黄土层螺钉桩承载特性试验研究  

Experimental study on bearing characteristics of screw-pile in loess layer

作　　者：邓友生[1,2] 庄子颖 肇慧玲 魏焕卫 陈茁[1,2] 吴阿龙 董晨辉 DENG Yousheng;ZHUANG Ziying;ZHAO Huiling;WEI Huanwei;CHEN Zhuo;WU Along;DONG Chenhui(College of Architecture and Civil Engineering,Xi’an University of Science and Technology,Xi’an 710054,China;Pile-Supported Structures Research&Test Center,Xi’an University of Science and Technology,Xi’an 710054,China;College of Civil Engineering,Shandong Jianzhu University,Jinan 250101,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]西安科技大学桩承结构研究中心,陕西西安710054 [3]山东建筑大学土木工程学院,山东济南250101

出　　处：《西安科技大学学报》2025年第1期129-137,共9页Journal of Xi’an University of Science and Technology

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

摘　　要：螺钉桩是一种新型可回收预制桩,具有经济、环保的特点。通过在桩侧表面增设螺纹结构,形同锯齿,可以改善传统桩土接触方式,能显著提升极限承载能力。为研究这种桩型的荷载传递机理与承载特性,采用模型试验与有限元分析相结合的方法,对比分析了螺钉桩和等截面桩在加载过程中的竖向承载特性及桩周土体位移特征,探索了螺纹段长度与螺纹间距对承载力的影响规律。结果表明:螺钉桩荷载-沉降曲线呈缓变型变化特征,极限承载力与桩身材料利用率均优于等截面桩;螺钉桩主要通过桩侧摩阻力传递上部荷载,桩侧阻力约为等截面桩的4.57倍,呈现端承摩擦桩的承载特性;螺钉桩桩侧表面独特的锯齿结构可以充分发挥桩周土体协同工作,以调动螺牙槽口内外侧土体间的抗剪力;增加螺纹段长度可以增大桩身侧面与土体间的齿状咬合区域,从而显著提升螺钉桩极限承载力和材料利用率;随着螺纹间距的增大,螺纹内外侧土体沉降差异变小,破坏方式发生变化。当距径比为0.75~1.0时,螺钉桩极限承载力与桩身材料利用率均取得较大值。研究成果可为螺钉桩基础的设计提供依据。Screw pile,a new type of recyclable prefabricated pile,has the characteristics of economical and environmental protection.By adding a screw structure on the surface of the pile side,similar to the form of sawteeth,the traditional pile-soil contact mode can be improved,with its ultimate bearing capacity increased significantly.In order to study the load transfer mechanism and bearing characteristics of this type of pile,model test and finite element analysis were adopted to compare and analyze the vertical bearing characteristic and the displacement characteristics of soil around the pile under the loading of screw pile and equal section pile,thus exploring the influence law of screw length and screw pitch on its bearing capacity.The results demonstrate that the load-settlement curve of screw pile shows the characteristics of slow change,and the ultimate bearing capacity and the utilization rate of pile material are better than those of equal section pile.The screw pile transfers the upper load mainly through the side friction resistance of the pile,and it is about 4.57 times that of the equal section pile,exhibit the bearing characteristics of the end bearing friction pile.The unique zigzag structure on the side surface of screw pile can give full play to the cooperative work of soil around the pile to mobilize the shear resistance between the soil inside and outside the screw notch.Increasing the length of the screw section can enlarge the dentate area between the side of the pile and the soil,thus significantly improving the ultimate bearing capacity and material utilization of the screw pile.With the increase of screw pitch,the difference of soil settlement between the inside and outside of the screw becomes smaller,and its failure mode changes.When the ratio of distance to diameter is 0.75~1.0,the ultimate bearing capacity of screw pile and the utilization rate of pile material are both larger.The research results could provide a basis for the design of screw pile foundation.

关 键 词：螺钉桩 模型试验 数值计算 极限承载力 材料利用率 

分 类 号：TU473.1[建筑科学—结构工程]