双八字组合型钢支撑预应力施加方法与校验

Prestressing Method of Double-Splayed Composite Steel Support and its Verification

以浙江省温州市龙湾中心区的城中村改造项目为背景,研究双八字组合型钢支撑在大跨度基坑中的预应力施加方法。结合工程概况,设计监测方案,提出预应力施加流程。采用BSC有限元模拟和结构有限元模拟对加压过程进行数值模拟测算,二者相对偏差不超过8%。将预应力施加方法应用于现场施工监测,单根型钢轴力数据满足平衡性,且BSC有限元模拟结果与实际监测数据增长趋势一致。提出的预应力施加方法可使双八字组合型钢支撑均匀合理受力,保证支护体系的安全性和稳定性;主支撑轴力监测数据无明显变化,预应力可以沿着型钢长度方向有效传递,立柱和托梁对其影响极小,几乎不产生力的损耗。提出的预应力施加流程安全可靠。

Taking the reconstruction project of urban village in Longwan central area of Wenzhou City,Zhejiang Province as the background,the prestressing method of double-splayed composite steel support in large-span foundation pit was studied.Combined with the general situation of the project,the monitoring scheme was designed,and the prestressing process was put forward.BSC finite element simulation and structural finite element simulation were used to simulate and calculate the pressurization process,and the relative deviation between them was less than 8%.The prestressing method was applied to the field construction monitoring,the axial force data of a single section steel met the balance,and the BSC finite element simulation results were consistent with the actual monitoring data growth trend.The proposed prestressing method can make the double-splayed composite steel support uniformly and reasonably stressed,and ensure the safety and stability of the supporting system.There is no obvious change in the monitoring data of the axial force of the main support,the prestress can be effectively transmitted along the length direction of the section steel,and the column and joist have little influence on it,almost without force loss.The proposed prestressing process is safe and reliable.