Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation  

作　　者：CHAI JunRui 1,2 & XU WeiSheng 2 1 College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China 2 College of Hydropower Engineering,Xi’an University of Technology,Xi’an 710048,China 

出　　处：《Science China(Technological Sciences)》2011年第S1期133-139,共7页中国科学（技术科学英文版）

基　　金：supported by the Research Fund for the Doctoral Program of Higher Education of China(Grant No.20096118110007);the National Natural Science Foundation of China(Grant Nos.10202015 and 50579092);the Program for New Century Excellent Talents in University (Grant No.NCET-05-0679);the Project sponsored by Hubei Provincial Science and Technology Department(HBSTD)(Grant No.2004ABB012)

摘　　要：The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is proposed.This model is used to the analysis of foundation rock mass of a high dam.If the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures appears.If the coupling effects are not considered,the fractures distribution affects the inner head more greatly.When the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more greatly.Therefore the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is proposed.This model is used to the analysis of foundation rock mass of a high dam.If the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures appears.If the coupling effects are not considered,the fractures distribution affects the inner head more greatly.When the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more greatly.Therefore the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

关 键 词：hydraulic engineering UNSTEADY SEEPAGE stress coupling FRACTURES NETWORK ROCK mass 

分 类 号：TV223.6[水利工程—水工结构工程]