摘要
制备软黏土地基的离心模型既是试验的前提和基础,同时也是技术难点。提出一种基于常规重力条件下分层预固结与离心机固结相结合的饱和软黏土离心模型的制备方法,详细阐述分层固结法的原理及步骤,分析固结过程中孔隙水压力及竖向位移的变化,并与压缩量的理论计算结果进行对比。结果表明:对于分层预压固结,在施加每一级荷载作用时,可将沉降速率0.2 mm/h以及超静孔隙水压力消散速率0.2 kPa/h作为软黏土模型固结稳定的条件;对于离心机固结,当离心加速度达到目标值5 h后,模型达到固结稳定状态,可将超静孔隙水压力消散达2 kPa/h且地表竖向沉降量达0.15 mm/h作为软黏土模型的离心固结的稳定条件。研究成果和试验步骤可供今后软黏土离心振动台试验的模型制备提供方法参考和技术支撑,对于提高软黏土离心模型的制备精度具有一定的科学意义。
The preparation of centrifugal model of soft clay foundation is both the prerequisite and foundation of the test,and at the same time,it is also a technical difficulty.In this paper,a centrifugal model preparation method for saturated soft clay is proposed based on the combination of layered pre-consolidation and centrifuge consolidation under conventional gravity conditions,the principle and steps of layered consolidation method are elaborated in detail,and the changes of pore pressure and vertical displacement in the process of consolidation are analyzed and compared with the theoretical calculations of compression amount.The results show that:for the layered pre-compression consolidation,the settlement rate of 0.2 mm/h and the dissipation rate of excess pore water pressure of 0.2 kPa/h can be taken as the conditions for the consolidation and stabilization of the soft clay model when applying each level of loading;for the centrifuge consolidation,the model achieves the consolidation and stabilization state when the centrifugal acceleration reaches the target value of 5 hours,and the dissipation of the excess pore water pressure of up to 2 kPa/h and the surface vertical settlement up to 0.15 mm/h can be taken as the stabilization conditions for centrifugal consolidation of soft clay model.The research results and test steps can be used to provide methodological references and technical support for the preparation of soft clay centrifugal shaking table tests in the future,which is of scientific significance for improving the preparation accuracy of soft clay centrifugal models.
作者
兰景岩
咸甘玲
王永志
王体强
刘翔宇
任鸿燚
汤兆光
LAN Jingyan;XIAN Ganling;WANG Yongzhi;WANG Tiqiang;LIU Xiangyu;REN Hongyi;TANG Zhaoguang(College of Civil Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China;Guangxi Key Laboratory of Geomechanics and Geotechnical Engineering,Guilin University of Technology,Guilin,Guangxi 541004,China;Key Laboratory of Earthquake Engineering and Engineering Vibration,Institute of Engineering Mechanics,China Earthquake Administration,Harbin,Heilongjiang 150080,China;Key Laboratory of Earthquake Disaster Prevention and Emergency Management Department,Institute of Engineering Mechanics,China Earthquake Administration,Harbin,Heilongjiang 150080,China)
出处
《岩石力学与工程学报》
EI
CAS
CSCD
北大核心
2024年第5期1282-1290,共9页
Chinese Journal of Rock Mechanics and Engineering
基金
国家自然科学基金资助项目(52368068)
广西自然科学基金资助项目(2021GXNSFAA220017)。
关键词
土力学
饱和软黏土
离心模型试验
分层固结排水
超孔隙水压力
soil mechanics
saturated soft clay
centrifugal model test
layered consolidation drainage
excess pore water pressure
