摘要
螺杆桩技术已经在多种类型工程中得到了应用,然而由于认识条件的局限和研究对象的复杂,其理论分析仍然落后于工程实践.采用基于离散单元法的颗粒流程序,建立了竖向受荷螺杆桩的数值分析模型,并利用已有试验结果对模型细观参数进行了标定,在此基础上分析了螺距、螺纹段长度和桩径等设计参数对螺杆桩承载特性的影响.研究结果表明:随着螺距的增加,螺杆桩极限承载力呈先增加后减小的发展特征,螺距为(1.0-1.33)D时,螺杆桩具有最佳的承载表现,不同螺距螺杆桩的螺纹段荷载分担比例最高而直杆段最小.螺杆桩极限承载力随着螺纹段长度的增加先线性增长,而后基本保持不变,建议合理的螺纹段长度一般不超过2/3L.桩径增加时,螺杆桩极限承载力呈近似线性快速增长.数值模拟结果可以为螺杆桩设计参数优化和承载力估算方法确定提供理论依据.
Half screw pile technique has been applied in many kinds of projects.However,due to the limitations of cognitive conditions and the complexity of research objects,the theoretical analysis is still lagging behind the engineering practice.The particle flow code based on discrete element method was used to establish the numeri-cal analysis models of vertically loaded half screw piles,the microscopic parameters of the models were verified by the existing experimental results.On this basis,the effects of the design parameters such as screw spacing,length of the threaded section and external diameter on the bearing characteristics of the half screw piles were analyzed.The research results show that the ultimate bearing capacity of the half screw pile reaches maximum and then decreases with the increase of screw spacing,the half screw pile has the best bearing performance where the screw spacing is(1.0-1.33)D,the load sharing ratio of the threaded section is the highest,while the straight section is the lowest.The ultimate bearing capacity of the half screw pile increases linearly with the increase of the length of the threaded section,and then basically remains unchanged,and it is suggested that the reasonable length of the threaded section is generally not more than 2/3 L.With the increase of external diameter,the ultimate bearing capacity of the half screw pile is approximately linear and increasing rapidly.The numerical simulation results can provide some theoretical references for optimizing the design parameters and establishing the bearing capacity estimation method of the half screw pile.
作者
陈亚东
于艳
孙华圣
王安汀
蔡江东
胡志军
CHEN Yadong;YU Yan;SUN Huasheng;WANG Anting;CAI Jiangdong;HU Zhijun(Faculty of Architecture and Civil Engineering,Huaiyin Institute of Technology,Huai′an 223001,China;Jiangsu Huaian Architecture Design Institute Co.Ltd.,Huaian 223300,China;College of Transportation Science&Engineering,Nanjing Tech University,Nanjing 210009,China)
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2018年第A01期20-24,共5页
Journal of Hunan University:Natural Sciences
基金
国家自然科学基金资助项目(51408254
51708245)
江苏省自然科学基金青年项目(BK20160426)~~
关键词
螺杆桩
离散元数值模拟
设计参数
承载力
half screw pile
discrete element numerical simulation
design parameter
bearing capacity
