摘要
粉细砂土地区深基坑变形具有显著的时间效应,该土的蠕变特性使护坡桩变形随时间的推移不断增大,支护不及时、施工停止时间过长等原因均可能导致基坑工程事故的发生.本文利用时间硬化蠕变模型反映基坑超期服役时的时间效应.通过粉细砂蠕变试验结果拟合蠕变模型参数,并将确定好的参数用于实际工程中的计算模拟,生成预测模型来计算基坑超期使用下的变形范围及趋势.结果表明:基坑土体变形随时间不断发展,水平变形速率两个月左右趋于平稳,坑外地表沉降速率在一个月左右趋于平稳,沉降值随着距坑边距离增大呈现先增大后减小的分布规律;所建立的时间硬化蠕变模型能够合理模拟超期服役下粉细砂基坑的变形规律,预测基坑未来稳定性,可以为超期服役基坑工程进度安排及后期管理提供依据.
Deep foundation pit engineering in fine sand soil area has significant time effect.The creep property of the soil makes the deformation of slope protection pile increase with time,and the reasons such as untimely support and long construction stop time may lead to the occurrence of foundation pit engineering accidents.In this paper,the time hardening creep model is used to reflect the time effect of excavation in extended service.The creep model parameters are fitted by the results of the fine sand creep test,and the determined parameters are used in the calculation and simulation of the actual project.The creep parameters are adjusted by using the measured data through parameter inversion,and the prediction model is generated to calculate the deformation range and trend of the foundation pit under the overuse.Results:The soil deformation of the foundation pit develops with time,the horizontal deformation rate tends to be stable about two months,and the surface settlement rate outside the pit tends to be stable about a month.The settlement value increases first and then decreases with the increase of distance from the pit edge.The time-hardening creep model established in this paper can reasonably simulate the deformation law of the foundation pit of fine sand in extended service and predict the future stability of the foundation pit.The research can provide a basis for the schedule and management of the foundation pit in extended service.
作者
党发宁
王海洋
高仓
薛宝祥
李杨
李涛
DANG Faning;WANG Haiyang;GAO Cang;XUE Baoxiang;LI Yang;LI Tao(State Key Laboratory of Eco-hydraulics in Northwest Arid Region,Xi′an University of Technology,Xi′an 710048,China;China Railway First Survey and Design Institute Group Co.,Ltd.,Xi′an 710043,China;Shaanxi Construction Ninth Construction Group Co.,Ltd.,Shaanxi Yulin,719000,China)
出处
《西安建筑科技大学学报(自然科学版)》
北大核心
2023年第1期41-51,共11页
Journal of Xi'an University of Architecture & Technology(Natural Science Edition)
基金
国家自然科学基金资助项目(51979225,51679199)。
关键词
粉细砂基坑
蠕变模型
蠕变参数
超期服役
fine sand foundation pit
creep model
creep parameters
extended service