组合荷载下单桩承载特性现场试验  

Field Test Study on Bearing Capacity of Single Pile Under Combined Loads

作　　者：赵春风[1,2] 王卫中[1,2] 赵程[1,2] 邱志雄 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092 [3]广东潮惠高速公路有限公司,广东广州510100

出　　处：《中国公路学报》2013年第6期59-64,72,共7页China Journal of Highway and Transport

基　　金：国家自然科学基金项目(41272295);广东省交通运输厅科技计划项目([2012]1379(2012-01-001));上海市重点学科建设项目(B308)

摘　　要：为了研究单桩在组合荷载作用下的承载特性,设计和加工了现场试验组合荷载加载装置,该装置可方便施加竖向荷载并保证桩顶水平位移不受限制。通过现场试验,研究组合荷载不同加载顺序下单桩的承载力、弯矩以及竖向荷载和水平荷载对单桩承载特性的相互影响。研究结果表明:预先施加水平荷载对单桩的竖向极限承载力影响较小,但相同竖向荷载下,单桩的沉降较大;水平荷载引起单桩上部侧阻力的减小,导致桩顶沉降增加;在水平荷载偏心距较小以及桩身自由段较小时,竖向荷载的预先施加减小了单桩的水平位移,提高了单桩的承载力;竖向荷载越大,桩身最大弯矩越小,竖向荷载有利于单桩水平承载性能的发挥。In order to study the bearing capacity of single pile under combined loads, a loading device which could facilitate the application of vertical load and avoid restraining the horizontal displacement of pile head under combined loads was designed and manufactured for field test. The bearing capacity, bending moment and the effects of vertical load and lateral load on bearing capacity of single pile were analyzed. The results show that the effect of lateral load on ultimate vertical bearing capacity is limited, but the settlement is larger under the same vertical load, and the shaft resistance decreases on the upper pile under lateral load, which causes the decrease of the pile head settlement. The lateral displacement is reduced and the lateral bearing capacity is improved when the vertical load is applied before the lateral one if the length of the pile above the ground surface and the eccentricity distance of the lateral load are small. The maximum moment along the pile decreases with the increase of the vertical load. This indicates that the vertical load improves the lateral bearing capacity of pile.

关 键 词：桥梁工程 单桩 现场试验 承载力 组合荷载 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]