土钉瞬态应力动力特性对比研究

Contrast research on dynamic behavior of transient stresses in soil nails

基于探索性的洞室土钉支护试验,概述了洞室土钉支护抗动载试验的基本情况,并给出了洞室拱顶土钉的测试数据。依照实验现象,考察对比了毛洞段与土钉支护构措段的瞬态应变和炸药药量的关系,及其两者的瞬态应变和加载次数的关系,构措段具有较好的降低应变的能力。依照一维粘弹性理论对拱顶土钉进行了Maxwell模型的参数拟合;并用此模型确定了土钉用建筑钢的动力粘性因数,其与前拟合公式者相近。

This study is based on tentative experiment on soil nail support in caverns. The general situ- ation of the field test on dynamic resisting force of the loess cavern is introduced,and the test results of the soil nails on the top of the arch are given. The naked part of the cavern is contrasted with the part that has the soil nail support together with the extended hole in terms of the relationship between. the transient strain and the TNT quantity. The relationship between the transient strain and the load- ing time is also contrasted. The cavern that has the soil nail support together with the extended hole has the best ability of reducing the strain and bearing the deformation. The one-dimensional viscoelas- tic Maxwell model is used in data fitting. The model is also used to determine the factdt of dynamic viscoelasticity of the steel bar,and the obtained factor is close to that used in the fitting formula.