胶结钙质砂与钢界面剪切力学特性的试验研究  

Experimental study on shear mechanical characteristics of cemented calcareous sand and steel surfaces

作　　者：吕海波[1,2] 蒋代苹 柴源 Lü Haibo;JIANG Daiping;CHAI Yuan(Guangxi Key Laboratory of Geotechnical Mechanics and Engineering,Guilin University of Technology,Guilin 541004,Guangxi.China;School of Architecture and Electrical Engineering,Hezhou University,Hezhou 542899,Guangxi.China;School of Civil Engineering and Architecture,Guangxi University.Nanning 530004,Guangxi,China)

机构地区：[1]桂林理工大学广西岩土力学与工程重点实验室,广西桂林541004 [2]贺州学院建筑与电气工程学院,广西贺州542899 [3]广西大学土木建筑工程学院,广西南宁530004

出　　处：《实验力学》2022年第4期497-506,共10页Journal of Experimental Mechanics

基　　金：国家自然科学基金(51169005,41272358);广西自然科学基金重点项目(2018GXNSFDA281038)。

摘　　要：在珊瑚礁上进行桩基工程建设很容易引起钙质砂胶结破坏和颗粒破碎,桩侧摩阻力减小,最终导致桩的承载力降低。为研究胶结钙质砂与结构物界面力学特性,以掺入硅酸盐水泥制备的胶结钙质砂为研究对象,利用室内应变控制式直剪仪,开展了一系列胶结钙质砂与钢界面剪切试验;探究了法向应力、粗糙度对界面强度的影响,并与相同粒径的未胶结钙质砂界面剪切试验结果进行了对比。研究结果表明:法向应力和粗糙度是影响接触面强度的重要因素。随着粗糙度的增大,当胶结钙质砂界面剪切破坏时,先发生界面滑移剪切破坏,继而发生界面附近胶结钙质砂剪切破坏。低法向应力下,胶结钙质砂和未胶结钙质砂界面剪切特性很接近,高法向应力下,两种钙质砂剪切特性差异较大。During the construction of pile foundation projects on coral reefs,it is easy to cause the cementation damage of calcareous sand and particle breakage.Thereby,the side friction resistance of the pile is reduced,which ultimately leads to the reduction of the bearing capacity of the pile.In order to investigate the mechanical characteristics of the interface between cemented calcareous sand and structure,a serious of shear tests on the interface between cemented calcareous sand and steel were carried out with the aid of strain controlled direct shear apparatus in laboratory,taking the cemented calcareous sand mad by Portland cement as research object.The influence of normal stress and roughness on interfacial strength were investigated,and it was further compared with the results of interfacial shear test with un-cemented calcareous sand with the same particle size.The results indicate that:the normal stress and roughness are significant factors affecting the interface strength.With the increasing of roughness,when the interface shear of cemented calcareous sand failure occurs,the shear slip failure of the interface comes out firstly,and then the shear failure appears on the cemented calcareous sand near the interface.At low normal stress,the interfacial shear characteristics of cemented calcareous sand and un-cemented calcareous sand are very similar,but at high normal stress,there is a great difference between them.

关 键 词：胶结钙质砂 界面剪切 界面强度 粗糙度 

分 类 号：TU411[建筑科学—岩土工程]