【摘要】 以地处高烈度活断层地区的敦煌—格尔木铁路阔克萨隧道为背景工程,采用地震动力仿真模拟方法,探讨采用注浆加固圈、减震层和超挖法等不同措施时隧道结构的抗震机理与效果。计算结果表明:采用无注浆加固,以及全环间隔注浆、全环接触注浆和局部注浆3种注浆加固方式时,隧道结构的位移以及二次衬砌的振动加速度均基本相同,但最大应力的降低较明显,其中采用全环间隔注浆方式时,隧道二次衬砌最大应力的降低幅度最大;设置减震层后,隧道衬砌的拉应力大幅度减小,但对衬砌的位移和振动加速度响应影响较小;采用超挖法施工时,施作1层衬砌就能满足抗震的要求,但应预留施作2层衬砌的空间;适合于高烈度活断层地区隧道结构抗震的综合措施为采用全环间隔注浆加固方式,其夹层围岩间隔距离为1m、加固圈厚度为3m;横向减震层厚度为150mm,纵向衬砌节段长度为8m;选用超挖法进行施工。更多还原

【Abstract】 With the Kuokesa Tunnel of Dunhuang-Golmud Railway in the area of high intensity active fault as engineering background and by the seismic dynamic simulation method,the aseismic mechanism and effect of tunnel structure with different seismic measures,such as the grouting reinforcement ring,shock absorption layer and ultra excavation method,were discussed.The calculation results show that the displacement of the tunnel structure and the vibration acceleration of secondary lining are basically the same under no grouting reinforcement,or under the reinforcement of full-ring spacing grouting,full-ring contact grouting and local grouting.But the maximum stress is reduced obviously,and the maximum stress of tunnel secondary lining is reduced the largest under full-ring spacing grouting.The tensile stress of tunnel lining is greatly reduced after setting up the shock absorption layer.But it affects little on the displacement and vibration acceleration of the lining.Constructing one layer lining can meet the seismic requirements,but the space should be reserved for two layers of lining when using ultra excavation method.The comprehensive seismic measure appropriate for tunnel in the area of high intensity active fault is to adopt full-ring spacing grouting.The distance of sandwich surrounding rock is 1m,the thickness of reinforcing ring is 3m,the thickness of lateral shock absorption layer is 150 mm and the length of the longitudinal lining segment is 8m.Ultra excavation method is chosen in construction.更多还原