滨海软土地区深大基坑群施工过程致灾机理及预警控制研究

项目名称： 滨海软土地区深大基坑群施工过程致灾机理及预警控制研究

项目编号： No.41330633

项目类型： 重点项目

立项/批准年度： 2014

项目学科： 地质学

项目作者： 王建华

作者单位： 上海交通大学

项目金额： 320万元

中文摘要： 由于基坑工程分析理论不成熟和监控预警不完善，滨海软土地区深大基坑施工的工程事故频发，诱发地面沉降等严重城市工程地质灾害。随着基坑规模的不断发展，同步施工相邻群坑群和超大面积分区开挖基坑群越来越多，其致灾机理更为复杂。本项目综合采用室内试验、理论分析和现场测试等方法，对滨海软土地区深大基坑群施工过程的致灾机理及预警监控方法开展研究。研制新型土工试验设备，揭示滨海软土在应力和渗流耦合作用下的响应机理，建立本构模型。考虑深大基坑群施工的物理、几何和时间多尺度特征，开发可分析开挖与抽水施工流固耦合的非线性多尺度数值方法，形成大规模、全过程精细分析工具。阐明基坑群施工过程的致灾机理与灾变规律，提出融合力学分析和监测数据的多参数灾变评估理论，建立深大基坑群施工过程诱发工程地质灾害的动态评估与预警控制平台。为滨海软土地区地下空间开发中重大工程的地质环境灾害效应分析与监测预警控制提供科学依据和实用方法。

中文关键词： 滨海软土;基坑群;渗流场;灾变机理;多尺度

英文摘要： Due to the immature of the design theory, monitoring and prediction system in excavation engineering, accidents of deep excavations occurred frequently in coastal soft soil area, which caused many severe geological disasters of city. The excavation group, which means a group of nearest excavations constructed at same time or the supper large excavation divided into small parts, has been developed because the scale of underground construction was increased fast. The mechanism of disasters caused by such excavation group is more complex and the risk of the disasters is much higher than single excavations. The mechanism of the geology disasters caused during excavation group in the soft soil of coast area is analyzed in this research by the lab tests, theoretical analysis and field monitoring. The prediction and control methods of the disasters are also studied. A new apparatus for soft soil tests is developed by the considering small strain effect and the influence of unloading and seepaging. The constitutive model of soft soil under the complex stress paths during excavation group is then presented based on the lab tests. By considering multi-scale characters of the geometric model and different materials during deep excavation group, a nonlinear multi-scale numerical method based is presented to finish the large, whole process, and extractive analysis. The coupling effect between unloading of excavation and pore water pressure reducing caused by dewatering is also considered in the numerical method. The mechanism of the geology disasters and its developing behavior can be obtained based on the field surveys, model tests and numerical analysis. Then the multi-parameter risk evaluation method is built by combining the mechanical calculation and monitoring data. Finally, a system including the dynamic prediction, pre-warning and feedback control on the geology disasters during large excavation group is developed. The results and productions of this research can be used in analyzing and preventing of the disasters in underground construction of coast area.

英文关键词： coastal soft soil;excavation group;seepage field;evolution of geology desaster;multiscale