强震区隧道施工塌方段震害机理及处治技术研究

汶川地震公路隧道普通段衬砌垮塌震害均发生在施工塌方段。依托汶川地震公路隧道普通段震害调查资料,对强震作用下隧道施工塌方段进行震害特征、震害机理及处治技术研究具有重要的意义。揭示了汶川地震区公路隧道施工塌方段震害特征:软弱围岩施工塌方段均出现了二衬垮塌震害,严重段落甚至出现衬砌整体垮塌震害。探明了强震区隧道施工塌方段震害机理:地震惯性力影响明显;强制位移影响较小。强震区隧道施工塌方段采取"回填注浆+交错设缝"的处治措施后,主应力和内力的减震率均在35%以上,这说明"回填注浆+交错设缝"处治措施对隧道施工塌方段抗减震具有明显效果,是一种行之有效的处治措施。研究结论对于高烈度艰险山区交通生命线的抗减震技术具有重要的意义。

Seismic damage mechanism and treatment technologies of construction landslide section of highway tunnels in highly seismic region

In the general section of highway tunnels, the seismic damage, which makes lining collapse, universally occurs in the construction landslide section during Wenchuan Earthquake. Based on the seismic damage survey data of the general section of highway tunnels, it is meaningful to analyze the seismic damage characteristics, seismic damage mechanism and treatment technologies of the construction landslide section of highway tunnels suffering intense earthquake. The seismic damage characteristics of the construction landslide section of highway tunnels in Wenchuan Earthquake regions reveal that the secondary linings in the construction landslide section of weak wall rock suffer collapse or even overall collapse in serious section. The seismic damage mechanism of the construction landslide section of highway tunnels is that the earthquake inertia force is significant and the forced displacement has small influence. After the measure of backfilled grouting and staggered construction joint in the landslide section of highway tunnels in the highly seismic region, the damping rates of the principal stresses and internal forces are all above 35%. It is shown that the processing is effective to the construction landslide section of highway tunnels to improve the anti-seismic capacity. The research results are of important singnificance to the anti-seismic technology in the communication of lifeline engineering in high-intensity earthquake moutainous areas.