导流隧洞混凝土衬砌结构有限元分析与研究

根据某水电站引水系统实际情况,采用ANSYS三维非线性有限元法,建立其引水系统中南导流隧洞的三维有限元模型,并对其钢筋混凝土衬砌结构进行分析,验证了衬砌方案和支护参数的合理性,提供衬砌配筋计算结果,并论证了现有衬砌和支护方案合理性,补充和完善加固处理措施.结果表明,南导流隧洞各段衬砌在计算工况下,水平位移最大值为0.256 mm,方向指向隧洞内部;垂直向最大位移为8.443 mm,方向向下;最大第一主应力为拉应力,其值为1.150 MPa;衬砌最大第三主应力为压应力,其值为-1.190 MPa,由于衬砌C25混凝土的抗压强度为11.9 MPa,故衬砌结构安全.但在侧墙与顶拱、侧墙与底板交界处应力值较大,应当采取适当措施加大结构的强度.

FEM Analysis of the Diversion Tunnel Lining Structure

According to the actual situation of the system of a hydropower station, the three dimensional finite element model of south-side diversion tunnel in the diversion system is established using ANSYS three dimensional non-linear finite element method. This paper then analyzes its reinforced lining structure and testifies the rationality of the lining scheme and support parameters. Meanwhile, the lining reinforcement calculation results are also provided to demonstrate the rationality of the existing lining support scheme, which can supplement and perfect the reinforcement measures. The results show that the maximum horizontal displacement of each lining paragraph of the south-side diversion tunnel is 0. 256 mm under natural conditions, directed towards the inside of the tunnel; the maximum perpendicular displacement is 8. 443 mm; the largest first principal stress is I. 150 MPa, and it is tensile stress; the third largest principal stress is compressive stress at 1. 190 MPa. The lining of C25 concrete compressive strength is 11.9 MPa, so the lining structure is safe. But, the high stress values of the border between the side wall and the top arch, and the border between the side wall and the bottom plate, calls for more efforts to intensify the structure.