锚固段侧阻力分布的一维滑移-软化半数值分析  

ONE-DIMENSIONAL SEMI-NUMERICAL ANALYSIS OF LATERAL SHEAR DISTRIBUTION OF ANCHORAGE SEGMENT CONSIDERING SLIPPING AND SOFTENING EFFECTS

作　　者：蒋良潍[1] 黄润秋[1] 蒋忠信[2] 

机构地区：[1]成都理工大学环境与土木工程学院,四川成都610059 [2]铁道第二勘察设计院,四川成都610031

出　　处：《岩石力学与工程学报》2006年第11期2187-2193,共7页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金"西部生态与环境"重大研究计划项目(90102002)

摘　　要：工程实际表明,预应力锚索(拉力型)锚固段侧阻力的沿程分布多呈单峰上凸曲线,而较多解析推导及半数值分析采用锚固体与孔壁界面的严格全程黏结假设,其计算结果难以解释这一现象。对此,以岩土介质的半无限弹性体假设为基础建立一维力学模型,利用半无限体Mindlin问题的位移解析解,以半数值法求得岩土体与锚固体的孔壁界面位移差值。通过引入侧阻力与位移差值的滑移-软化模型关系,对锚索锚固段的侧阻力分布进行半数值求解探索和算例讨论。相对于锚固段严格全程黏结假设,考虑孔壁界面侧阻力滑移-软化特性更符合实际情况,在张拉力作用下,锚固段始端一定范围的滑移使该区段侧阻力降低,应力向深处转移调整,从而形成侧阻力分布的单峰曲线。In most practical prestressed anchoring engineering, it is indicated that the distribution of lateral shear along anchorage length presents unimodal curve on the mortar-rock interface. The hypothetic model of thorough gluing bond along anchorage length is adopted in former theoretic analysis; and their results are not accordance with the practice. Slippage on the interface ought to be taken into account. Based on Mindlin＇s displacement solution of elastic semi-infinite body, one-dimensional mechanical model is established respectively for the semi-numerical calculation of the displacement of surrounding rock mass and axial displacement of grouting mortar. Slippage can be calculated by the difference of above displacements on the interface. By introducing the strength softening effect of the relationship between shear stress and slippage on the interface, semi-numerical calculation method of lateral shear distribution is put forward and further discussed. Compared with former models of thorough gluing bond, the slipping and strength softening effect model is more corresponding with practical projects. If slippage occurs in beginning anchorage segment after stretching force applied, lateral shear is reduced; and the stress redistribution forms a unimodal curve of lateral shear distribution.

关 键 词：岩土力学 锚固段 侧阻力分布 单峰曲线 弹性半无限体 孔壁界面 滑移-软化效应 

分 类 号：TU45[建筑科学—岩土工程]