抗拔螺旋桩叶片与地基相互作用试验研究  

EXPERIMENTAL ANALYSIS ON THE LAMINA-SOILS INTERACTION IN PULLOUT SCREW PILE FOUNDATION

作　　者：董天文[1,2] 梁力[2] 王炜[2] 王明恕[2] 

机构地区：[1]辽宁省交通高等专科学校 [2]东北大学资源与土木工程学院,辽宁沈阳110004

出　　处：《工程力学》2008年第8期150-155,163,共7页Engineering Mechanics

基　　金：沈阳市科技攻关项目(1041023-4-02)

摘　　要：复杂的桩体表面几何形状对螺旋桩的桩土相互作用影响显著,该问题研究有助于揭示抗拔螺旋桩的工作机理。基于深基础承载力理论对螺旋桩基础的抗拔承载性状分析,提出了修正的叶片距宽比参数(叶片间距与叶片净半径的比),通过12次具有3种叶片距宽比的螺旋桩基础抗拔模型试验,实测了加载过程中螺旋桩基础的地基应力,研究了叶片与地基间的荷载传递规律和影响因素。试验表明:叶片距宽比小于5时,各层叶片的应力扩散作用较弱;在叶片距宽比小于3时,叶片与地基的荷载传递可认为是沿着叶片外径发生;叶片距宽比为5时,抗拔螺旋桩基础的桩土相互作用较强,首层叶片上部地基出现滑裂破坏。The pile-soil interaction was observably affected by the geometrically complex shape of screw pile, and the analysis of this problem was helpful to explain its pullout characteristics. On the basis of beating capacity theory of deep foundation, the bearing capacity characteristics of pullout screw pile foundation were investigated, and the modificatory RDD （the ratio of the laminas distance to the net radius of lamina） was proposed. By 12 model pullout tests of screw pile with 3 RDDs, the soil stresses during the pullout process were measured, and the load-transfer mechanism was investigated. The pullout test results show that （1） the stress dispersion in lamina-soils is less for RDD〈5; （2） the load-transfer in lamina-soils occurs along the outer perimeter of laminas for RDD〈3; （3） for RDD=5, the pile-soil interaction of pullout screw pile foundation is significant, and the slide failure may occur at the ground above the first layer lamina.

关 键 词：桩基础 螺旋桩 抗拔试验 地基应力 桩土相互作用 

分 类 号：TU443[建筑科学—岩土工程]