关键词: 深圳大运中心, 岩溶发育特征, 地面塌陷, 力学分析, 危险性评价

Abstract: Collapse of large area occurred in Shenzhen universiade sports center during its pile foundation construction. Because the project is very important, and the ground and foundation are very complicated, we need to assess the hazard of karst ground collapse in order to reduce accidents. Firstly, we employed exploration methods inclusive of high-density electrical method, geologic radar, CT tomography, and drilling to investigate the development of soil holes and karst caves. On this basis, we built the statics model of the ground collapse through engineering geological analysis. Furthermore, we summarized the factors affecting the karst ground collapse and established a risk assessment index system based on the analysis of space distribution regularity of karst development and formation mechanism. The index system includes 4 first-level indicators (karst foundation condition, cover layer characteristics, building attributes and hydrogeological condition) and 8 secondary level indicators. At last, we adopted MapGIS and PLS (Partial Least Squares) Path Model to assess the hazard of karst ground collapse, and divided the ground collapse hazard into four levels: high, relatively high, relatively low and low, accounting for 1.05%, 10.71%, 19.39%, and 68.85% of the whole site respectively. The assessment and prediction results are objective and reasonable, and the proposed system can be used in similar projects.

Key words: Shenzhen universiade center, karst development, ground collapse, mechanics analysis, hazard assessment