采动区公铁立交桥抗变形加固研究

Study on Anti-deformation Reinforcement of Highway-railway Overpass Bridge in Mining Area

地下煤炭资源大量开采引起的地表变形直接作用于地面建筑物基础,进而使上部结构产生附加应力和位移,严重影响其安全性能和正常使用。结合煤矿区公铁立交桥实际受采动影响情况,通过有限元建模对原桥在地表变形作用下的应力水平、应力分布和危险域进行分析。基于分析结果提出桥体抗变形加固方案,并对加固后桥体进行建模分析。对比加固前后桥体的应力状态,桥体受力关键部位应力水平均有一定程度的降低。依据等效应力破坏准则对加固后桥体的安全性能进行评价,加固后桥体能够满足正常使用的要求,保证采动影响下公路和铁路的运营。

The surface deformation caused by the exploitation of underground coal resources is directly acting on the ground building foundation,which leads to additional stress and displacement of the upper structure,and seriously affects its safety performance and normal use.In this paper,the stress level,stress distribution and danger domain of the original bridge under surface deformation are analyzed by the finite element modeling,combined with the actual mining influence of a railway overpass in a mining area.Based on the analysis results,a bridge deformation resistant reinforcement scheme is proposed,and a modeling analysis of the strengthened bridge body is carried out.The stress states of the bridge before and after the reinforcement are compared,the stress level of the key parts of the bridge is reduced to a certain extent.According to the equivalent stress failure criterion,the safety performance of the reinforced bridge body is evaluated.After the reinforcement,the bridge can meet the requirements of normal use,and the operation of the road and railway is ensured under the mining influence.