强震区隧道软岩洞口段刚柔并济抗减震措施模型试验研究

Model test study of rigid-flexible combined anti-seismic measures of soft rock tunnel portal part in meizoseismal area

为进一步提高强震区隧道软岩洞口段的抗震安全性,以白云顶隧道为研究背景,利用大型振动台,对隧道软岩洞口段采用结构加强并施设减震层的刚柔并济抗减震措施进行模型试验研究。试验结果表明:仅采取结构加强措施,隧道洞口段全段结构安全系数最小值增长百分比在30%-60%之间;仅施设减震层,隧道洞口段全段结构安全系数最小值增长百分比在55%-70%之间,减震层在减小地震震动和强制位移向二衬传递方面作用明显,减震效果显著;采取结构加强并施设减震层,隧道洞口段全段结构安全系数最小值增长百分比在105%-160%之间,刚柔并济抗减震措施抗震效果最佳。

In order to improve the anti-seismic performance of soft rock tunnel portal part in meizoseismal area,this paper,by taking the Baiyunding tunnel as the research background,conducts a large-scale shaking table model test research for the rigid-flexible combination of aseismic and damping measures by strengthening the structure and meanwhile applying shock absorbing layers.The results show that the enhance percentage of the structure minimum safety factor of the whole tunnel portal part is 30%-60% by only taking structure strengthening measures;The enhance percentage of the structure minimum safety factor of the whole tunnel portal part is 55%-70% by only applying the shock absorbing layer,which indicates its remarkable shock absorption effect by significantly reduce the seismic shock and force the displacement to the secondary lining.The enhance percentage of the structure minimum safety factor of the whole tunnel portal part is 105%-160% by strengthening the structure and meanwhile applying the shock absorbing layer,which shows that the anti-seismic effect of the rigid-flexible combination of aseismic and damping measures is the best.These research results can provide reference for the earthquake fortification design of traffic tunnel in meizoseismal regions.