月牙形非封闭空间索桁架结构预应力施工技术

Prestressed Construction on Space Cable-truss Structure with Crescent Non-closed Plan

乐清体育场挑蓬采用月牙形非封闭空间索桁架结构,由刚性外环梁柱、内环索、上径向索、下径向索、吊索和压杆构成,属于张力结构体系。本工程索桁架共38榀,各榀的悬挑长度和张拉力差异大,在中部索桁架的悬挑端部存在上、下径向索交叉和上、下环索分叉,其间布置了压杆。为减少施工支架搭设费用,采用发明专利技术"索桁架固定千斤顶斜向牵引整体提升的无支架施工方法",分3个施工阶段:低空无应力组装、空中斜向牵引提升和高空分级同步张拉。在施工全过程模拟分析中,由于存在刚体大位移和拉索大悬垂现象,因此采用发明专利技术"确定索杆系静力平衡状态的非线性动力有限元法"进行分析,确定全过程的结构位形和内力状况。

Cable-truss structure is applied on space cable-truss roof structure with crescent non-closed plan of Yueqing Stadium, which consists of rigid beams and columns, circle cables, radial cables, suspender cables and compression bars. The whole structure includes 38 cable-trusses, and half of them have different overhang length and tensioning force. There exist bifurcations and compression bars between some upper radial cables and lower radial cables in the middle part of structure, and so do circle cables. In order to decrease the cost of support facility, an inventive patent technology called ＂ non- bracket tow-lifting with fixed jacks construction technology＂ is applied on this project. There are three steps of the integral installing method,namely, a processing of assembling stressless cable-bar on ground, to tow-lifting and tensioning the whole cable-truss in the air. Inventive patent technology of ＂ the nonlinearity power finite element method for assuring static equilibrium state of cable-bar＂ is applied in order to solve the problem in construction simulation analysis and confirm the form of structure and internal tension. The results show that the above construction scheme is reasonable.