公路梁桥加宽基础沉降控制分析

Analysis on Foundation Settlement Control in Highway Beam Bridge Widening

随着公路交通承载压力不断增大,梁桥加宽改造被广泛应用于不同等级公路中。新、旧梁桥加宽过程中产生的差异性沉降极易造成桥头跳车、梁体倾斜、上部结构开裂等病害,从而危害公路通行的稳定性,因此,开展梁桥加宽力学响应及沉降控制分析具有重要意义。文章依托江苏省某三跨T梁两侧对称加宽改造项目,采取MARC有限元软件进行桩基础承载特性分析,并对不同注浆、桩长下的桩基础差异性沉降进行研究。结果表明,新、旧桩基础沉降差随上覆荷载的增大而增大;桩基础沉降差随注浆强度增大而减小,桩侧阻力呈增大趋势;桩基础沉降差随桩长增加而减小(临界桩长为18 m)。

With the increasing bearing pressure of highway traffic,beam bridge widening renovation is widely used in highways with different grades.The differential settlement generated in the widening process of new and old beam bridges can easily cause diseases such as bridgehead jump,beam body tilt,and superstructure cracking,thus endangering the stability of highway traffic.Therefore,it is of great significance to carry out the analysis of mechanical response and settlement control in beam bridge widening.Based on the symmetrical widening renovation project on both sides of a three-span T-beam in Jiangsu Province,MARC finite element software is used to analyze the bearing characteristics of pile foundation,and the differential settlement of pile foundation under different grouting and pile length is studied.The results show that the settlement difference between new and old pile foundations increases with the increase of the overlying load.The settlement difference of pile foundation decreases with the increase of grouting strength,and the pile side resistance shows an increasing trend.The settlement difference of pile foundation decreases with the increase of pile length(the critical pile length is 18 m).