既有桥高锥体近接工程支护型式研究

Research on the support pattern of the adjacent construction works in a high cone for existing bridges

介绍小龙门大桥近接行车线增建Ⅱ线桥台时,为了解决高、大锥体中深挖基坑,在坑壁防护中遇到的施工难题,利用结构设计原理,进行力学分析,设计了一种名曰"桩中埋梁、梁上焊挡"的永临结合新型挡护结构。不但解决了施工难题,达到了安全防护之目的,而且工期短、用料省,其方法值得在同类近接工程中参考。

In building the 2nd railway bridge abutments just adjacent to the traffic road on the Xiao Longmen Bridge, a new type of retain and support structure, called 'burying girders in pile and welding aprons on girder', is designed to solve the difficulties in excavating the deep foundation trenches in a high and big cone and supporting the trench walls. In designing this structure, a structural design theory is used, a mechanical analysis is carried out and temporary and permanent combination is turned to. The method, with the shortest construction period and most economical use of materials, can be used not only to solve construction difficulties but also to attain the goal of safe support. It is worth being promoted and applied in the same type of projects.