胶拼连续梁吊杆力精度及胶接缝应力控制

Force Accuracy of Adhesive Continuous Beam Suspension Rods and Stress Control of Adhesive Joints

铁路胶拼连续梁拼装时吊杆力偏差难以避免,通过数值计算方法,研究郑济铁路(郑州—济南)3×56 m胶拼连续梁吊杆力偏差对拼装线形、胶结缝应力的影响,以及避免应力超限的控制措施。结果表明:综合考虑拼装线形、施工过程胶结缝应力及成桥运营阶段结构受力,应按照1%的精度控制吊杆力;利用压力环对胶拼节段预先称重再拼装的控制方案,可精确控制吊杆力,控制精度为±0.5%;通过减小一次悬拼节段长度可提高结构对吊杆力的容许偏差能力;设计时采用长悬臂吊拼、施工时吊杆力偏差过大使得胶结缝应力对吊杆力敏感性过高,这是导致胶拼梁施工过程产生裂缝,甚至运营后漏水问题的重要原因。

It is difficult to avoid the force deviation of the suspension rod during the assembly of railway adhesive continuous beams.By using numerical calculation methods,the influence of force deviation of suspension rods on the assembly alignment and adhesive joint stress of Zhengzhou-Jinan railway 3×56 m adhesive continuous beams was studied,as well as control measures to avoid stress exceeding the limit.The results indicate that taking into account the assembly alignment,the stress of the adhesive joint during the construction process,and the structural stress during the bridge operation stage,the suspension rod force should be controlled with a precision of 1%.The control scheme of pre weighing and reassembling the adhesive segment using a pressure ring can accurately control the suspension force,with a control accuracy of ±0.5%.By reducing the length of a suspended assembly segment,the structure can have a higher tolerance for deviation from the suspension force.The use of long cantilever suspension during design and excessive deviation of suspension rod force during construction can lead to high sensitivity of adhesive joint stress to suspension rod force,which is an important reason for cracks and even water leakage problems during the construction process of the adhesive beam.