地铁车站深基坑钢支撑体系轴力预测及安全预警模型研究  

Research on Axial Force Prediction and Safety Warning Model of Steel Bracing System in Deep Foundation Pit of Subway Station

作　　者：陈焕 张可[1] 蒋一波[2] 曹孟晗 CHEN Huan;ZHANG Ke;JIANG Yibo;CAO Menghan(School of Business,HoHai University,Nanjing 211106,China;Jiangsu Huaiyin Water Conservancy Construction Co.,Ltd.,Huaiyin 223005,China)

机构地区：[1]河海大学商学院,江苏南京211106 [2]江苏淮阴水利建设有限公司,江苏淮阴223005

出　　处：《防灾减灾工程学报》2023年第3期576-587,共12页Journal of Disaster Prevention and Mitigation Engineering

基　　金：江苏省水利科技项目(2019054)资助。

摘　　要：随着我国基坑开挖数量和规模的不断增长,基坑事故率也随之上升,钢支撑轴力是衡量基坑围护支撑体系稳定性的重要指标之一。钢支撑轴力可利用传感器进行监测,但传感器失效后,该监测点将无法准确监测支撑轴力数据。故此,为保证基坑围护钢支撑体系的稳定,以宁波市某地铁车站深基坑的钢支撑体系作为研究对象,通过两道钢支撑架设之间的轴力变化进行分析,对钢支撑轴力数据进行预测,并对钢支撑体系进行安全预警。首先,由于轴力监测传感器存在“浴盆曲线”特性,故所得原始监测数据具有贫信息、小样本的特点,在此特性基础上,对基坑钢支撑轴力数据进行检验与处理,使之符合灰色预测模型建立条件;其次,建立灰色预测模型,并对模型的精度进行计算和后验差检验;最后,以灰色预测模型所得数据为基础,结合钢支撑的变形特征和指标,建立置信区间估计法安全预警模型,取显著性水平α=5%、α=2%作为分界点,对深基坑的钢支撑体系进行预警等级划分,并判断当前钢支撑体系的运行状态。结果表明∶灰色预测模型精度良好,同时得出钢支撑体系处于安全的运行区间,模型判定结果与该地铁车站深基坑的钢支撑体系的实际情况相符,证明这种预测及安全预警模型可以用于判断钢支撑体系的稳定性。The accident rate of foundation pits rises with the continuous increase in the number and scale of excavation of foundation pits in China.The axial force of steel bracing,which can be monitored by the sensor,is one of the essential indexes to measure the stability of the bracing system of foundation pits.However,the monitoring point cannot accurately monitor the data of strut axial forces after sensor failure.Therefore,the steel bracing system of the deep foundation pit of a subway station in Ningbo City was taken as the research object to explore how to ensure the stability of the steel bracing system of the foundation pit.Based on the analysis of the change in the axial force between the two steel bracing erections,the data of the axial force of the steel bracing was first predicted in this study.Then,the safety warning of the steel bracing system was provided.Specifically,the original monitoring data obtained are characterized by poor information and small samples due to the“bathtub curve”characteristic of the axial force monitoring sensor.Thus,the axial force data of the steel bracing in the foundation pit were tested and processed to make it conform to the establishment conditions of the gray prediction model.Next,a gray prediction model was established,the accuracy of the model was calculated,and a posteriori test was conducted.Finally,the safety warning model of the confidence interval estimation method was established based on the data obtained from the gray prediction model and the deformation characteristics and indexes of the steel bracing.With the significance levelsα=5%andα=2%as the demarcation points,the warning grades of the steel bracing system of the deep foundation pit were divided,and the operating state of the current steel bracing system was judged.The results demonstrated that the gray prediction model had good accuracy.Meanwhile,the steel bracing system was within a safe operating range.The judgment results of the model were consistent with the actual situation of the steel bracing sy

关 键 词：钢支撑体系 灰色预测 置信区间估计法 安全预警 

分 类 号：C939[经济管理—管理学]