混凝土中锚杆锚固荷载传递特性研究

Characteristic research on the anchorage load transfer of bolt in concrete

混凝土中锚杆的荷载传递特性主要取决于螺纹钢筋-混凝土界面的剪切特性。基于螺纹钢筋-混凝土结构面剪胀及破坏机制,建立了适应于混凝土中锚杆荷载传递模型,求得了塑性破坏条件及弹性条件下锚杆轴力和剪应力的解析解。探讨了锚杆轴力和剪应力随锚固深度变化的分布规律,分析了不同拉拔力、锚杆直径、剪胀角对荷载传递的影响,并提出有关设计建议。深入分析了初始侧压应力对锚固段始端位移及其对锚杆-混凝土界面相对位移的影响,同种条件下,初始侧压应力越高,锚杆承载力越高。所得结果可以为混凝土中的锚杆设计和计算提供一种理论参考,具有一定工程实际意义。

The load transfer characteristics of blot in concrete are mainly decided by the shear behavior of reinforecement-concrete interface.Based on the dilatancy and failure mechanisms of the interface between reinforecement-concrete and surrouding concrete,a new load transfer function suitable for the blot in concrete is set up;analytical solutions for the shear stress and axial force of bolt in concrete are obtained under the conditions of failure and elasticity of the surrounding concrete.The distributions of shear stress and axial force along the bolt length are discussed,which can explain that the diffierent pullout force,the diameter of bolt and dilatancy angle influence the load transfer characteristics of blot in concrete,and some useful suggestions for bolt in concrete design are also proposed.In-depth analysis of the influence of the initial lateral stress for shifting displacement of the anchoring and the relative displacement of the interface between reinforecement-concrete and surrouding concrete,under the same conditions,the higher the initial lateral stress,the blot capacity is higher.The results can provide a theoretical reference for the design and calculation of blot in concrete,and has certain practical significance.