Research And Application On Design Of Power Tunnel In Complicated Environment With Shallow Tunneling Method

As the increasing demand of electric power, the current electric power net could not meet the demands of a city with millions of people. So it is a trend to construct power tunnel with high voltage and complicated network. Based on the220kV cable project of Xiang Tan, this paper studies the layout of tunnel, the cross sectional design, the profile design, the design of the main structures, the design of the auxiliary structures and control measures of construction through literature researches, engineering analogy method, numerical analysis and other methods. The main ideas are as follows:(1) The power tunnel, with shallow bury, weak strata, poor stability, numerous pipelines and surface traffic load, is designed and excavated by shallow underground excavation method trough scheme comparison and selection.(2) Based on geological conditions, this paper studies the layout of tunnel and the design of cross section, vertical section, tunnel lining, shaft and water preventing and draining system through engineering analogy method.(3) Taking advantage of three-dimensional finite element numerical calculation to analyze the stability of surrounding rock and reinforce area, meanwhile the safety of tunnel structures and shaft structures are studied. The results show that the schemes satisfy design requirements.(4) The paper summarizes control measures of power tunnel construction according to project characteristics. In view of the existing risk source, corresponding control measures are proposed.