组合式消能棚洞结构受荷性能研究

Study on Load Performance of Combined-type Energy Dissipation Shed Tunnel

落石棚洞是公路交通中常见的危岩地质灾害防治结构,可分为靠垫层来吸收落石冲击能量的传统落石棚洞和靠弹簧耗能减震来吸收冲击能量的新型落石棚洞两类。运用薄板理论、结构力学以及变形协调理论对组合式消能棚洞结构受荷性能进行了研究,得到了顶板在落石冲击力作用下内力解析解以及棚洞横梁、纵梁的内力计算表达式。以国道G319武隆境内的某棚洞为例,对消能棚洞的内力进行了分析,采用消能棚洞结构形式后,横梁最大弯矩以及纵梁上下侧最大弯矩分别降低了15.0%,17.3%和6.9%,说明消能棚洞结构内力消减效果明显,较大地提高了其承载能力。

The rockfall shed tunnel is a kind of common geological hazard prevention structure in highway traffic, which is mainly classified into two kinds, one is the traditional shed tunnel which absorbs the rockfall impact energy by the cushion layer; the other is the new shed tunnel which absorbs the impact energy by the spring energy dissipation and seismic mitigation. The paper studied load performance of a Combined-type energy dissipation shed tunnel through using the theory of thin plates, the theory of structural dynamics and coordinated deformation, getting the internal force analytical solution under the action of a rockfall impact and the internal force calculation expressions of the shed tunel cross beam and longitudinal beam. Taking the shed tunnels of the national highway G319 in Wulong for example, the internal force of energy dissipation shed tunnel was analyzed. The results show that, after energy dissipation shed tunnel being adopted, the maximum bending moment of the crossbeam and the upper and lower side of longitudinal beam decreases 15.0 % , 17.3 % and 6.9 % respectively. It shows that the effect of internal force dissipation for energy dissipation shed tunnel is obvious and the bearing capacity of shed tunnel has been -reatlv increased.