摘要
为研究岩质边坡锚固界面的剪切作用,采用相似材料制作拉拔试件,借助多功能力学试验机和静态电阻应变仪,进行了不同锚固长度试件的静态拉拔试验,分析了拉拔荷载作用下锚杆-砂浆和砂浆-岩体两锚固界面上的剪应力分布规律。结果表明:相似材料的物理力学性质能够较好地反映出原型材料的特性,利用岩体、水泥砂浆和锚杆的相似材料制作拉拔试件进行锚固相似模型试验是可行的;不同循环荷载作用下,拉拔试件中的锚杆与锚固体上的轴力随着锚固长度的增加,呈现出指数规律衰减,且体现出了锚杆加固岩土体时具有有效锚固长度的特征;锚杆-砂浆和砂浆-岩体两锚固界面上的剪应力分布不均,沿锚固长度呈现为先增大后减小的单峰值曲线变化规律,从锚杆端部至剪应力峰值点,剪应力值迅速增大,其作用范围较小,但峰值点后剪应力值平缓下降,作用范围相对较大,并且随着拉拔荷载的增大,剪应力峰值逐渐向锚固深部转移;不同锚固长度拉拔试件的锚固失效均发生在砂浆-岩体界面上,同时锚固体界面上经历3个阶段,即弹性变形阶段、塑性变形阶段和脱黏滑移阶段。首次借助相似模型试验获得了岩质边坡锚固界面剪应力分布,揭示了锚固机理,不仅对相关试验,而且对边坡锚固的设计施工具有重要参考价值。
In order to study the shear action of the anchorage interface of rock slope,the pull-out specimens are made of similar materials. With the help of multifunctional mechanical testing machine and static resistance strain gauge,the static pull-out test on the specimens with different anchorage lengths is carried out,and the distribution laws of shear stresses on the anchorage interfaces of bolt-mortar and mortar-rock mass under the action of pull-out load are analyzed. The result show that（ 1） the physical and mechanical properties of similar materials can reflect the characteristics of the prototype materials well,and it is feasible to use the similar materials of rock mass,cement mortar and bolt to make the pull-out specimens for anchorage similar model test;（ 2） under different cyclic loads,the axial force of bolt and anchorage solid in the pull-out specimens show an exponential attenuation with the increase of anchorage length,and it shows the characteristics of effective anchorage length when the bolt reinforces the rock and soil;（ 3） the distributions of shear stresses on the anchorage interfaces of bolt-mortar and mortar-rock mass are not uniform,and show the change laws of the single peak curves along the anchorage length which first increasingand then decreasing,the value of shear stress increases rapidly and its range of action is small from the end of the bolt to the peak point of shear stress,but the value of shear stress after the peak point decreases gently and the range of action is relatively large,and the peak value of shear stress gradually shifts to the depth of anchorage with the increase of pull-out load;（ 4） the anchorage failure of the pull-out specimens with different anchorage lengths occurred at the mortar-rock mass interface,and the anchorage interface has experienced elastic deformation stage,plastic deformation stage,and the debonding slip stage. For the first time,the shear stress distribution on the anchorage interface of rock slope is obtained by similar model tests.The anchoring mechanism is revealed,which is of important reference value not only for the related tests but also for the design and construction of slope anchorage.
作者
姚国强
言志信
龙哲
翟聚云
YAO Guo-qiang;YAN Zhi-xin;LONG Zhe;ZHAI Ju-yun(School of Civil and Traffic Engineering,Henan University of Urban Construction,Pingdingshan Henan 467000,China;School of Civil Engineering and Architecture,Anhui University of Science and Technology,Huainan Anhui 232000,China)
出处
《公路交通科技》
CAS
CSCD
北大核心
2018年第10期34-41,共8页
Journal of Highway and Transportation Research and Development
基金
国家自然科学基金项目(41372307
51478065)
河南省科技攻关项目(162102310390)
关键词
道路工程
剪应力分布
拉拔试验
锚固界面
岩质边坡
锚杆
road engineering
shear stress distribution
pull-out test
anchorage interface
rock slope
bolt
