摘要
为合理掌握富水区基坑降水后的沉降变形规律,将基坑降水后的地表沉降解析计算和后续变形趋势分析相结合,分别服务于基坑施工前设计和施工过程管理两个阶段,尽可能为基坑安全施工提供理论支撑。以基坑勘察成果为基础,根据土体有效应力原理开展基坑沉降解析计算。结合基坑施工过程中的沉降监测成果,通过变分模态分解、V/S分析实现基坑沉降变形趋势判断。分析结果表明:经基坑降水后的地表沉降解析计算,沉降计算值均不同程度地小于沉降实测值,并统计得到项目区的沉降计算值修正系数为1.06,且随沉降计算点距降水井距离的增大,地表沉降逐步减小,大致于15 m以外的沉降影响可忽略。同时,VMD的两次降噪处理能有效求得基坑沉降变形的最终趋势信息,再经V/S分析,得出沉降累计序列的Hurst指数均大于0.5,速率序列的Hurst指数均小于0.5,两者综合得出基坑沉降仍会增大,但增大速率趋于减弱,总体趋于稳定。
To grasp reasonably the settlement and deformation laws of the foundation pit in the rich water area after dewatering,it is proposed to combine the analytical calculation of surface settlement after dewatering with the subsequent deformation trend analysis,which will serve the two stages of pre-construction design and construction process management of the foundation pit to provide theoretical support for the safe construction of the foundation pit as much as possible.Based on the results of the foundation pit survey,the settlement analysis calculation of the foundation pit is carried out according to the principle of effective stress of the soil.Based on the settlement monitoring results during the foundation pit construction process,the deformation trend of the foundation pit settlement is determined through variational mode decomposition and V/S analysis.The analysis results show that the surface settlement analysis calculation after foundation pit dewatering finds that the calculated settlement values are to varying degrees smaller than the measured settlement values.The correction factor for the settlement calculation values in the project area is calculated to be 1.06,and the surface settlement is gradually decreased as the distance between the settlement calculation point and the dewatering well is increased.The settlement impact beyond 15 m can be ignored.At the same time,the two denoising treatments of VMD can effectively obtain the final trend information of foundation pit settlement deformation.After V/S analysis,it is found that the Hurst exponent of the cumulative settlement sequence is greater than 0.5,and the Hurst exponent of the rate sequence is less than 0.5.The combination of the two shows that the foundation pit settlement will still be increased,but the rate of increase tends to weaken,and the overall trend tends to be stable.
作者
秦凯
党卫红
蒋麟
赵治海
庞旭卿
QIN Kai;DANG Weihong;JIANG Lin;ZHAO Zhihai;PANG Xuqing(Northwest Research Institute of Engineering Investigations and Design,Xi'an 710003,China;School of High Speed Railway Engineering,Shaanxi Railway Institute,Weinan 714000,China)
出处
《大连交通大学学报》
2025年第4期83-89,共7页
Journal of Dalian Jiaotong University
基金
陕西省教育厅自然科学基金项目(2013JK0990)
渭南市科研发展计划项目(2015KYJ-3-2)
陕西铁路工程职业技术学院科研基金(kY2019-47)。
关键词
基坑
降水
沉降解析计算
降噪处理
变形趋势
excavation pit
precipitation
settlement analysis calculation
noise reduction processing
deformation trend
