论文部分内容阅读
关于桥式超重机(以下简称桥吊)大梁下挠的修复方法很多。以往常用火焰矫正法,这无疑是一种行之有效的方法。但火焰矫正法的明显缺点是技术操作复杂,修理工时多。为了巩固矫正效果,还要增焊钢板,这样会使大梁产生局部热应力,以致修理质量不太理想。从六十年代中期起,鞍钢等地在矫正桥吊大梁下挠方面,成功地采用了计算预应力钢筋张拉法。特别是对50吨以下的中小型桥吊来说,预应力矫正法较之火焰矫正法有着明显的优点。但是用计算预应力的张拉法也有缺点,用此法必须在施工前根据所检修的桥吊情况,对张拉钢筋所需要的预应力进行理论计算,而且在施工时还需要具备张拉测力条件。因此有些单位没有条件采用,使这种先进的修理工艺难以普遍推广。我们在进行桥吊大梁下挠修理时,摸索采用了测
On the bridge overweight machine (hereinafter referred to as the bridge crane) under the beam deflection repair method many. In the past commonly used flame correction method, which is undoubtedly an effective method. However, the obvious drawback of flame correction is the technical complexity of the operation, repair time and more. In order to consolidate the correction effect, but also welding steel plate, it will make the girders local thermal stress, so that the quality of the repair is not ideal. Since the mid-1960s, Anshan Iron and Steel and other places in the correction of the girder girder flexor bridge, the successful use of prestressed steel tensioning method. Especially for small and medium-sized bridge cranes up to 50 tons, the prestressing correction method has obvious advantages over the flame rectification method. However, the prestressing method of tensioning also has its drawbacks. In this method, the prestressing force required for tensile reinforcement must be theoretically calculated before construction according to the condition of the bridge to be repaired. In addition, tension testing Force conditions. Therefore, some units have no conditions to adopt, so that the advanced repair process is difficult to universally promote. We are carrying out bridge girder under the next scratch repair, groping with the test