荷载作用下挤扩支盘桩支护特性数值模拟分析

采用室内试验和数值分析相互验证方法，对单排挤扩桩和悬臂直桩基坑支护的桩顶位移和受力特征进行了研究，进而对基坑双排挤扩桩支护特性进行了分析。试验结果表明，与悬臂直桩相比，挤扩桩支护桩顶位移小，挤扩桩支盘提供的抗倾覆力矩有效地改善了挤扩桩的工作性状；与单排挤扩桩相比，双排挤扩桩基坑支护结构刚度大，在桩身内力分配以及控制基坑变形等方面有较大优势，是深基坑工程中经济合理的支护形式。

Numerical analysis of the squeezed branch piles under loading for protecting foundation excavation

The displacement characteristics in the top of the cantilever piles and the squeezed branch piles, and the axial force and the distribution of bending moment of these single row piles for protecting foundation excavation are analysed by model test and numerical simulation, and that is also studied for the double rows squeezed branch piles. The model test and numerical simulation show that the displacement in top of the squeezed branch pile decreases, the multiple bending moments are distributed more evenly, and the maximum bending moment decreases compared with the cantilever piles. It is concluded that the double rows squeezed branch piles have many siginificant advantages, including displacement, structure stifness, axial force and bending moment compared with the single row ones, and the double rows squeezed branch piles is a reliable and economical method to retain and to protect foundation excavation.