The Study of Stability and Processing Technology of Karst Caves in Changsha Metro Line1
|School||Central South University|
|Keywords||karst development mechanism stability evaluation disaster treatment Changsha Metro Line1|
The karst is complex, hidden and diversified. In the project constructions, problems like karst collapse, karst water gushing and sand gushing may occur, which will affect construction progress and safety of later use and, even worse, lead to life-safety incidents. The karst is one of geological problems in the subway construction and municipal construction. Therefore, the purpose of analyzing karst stability is to make a reasonable assessment on karst problems to conduct projects’ design and constructions and to ensure the quality and safety of the projects. It is of significance to explore a reasonable yet effective theory and method to assess karst stability so as to meet the requirement on quality and safety.This paper aims to study the Karst stability on the basis of the karst features of Changsha Metro Line1. The paper discusses the state of karst from the karst development mechanism and expounds that karst development is affected by underground hydraulic action, together with such main controlling factors as the lithologic characteristic and the geological structures. Petrography character provides the foundation for the karst while offer place and space. Underground water erodes rocks, which is the main external factor to cause karst fissures.According to the mechanism of karst, the paper further discusses the influence of karst on metro construction and assesses karst stability by qualitative and quantitative analysis, based on the state of karst in the project of Changsha Metro Line1. And then the conclusion that karst stability in metro stations and tunnels of the project is given.According to assessment on karst stability evaluation and features of underlying karst of different types, the paper provides several solutions to problems occurring at different parts of the project. These solutions include excavation backfill, pressure grouting and structure across.