双排围护桩支护结构排距变化时变形和受力性能的三维非线性模拟计算

3-D Nonlinear Analysis of Deformation and Force of Double-row Retaining Piles with Distance Variation

双排围护桩支护结构与常规深基坑支护结构相比,具有侧向刚度大、水平位移小和不需要加内支撑等优点,而且施工方便,减少投资,具有广阔的应用前景。但是作为一种新型的深基坑支护形式,它在理论研究上尚不成熟,目前尚无统一的设计计算方法。特别地,前后排桩排距是影响双排桩作用性能的关键因素,但是对前后排桩排距改变时,结构的变形和受力变化的研究很少,且均局限在二维分析计算中,对于空间门架式结构的双排围护桩结构存在较大的局陷。本文应用大型有限元程序ADINA,针对影响双排桩工作性能的主要因素———前后排桩排距,设计前后排桩排距在2d,3d,4d,5d,6d,8d(d为前后排桩直径)之间变化,计算了双排围护桩结构的三维位移场和应力场的变化。通过计算得出,在前后排桩排距为4d时,双排桩结构的变形和受力性能最佳,为该种支护结构的优化设计提供了可量化的依据。

The retaining structure of double-row piles with large lateral rigidity doesn＇t increase in the transverse of support to small displacement, doesn＇t need inner sustain characteristics, it also facilitates the construction and investment, with a broad application prospects compared with general support structures. However, the theory researching is not ideal and has no unitive method for designing as a new kind of retaining structure. Especially, the researching is scarcely any in the effects of the distance between front and back row piles on lateral displace- ment and internal force of the retaining structure. Furthermore, the researching all limites in 2-D analysis, so it has limitation of the 3-D structure. Aimed at the first element--the distance between the tow row piles, the paper arranges finite element procedure ADINA analyses the 3-D deformation and 3-D force of the structure while the distance variation in 2d, 3d, 4d, 5d, 6d, 8d （d is the diameter of piles）. From the analysis, it is concluded that when the distance with the tow rows is 4d, the structure＇s deformation and force are optimum.