水工压力隧洞内衬及围岩应力与变形数值计算

Numerical Simulation Study of Stress and Deformation of Hydraulic Pressure Tunnel Lining and Surrounding Rocks

应用三维快速有限差分软件FLAC3D,对柏叶口水库泄洪发电隧洞进行了数值仿真计算,研究了开挖后高水压作用下洞室特别是泄洪洞与发电支洞交叉口位置管壁及围岩的应力场、位移场及其动态变化规律。结果表明:施加内水压力后,衬砌最大下沉和隆起量均有所减小;在0.78 MPa内水压力下,衬砌管壁局部产生较大的拉应力,将导致混凝土出现较大范围的裂缝;在内水压力下,泄洪洞和发电支洞交叉位置产生较大的拉应力集中,以两洞相交位置小角度一侧应力最大,将出现较大范围的拉裂缝。

The spillway and power tunnels of Baiyekou Reservoir under internal water pressure were simulated by three-dimensional fast lagrangian analysis of continua（FLAC3D） method.During the excavation process,the stress and displacement fields of the tunnels that internal water pressure is high have been researched,especially the stress,displacement and their dynamic variation at the intersection between the spillway and branch tunnel and inside wall of tubes.The results show that either maximum subsidence or upheaval decreased after adding internal water pressure,under the 0.78 MPa internal water pressure,high tensile stresses will appear at the lining especially the intersection between the spillway and power tunnel,and the maximum tensile stress appears at the small angle side the two tunnels intersect that will cause cracks.