【作者】 叶小强；

【导师】 洪晓林； 金初阳；

【作者基本信息】 南京水利科学研究院 ， 水工结构工程， 2006， 硕士

【摘要】 在大跨度预应力混凝土连续梁桥工程中，广泛采用自架设悬臂挂篮施工工艺，桥梁结构在施工期内将产生复杂的内力和位移变化。为确保施工安全和质量，尤其是成桥线形，必须对上部箱梁结构进行施工力学分析和施工现场监控。 首先，系统地集成大跨度预应力混凝土连续梁桥悬臂施工的施工力学和仿真知识体系，提出不仅要考虑具体实际结构几何模型的转换，空间效应分析了悬浇节段阶段、落梁施工阶段和合拢阶段的结构内力重分布和位移变化；而且要考虑施工期建筑材料力学性能的时效性和预应力荷载的全程损失。在仿真模型参数选取上，根据文献资料和实际应用经验，提出合理的应用参数。兼合两者效应分析，介绍了施工全过程仿真计算流程和软件程序实现，并分别建立二维整体模型和通用三维局部模型。 然后，阐述了施工挠度监测的具体方案和施工监控的一般方法。针对大跨度预应力混凝土连续梁桥的线形控制技术，分别介绍设计标高、竣工标高、立模标高的计算方法。尤其是线形纠偏时，考虑现场施工误差的特殊性和施工力学仿真的精度，为满足光顺和逼进的统一，根据光顺样条函数流形的基本性质，提出切实可行的线形误差调整方法——光顺样条法，确保成桥线形视觉效果。 最后，结合S249京杭运河特大桥施工监控的结果，较详细地比较了梁体阶段挠度、累计挠度、测点应力的计算值和实测值的关系。结果表明，现场实测数据和理论分析相吻合，桥梁最终合拢误差小于规范要求值，可为类似工程提供参考依据。更多还原

【Abstract】 Construction mechanics and construction monitoring are new disciplines to study the complicated constructing of civil engineerings. Nowadays balanced cantilever-casting construction plays an essential role as an advanced erection craft for long-span PC continuous girder bridges, however, inter force and displacement are changed sophisticated in segments during the construction. To ensure safety and quality during the construction, especially for the geometrical aesthetic appeal, construction simulation and monitoring must be carried out.Firstly, the construction mechanics and simulation for long-span PC continuous girder bridge are integrated. Separately analyses from two aspects: on one hand, considered the geometrical transformation of structural model, re-distribution effects should account spatially for the sequence as well as the schedule of construction, such as cantilever segments cast-in place phase; temporary concretion free phase and close-up phase. On the other hand, considered the building materials performance and pre-stress loss by time, viewpoints and applicable parameters are proposed. As a whole, the computer programs available to track the stress and displacement history of segmental bridge are introduced, as the software simulation method, the two dimensional global FEM model and 3D partial FEM model are established separately in the paper.Secondly, the deflection surveying programmers and construction control method are elaborates, and the conception of geometric control of long-span PC continuous bridge is introduced. To ensure the aesthetical pleasing of the bridge, Smoothing spline method is brought forwardsin the paper. It is indicated that elevation adjustment should meet the smoothing impacts and fitting.Finally, monitoring results of the project of S249 Bridge across Beijing-hangzhou Grand Cannel are introduced, the real deflection, displacement and stress of segments are accordance with computing. The close-up error of the bridge is satisfied with the Chinese standard. The method of the paper is proved feasible for brige monitoring.更多还原