【摘要】 为了研究浅埋砂土地下电力隧道结构在双向地震作用下的行为反应,采用大型岩土软件FLAC3D对浅埋砂土地下电力隧道进行数值模拟。建立了双向地震作用下砂土电力电缆隧道的三维计算模型,地下水位为1 m。计算了在水平和竖直地震荷载作用下,埋地电力隧道的动力响应,并对典型截面的典型点的加速度、位移、应力进行监测。计算结果表明,在上海人工地震波作用下,电力隧道结构水平残余位移10.9 mm,竖向残余位移4.3 mm,隧道结构产生的永久变形为11.7 mm,隧道结构顶部和底部之间的水平相对位移3.6mm,竖向相对位移为4.3mm。地表水平残余变形几乎为0,竖向残余变形0.18 mm。结构自振频率45 Hz。隧道结构剪应力、主应力大小随着动荷载的输入应力幅变化很小,在1%左右;第一主应力和第三主应力的最大值在隧道侧壁C点。数值分析结果表明,在砂土地基下隧道产生剪切、拉伸破坏以及发生共振的可能性较小,侧壁是竖向抗震的薄弱环节。更多还原

【Abstract】 In order to study the seismic response of power tunnel shallow buried in soft soil subjected to the horizontal and vertical earthquake,the large-scale geotechnical software FLAC3 D was adopted for the numerical calculation.A threedimensional model was established,and the ground water table is 1m underground.The accelerations,displacements and stresses of typical points of typical sections are monitored in the entire process of earthquake.The results shows that under Shanghai artificial seismic wave,the residual horizontal displacement of the tunnel is 10.9mm,and vertical displacement is 4.3mm,and the permanent deformation of the tunnel is 11.7mm.The relative horizontal displacement of the roof and bottom of the tunnel is 3.6mm,and the relative vertical displacement of the roof and the bottom is 4.3 mm.The residual horizontal displacement of the ground is nearly 0 and vertical displacement is0.18 mm.The natural frequency of tunnel is 45 Hz.The whole shear stress and the principle stresses change a little with the input of dynamic loads,and the maximum stress amplitude is about 1%.The maximum of the first and third principal stresses appear at side wall.In conclusion the probability of shear,tensile and resonance of tunnel failure is small.The side wall is the weakness under earthquake.更多还原