摘要
考虑非偏压与偏压2种情况,从能量的角度出发,采用拟静力法研究水平地震力与竖直地震力对浅埋隧道稳定性的影响。研究结果表明:在静态条件下,由本文极限分析法计算所得的结果非常接近于由极限平衡法计算所得结果,验证了本文方法的正确性;在参数分析中,随着侧压力比例系数的增加,竖直方向的围岩压力减小,水平方向的围岩压力增大,破裂角呈减小的趋势,而偏压对浅埋隧道的稳定性也有一定影响,但侧压力比例系数的影响更大;在采用拟静力法进行动态稳定性分析时,水平地震效应系数增加,浅埋隧道的围岩压力与破裂角增大;当竖直地震效应比例系数增加时,浅埋隧道的围岩压力增大,破裂角却减小,且效果明显,可见竖直地震力与水平地震力一样,对浅埋隧道的稳定性有较大影响,在进行支护设计时不容忽略。
Based on two cases of non-bias and bias, from the view of energy, the influence on stability of shallow tunnels from horizontal and vertical earthquake force was studied using the quasi-static method. The results show that on static condition, the results calculated by the limit analysis method are very close to those obtained by the limit equilibrium method, which verifies the correctness of this method. With the increment of proportional coefficient of lateral pressure, vertical earth pressure declines while horizontal earth pressure increases, and break angle shows decreasing trend. Effect of asymmetric loads on the stability of shallow tunnels is less than that of proportional coefficient of lateral pressure. The earth pressure and break angle both increase with the increase of the horizontal seismic effect coefficient. With the increase of vertical seismic proportional coefficient, the earth pressure increases but the break angle decreases obviously. Therefore, vertical earthquake force, just like horizontal earthquake force, has significant effect on the stability of shallow tunnels, which can not be neglected in the design of support structures.
引文
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