蚕茧形大跨度煤棚钢结构施工技术

CONSTRUCTION TECHNOI OGY OF STEEL STRUCTURE FOR LARGE-SPAN COAL SHED OF COCOON SHAPE

华润某电厂为双条形空间网架结构,结合现场施工条件及工期限制,经多种网架拼装方案的对比,择优采用“对称分块拼装高空散装”的施工工艺。考虑到双条形平行网架对风荷载比较敏感,采用有限元软件Fluent分析了不同风向角下煤棚结构表面的风荷载体型系数。经CFD分析得到:半球与弧线屋盖交界处附近体型系数约为–0.6,通风天窗顶部体型系数取–1.5。考虑到蚕茧形网架结构施工复杂,采用3D3S软件对空间网架的拼装过程进行杆件内力验算,计算结果显示,结构应力及位移均在设计值范围内,构件杆件的超应力杆数和超长细比杆数均为零,具有富足的施工安全储备。

The CR Wujianfang Power Plant adopts a double strip spatial truss structure.Based on on-site construction conditions and time constraints,and after comparing various grid assembly schemes,the construction process of symmetrical block assembly and high-altitude bulk loading is preferred.Due to the significant sensitivity of the structure to wind load ratio,the finite element software Fluent was used to analyze the wind load shape coefficient on the surface of the coal shed structure under different wind directions.According to CFD analysis,the shape coefficient near the junction of the hemisphere and the curved roof is approximately–0.6,and the shape coefficient at the top of the ventilation skylight is taken as–1.5.Considering the complex construction of the cocoon shaped grid structure,3D3S software was used to verify the internal force of the members during the assembly process of the spatial grid.Calculation had shown that the structural stress and displacement are within the design value range,and the number of overstressed and slenderness ratio members of the component members is zero,which has abundant construction safety reserves.