文献类型：期刊文献

英文题名：Characteristics of Karst Cave Development in Urban Karst Area and Its Effect on the Stability of Subway Tunnel Construction

作者：Xue, Fei[1];Cai, Minjun[1];Wang, Tianzuo[1];Zhao, Tongyang[1]

机构：[1]Shaoxing Univ, Coll Civil Engn, Key Lab Rock Mech & Geohazards Zhejiang Prov, Shaoxing 312000, Peoples R China

年份：2021

卷号：2021

外文期刊名：ADVANCES IN CIVIL ENGINEERING

收录：SCI-EXPANDED(收录号：WOS:000665076500002)、、Scopus(收录号：2-s2.0-85106394710)、WOS

基金：The authors would like to acknowledge the financial support for this study provided by the Natural Science Foundation of Zhejiang Province (LQ20E080006), the Shaoxing Public Interest Research Projects (2017B70002), and the Research Projects of Shaoxing University in 2018 (2018LG1004).

语种：英文

外文摘要：The existence of karst caves poses a large threat to safe tunnel construction in a karst area. This paper presents a synthetic method to evaluate the collapse risk before subway tunnel construction with Yang-Jian interval tunnel as a case study. The crosshole seismic Computed Tomography (CT) integrated with Geological Drilling (Geo-D) was first applied to accurately delineate the karst location and its scale. Then, 483 groups of seismic wave CT images were recorded, and 524 karst cave anomalies were found. The height of karst caves in the study area is 1-20 m and mainly concentrated at approximately 5 m. The vertical distance between the karst cave and the tunnel is mainly within 15 m. According to the detection results, a series of numerical models were built and calculated using FLAC3D to investigate the effect of different sizes and locations of karst caves on the displacement and stability of the surrounding rock in tunnels. Afterwards, based on the simulation results, the disturbance degree evaluation index was established to quantitatively evaluate the risk level of karst caves. The evaluation results indicate that the buried depth of the karst cave greatly affects the disturbance degree. No treatment is required for the deeply buried karst cave that is more than 7 m from the tunnel. When the distance between the cave and the tunnel is less than 7 m, there is a critical size of the cave. Karst caves that are larger than that critical value must be filled with a single slurry or binary slurry before tunnel construction to eliminate the risk of tunnel collapse. This study can be used to provide a more efficient and economical program for metro tunnel construction above a karst cave.