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为了找出爆炸动力作用下的隧道衬砌结构薄弱部位和力学规律,建立了土体隧道动力分析整体有限元模型;利用显式动力有限元程序Ansys/Ls-dyna进行了数值模拟,探讨了土体隧道衬砌结构在爆炸作用下不同部位的时间历程曲线;分析了爆炸作用下土体隧道衬砌结构的动力响应。结果显示:隧道衬砌结构肩部在x、y方向的位移都较大;隧道衬砌结构顶部在y方向的位移较大;隧道衬砌结构顶部、肩部的加速度峰值最大并且加速度曲线均出现了两次或多次峰值。这反映了爆炸冲击波有比较强烈的多次反射;各部位压力时程曲线波动较大,按照肩部、顶部、胯部、底部、腰部的顺序先后到达峰值;顶部和肩部σx峰值最大,顶部和底部σy峰值最大,顶部、肩部、底部τmax峰值最大。顶部和肩部出现最大拉应力说明爆炸对拱顶拱肩损伤较大,隧道衬砌结构将会最先在这两处发生破坏。
In order to find out the weak parts and mechanics laws of tunnel lining structure under the action of explosive force, the overall finite element model of soil tunnel dynamic analysis was established. The explicit finite element program Ansys / Ls-dyna was used to carry out numerical simulation. The time history curve of tunnel lining structure under different explosive parts is analyzed. The dynamic response of soil tunnel lining structure under explosion is analyzed. The results show that the displacement of the tunnel lining structure in the x and y directions is large. The displacement of the top of the tunnel lining structure in the y direction is larger. The acceleration peak of the top and shoulder of the tunnel lining structure is the largest and the acceleration curve appears twice Or multiple peaks. Which reflects the strong multiple reflections of the blast shock wave. The pressure history of each part fluctuated greatly and reached the peak value in the order of shoulder, top, crotch, bottom and waist. The top and shoulders had the largest peak value of σx and the top And the bottom of the peak σy maximum, top, shoulder, bottom maximum τmax peak. The maximum tensile stress on the top and the shoulder indicates that the blast damage to the arch vault shoulder is greater, and the tunnel lining structure will be the first to be damaged at these two locations.