夯筑土遗址木锚杆四锚系统锚固机制物理模型试验研究  

Physical model test on working mechanisms of an anchor group system with four wood bolts in rammed earthen sites

作　　者：李金峰 张景科[1,2] 王南[1,2] 赵林毅[3] 郭青林[3] LI Jinfeng;ZHANG Jingke;WANG Nan;ZHAO Linyi;GUOQinglin(College of Civil Engineering and Mechanics Lanzhou University,Lanzhou Gansu 730000,China;Key Laboratory of Mechanics on Disaster and Environment in Western China,The Ministry of Education of China,Lanzhou University Lanzhou,Gansu 730000,China;National Research Center for Conservation of Ancient Wall Paintings and Earthen Sites,Dunhuang Academyy Dunhuang,Gansu 736200,China)

机构地区：[1]兰州大学土木工程与力学学院,甘肃兰州730000 [2]兰州大学西部灾害与环境力学教育部重点实验室,甘肃兰州730000 [3]敦煌研究院国家古代壁画与土遗址保护工程技术研究中心,甘肃敦煌736200

出　　处：《岩石力学与工程学报》2019年第11期2321-2331,共11页Chinese Journal of Rock Mechanics and Engineering

基　　金：国家自然科学基金资助项目(51578272)~~

摘　　要：选择夯筑土遗址木锚杆四锚系统为研究对象,构建尺寸为2 m×2 m×0.5 m室内试验模型,运用自主研发的拉拔试验测试系统,获得四锚锚固系统的荷载位移关系与破坏模式。基于三维有限差分数值模拟方法,分析夯筑土体的位移场与应力场、单根锚杆轴应力以及锚杆–浆体界面的应力分布特征。研究结果表明,荷载位移关系前期处于弹性阶段,后期进入塑性阶段。单根锚杆周围土体的破坏半径约为26cm,杆间裂纹相互贯通,群锚系统呈现典型的复合锥形破坏。数值模拟结果表明,所选取的四锚对角线L1、边线L2、中线L3三条测线位移分布特征相同,均呈对称的抛物线分布。四锚锚固系统的受力区集中在试样中部土层。随着荷载增加,锚杆–浆体界面的剪应力向锚杆末端转移,上部界面脱黏破坏。受到夯筑工艺影响,夯筑土遗址群锚破坏模式可能会沿着土层分离。研究结果对夯筑土遗址木锚杆群锚锚固系统设计具有较高的参考价值。A model test of a four-anchor system applied in the earthen site with a size of 2 m×2 m×0.5 m was carried out through a self-developed pull-out system,and the failure mode and load-displacement relationship were studied.Based on the three-dimensional finite difference method,the displacement and stress fields of rammed soil,the axial stress of a single bolt and the stress distribution of the anchor-slurry interface were analyzed.The results show that the load-displacement curve shows elastic first and then plastic.The crack radius of the soil around an anchor is about 26 cm,and the cracks among anchors are connected with each other.The failure mode of the four-anchor anchorage system is a typical composite cone failure.The numerical simulation test reveals that the load-displacement distributions of the three selected measuring lines of the four anchor system including diagonal L1,sideline L2 and center line L3 are all symmetric parabola.The stress area of the four-anchor anchorage system is concentrated in the middle soil layer of the sample.With increasing the load,the shear stress of the boltslurry interface will transfer from the top to the bottom of the bolt,and the upper interface will debond.Under the influence of the ramming construction technology,the anchor group may separate along the soil layer.The research results have high reference value for the design of the anchor group system with wood bolts in earthen sites.

关 键 词：土力学 夯筑土遗址 四锚系统 群锚效应 模型试验 数值模拟 

分 类 号：TU443[建筑科学—岩土工程]