黄土-螺纹桩接触面直剪试验  

Direct Shear Test of Loess Threaded-Pile Contact Surface

作　　者：康卿瑜 吕擎峰[1] 杲斐 续晓花 李钰 Kang Qingyu;LüQingfeng;Gao Fei;Xu Xiaohua;Li Yu(College of Civil Engineering and Mechanics,Lanzhou University,Lanzhou 730000,P.R.China;College of Civil Engineering,Tianshui Normal University,Tianshui,Gansu 741000,P.R.China;China Railway Bureau Croup Co.Ltd.,Lanzhou P.R.China)

机构地区：[1]兰州大学土木工程与力学学院,兰州730000 [2]天水师范学院土木工程学院,甘肃天水741000 [3]中铁二十一局集团有限公司,兰州730070

出　　处：《地下空间与工程学报》2025年第2期533-539,共7页Chinese Journal of Underground Space and Engineering

基　　金：甘肃省科技重大专项(19ZD2FA001);中国铁建科技研发计划项目(2019-B08);甘肃省自然科学基金(22JR5RA805);甘肃省建设科技项目(JK21-47)。

摘　　要：螺纹桩构造复杂,对其受力分析一直是研究难点。本文基于3D打印技术制作螺纹桩接触面,通过直剪试验,对黄土-螺纹桩接触面摩擦特性进行了研究。分析了接触面的剪应力应变曲线、剪切刚度、内摩擦角及黏聚力,讨论了干密度、含水率和螺距对接触面摩擦特性的影响。结果表明:黄土-螺纹桩接触面在剪切试验过程中经历了非线性弹性变形、塑性破坏和剪切滑移;当干密度减小、含水率增大、法向应力增大时,应力应变曲线非线性弹性变形特征加剧,应变软化潜力降低;接触面切向刚度与干密度呈正相关,与含水率呈负相关;接触面黏聚力主要受干密度和含水率的影响,而螺距对接触面内摩擦角的影响较大;基于摩擦特性,建议螺纹桩最佳螺距和桩径相同。The structure of screw threaded pile is complex,and its force analysis has always been a difficult research point.To study the friction characteristics of the loess-threaded contact surface,In this paper,3D printing technology is used to make threaded contact surfaces,and combined with direct shear test.This research analyzed shear stress-strain curves,shear stiffness,internal friction angle,and cohesion of the contact surface,and the influences of dry density,water content,and screw thread pitch changes on the friction characteristic were also discussed.The research revealed the loess-screw thread contact surface experienced nonlinear elastic deformation,plastic failure,and shear slippage during the shear test process.When the dry density decreases,water content increases,and normal stress increases,the nonlinear elastic deformation characteristic of the stressstrain curve intensifies,and the potential of strain softening reduces.The tangential stiffness of the contact surface is positively correlated with dry density and negatively correlated with water content.The cohesion of the contact surface is mainly affected by dry density and water content,while the screw thread pitch has a significant impact on the internal friction angle of the contact surface.Based on the friction characteristics,it is recommended that the optimal screw thread pitch and pile diameter of screw threaded pile be the same.

关 键 词：螺纹桩接触面 摩擦特性 切向刚度 内摩擦角 黏聚力 螺距 

分 类 号：TU473[建筑科学—结构工程]