者
刘建民
邱月
郭婷婷
宋文智
谷川
LIU Jian-min;QIU Yue;GUO Ting-ting;SONG Wen-zhi;GU Chuan(Shandong Earthquake Agency,Jinan,Shandong 250014,China;Shandong Institute of Earthquake Engineering,Jinan,Shandong 250021,China;State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology,Shandong University of Science and Technology,Qingdao,Shandong 266590,China;China MCC20 Group Corp.Ltd.,Shanghai 201999,China;College of Architecture and Civil Engineering,Wenzhou University,Wenzhou,Zhejiang 325035,China)
出处
《岩土力学》
EI
CAS
CSCD
北大核心
2020年第3期773-780,共8页
Rock and Soil Mechanics
基金
国家自然科学基金项目(No.51578426,No.51809160)
山东省自然科学基金(No.ZR201702160366)
山东省地震局重点基金(No.JJ1801)
山东省地震局青年基金(No.JJ1806Y)
山东科技大学人才引进科研启动基金项目资助(No.2017RCJJ004)。
关键词
粉质黏土
振动荷载
超固结比
似超固结比
孔压
抗剪强度
silty clay
vibration loading
over-consolidated ratio
similar over-consolidated ratio
pore pressure
shear strength
