岩体离层作用下锚杆受力特性全历程分析

发布时间：2018-03-26 00:33

本文选题：岩土工程　切入点：锚杆　出处：《岩石力学与工程学报》2017年09期

【摘要】：针对岩体离层作用下锚杆受力特性全历程分析问题,基于锚固界面的双指数曲线模型,采用荷载传递方法,建立离层作用下锚杆受力特性的非线性解答,分析离层发展全历程过程中锚杆轴力和界面剪应力分布,以及岩体离层锚杆轴力曲线的特性,并采用模型试验数据进行对比验证。结果表明:锚杆轴向应变的计算值与实测结果基本一致。离层发展过程中,锚杆轴力呈现先增大后减小的特性,且在离层发展后期具有明显的非线性特征。离层产生的锚杆轴力和界面剪应力均呈现明显的不均匀分布和非线性特征,且二者均随着离层的发展向两端传递。离层位置对锚杆的受力特性有很大影响:离层位于锚杆中心时,其两侧的锚杆轴力与界面剪应力均成对称分布,且随着离层发展的演变规律相同;离层偏离锚杆中心时,两侧锚杆轴力与界面剪应力分布则明显不同,界面剪应力在离层位置处存在着跳跃点,且锚固长度较小一侧的锚固界面先产生塑性变形直至整体滑移破坏,决定了锚杆所能承受的离层和抗拔荷载大小。研究结果为岩体离层作用下锚杆的受力分析提供了理论参考。
[Abstract]:Aiming at the whole history analysis of the stress characteristics of anchors under the action of rock mass separation, based on the double exponential curve model of anchoring interface, the nonlinear solution of the stress characteristics of anchors under the action of rock mass separation is established by using the method of load transfer. The axial force distribution and interface shear stress distribution of anchors and the characteristics of axial force curves of anchors in rock mass are analyzed during the whole course of development. The results show that the calculated values of the axial strain of the anchor rod are in good agreement with the measured results, and the axial force of the anchor rod increases first and then decreases during the development of the separated layer. The axial force and interfacial shear stress of the anchor are distributed unevenly and nonlinearly during the later stage of the development of the separation layer, and the axial force and the interfacial shear stress of the rock bolt produced by the separation layer show obvious non-uniform distribution and nonlinear characteristics. And both of them are transferred to both ends with the development of the separated layer. The location of the detached layer has a great influence on the mechanical characteristics of the anchor rod. When the separated layer is located in the center of the anchor rod, the axial force and the interface shear stress of the anchor rod on both sides are symmetrically distributed. The distribution of axial force and interfacial shear stress is obviously different when the separated layer deviates from the center of the anchor, and the interfacial shear stress has a jump point at the location of the separated layer. The anchoring interface on the smaller side of the anchoring length first produces plastic deformation until the whole slip failure, which determines the magnitude of the uplift and uplift load that the anchor can bear. The research results provide a theoretical reference for the analysis of the stress of the anchor rod under the action of rock mass separation.
【作者单位】：湖南大学岩土工程研究所;
【基金】：国家自然科学基金资助项目(51508180) 中国博士后科学基金(2015M570678) 中央高校基本科研业务费~~
【分类号】：TU476

【相似文献】