龙华区观湖街道观城第一期城市更新单元项目共有9个地块,01～09地块围绕背夫山分部,各地块裙房二层通过背夫山生态云谷公园云环连桥连接,各座连桥首尾连续连接相通,且连桥下方道路的净高不小于5 m,其可保证市政道路的通行要求.研究依托观城08地块项目云环组合连桥施工技术进行分析,因裙房标高及市政道路净高限制,连桥最大板厚为1.5 m,最大跨度为39.8 m,连桥结构板里含有暗梁,暗梁均为预应力梁.预应力梁采用后张法进行施工,连桥结构混凝土强度等级为C50(自密实),要求混凝土强度达到90%以上方可张拉,张拉控制应力取σcon=0.75fptk,Φs15为低松弛钢绞线,fptk=1 860 MPa,外径d=15.20 m.
CONSTRUCTION TECHNOLOGY OF CONTINUOUS COMBINATION CAST-IN-PLACE PRESTRESSED BRIDGE
The first phase of urban renewal unit project in Guancheng,Guanhu Street,Longhua District con-sists of 9 plots,with plots 01～09 surrounding the Beifu mountain branch.The second floor of each plot's podium is connected by the Beifu Mountain Ecological Cloud Valley Park Cloud Ring Bridge,and the ends of each bridge are continuously connected.The net height of the road below the bridge is not less than 5 meters,which can ensure the traffic requirements of municipal roads.Based on the analysis of the construction technology of the cloud ring com-posite bridge in the Guancheng 08 plot project,due to the height restrictions of the podium and the clear height of the municipal road,the maximum plate thickness of the bridge is 1.5 meters and the maximum span is 39.8 meters.The structural plate of the bridge contains hidden beams,all of which are prestressed beams.The prestressed beam is constructed using post tensioning method.The concrete strength grade of the bridge structure is C50(self compact-ing),and it is required that the concrete strength reach above 90%before tensioning.The tensioning control stress is taken as σcon=0.75 fptk,and the Φs15 is a low relaxation steel strand with fptk=1 860 MPa and an outer diameter d=15.20 m.
万方数据
维普
