钢纤维高强混凝土三桩承台受力性能数值分析

Numerical Analysis of Mechanical Behavior of Steel Fiber Reinforced High Strength Concrete Three Pile Caps

为进一步探讨不同混凝土强度等级和钢纤维含量的钢纤维高强混凝土三桩承台的力学性能及破坏特征,在模型试验的基础上,建立钢纤维高强混凝土三桩承台数值模型进行有限元非线性分析,得到承台的开裂荷载、极限荷载、荷载—位移曲线及承台内部应力应变的变化规律,并与试验结果进行了对比分析。结果表明,钢纤维高强混凝土三桩承台的开裂荷载和极限荷载的计算值与试验值吻合较好;钢纤维在高强混凝土承台中的早期阻裂作用明显,承台的承载力较普通混凝土承台有较大提高。钢纤维高强混凝土三桩承台传力机理符合空间桁架的传力特点,承台为冲切破坏。

The mechanical behavior and failure characteristics of steel fiber reinforced high strength concrete(SFHSC)three pile caps with different concrete strength and content of steel fiber-are studied through the finite element nonlinear analysis.The numerical model of SFHSC three pile caps is established on the basis of test model.And the cracking load,ultimate load,load deflection curve and the internal stress and strain of the three pile caps are obtained and compared with that of the experimental caps.The results indicate that the calculated values of cracking load and ultimate load of SFHSC three pile caps are in good agreement with the experimental values;The crack restrain effect of steel fiber on the SFHSC caps is obvious in the early crack developing stage,and the bearing capacities of caps are improved evidently.The transfer mechanism of SFHSC three pile caps can be similar to that of space truss,and the failure mode of the caps is the punching failure.