平弯桥梁顶推施工受力理论分析

Theoretical Analysis on the Force of Jacking Construction of Flat Curved Bridge

以大曲率平弯钢箱梁桥顶推施工过程为研究背景,对同时受钢索拖拉力和步履千斤顶共同作用下的顶推过程进行分析。研究中通过力的平衡方程导出拖拉力和向前的顶推力间的关系,并利用三弯矩方程分析各支座处的支反力及相应摩擦力,得到顶推过程中导梁的受力及导梁将到达前方桥墩时前端的竖向位移。最后,以东莞长安至深圳南山高速公路二期工程B匝道桥第七联大曲率平弯顶推施工钢桥为例,计算得到拖拉力,步履机顶推力及摩擦力间的关系。

In this paper,the jacking construction process of large curvature flat-curved steel box girder bridge is taken as the research background,and the forces acting on the bridge under the action of both the cable pulling force and the walking Jack are analyzed.In this study,the relationship between drag force and forward top thrust is derived by the balance of force,and the counterforce and corresponding friction force at each support point are analyzed by the three-bend ingesting moment equation,and the force of the guide beam and the vertical displacement of the guide beam will reach the front end of the bridge in front are obtained.An example of this paper is based on the seventh junction of B ramp bridge in the two phase of Changan to Shenzhen Nanshan Expressway in Dongguan.The relationship between traction force,pedestrian thrust force and friction force is calculated.