竖向力与扭矩共同作用下单桩承载特性试验  

Test of Bearing Characteristics of Single Piles under the Action of Vertical Force and Torque

作　　者：江杰[1,2,3] 王顺苇 欧孝夺[1,2,3] 龙逸航 张探 JIANG Jie;WANG Shun-wei;OU Xiao-duo;LONG Yi-hang;ZHANG Tan(College of Civil Engineering and Architecture,Guangxi University,Nanning 530004,China;Key Laboratory of Disaster Prevention and Structural Safety of Ministry of Education,Guangxi University,Nanning 530004,China;Guangxi Key Laboratory of Disaster Prevention and Engineering Safety,Guangxi University,Nanning 530004,China)

机构地区：[1]广西大学土木建筑工程学院,南宁530004 [2]广西大学,工程防灾与结构安全教育部重点试验室,南宁530004 [3]广西大学,广西防灾减灾与工程安全重点试验室,南宁530004

出　　处：《科学技术与工程》2021年第6期2433-2438,共6页Science Technology and Engineering

基　　金：国家自然科学基金(52068004,51978179);广西自然科学基金(2018JJA160134);广西重点研发计划项目(桂科AB19245018)。

摘　　要：为研究竖向力(V)和扭矩(T)共同作用下单桩的承载特性及内力分布规律,通过自主设计的试验装置,进行了一系列的竖向力和扭矩组合加载试验。为方便推广应用,对试验结果进行拟合,得到了竖向力和扭矩共同作用下单桩承载力计算公式。研究表明:在V-T组合荷载的作用下,单桩的承载力较单一荷载作用下降低,且当先施加的荷载(V或T)大于其极限值的1/3时V-T组合效应更加明显;V→T加载路径下的桩身扭矩和T→V加载路径下的桩身轴力,均随着桩深的增加而减小,且减小的速度加快;V→T加载路径下的桩身轴力和T→V加载路径下的桩身扭矩,分别会随着T和V的增加而减小,但减小的幅度较小;V→T加载路径下的单桩承载力较T→V加载路径下要高,因此应尽量避免单桩预先受到扭矩作用,防止因形成T→V加载模式而造成单桩的极限承载力的降低。To study the bearing characteristics and internal force distribution of single piles under the combined action of vertical load(V)and torque(T),a series of tests with combined load of the vertical force and the torque were carried out by means of the test device which has been designed independently.In order to facilitate the popularization and application of this research,a formula for calculating the bearing capacity of single piles under the combined action of the vertical force and the torque was obtained through fitting the test results.Results show that:Under the action of combined V-T load,the bearing capacity of single piles is reduced compared with that under a single load,and the combined V-T effect is more significant when the load which is applied earlier(V or T)greater than 1/3 of the limit value;The pile body torque under the V→T loading path and the pile shaft force under the T→V loading path both decrease with the increase of the depth or a higher rate of decreasing.The axial force of the pile shaft under the loading path of V→T and the torque of the pile shaft under the loading path of T→V will decrease with the increase of T and V,respectively,while the amount of decrease is minor.The bearing capacity of a single pile under the load path of V→T is higher than that under the load path of T→V.Therefore,it should be ensured that the single piles is not subjected to a torque in advance so as to prevent against a drop in the ultimate bearing capacity of a single pile,which is caused by formation of the loading mode of T→V.

关 键 词：单桩 承载特性 桩身内力 模型试验 V-T组合荷载 

分 类 号：TU473.11[建筑科学—结构工程]