带帽管桩联合袋装砂井复合地基力学特性研究  

Study on Mechanical Properties of Composite Foundation of Capped Piles Combined with Sand Bag Well

作　　者：吴永立 尹建兵 WU Yongli;YIN Jianbing(China Communications Construction Co.,Ltd.,Nanjing 210000,China;CCCC Third Harbor Engineering Co.,Ltd.,Shanghai 200032,China)

机构地区：[1]中国交通建设股份有限公司,南京210000 [2]中交第三航务工程局有限公司,上海200032

出　　处：《路基工程》2021年第3期70-75,共6页Subgrade Engineering

基　　金：广东省交通运输厅科技项目(科技-2015-02-015)。

摘　　要：基于有限元方法建立带帽管桩联合袋装砂井复合地基模型,对比分析了桩土应力比、刺入量、桩身轴力、桩侧摩阻力的变化规律。研究结果表明:桩土应力比随桩间距增加先减小后增大,桩土应力比与桩帽直径、垫层模量、垫层厚度呈正相关,其增加速度会随垫层模量大于120 MPa或垫层厚度大于30cm后变缓;刺入量、桩侧摩阻力均与桩顶荷载呈正相关,袋装砂井在荷载小于100 kPa时能有效增加桩侧摩阻力;桩身轴力会随桩间距、垫层模量、桩帽直径增加先增大后减小,轴力在19 m左右会趋近相等;使用桩帽能增加桩土应力比、下刺入量和桩侧摩阻力。Finite element analysis was based on to establish the model of composite foundation of capped piles combined with sand bag well herein,and then to analyze by comparison the change law of pile-soil stress ratio,penetration,axial force of pile body and friction of pile side.The result shows that,the pile-soil stress ratio first decreases and then increases with the increase of pile spacing,and it positively correlated with the diameter of pile cap,the cushion modulus and the thickness,when the cushion modulus is greater than 120 MPa or the cushion thickness is greater than 30 cm,its increment slows down;both the amount of penetration and the friction of pile side are positively correlated with the load on the pile top and,when the load is less than 100 kPa,the sand bag well may increase the side friction effectively;the axial force of pile body first increases and then decreases with the increase of pile spacing,cushion modulus and pile cap diameter,and it tends to be the same at about 19 m;the use of pile cap may increase pile-soil stress ratio,downward penetration and friction of pile side.

关 键 词：复合地基 带帽管桩 袋装砂井 有限元分析 桩土应力比 

分 类 号：TU473[建筑科学—结构工程]