基于在机开挖离心模型试验的改进MSD法评估  

Evaluation of improved MSD method based on centrifugal model tests on in-flight excavation of foundation pits

作　　者：曹明洋 马险峰[1,2] CAO Mingyang;MA Xianfeng(Department of Geotechnical Engineering,Tongji University,Shanghai 200092,China;Key Laboratory of Geotechnical and Underground Engineering of Ministry of Education,Tongji University,Shanghai 200092,China)

机构地区：[1]同济大学地下建筑与工程系,上海200092 [2]同济大学岩土及地下工程教育部重点实验室,上海200092

出　　处：《岩土工程学报》2024年第1期190-198,共9页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(41272290)。

摘　　要：研发了一套应用于高离心力场条件下在机基坑开挖装置和支撑施加系统,开展了多支撑支护的黏土基坑开挖的离心模型试验。将开挖引起的墙后地表沉降与挡墙变形的试验数据与已发表的相关研究成果进行对比分析,证明了该套在机开挖装置和支撑系统可有效模拟实际基坑工程的土体开挖及支撑。在离心试验数据的基础上,对基坑体系的变形机制进行了修正,提出了全量变形机制计算的改进动员强度法(mobilizablestrengthdesign,MSD)。应用改进MSD法计算多支撑开挖的挡墙变形曲线,并将计算结果与现场监测数据对比。结果表明:改进MSD法预测结果与实测数据较吻合,论证了改进MSD法的有效性。A set of novel device for the centrifugal model tests on the whole process of excavation is developed to investigate the influences of excavation on wall displacement and ground settlement.The test data of excavation-induced ground settlement behind the retaining wall and wall deformation are compared with the published research results,and it is determined that the device can effectively simulate the excavation process under high centrifugal force field test conditions.Based on the centrifugal test data,the deformation mechanism of the foundation pit system is modified and the improved mobilizable strength design(MSD)is proposed.The improved MSD method is used to calculate the deformation curves of retaining walls for multi-pillar excavation,and the calculated results are compared with the field monitoring data.It is shown that the predicted results by the improved MSD method are consistent with the measured data,and the applicability of the improved MSD is demonstrated.

关 键 词：基坑开挖 离心模型试验 在机开挖装置 改进MSD法 

分 类 号：TU43[建筑科学—岩土工程]