超厚钢管约束混凝土推出试验力学模型

Mechanic Model of Push-Out Test of Over-Thick CFST

目的研究超厚-钢管约束混凝土柱受压推出试验的力学行为,揭示钢管/混凝土粘接滑移规律.方法建立超厚-钢管约束混凝土柱受压推出的轴对称弹性力学模型.测量超厚-钢管约束混凝土柱的轴向位移和钢管的轴向位移.在试验的基础上,引入粘接层的概念,建立粘接切应力-粘接切应变关系.结果钢管、混凝土之间的切应力沿高度均匀分布,钢管与混凝土之间有沿轴向的均匀滑移,因此由超厚-钢管约束混凝土柱受压推出试验可以比较精确地测出超厚-钢管约束混凝土之间的粘接切应力.结论轴对称弹性力学模型用于模拟超厚-钢管约束混凝土柱受压推出是正确的.在钢管和混凝土之间存在粘接薄层,钢管与混凝土之间沿轴向的滑移可以等效为粘接层的剪切变形,由推出试验可以确定粘接层的剪切应力-应变关系.

Analyze mechanical behavior of over-thick concrete filled steel tube（over-thick CFST）subjected to axial compression and reveal adhesive slip law of steel tube/concrete.Axial symmetry elasticity modeling of the concrete column which is constrained by over-thick steel tube and pushed out under axial compressive load is set up.The push-out test was carried out and axial displacements of concrete column and steel tube were measured.On the base of the test,the adhesive layer between the concrete and the steel tube is introduced and shearing stress-shearing strain curve is set up.The results show that the adhesive stress between steel tube and concrete is uniform along the height,and uniform slipping along the height exists.Therefore the adhesive stress between steel tube and concrete can be precisely measured by push-out test of over-Thick CFST subjected to axial compression.The following conclusions can be drown that axial symmetry elasticity modeling is correct for simulating push-out test of over-Thick CFST.There is an adhesive thin player between steel tube and concrete,the slip can be equivalent to shearing deformation of the adhesive layer.The relation of shearing stress-shearing strain can be determined by the push-out test.