微型桩群框架结构加固边坡离心模型试验研究

Centrifugal Model Test of Slope Reinforced by Micro Pile Group Frame Structure

构建微型桩群框架结构进行土工离心模型试验,通过监测边坡模型位移、土压力和桩身应变,研究微型桩群斜向框架结构加固边坡的受力机理。结果表明:微型桩群框架结构能有效加固边坡;微型桩嵌固深度较深的边坡加固效果优于布桩数量较多的边坡,微型桩嵌固深度是影响加固效果的重要因素;微型桩的布设导致次生滑面、桩土脱空现象的形成,并影响滑体中土压力的分布和大小;桩身弯矩分布呈反S形,桩身在滑面分界处呈单点弯曲屈服,桩-滑床复合结构承受了滑体的下滑力。

The micro pile group frame structure was constructed for geotechnical centrifuge model test.Through monitoring the displacement,soil pressure and pile strain of the slope model,the stress mechanism of slope reinforced by micro pile group inclined frame structure was studied.The results show that the micro pile group frame structure can effectively reinforce the slope.The reinforcement effect of the slope with deeper embedded depth of micro piles is better than that of the slope with more piles,and the embedded depth of micro piles is an important factor affecting the reinforcement effect.The placement of micro piles can lead to the formation of secondary sliding surface and pile soil void,and affect the distribution and magnitude of earth pressure in the sliding mass.The bending moment distribution of the pile shaft is anti S-shaped,and the pile shaft presents single point bending yielding at the boundary of the sliding surface.The pile sliding bed composite structure can bear the sliding force of the sliding body.