The past study of single-anchored anchorage did not consider the important influence of the inherent mechanical properties of the anchored geo-material on the anchorage effect,and even did not attempt to optimize the designed parameters in anchorage engineering. Based on the dual-strength frictional properties of the soil' adhesion and internal friction,the self-supporting mechanism of soil anchoring structure was investigated according to the compositional characteristics of the total shear displacement of the mortar anchor and the residual bearing zone in soil. By using the shear stress exponential distribution of the interface and elastic theory and taking into account the internal friction of the soil in the residual load-bearing zone under debonding conditions,a formula was established for calculating the nonlinear shear stress at the boundary between the residual load bearing zone and the main load-bearing zone. Based on the conditions of static balance,the formula for calculating the lower limit of the anchorage section length of an anchor was proposed. It demonstrated by a an case study that in the interface of theresidual load-bearing zone,the maximum value of the shear stress considering the friction coefficient in the anchored soil was reduced by 13. 9% as compared with the one without considering the friction coefficient,and the obtained length of the anchorage section of the anchor rod could be reduced by 12. 5%. The frictional characteristics of the anchored soil can provide useful reference for the anchorage stability,the improvement of ultimate anchorage capacity and the reduction of construction works and cost.%单锚锚固的研究均未考虑受锚土体材料固有力学属性对锚固效果的重要影响,甚至也没有对工程锚固参数进行优化设计.依据土体粘结力和内摩擦力的双强度摩擦属性,从砂浆锚固体与残余承载区土体总剪切位移的构成特点出发,分析土锚结构的自承作用,运用界面的剪应力指数分布和弹性理论知识,考虑脱粘条件下残余承载区土体的内摩擦性,建立了残余承载区与主承载区边界非线性剪应力的计算式;通过静力平衡条件,建立了锚杆锚固段长度下限值的计算式.结合算例分析表明:在残余承载区界面,考虑土体内摩擦特性剪应力最大值比未考虑土体内摩擦特性剪应力最大值减少13.9%,同时锚杆锚固段设计长度减少12.5%.锚固土体内摩擦特性能对锚固工程稳定性、提高极限锚固力、减少工程量和降低成本提供有益参考.
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