دانلود Numerical Simulation of Stability for Underground Powerhouse Cavern Group of Jinping Hydropower Station

Abstract

A  brief  introduction  is  given  to  the  great  challenge during  construction  of  Jinping  hydropower  station  for  four tunnels  with  small  space,  which  is  a  key  cascade  underground  hydropower  project,  located  in  the  Southwest  China,  at  the Yalong  River.  The  vertical  geo-stress  (63MPa)  is  highest  in similar  engineering  in  China.  Through  numerical  simulation, comparison with displacements, energy density and plastic zone of surrounding rock, a detailed  description is carried  out to  calculate  and  analyze  for  different  spaces  between  adjacent tunnel’s  centers.  Horizontal  displacements  of  two  lateral  walls are unsymmetrical extremely. But it is symmetric fundamentally for walls of medial tunnels. Consequently, more attention  should  be  paid  to  outboard  tunnels  displacement during  construction  of  cavern  group.  There  is  increasing  zone of  energy  occurrence  at  surrounding  rock  upper  the  vault) 2m~3m), which plays an important role in integral stability of cavern  group  and  needs  to  be  strengthened  for  design.  The minimum safety space between adjacent tunnel is 40~45m. The actual space of Jinping hydropower cavern group is 60m, so it is safe. Not only is the analysis method fit for Jinping hydropower  station,  but  it  can  be  as  reference  for  similar  cavern group engineering.