ISSN 1000-3665 CN 11-2202/P

    无连梁双排抗滑桩与单排抗滑桩水平推桩模型试验对比研究

    Comparison Study of Horizontal Push-Pile Model Tests between Non-Beam Double-Row Anti-Slide Piles and Single-Row Anti-Slide Piles

    • 摘要: 在大型滑坡防治工程设计中,采用何种形式的抗滑桩进行支护是一个关键问题。为了研究双排抗滑桩与单排抗滑桩加固边坡的效果,通过大型物理模拟模型开展了无连梁双排桩与单排桩水平推桩的对比试验,并深入分析了坡体破坏模式及桩体受力特性方面的差异。结果表明:坡体破坏时,单排桩在桩间前后出现土拱效应,而双排桩却因为绕流的原因形成了“八”字形裂缝且后排桩还出现了挠曲现象。无论是单排桩还是双排桩,其桩顶位移曲线都展现了压密变形、弹性变形、加速变形和塑性破坏四个阶段特征,在加速变形阶段,后排桩桩顶位移大约是前排桩的2倍,单排桩桩顶位移大约是同桩位前排桩的1.5倍,受到“遮挡效应”的影响,双排桩的抗滑效果比单排桩好15%左右;而桩侧土压力均沿着桩身大致呈三角形—梯形的分布,并且桩后土压力都大于桩前土压力;在桩身弯矩方面,二者均呈现出类似于抛物线的分布趋势,并且在靠近滑面处(滑面之上7 cm)弯矩最大。此外,在水平推力相同的情况下,后排桩的弯矩最大,其次是单排桩,前排桩弯矩最小。由于后排桩的存在使得前排桩的最大弯矩比单排桩降低了27%左右,从而提高了抗滑桩的抗滑效果。研究结果将为滑坡防治工程的设计和治理提供指导。

       

      Abstract: In large-scale landslide control engineering design, the choice of anti-slide pile support form is a crucial issue. In order to investigate the effectiveness of double-row anti-slide piles compared to single-row reinforcement for slopes, this study conducts comparative tests of unconnected double-row piles and single-row piles using a large-scale physical simulation model, and the differences in slope damage modes and pile force characteristics were analyzed in depth. The results indicate that during slope failure, single-row piles exhibit soil arching effects between the piles, while double-row piles form “eight”-shaped cracks due to flow around the piles, with the rear piles experiencing bending. Both single-row and double-row piles exhibit four stages of deformation characteristics in their pile head displacement curves: densification deformation, elastic deformation, accelerated deformation, and plastic failure. In the accelerated deformation stage, the pile head displacement of rear piles is approximately twice that of front piles for double-row piles, and for single-row piles, it is approximately 1.5 times that of the front piles. Due to the "shielding effect", the anti-slide effect of double-row piles is about 15% better than that of single-row piles. The lateral soil pressure along the pile body generally exhibits a triangular-trapezoidal distribution, with the soil pressure behind the pile greater than that in front of the pile. Regarding pile bending moments, both exhibit a distribution trend similar to a parabola, with the maximum moment occurring near the sliding surface (7 cm above it). Additionally, under the same horizontal thrust, the rear pile experiences the maximum bending moment, followed by the single-row pile, while the front pile experiences the minimum bending moment. The presence of rear piles reduces the maximum bending moment of front piles by about 27% compared to single-row piles, thus enhancing the anti-slide effect of the pile. These research findings will provide guidance for the design and treatment of landslide control engineering projects.

       

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