Seismic Response Primary Analysis On Underground Rock Tunnel For Hydropower Station

The response and safety of rock tunnel under earthquake are the difficulties and hot pots for construction of hydraulic engineering in the intensive earthquake area of West China.It has strategic meaning that how to assuring the tunnel working well during earthquake.To analyse the seismic response on underground rock tunnel for hydraulic station,this paper briefly describes the present development situation of underground rock tunnel for hydraulic station in China,also sums up the characteristics of earthquake damage and structure of such engineering.Based on the data of Xiaowan underground rock tunnel for hydraulic station which is situated on the Lancang River of Yunnan province,the transient dynamic method of ANSYS compute software is used to preliminarily analyse the influence of the tunnel depth,the cross sectional shape of tunnel,the elastic modulus of tunnel lining,the level of surrounding rock and earthquake frequence on displacement and stress response of tunnel lining on the basis of studies on foundation radiation damping,foundation lateral calculation rang and magnifying and filter of surrounding rock ground,then in the paper,some seismic response regularities are summed up.On the basis,the paper builds a 3-D tunnel finite element model with Xiaowan underground rock tunnel for hydraulic station as a example,and analyses the seismic stability of the tunnel.And this chapter mainly analyse the tunnel lining response under the horizontal earthquake,vertical earthquake and two way directional earthquake.The result show that the weak link is changed and the maximum response value is enhanced when the vertical earthquake is loaded,which can explain that it is dangerous when the vertical earthquake is ignored.The specific work of the paper is:1 Summarize the present development situation,characteristic of earthquake damage, and present situation and development of numerical analysis method of underground rock tunnel for hydraulic station.Propose a numerical analysis method in this paper;2 Summarize the basic theory of dynamic finite element;3 Analyse the effect of foundation radiation damping,foundation lateral calculation rang and magnifying and filter of surrounding rock ground to prepare for future work;4 Study the seismic response regularities of the influence of the tunnel depth,the cross sectional shape of tunnel,the elastic modulus of tunnel lining,the level of surrounding rock and earthquake frequence on displacement and stress response of tunnel lining,through lots of numerical analysis;5 Analyse the seismic stability of underground rock 3-d tunnel for hydraulic station;6 Summarize this paper,discuss the deficiency of the paper and give a propose for the following study work.