Field test、theory analyse and numerical simulation ,these three methods are used on the thermodynamic calculation for the underground transformer conveyance tunnel in Ertan hydropower station in this paper.

In this article the changes of traffic forms due to the technology development, the direction of the city traffic development and the necessity of the exploitation of underground traffic are med.

In this paper, the combined development mode of underground traffic and urban green area is put forward by analyzing the urban green areas and urban traffic problems at present in China.

The inlet of traffic hole at the left side Laxiwa hydropower station in Qinghai is introduced,and the excavating and supporting techniques in different soil conditions are proposed.

During excavation of the left upper access tunnel of the Laxiwa hydropower station, due to geologic reason a large collapse of about 1000 m3 occurred at station No.

Analysis of the instability criteria of the surrounding rock of underground cavern;

Development and application of rock-mass mechanical parameters back analysis software system for underground cavern;

Study on monitoring and prediction information system for underground cavern construction;