考虑孔壁界面滑移-软化的预应力锚索锚固段侧阻力分布

较多理论分析得到锚索锚固段侧阻力的沿程分布呈下凹衰减曲线,与工程实际的单峰曲线差异很大,缘其全程粘结、共同变形假设不甚合理。作者采用简便的荷载传递法,分析了全程粘结所满足的变位协调条件,导出了滑移临界荷载判别式。分析认为,由于孔壁界面滑移的软化效应,侧阻力曲线始端变为上升曲线。因此侧阻力曲线由两部分组成:侧阻力峰值之前部分为始端滑移段,呈上升曲线;而侧阻力峰值之后的部分为粘结段,呈下凹衰减曲线。在锚固的理论分析中,应对界面滑移及软化因素对侧阻力分布的影响予以足够重视。

Lateral shear distribution along anchorage length in anchoring cables considering slippage and softening affect of grout-rock interface

Gained from some academic analysis and many practical projects,there is a distinct difference between lateral shear distribution curves along anchorage length of anchoring cables in theory and in practice.Academic curve is a negative exponential line,whereas practical curve is a single-peak line.The difference results in the hypothesis of thorough gluing bond and deforming together in academic analysis which is not rational to an extent.Based on the load transfer method,the deformation compatibility condition for the gluing hypothesis is discussed,and the load expression for distinguishing gluing or slipping is obtained.Taking account of the strength softening effect of slippage,the beginning section of lateral shear curve is an ascending curve.The lateral shear curve along anchorage length is made up of two parts.Preceding the shear peak point,there is a slippage section presenting an ascending lateral shear curve;after the peak point,there is a gluing segment which presents a sunken shear curve.In academic analysis of lateral shear distribution in anchoring systems,the slippage and its softening effect ought to be taken account.