螺旋桩承载特性受桩体几何结构影响的试验研究  

The Experimental Study on the Bearing Capacity of Steel Screw Piles Owing to the Effects of Geometrical Structures of Piles

作　　者：张新春[1] 韩春雨[1] 白云灿 曹应平 ZHANG Xinchun;HAN Chunyu;BAI Yuncan;CAO Yingping(Department of Mechanical Engineering,North China Electric Power University, Baoding 071003, China)

机构地区：[1]华北电力大学机械工程系

出　　处：《结构工程师》2019年第2期178-183,共6页Structural Engineers

基　　金：国家自然科学基金项目(11402089);河北省自然科学基金项目(A2017502015);中央高校基本科研业务费专项资金资助项目(2017MS153)

摘　　要：由于具有结构简单、快速施工、高承载能力和绿色环保等优点,螺旋桩基础广泛应用于各类特殊岩土工程问题中。除了土质条件和埋置深度,螺旋桩基础的承载特性还受桩体几何尺寸的影响。通过模型加载试验,具体研究了叶片与桩身直径比D/d、叶片数量、叶片形式以及加载方式对螺旋桩基础承载特性的影响。研究结果表明,对于砂土,在埋置深度和叶片数量相同的前提下,叶片与桩身直径比值D/d越大,螺旋桩叶片的端承作用越大;在固定长度内增加叶片数量,分层叶片螺旋桩能够提高承载性能,但当叶片数大于3时,其承载特性的提高趋势减缓,连续型叶片螺旋桩综合承载能力较分层叶片螺旋桩差。此外,在斜向上拔荷载的加载中,当斜向倾斜角为45°时,其桩顶位移较大,并且斜向荷载作用下水平位移始终大于竖直位移。研究将对螺旋桩的结构设计及实际工程应用具备一定的指导意义。Due to the advantages of simple structure,fast construction,high bearing capacity and green environmental protection,the screw pile foundation is widely used in all kinds of special soil conditions.Except the soil conditions and the embedded depth,the bearing capacity of the screw pile foundation also depends upon geometrical size of steel pile.In this paper,the influence of the ratio of helix-to-shaft diameter(D/d),the blade numbers,the blade form and the loading forms on the bearing capacity of screw piles are experimentally investigated by model loading tests.Research results show that for the sand,under the condition that the embedded depth and the blade number are all the same,the end bearing effect of the blades for screw pile improves with the increasing of D/d.When the pile length is fixed,the bearing performance of layered helical blade pile will enhance with increasing the blade number.However,when the blade number is greater than 3,the bearing performance for screw pile is reduced.The bearing capacity of continuous helical blade piles is slightly lower than the layered screw ones.Moreover,under the inclined uplift loads,the pile top displacement is larger than the other conditions when the inclined angle is 45°.And the horizontal displacement of the pile is always greater than the vertical displacement under the inclined uplift loads.These researches will provide some guidance on the structural design and engineering application of the screw pile foundations.

关 键 词：输电线路工程 螺旋桩基础 叶片数量 叶片与桩身直径比(D/d) 承载特性 

分 类 号：TU473.1[建筑科学—结构工程] TM75[建筑科学—土工工程]