根据界面黏滑本构模型假定和剪切位移法基本原理,推导了土层锚杆拉拔临界松动荷载理论公式和锚杆拉拔荷载与松动长度内在关系表达式。界面黏滑特性致使锚杆剪应力重新分配,引起荷载进一步往里端传递,加剧里端锚固体损伤劣化。依据界面抗剪强度与残余强度之间大小关系将土层锚杆拉拔松动破坏类型划分为渐进式和突发式两种形式,并给出了破坏类型定量判别标准及其所对应的锚杆拉拔极限荷载理论解。最后,结合已有的锚杆拉拔试验资料,通过计算对比分析,验证了方法的可行性。
According to the presumption of the interface stick-slip constitutive model and the fundamental principles of the shear displacement method,a theoretical formula for the critical loose pullout load of soil anchors and an inherent relationship formula between anchor pullout load and loose length are derived.The redistribution of anchor shear stress is caused by stick-slip properties of the interface,and the loading is transmitted to the remote end of anchorage system,which aggravates the deterioration of interior anchor.Based on the size relationship between interface shear strength and residual strength,the failure types of soil anchors can be divided into progressive and bursting ones.The discriminant criterion and the theoretical solution to the ultimate load in accordance with the failure of anchor pullout are proposed.Finally,based on the data of anchor pullout tests,the feasibility of the proposed method is verified through calculation and comparative analysis.