摘要
采用颗粒流数值仿真技术,从细观力学角度对砂土中竖向受荷现浇混凝土薄壁管桩(简称PCC桩)与土相互作用过程中的传力机理、桩内外侧土体位移场分布特征及细观结构参数变化规律进行研究。结果表明:PCC桩侧阻力及端阻力在加载初期同步发挥,桩外侧摩阻力始终明显高于桩内侧,桩芯土体承载力发挥不充分,PCC桩承载力主要由桩外侧摩阻力控制;桩外侧摩阻力在桩身中部及靠近端部发挥较为充分,在0.65 L入土深度处外侧摩阻力明显弱化;桩内侧土体在桩身上段范围内位移矢量较小,桩端以上3 d1范围内土颗粒由于土塞效应的存在随桩身一起发生刺入变形,桩外侧土体在桩身中部位移影响范围达到2 d,整个桩外侧位移影响区呈弧形分布;桩周土体接触力链及孔隙率变化与PCC桩宏观力学表现保持一致。研究成果对于进一步明确PCC桩与土相互作用的内在机理具有意义。
In order to further reveal the mesoscopic interaction mechanism of a cast-in-situ concrete thin-wall pipe pile, the load transfer mechanism, the inside and outside soil displacement field distribution character, and the mesoscopic structure parameters change rule in PCC pile-soil interaction process, are studied by the two- dimensional particle flow numerical simulation technology. The results of numerical analysis show that the bearing capacity of a PCC pile is mainly controlled by the outer friction resistance, that the out friction re- sistance of a PCC pile has always been significantly higher than the inner friction resistance, and that the inner soil bearing capacity is insufficient. The outer friction resistance of a PCC pile plays more fully at the central region and pile tip, but it is weakened obviously at the 0.65L penetration depth. The soil displacement vector inside a PCC pile is lesser at pile upside scope; the soil particles in the range above 3d, pile tip happens stab deformation together with pile body because of the soil plug effect ; the outside soil displacement vector of pile body in central influence scope reaches 2d; the entire pile outside displacement affected zone presents a circu- lar arc distribution; and contact force and porosity variations of soil inner and outer pile are consistent withPCC pile macro mechanical performance. The results are important for further clarification of PCC pile - soil interactions.
出处
《河南理工大学学报（自然科学版）》
CAS
北大核心
2015年第3期406-410,共5页
Journal of Henan Polytechnic University（Natural Science）
基金
国家自然科学基金资助项目(51408254)
江苏省自然科学青年基金资助项目(BK20130419)
关键词
管桩
颗粒流
桩侧摩阻力
土塞效应
pipe pile
particle flow code
pile friction resistance
soil plug effect
作者简介
陈亚东（1981-），男，江苏滨海人，博士，副教授，主要从事土与结构相互作用方面的研究与教学工作。E-mail：chenyundons2004@163．com
