滇池草海区域主要工程地质问题及方案分析

Schemes Analysis and Main Engineering Geological Problems in Caohai of Dianchi Lake

研究目的:草海是滇池的一个重要组成部份,草海区域与昆明市西南部的交通建设关系密切,对滇池的工程地质条件具有代表性。研究草海区域的主要工程地质问题,不仅有利于草海区域的工程建设,而且对认识滇池的工程地质条件具有重要意义,对滇池片区的工程方案及措施有很好的指导作用。研究结论:(1)滇池草海区域工程地质条件复杂,主要工程地质问题为泥炭质土、区域性大断裂及地震、高烈度地震区的砂土液化及软土震陷、浅层天然气等,对工程影响较大;(2)穿越草海可采用隧道方案和桥梁方案,综合比选采用隧道方案更好,隧道施工可采用明挖施工和盾构施工两种工艺,明挖施工又可采用围堰明挖和筑岛明挖两种施工方法,盾构施工对自然生态环境的影响最小;(3)滇池的地质条件与草海区域相似,存在同样的工程地质问题,穿越滇池的道路工程宜采用盾构隧道方案;(4)本文的研究成果可供软土地区的地下工程进行参考和借鉴。

Research purposes： Caohai is an important part of Dianchi lake, Caohai and transportation construction in the southwest of Kunming city have a close relationship. It has a representability to the engineering geological conditions of Dianchi lake. Studying Caohai main engineering geological problems is advantageous to the Caohai area engineering construction, has great significance to recognize the engineering geological conditions of Dianchi lake, and has very good guidance function to engineering schemes and measures of Dianchi lake area. Research conclusions： （ 1 ） Caohai engineering geology condition of Dianchi lake is complex, the main engineering geological problems are peat soil, regional major fault and earthquake, the area with high seismic intensity of sand liquefaction and soft soil subsidence, the shallow natural gas and so on . They have a large influence on engineering. （2） The engineering through Caohai can use tunnel and bridge scheme, the tunnel scheme is better by comprehensive comparison. Tunnel construction can use two process of cut and cover method and shield tunnelling method, cut and cover method can use two kind of construction methods of cofferdam cut and build island cut, shield tunnelling method has minimum impact to natural ecological environmental. （3）The geological conditions of Caohai and Dianchi lake areaare similar, have the same engineering geological problem. The road engineering through the Dianchi lake should use shield tunnel scheme. （4）The research results can provide references for underground engineering of soft soil area.