双排支座方案在先简支后连续梁桥施工中的应用

该文介绍了双排支座方案在先简支后连续梁桥施工的应用。某工程原设计方案是在桥墩上设置临时支座,中间保留永久支座,永久支座暂不受力,由临时支座参与结构受力,临时支座每跨之间为简支体系,待一联全部吊装完成后,使结构连成整体的连续结构体系,再将临时支座取掉,使永久支座参与结构受力,完成结构体系的从简支到连续的转换。临时支座施工工艺繁琐,操作麻烦,且施工安全方面存在隐患。双支座法是在墩顶中心线两侧对称布置两排永久支座,直接参与结构受力,通过现浇连续段和墩顶负弯矩施工形成结构连续。双支座法并没有改变结构连续的性质,且施工较方便,施工过程中应特别注意对现浇连续段的质量的控制。

Application of Double-row Bearing Scheme in Construction of Pre-simple-supported Post-continuous GirderBridge

The article introduces the application of double-row bearing scheme in construction of pre-simple-supported post-continuous girder bridge.The original design scheme is to install the temporary bearings on the bridge piers,the middle is retained for the permanent bearing,and the permanent bearing is not temporarily stressed.The temporary bearings participate in the structural stress.The simple-supported system is among the spans of temporary bearings.The temporary bearings are not demolished until the structure is connected into the integrated continuous structure system after the completion of hoisting a segment completely so as to make the permanent bearing participate in the structural stress and complete the transformation from the simple-supported structural system to continuous one.The construction technology of temporary bearing is tedious and annoying,its construction is trouble and the hidden dangers exist in the construction security.The double-bearing method is to symmetrically install two rows of permanent bearings at both sides of the central line on the top of pier.The permanent bearings directly participate in the structural stress.The cast of continuous section in site and the negative bending moment construction of pier top form the structural continuum.The double-bearing method does not change the property of structural continuum,and its construction is more convenient.The special attention should be paid to the quality control of the cast-in-situ continuous section in the course of construction.