采空区下沉盆地防积水淹没框架桥“桥上建桥”力学特性研究

为防止采空区下沉盆地框架桥被积水淹没,提出2种治理方案,采用ANSYS建立其有限元模型,研究不同土压力作用下框架桥“桥上建桥”的可行性。研究结果表明,①采空区下沉盆地压缩区原有框架桥随着侧土压力的增大,其合位移随之增大;②采空区下沉盆地压缩区原有框架桥随着侧土压力的增大,其第一主应力也随之增大;③极限被动土压力作用下,原有框架桥可采用加大截面法进行加固,但加大截面尺寸较大,不经济;④通过松动框架桥两侧土体,减小框架桥侧土压力,然后在其上续建新框架桥,形成组合框架桥,可以节省混凝土,更为经济。

In order to prevent the frame bridge in the subsidence basin of the goaf from being submerged by water accumulation,two treatment schemes are proposed.The finite element model is established by ANSYS,and the feasibility of"building a bridge on the frame bridge"under different earth pressure is studied.The research results show that:①the combined displacement of the original frame bridge in the compression area of the subsidence basin in the goaf increases with the increase of lateral earth pressure;②The first principal stress of the original frame bridge in the subsidence basin compression area of the goaf increases with the increase of the lateral earth pressure;③Under the action of ultimate passive earth pressure,the original frame bridge can be strengthened by increasing section method,but the increasing section size is large and uneconomical;④By loosening the soil on both sides of the frame bridge,reducing the earth pressure on both sides of the frame bridge,and then continuing to build a new frame bridge on it to form a composite frame bridge,it can save concrete and be more economical.