多次分段注浆钢花管单桩抗滑性能模型试验研究

采用现场原型试验，从滑坡推力、桩身土压力、桩身弯矩等方面研究了多次分段注浆钢花管单桩的抗滑性能，分析了多次分段注浆钢花管注浆效果和破坏模式。试验结果表明：采用多次分段控制注浆技术，钢花管周边形成“树根状”水泥柱复合抗滑体，这种结构可以有效提高桩周土体抗剪强度，有效地增强了钢花管单桩结构的抗滑性能。6.0 m桩长的多次分段注浆钢花管，与常规钢花管相比，单桩水平抗滑力提高了35 kN，其水平承载力相比常规钢花管提高约50.72%，更好地阻止了滑坡的产生，钢花管在滑坡推力作用下发生弯曲破坏，最大弯矩值出现在滑面附近，因此，建议在结构设计中加强滑面附近的桩体配筋设计，以增强滑面附近的抗弯破坏能力，从而达到更好的抗滑效果。

Model test study on anti-sliding performance of multiple segment grouting steel-tube

Based on field prototype tests, the anti-sliding performance of single pile with steel-tube grouted for multiple times is studied. The steel-tube is analyzed in aspects of landslide thrust, soil pressure and bending moment of pile body, and the grouting effect and failure mode. The test results show that the root shaped anti-sliding bodies composited by cement column are formed by multiple sectional control grouting technology. This structure can effectively improve the shear strength of the soil around the pile, and enhance the anti-sliding performance of the steel-tube single pile structure effectively. Compared with the conventional steel pipe, the horizontal anti-sliding force of single pile is increased by 35 kN, and the horizontal bearing capacity is increased by about 50.72% compared with the conventional steel-tube, and better prevents landslide. The bending failure of the steel-tube occurs under the action of landslide thrust, and the maximum bending moment appears near the slip surface. It is suggested that the reinforcement ratio of the piles near the sliding surface should be properly enhanced to improve the anti-sliding ability.