Metro construction has become a symbol of rapid economic development,and its subway construction has en-tered a rapid development stage.However,buried karst may exist in urban areas,which will bring great potential safety hazards to subway construction.Therefore,it is necessary to carry out urban buried karst detection,analyze karst develop-ment characteristics and development mechanism,and ensure the safety of subway construction.Taking the tunnel cross-ing area of a section of Wuxi subway as the research area,firstly,the karst development characteristics are studied by geo-logical analysis and cross-hole CT detection.It is found that the scale of karst development in the area is not large.Affect-ed by geological structure and limestone distribution,most of the karst caves are developed along the stratigraphic inter-face and rock mass fissures,and have obvious longitudinal strong and weak zoning characteristics.Most of the karst caves are completely filled or partially filled,and the composition of the fillings mainly comes from the overlying rock and soil layer.Secondly,based onbiaxial compression infinite plate,the calculation model of single karst cave and double-hole karst cave in the foundation of the field area is established,and the stability of the surrounding rock of the karst cave is theoretically analyzed by using the Griffith criterion,and the calculation formula of the foundation stability in the karst de-velopment area is derived.Finally,combined with the subway tunnel design scheme and karst detection results,it is found that the karst caves in the field area are located under the bottom of the tunnel,which has a certain impact on the tunnel construction,and it is recommended to use the grouting method for treatment.The research results can provide reference for the design and construction of subway in urban shallow karst area.
关键词
埋藏型岩溶/跨孔CT探测/岩溶发育特征/地基稳定性/无锡地区
Key words
burial karst/cross-hole seismic CT/characteristics of karst development/foundation stability/Wuxi Area
维普
万方数据