大跨梁网预应力分区张拉的影响分析
Effect Analysis of Prestressing Subarea Tension of Large-span Beam

针对长沙百米深矿坑冰雪世界工程中部3×104 m2预应力平台，为了比较分区施工与设计一次成形的差异，基于有限元软件MIDAS/Gen，对其施工全过程进行有限元模拟。在自重荷载作用下，对比了分区施工与一次成形梁的弯矩图；在自重荷载与预应力荷载的共同作用下，对比了梁的弯矩图和梁底、梁顶的应力云图，从工程施工角度提出了分区施工的技术措施。结果表明：梁跨中与支座的总弯矩是相等的，由此说明分区施工模拟分析是可行的；分区张拉施工取得的效果与设计一次成形预应力张拉的效果基本吻合。
Aiming at the construction of 3×104 m2 prestressed platform of central part of Ice and Snow World project at the 100 m deep pit in Changsha, in order to compare the differences between subarea construction and one？？time construction, based on the finite element software MIDAS/Gen, the finite element simulation of whole construction process was carried out. Under the action of self weight load, the bending moment diagrams of the subarea construction and the once？？tension forming beam were contrasted. Under the combined action of self weight load and prestress load, the moment diagrams of the beam and the stress nephograms of the bottom and top of the beam were contrasted. The technical measures of subarea construction were put forward from the angle of engineering construction. The results show that the total bending moment of beam midspan is equal to that of the support, so the simulation analysis of subarea construction is feasible. The effect of subarea tension construction is basically consistent with the effect of once？？tension forming