基于界面本构模型的锚杆张拉受力分析

为明确锚杆拉拔过程的受力情况,引入2种考虑残余强度的锚固界面软化本构模型,并分析了模型参数的具体物理意义。从锚杆的荷载位移现场实测数据出发,通过2个工程实例,基于粒子群优化算法反演模型参数,并利用反演得到的界面模型参数,通过荷载传递微分方程进行正分析,对不同张拉荷载下锚固体的轴力以及界面剪应力分布进行预测。预测结果与试验数据吻合良好,证明了引入模型的合理性以及反演方法的可行性。同时分析了锚杆张拉时的受力变化过程,拉拔过程中,锚杆锚固段剪应力分布由一条最大值在张拉端的单调曲线演变为一条单峰曲线且峰值不断向远端传递。研究成果可为锚杆的设计与施工提供一定的参考。

Stress Analysis of Anchor in Tension Based on Interface Constitutive Model

In an attempt to determine the stress condition of anchor in drawing process, two softening constitutive models for anchoring interface in consideration of residual strength are introduced, and the physical meanings of the parameters are analyzed. According to field data of load-displacement relation, parameter inversion of interface constitutive model was conducted by particle swarm optimization algorithm in two engineering examples. With the parameters of the interface model obtained by inversion, by solving the loading transfer differential equation, the axial force and the interfacial shear stress distribution of anchor under different drawing loads are predicted. The predicted results are in good agreement with the experimental data, which proves the rationality of the introduced models and the feasibility of the inversion method. Moreover, the stress variation process of anchor was analyzed. Results reveal that during the drawing process, the shear stress distribution evolves from a monotone decaying curve with the maximum value at the pull end into a single peak curve, with the peak extending to the far end. The research results of this paper provide a basis for the design and construction of anchor bolts.