微型组合抗滑桩距径比的模型试验

Model research on the distance-to-diameter ratio of the micro-piles composite structure

针对碎石土滑坡沿基岩顶面滑移的问题,在平行布置3排微型组合抗滑桩进行加固的条件下,通过开展微型组合抗滑桩的模型试验和有限元分析,研究微型组合抗滑桩在不同距径比条件下土拱效应的形成特点与承载机理,在此基础上得出了最佳的距径比。结果显示,微型组合抗滑桩在一定的荷载作用下,首先沿受力方向第1排桩间形成土拱效应,然后随距径比的增加,依次在第2排、第3排桩上形成土拱效应,并且前排桩的荷载分担比明显大于后排桩的荷载分担比;当距径比小于3和大于11时,没有明显的或者不存在土拱效应,距径比为7和8时土拱效应最为理想。

Aimed at solving the problem of gravel soft landslide slip along the bedrock surface, the authors studied the formation of the soil arching effect and the load-beating mechanism under the condition of parallel arrangement of three rows of micro combined anti-slide pile reinforcement and according to the model test and finite element analysis. The result reveals the optimum distance-to-diameter ratio. As the result shows,in a certain load, the soil arching effect is first formed at the first row of micro-piles, and then with the increase of distance-to-diameter ratio, the soil arching effect is gradually formed at the second and third row; furthermore, load sharing ratio in the front row is significantly greater than that of the rear one. Soil arching effect is inconspicuous or non-existent when the distance-to-diameter ratio is less than 3 or greater than 11. The most ideal distance-to-diameter ratio is 7 and 8.