双套拱斜拉桥拱塔竖转提升测控技术

Survey and Control Techniques for Vertical Rotation and Lifting of Arch Pylons of Double-Set Arch Pylon Cable-Stayed Bridge

荆邑大桥为双套钢拱斜拉桥,钢拱塔采用工厂预制节段、工地焊接组拼、主塔和副塔液压同步提升的施工方法。为保证拱塔施工安全并在满足精度要求的条件下就位,给出拱塔结构竖转提升施工测控技术,即通过观测全站仪距拱塔顶反射靶标的空间距离实现拱塔提升角度测控;通过观测提升吊点附近反射靶标的空间坐标实现拱塔平整度测控;通过监测拱塔提升过程中结构最大应变处的应力保证拱塔本身的安全性;通过控制门架位移保证施工过程中门架安全。荆邑大桥拱塔的竖转提升实践证明,该方法是正确和可操作的,测控精度满足工程要求。

The Jingyi Bridge is a double-set steel arch pylon cable-stayed bridge. The steel arch pylons of the Bridge were constructed by the method of manufacturing the pylons in blocks in shop, assembling and welding the blocks into pylons in field and synchronously lifting both the primary and secondary pylons by hydraulic equipment. To ensure that the construction of the py- lons could be carried out in a safe way and the pylons could be set in place under the condition that the accuracy requirements would be satisfied, the survey and control techniques/or the vertical rotation and lifting of the pylons were formulated, namely, the survey and control of lifting angles of the pylons would be realized through observation of the spatial distance from the total station to the reflection targets set at the pylon tops, the survey and control of evenness of the pylons would be realized through observation of the spatial coordinates of the reflection targets set nearby the lifting points, the safety of the pylons themselves would be ensured through monitoring of the stress at the structural maximum strain in the lifting process of the pylons and the safety of the portal frames in the construction process would be ensured through control of the displacement Of the frames. The construction practice of the vertical rotation and lifting of the pylons of the Bridge proves that the techniques are correct, operational and the control accuracy can satisfy the construction requirements.