钢管混凝土支架节点压弯承载性能数值模拟

Numerical simulation of compression bending bearing property of concrete filled steel tubular support joints

  • 摘要: 针对深部巷道中钢管混凝土支架受偏压荷载作用,节点作为薄弱部位容易失效的问题,采用ABAQUS数值模拟软件分析了套管、法兰连接节点2种节点连接形式在压弯荷载作用下的受力承载性能。基于压弯荷载作用下的Mu-Nu曲线,分别分析了套管连接、法兰连接节点的参数影响规律,从而给出了支架中不同节点连接形式的参数设计建议,同时根据套管连接节点与法兰连接节点的优化参数,进行不同节点形式的承载性能对比分析。结果表明:①混凝土强度等级是节点压弯承载性能的重要影响因素,偏压系数越大,影响越不明显;随着偏压系数的变化,套管长度、套管壁厚、套管间隙、螺栓数量、法兰厚度对压弯承载性能的影响程度改变;②套管长度越长、套管壁厚越大、套管间隙越小,套管连接节点的压弯承载力越大;螺栓数量越多、法兰厚度越大,法兰连接节点压弯承载力越大,螺栓强度等级对压弯承载力的影响不明显;③在偏压工况下,套管连接节点相对于无节点构件承载性能明显降低,无法实现等强连接;法兰连接节点的荷载−位移曲线与无节点构件类似,偏压工况下承载力仅下降1.7%左右;④压弯荷载作用下的法兰连接节点的极限承载力与刚度都优于套管连接节点,是一种强节点连接形式。支架节点参数对支架承载性能影响显著,且影响程度随偏压系数的改变而变化。法兰连接节点具有良好的压弯承载性能,宜应用于支架节点。研究结果可为钢管混凝土支架节点设计提供建议,以期充分发挥支架支护性能。

     

    Abstract: Aiming at the problem that the joints of concrete filled steel tubular support under eccentric compression load in deep roadway are easy to fail as weak parts, the mechanical bearing property of casing connection joints and flange connection joints under compression bending load is analyzed by using ABAQUS numerical simulation software. Based on the Mu-Nu curve under compression bending load, the influence laws of the parameters of the casing connection joints and the flange connection joints are analyzed respectively, and the parameter design suggestions of different types of joints in the support are given. At the same time, the bearing property of different types of joints is compared and analyzed according to the optimal parameters of the casing connection joints and the flange connection joints. The results show that: ① the strength grade of concrete is the important influencing factor of the compression bending bearing capacity of the joints, the greater the degree of eccentricity, the less obvious the influence; with the change of the degree of eccentricity, the influence of casing length, casing wall thickness, casing gap, the number of bolts and flange thickness on the compression bending bearing capacity is changed; ② With the increase of casing length, the increase of casing wall thickness and the decrease of casing gap, the compression bending bearing capacity of casing connection joints increases; with the increase of the number of bolts and flange thickness, the compression bending bearing capacity of the flange joints increases, and the strength grade of the bolts has no obvious influence on the compression bending bearing capacity; ③ Under the bias condition, the bearing capacity of the casing connection joints is significantly lower than that of the member without a casing or flange, and the equal strength connection cannot be realized. The load-displacement curves of the flange connection joint are similar to that of the member without a casing or flange, and the bearing capacity only decreases by about 1.7% under the bias condition; ④ The ultimate bearing capacity and stiffness of the flange connection joints are better than that of the casing connection joints, which is a kind of strong connection joint. The degree of load eccentricity and support joints parameters have a significant impact on the bearing capacity of the support. The flange connection joints have good bending bearing capacity and should be applied to the support joints. The research results can provide suggestions for the design of concrete-filled steel tubular support joints in order to give full play to the bearing property of the support.

     

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