压力分散型锚索非均匀剪应力设计方法

目前的研究已经认识到预应力锚索（杆）锚固段剪应力沿长度分布并不是均匀的，非均匀剪应力设计方法是预应力锚索设计的发展方向，但设计中仍采用均匀剪应力的设计方法，其原因在于没有建立起广泛认可的剪应力分布模式和计算方法。压力分散型锚索承载力高，锚固段剪应力分布更为集中，采用非均匀剪应力设计方法对于压力分散型锚索进行设计的必要性更为显著。根据3组室内足尺模型试验测得的锚固段剪应力分布规律，采用数值计算方法进行多因素影响计算，分析了压力分散型锚索锚固段注浆体与围岩界面剪应力分布特征，总结出2种分布模式，并确定了分布模式曲线的关键参数。根据所提出的2种分布模式进行公式推导，建立了压力分散型锚索非均匀剪应力设计方法，采用该方法计算得到的结果可以很好的与数值计算及模型试验结果相吻合。

Non-uniform shear stress design method for pressure-dispersive anchors

The existing studies indicate that the shear stress between grout body and rock mass along the anchoring segment of a prestressed anchor is not uniform.The non-uniform shear stress design method is one of the development trends for prestressed anchor design,but the current design methods still treat the shear stress as uniform one.The reason lies in that widely recognized shear stress distribution pattern and formula have not been established.However,the bearing capacity of pressure-dispersive anchors is much higher than that of the tension ones,which means that the shear stress between grout body and rock mass in anchoring segment is more concentrated.So the non-uniform shear stress design method is more necessary to pressure-dispersive anchor.Three indoor full size simulating experiments are undertaken to get the shear stress,and multi-factor numerical simulations are done to discover distribution characters of the shear stress.Two distribution patterns are drawn from the indoor tests and calculations,and key parameters of the shear stress distribution curves are confirmed through the numerical calculations.Equation derivations are done based on the two distribution patterns,and a non-uniform shear stress design method of pressure-dispersive anchor is finally established.It is proved that the proposed method agrees with the indoor experiments and numerical simulations.