跨高速铁路运营线钢箱梁拖拉快速施工方案与控制

Rapid Dragging Construction Scheme and Control of Steel Box Girder Cross High Speed Railway Operation Line

为研究桥梁跨越繁忙高速铁路运营线的施工方案与施工控制,以常益长高速铁路(常德—益阳—长沙)跨既有石长铁路(石门—长沙)拱形塔斜拉桥的钢箱主梁施工为依托,开展施工方案分析,通过有限元分析研究施工临时塔索方案及施工全过程主梁受力与变形,并结合现场实测对施工进行控制。结果表明:基于滚轮式重物移送器两侧相对拖拉法施工及无合龙段的合龙施工方案能够满足一个天窗期内快速施工要求。临时塔索方案合龙面高差为0.2 mm,转角差基本为0,扣塔受力与稳定性良好,拖拉至就位全过程中主梁应力均在合理范围内,满足合龙要求。各关键工况下线形及应力监控理论值与实测值吻合良好,线形误差在2 mm以内,控制截面主梁上下缘应力最大误差均在10%以内,应力远小于容许应力200 MPa,施工过程控制精度高。

In order to study the construction scheme and construction control of the bridge crossing the busy high speed railway operation line,based on the construction of the steel box girder of the arch tower cable-stayed bridge of the Changyichang(Changde-Yiyang-Changsha)high speed railway crossing existing Shichang(Shimen-Changsha)railway,the construction scheme analysis was carried out.The construction temporary tower cable scheme and the stress and deformation of the girder during the whole construction process were studied through finite element analysis,and the construction was controlled in combination with the field measurement.The results show that the closure construction scheme based on the relative dragging method on both sides of the roller type heavy load transfer device and the closure construction scheme without closure section can meet the requirements of rapid construction in a skylight period.The height difference of the closure surface of the temporary tower cable scheme is 0.2 mm,and the angle difference is near zero.The stress and stability of the tower buckle are good.The stress of the main girder is within a reasonable range during the whole process of dragging to the position,meeting the closure requirements.The theoretical values of alignment and stress monitoring under all key working conditions are in good agreement with the measured values,the alignment error is within 2 mm,the maximum error of the upper and lower edge stress of the main girder of the control section is within 10%,the stress is far less than the allowable stress of 200 MPa,and the control accuracy of the construction process is high.