【摘要】 通过波函数展开法给出平面SV波入射下深埋圆形隧道"围岩—减震层—初期支护—二次衬砌"减震结构的动力响应解析近似解,分析了减震层厚度、弹性模量对衬砌结构动应力集中系数的影响,并开展了跨断层隧道抗减震研究大型振动台模型试验,通过分析跨断层及其设置减震层后隧道衬砌动力响应特性和破坏形态,得到以下有益结论:减震层与围岩弹性模量比越低,减震层厚度越大,衬砌动应力集中系数越小;减震层与围岩弹性模量的最优减震比在1/10~1/20,最优减震层厚度不宜大于0.2 m;跨断层破碎带隧道设置减震层可以明显降低跨断层衬砌结构加速度峰值和衬砌动应变幅值;断层处隧道衬砌裂缝分布数量多、复杂,多集中于拱脚、拱肩,并分布有剪切错动引起的环向裂缝,设置减震层后,断层处隧道衬砌裂缝明显减少,衬砌受力得到明显改善;断层处地表出现了平行断层方向为主的的贯通裂缝和大量斜裂缝,说明断层处以剪切破坏为主,设置减震层后,地表裂缝明显减少。更多还原

【Abstract】 Based on the wave function expansion method, the dynamic response analysis of a deep buried cylindrical composite-lining cavity with a new buffer layer mode, namely "rock- buffer layer-primary support-secondary lining" mode,in an elastic space subjected to incident plane SV waves is made. The factors affecting the dynamic stress concentration of the lining structure, elastic modulus and thickness of the buffer layer are discussed. By conducting the large-scale shaking table model tests on the tunnel across the fault zone, some engineering significant conclusions are drawn by analyzing the dynamic properties and fracture patterns of the tunnel across the fault and that with buffer layer. With the lower elastic modulus and smaller thickness of the buffer layer, the dynamic stress concentration of the secondary lining decreases, but the best ratio of the elastic modulus of the buffer layer to that of the surrounding rock is between 1/10~1/20, and the optimal thickness of the buffer layer is no larger than 0.2 m. With the buffer layer, the lining peak acceleration and the dynamic strain amplitudes of the lining decrease. Most of the complex and wider cracks of the lining concentrate on the spandrel and arch foot when the tunnel crosses the fault zone, however, the number of lining cracks decreases with shock sorption joint layers, which shows that the force status of the lining is significantly improved. Wider cracks occur on the ground surface along the fault, and many smaller cracks intersect the fault, which shows that the tunnels and surrounding rock are damaged by shearing force when it crosses the fault, and the number of the crack on the top surface is reduced with the buffer layer. The research conclusions may provide references for the shock and sorption design of tunnels across fault, and they are of important practical engineering significance.更多还原