黄土地基阶梯型截面桩承载模型试验与计算  

Model Tests and Calculations on Bearing Capability of Step-type Section Pile in Loess Base

作　　者：邓友生[1] 马二立 马建军[2] 李文杰 张克钦 李龙[1] DENG Yousheng;MA Erli;MA Jianjun;LI Wenjie;ZHANG Keqin;LI Long(School of Architecture and Civil Engineering,Xi′an University of Science and Technology,Xi′an 710054,China;School of Civil Engineering and Architecture,Henan University of Science and Technology,Luoyang 471023,China)

机构地区：[1]西安科技大学建筑与土木工程学院,陕西西安710054 [2]河南科技大学土木建筑学院,河南洛阳471023

出　　处：《河南科技大学学报（自然科学版）》2024年第4期57-63,72,M0006,共9页Journal of Henan University of Science And Technology:Natural Science

基　　金：国家自然科学基金项目(51878554,41672308);陕西省自然科学基础研究计划重点项目(2018JZ5012)。

摘　　要：为研究黄土地基阶梯型截面桩的荷载传递机理,通过室内模型试验与有限元计算,分析阶梯型截面桩竖向静荷载下的桩身轴力、桩侧摩阻力、桩顶沉降和桩身不同深度荷载分担比,并探索了变径比对其工作性能的影响,并对其进行优化设计。结果表明:在相同荷载下,阶梯型截面桩的桩顶沉降明显小于等截面桩,当变径比在0.8~0.9时,沉降控制效果最佳,其材料利用率最高;若二者极限承载力相同时,阶梯型截面桩的最高材料利用率为等截面桩的1.06倍。阶梯型截面桩为摩擦型桩,变截面位置土体对桩体具有支承作用,其变径处底面土体能承担部分桩顶荷载。桩侧能够分担更多桩顶荷载,减轻桩端土体承载,当变径比在0.8~0.9时,侧摩阻力发挥程度更高。在桩体用料相同时,与等截面桩相比,阶梯型截面桩能大幅度提高承载能力。To study the load transfer mechanism of step-type section piles in loess base,the laboratory model tests and finite element calculations were utilized to analyze the axial force,lateral friction resistance,pile top settlement,and load sharing ratio at various depths of step-type section piles under vertical static load.The study explored the impact of the change in diameter ratio on its operational performance and conducted an optimization design.The results indicate that under the same load,the pile top settlement of the step-type section pile is noticeably less than that of the constant section pile.The best control effect on settlement,with the highest material utilization,is achieved when the diameter change ratio is 0.8~0.9.If the ultimate bearing capacities are equal,the highest material utilization rate for the step-type section pile reaches 1.06 times that of the uniform cross-section pile.The step-type section pile acting as a friction pile,receives support from the soil at the variable cross-section.The soil at the base of the variable diameter portion can bear part of the pile top load,while the pile sides can share a greater portion of the pile top load,thus reducing the load on the pile end soil.The lateral friction resistance is more effectively utilized when the diameter change ratio is 0.8~0.9.When the material usage is the same,the step-type section pile significantly increases the bearing capacity compared to the constant section pile.

关 键 词：阶梯型截面桩 等截面桩 变径比 模型试验 有限元分析 

分 类 号：TU473.1[建筑科学—结构工程]