预应力锚索桩板墙变形特性研究

为了掌握预应力锚索桩板墙的变形规律,查明其影响变形的参数,通过现场实测与数值计算方法对预应力锚索桩板墙的变形进行了研究。实测结果表明,预应力锚索桩板墙在施工阶段最大变形发生在墙的中部,施工完成后,由于锚索的预应力损失、岩土体蠕变以及车辆荷载的作用等原因,变形最大位置逐渐转移到了墙的上部;计算结果表明,墙后填料强度、墙背粗糙度、桩板的柔度、锚索预应力和位置等都对挡墙的水平位移影响显著。为控制挡墙的最大变形,在填料选择方面,要采用变形模量较大,摩擦角较大的填料进行填筑,填料摩擦角以不能低于20°为宜;在桩板的选择方面,要保证桩板粗糙度较大,桩板柔度较小的桩体,桩板的柔度系数宜控制在0.25～0.5范围内;在锚索预应力的大小与作用点位置选择方面,锚索预应力不宜超过600 kN,单排锚索宜作用在0.2H～0.3H高度位置。

Study on Deformation Behaviors of Prestressed Anchored Sheet Pile Wall

In order to hold the deformation rules and find out the affecting parameters of anchored sheet piles, the study of anchored sheet pile wall deformations was performed with actual measurement and numerical methods. The result of actual measurement shows that the maximum deformations lie in middle part of the wall at the construction stage and after construction, the maximum deformation position gradually shifts to the top of the wall owing to the loss of pre-stress of anchor, the creep of rock and earth and the action of vehicle loads. The computing result shows that horizontal displacement of sheet pile is remarkably affected by the strength of filling material, the roughness of the back of the retaining wall, the flexibility of the pile, the anchor cables pre-stress and the position of the anchor cable. In order to control the maximum deformation of retaining wall, while choosing filling material, the material with larger deformation modulus and friction angle is preferable, which friction angle should not be less than 20°; while choosing pile and board, the larger roughness and the less flexibility coefficient of pile and board is preferable, the flexibility coefficient of pile should be controlled between 0.25 and 0.5; while choosing pre-stress and position of the cable, the former should not larger than 600kN,and the latter had better be controlled between 0.2H and 0.3H.