负载条件下格构式型钢混凝土柱受力性能研究

Study on mechanical behavior of latticed steel reinforced concrete columns under initial load

为研究逆作法基坑开挖施工中的格构式支承立柱初应力和外表清洁度对劲性混凝土柱受力性能的影响,对钢筋混凝土柱、普通型钢混凝土柱和考虑初应力和外表面清洁度影响的型钢混凝土柱进行了非线性数值分析和2/3缩尺静力偏压试验。数值分析结果表明,普通型钢混凝土柱在达到极限承载力时,格构型钢柱和混凝土各自分配的轴力分别达到其峰值承载力;格构式型钢混凝土柱中的钢格构立柱的初应力对其极限承载力影响较小。试验结果表明,三根试件均表现为受压侧混凝土受压破坏,初应力对格构式型钢混凝土柱极限承载力的影响较小,考虑初应力作用的型钢混凝土柱的极限承载力比普通钢筋混凝土柱大42.5%。

In order to study the influence of the initial stress and surface cleanliness of the latticed column on the mechanical performance of the latticed steel reinforced concrete(LSRC)column in the construction of the top-down foundation pit excavation,non-linear numerical analyses and 2/3-scale static eccentric compression tests were carried out on one reinforced concrete(RC)column,one ordinary LSRC column and one LSRC column considering the initial stress and the external surface cleanliness of the latticed steel column.Numerical analysis results show that the axial forces distributed by the latticed steel column and the concrete have reached their peak bearing capacities respectively when the ordinary LSRC column reached its ultimate bearing capacity.The initial stress of the latticed steel column has little influence on the ultimate bearing capacity of the LSRC column.The static test results show that the three specimens all present the compression failure of the concrete on the compression side,and the initial stress almost has no influence on the ultimate bearing capacity of the LSRC column.The ultimate bearing capacity of the LSRC column considering the initial stress is 42.5%higher than that of the RC column.