基于现场实测数据的深基坑工程可靠度研究

Reliability Analysis of Deep Excavation Based on Field Monitoring Data

研究目的:深基坑开挖活动存在着各种不确定性因素,现场监测数据常常无法直接反映基坑当前的稳定状态。针对杭州地铁彭埠站的深基坑开挖工程,结合贝叶斯修正和Monte Carlo有限元方法,基于现场监测数据对基坑开挖过程中的安全度进行了实时的可靠度评估。研究结论:研究结果表明,根据现场实测数据来评估基坑的失稳概率的方法比常规方法更为合理。该方法可有效地提高基坑稳定性分析的准确性,并避免测斜结果误差引起的问题;可选取地下连续墙的水平位移实测值作为可靠度分析的输入信息;破坏准则的选取对稳定性分析结果有很大的影响。本方法可以弥补传统可靠度分析的不足,为基于现场实测数据的深基坑安全性评估提供了新的途径。

Research purposes： monitoring data cannot directly Bayesian updating with Monte excavation of Pengbu station of There are considerable uncertainties existing in deep excavation activities and the field reflect the present excavation stability condition in most cases. In this paper, combing Carlo finite element method, real - time reliability assessment of stability during the Hangzhou Metro is performed based on field measurement data.Research conclusions：The results show that, in comparison with conventional method, it is more rational to estimate the failure probability of deep excavation by use of field monitoring data. This method can effectively enhance the accuracy of excavation stability analysis and avoid the problems resulting from the errors of the inclinometer readings. The horizontal displacement monitoring data of the diaphragm wall can be used as the input information of reliability analysis. The selection of failure criteria has a significant influence on the stability analysis results. The proposed method can compensate for the limitations of conventional reliability analysis and is a promising alternative method for stability analysis of excavation based on field monitoring data.