摘要:
依托穿越活动断层某直墙式管道隧道工程，开展逆断层错动作用下隧道结构响应模型试验，分析了衬砌竖向位移、应变及内力分布规律，结合裂缝扩展形态探究了衬砌破坏机制。研究结果表明：隧道拱顶竖向位移沿纵向呈S形分布，影响范围随断层错动量增加而增加，断层错动量50mm工况下，核心影响区为断层内部，一般影响区为断层错动面沿上盘侧0.9D~3.7D、下盘侧0.9D~2.6D（D为隧道宽度）；断层错动面附近衬砌发生拉伸破坏，拉应变峰值主要出现在墙脚，隧道衬砌仰拱、墙脚和拱脚损伤程度相较于其他部位更严重；位于断层内和上盘侧衬砌断面弯矩和轴力量值较下盘侧迅速增加，受断层走向与隧道轴线交角影响，断层错动面附近隧道内力呈现非对称分布，45°对角线方向轴力和弯矩量值相对较大，衬砌发生扭转、弯曲变形，墙脚、仰拱和拱肩受力较为不利；隧道衬砌仰拱、墙脚纵向开裂破坏，断层错动面附近受剪切作用，同时伴随隧道拱脚和边墙发生斜向剪切破坏。研究成果可为穿越逆断层直墙式管道隧道结构抗错设计提供参考。
Abstract:
Based on an arched pipeline tunnel with straight walls passing through an active fault, the model test was conducted under the action of a reverse fault. The vertical displacement, strain, and internal force distribution of the lining were analysed. Additionally, the failure mechanism of the lining was explored in combination with the crack propagation morphology. The research results indicate that: (1) The vertical displacement of the tunnel arch is distributed in an S-shape along the longitudinal direction, and the influence range increases with the fault displacement. While the fault displacement is 50mm, the core affected area is within the fault, and the general affected area is 0.9 D~3.7 D along the fault displacement surface on the hanging wall side and 0.9 D~2.6 D along the footwall side, where D is the tunnel width. (2) The lining near the fault displacement surface experiences tensile failure, with the peak tensile strain mainly occurring at the foot of the wall. The damage to the inverted arch, foot of the wall, and arch foot of the tunnel lining is more severe compared to other areas. (3) The bending moment and axial force of the lining section located within the fault and on the hanging wall side increase rapidly compared to the ones on the footwall side. Due to the intersection angle between the fault direction and the tunnel axis, the internal forces of the tunnel near the fault displacement surface show an asymmetric distribution. The axial force and bending moment in the 45 ° diagonal direction are relatively large, and the lining undergoes torsional and bending deformation. The stress on the wall foot, inverted arch, and arch shoulder is relatively unfavorable. (4) The arch and wall foot of tunnel lining are longitudinally cracked and damaged, and the area near the fault displacement surface is subjected to shear action, accompanied by oblique shear failure of the arch foot and side walls. The research results can provide reference for anti-breaking structural design of the arched pipeline tunnel with straight walls crossing reverse faults.
百度学术
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