摘要 地下连续墙槽段开挖为连续下切的动态过程,槽壁稳定性控制仍依赖于工程实践经验,缺乏成熟的理论指导,槽壁失稳事故时有发生。基于泥浆渗透成膜实验成果及有效护壁压力的动态演化规律,研究了槽壁土体在旋转破坏模式下的富余护壁压力分布规律,获得了槽壁稳定性控制因素及稳定性控制条件,建立了泥浆护壁条件下以土体等效内摩擦角、开挖深度及开挖下切速率、泥浆黏度及重度为参量的槽壁稳定性判据,揭示了槽壁稳定施工的关键控制要素。研究成果在福州地铁5号线建新南路60 m深地下连续墙工程中的应用表明:地表以下10 m内及开挖面以上3 m范围为槽壁稳定性薄弱环节,与现场实际吻合,以富余护壁压力为依据的槽壁稳定判据可较方便地指导施工作业。 As the trench excavation process is a continuous undercutting process,the stability control of trench wall still depends on the experience of engineering practice,and the criterion of trench wall stability has not been finally resolved theoretically,stability accidents happen frequently.In this paper,based on the test results of slurry infiltration and film formation,using the principle of earth pressure balance on both sides of the slurry film,considering the rotating failure mode of the trench wall earth,the spatial distribution of the excess protective wall pressure along the trench depth is studied and the result shows that:the main factors affecting the stability of the trench wall are the equivalent internal friction angle of the earth,followed by excavation depth and excavation speed,and then the viscosity and gravity of the slurry.A new stability criterion of trench wall is set up based on the main affecting factors.The application of the study results in 60 m depth diaphragm wall at Xinjiannanlu of No.5 subway in Fuzhou city,Fujian Province,showed that the analyzed weak stability area is located within 10 m below the surface and 3 m distance from the excavation surface,which is in accordance with the practical site condition.The stability criterion of groove wall based on surplus wall pressure can guide construction conveniently.
出处 《水利水电快报》 2021年第4期49-53,58,共6页 Express Water Resources & Hydropower Information
关键词 地下连续墙 槽壁稳定 稳定性判据 泥浆护壁 旋转型破坏 diaphragm wall stability of trench wall stability criterion slurry trench wall protection rotating failure
