根据平行钢丝斜拉索的结构特征，采用变宽度摩擦型叠梁模型研究其层间滑移 的扩展规律． 当库伦摩擦型叠梁层间剪力超过层间最大摩擦抗力的时候，叠梁将发生层间 滑移． 通过节段分析方法推导了考虑层间摩擦力作用的变宽度叠梁截面剪应力计算公式， 从而确定了摩擦型叠梁层间滑移扩展过程的规律; 然后采用传递矩阵法求解叠梁滑移的 扩展长度;最后与 ANSYS 数值模拟计算结果进行对比，验证本文计算方法的准确性． 

 According to the structural characteristics of the parallel steel wire rope， the slippage development mechanism between the wires can be studied by the frictional variable width laminated beam model． When the inter layer shear force of the coulomb’s frictional laminated beam exceeds the maximum friction resistance between layers， the slippage between layers will occur． In order to accurately study the interlaminar slip mechanism of the frictional variable width laminated beams， the formula for calculating the shear force of the frictional variable width laminated beams considering interlaminar friction is derived by the section analysis method， then determines the interlaminar slippage law of the frictional laminated beams; And then the Transfer Matrix method is used to calculate the slippage length; Finally， the ANSYS numerical simulation results are compared to verify the accuracy of the algorithm．