大跨度局部自平衡混凝土拱壳结构专项分析研究  

Specialized analysis and research of large-span local-self-balanced concrete arch shell structure

作　　者：程卫红 刘枫 张高明 CHENG Weihong;LIU Feng;ZHANG Gaoming(China Academy of Building Research,Beijing 100013,China;National Engineering Research Center of Building Technology,Beijing 100013,China)

机构地区：[1]中国建筑科学研究院有限公司,北京100013 [2]国家建筑工程技术研究中心,北京100013

出　　处：《建筑结构》2023年第15期22-27,共6页Building Structure

摘　　要：京沈客专在北京朝阳站段(里程DK14+400~DK15+050)封闭式声屏障采用结构跨度约40m的大跨度混凝土拱壳结构形式,主拱结构之间应用单向简支的SP预应力预制板,主拱高位设置预应力拉索形成局部自平衡体系。针对预制壳板安装和预应力拉索张拉的工序开展不同施工方案对比分析,对比不同施工方案对应的结构受力和配筋设计情况。利用规范公式近似计算主拱混凝土的收缩应变和徐变应变,开展考虑混凝土收缩徐变的施工模拟分析,对收缩徐变造成的结构受力状态变化进行详细的研究。利用考虑塑性铰的动力时程分析方法分别对结构单体中间跨和边跨进行断索专项分析,研究了主拱结构的抗连续倒塌能力以及拉索更换的可行性。研究表明:考虑混凝土的收缩徐变,预应力拉索会产生一定的索力松弛,跨中段主拱的轴力也会有所下降,但不影响主拱结构受力的安全性。中跨或边跨发生断索时主拱结构均不会发生倒塌破坏,通过设置连系梁,混凝土拱壳结构具有较高的安全冗余度。Large-span concrete arch shell structure was applied in the fully enclosed sound barrier of Beijing-Shenyang Passenger Dedicated Line near Beijing Chaoyang Station(mileage DK14+400~DK15+050),with a structure span of about 40m.One-way simply supported SP prestressed precast plates was adopted between the main arches.Prestressed cables were set at a high position of the main arch to form a local-self-balanced system.A comparative analysis of different construction schemes was carried out about the installation of prefabricated shells and tension construction of prestressed cables.Structural forces and reinforcement designs of different construction schemes were compared.Construction simulation analysis was carried out with concrete shrinkage and creep considered.Concrete shrinkage strain and creep strain was calculated with an approximate method based on specification formula.The changes in the structural force state caused by shrinkage and creep have been studied in detail.Cable breaking analysis was carried out on both middle span and side span of the structure with dynamic time-history analysis method considering plastic hinges.The collapse resistance ability of the structure and the feasibility of cable replacement was both studied.The results show that considering the shrinkage and creep of concrete,a certain amount of cable relaxation will occur in the prestressed cable,and the axial force of the main arch in the middle section will also decrease,but it will not affect the safety of the main arch structure.When the cable in the middle span or side span breaks,the main arch structure will not collapse and fail.The concrete arch shell structure has a high safety redundancy by setting up the connecting beam.

关 键 词：京沈客专 局部自平衡 大跨度混凝土拱壳 施工方案 收缩徐变 施工模拟 断索分析 

分 类 号：TU375.5[建筑科学—结构工程]