下伏矿采施工对既有隧道结构影响三维模拟分析
3D numerical analysis of influence of construction of underlying mining area on existing road tunnel structures
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摘要: 高速公路隧道穿越下伏矿采区施工相互影响评价及处治技术研究,是目前高速公路建设中亟待解决的问题之一。基于有限元方法,建立下伏矿采区公路隧道三维数值模型,分析隧道与下伏矿采区施工过程中结构的变形及应力变化特征,探究下伏矿采区施工对既有隧道结构的影响。模拟计算表明,下伏矿采区的存在对隧道结构和围岩稳定性的影响是显著的,矿采区对隧道结构在纵向的影响区域约为矿采区中心线两侧25 m左右,而矿采区本身施工对隧道结构产生主要影响的区域为矿采区工作面距隧道中心线前后30 m左右,在该区域必须考虑下伏矿采区对既有隧道结构的不利影响,并采取相关监测和预加固措施。Abstract: Based on the FEM method, a 3D numerical model for mining areas under the existing road tunnels is established. The analysis is made on the deformation and mechanical characteristics of structures during the construction of tunnels and mining areas so as to investigate the influence of construction of underlying mining areas on the existing tunnel structures. The results show that the influence of the underlying mining areas on the road tunnels is significant. The effect range of the mining area on the road tunnels is about 25 m from its centerline alone the tunnel axis, while the main effect distance of construction of the mining area on the tunnel structures is about 30 m before and after the centerline from the working face to the tunnel. The adverse effect must be taken into consideration during the design and construction of road tunnels in the mining area, and some monitoring and pre-strengthening methods should be adopted.