索穹顶无支架提升牵引施工技术及全过程分析  

Research on non-bracket tow-lifting construction technology and complete process analysis of cable dome

作　　者：罗斌[1] 郭正兴[1] 高峰[1] 

机构地区：[1]东南大学土木工程学院,江苏南京210096

出　　处：《建筑结构学报》2012年第5期16-22,共7页Journal of Building Structures

基　　金：国家自然科学基金项目(51008066);863计划项目(2007AA04Z441);江苏省自然科学基金项目(BK2006104);东南大学国家自然科学基金预研项目(KJ2010404)

摘　　要：索穹顶施工是将索杆系经由无应力组装状态、低应力松垂状态向高应力成型状态转变的过程。基于索穹顶无支架提升牵引施工方法,在地面组装内拉环和脊索网,随后续提升牵引在低空组装其它索杆系;以外压环为支座利用工装索交替提升内拉环和牵引外脊索,直至外脊索与外压环连接就位,对外斜索同步张拉结构成型。该方法高空作业少、张拉效率高。基于非线性动力有限元的索杆系静力平衡态找形分析方法,建立整体运动方程,通过一级动力平衡迭代和二级模型更新迭代,由初始静力不平衡态,经由动力平衡态收敛于静力平衡态,并通过总动能峰值及时间驻点确定、时间步长自动调整和静力平衡态检验等,保证分析结果的稳定和高效。结合索穹顶实际工程进行了提升牵引和张拉全过程分析及扰动稳定分析,研究结果表明:索杆系位形经历了分别与提升牵引、牵引张拉初期和张拉后期对应的悬垂、调整和刚化3个阶段;脊索网呈"ω"形是保证索杆系低应力悬垂位形稳定的重要条件之一;位形调整阶段存在"拐点",拐点的位形稳定性在全施工过程中最弱,在高矢跨比索穹顶中应特别关注。Stress state of the cables of a cable-dome structure during the construction process consists of the initial state without stress, low stress relaxation state during erection and high tensile stress state after the doom shape formed. The new construction method of non-bracket tow-lifting is put forward, by which the inner tensile ring and ridge cables net are assembled firstly on ground while other cables and struts assembled at low altitude following subsequent lifting and towing. The inner tensile ring is lifted and outer ridge cables are towed alternatively by tool cables connected with outer compressive ring until outer ridge cables are connected with outer compressive ring. At last the outer inclined cables are simultaneously tensioned to form. This method requires few operations at high altitude and has high tensioning efficiency. The new form-finding method of cable-strut system is also put forward, which is based on nonlinear dynamic finite element method and static equilibrium of whole cable system. The kinematical equation is established. The system configuration is from initial static unbalanced state to dynamic equilibrium state and converged at static equilibrium state by dynamic equilibrium iteration of first class and model-updating iteration of second class. The stability and efficiency of the method can be ensured by the determination kinematical energy peak and stationary points, updating time-step automatically and verifying static equilibrium state, etc. Based on an actual cable dome construction project, the tow-lifting and tensioning process and disturbance stability are analyzed. The configurations are changed through three phases of overhanging, adjusting and rigiding during construction. The ridge cables net in ‘ω＇ shape is important to keep overhanging configuration stable. An inflection which configuration stability is the worst needs special attention. So for cable domes of high rise-to-span point exists in adjusting phase, at ratio the stability at inflection pointneeds special a

关 键 词：索穹顶 施工技术 无支架提升牵引 非线性动力有限元分析 找形 全过程分析 

分 类 号：TU393.3[建筑科学—结构工程] TU745.2