中文摘要：

采用黏土为边坡介质,土压力盒、位移计、应变片等为测试手段,进行了裸坡与微型桩群加固边坡的离心模型试验,研究微型桩群加固边坡的受力机理。试验结果表明,加桩边坡模型的坡面水平位移远比裸坡模型小,且桩间距越小,坡面水平位移越小。加桩模型中第1排桩桩侧土压力随时间逐渐减小,土压力总体上沿深度方向逐渐增大,第2排桩桩侧土压力时程曲线与第1排桩土压力的时程曲线有一定的相似性;试验开始阶段,坡体产生的土压力第2排桩承担比例较第1排桩大,随着试验的进行,第1排桩承担比例会逐渐增大,试验结束时,桩间距为2.0cm模型中第1排桩与第2排桩的土压力分担比为1∶0.8,桩间距为3.0 cm模型中第1排桩与第2排桩的土压力分担比为1∶0.6,且桩间距越大,第1排桩所承担的土压力越大。桩体上各测点弯矩随时间呈复杂的非线性关系,弯矩数值由正值单调减小为负值,弯矩变化的梯度随时间减小;第1排桩桩身正弯矩最大值出现在9.5 cm附近,负弯矩最大值出现在底部的12.5 cm位置;第2排桩桩身正弯矩最大值出现在7.5 cm附近,负弯矩最大值出现在5.0cm附近;第1、第2两排桩在5.0～10.0 cm深度区间内由于边坡内土体滑动带的影响,造成弯矩变化剧烈。研究结果可为微型桩的设计提供一定的科学依据。

英文摘要：

With clay as the slope medium and soil pressure cell,displacement meter,strain foil as the integrated test facility,a series of model tests of micropiles and slopes were carried out.The control mechanism,soil pressure and bending moment of the micropiles for slope reinforcement were studied.The test results showed that the horizontal displacement of slopes with micropiles reinforced is smaller than that of the bare slope,and the smaller the pile spacing,the smaller the horizontal displacement of slope.In the slope model with micropiles reinforced,pile lateral earth pressure on the leading row micropiles gradually decreases with time,the whole earth pressure increases along the depth direction,pile lateral earth pressure-time curve on the rear row micropiles and the leading row has some similarities.At the beginning of test,the slope earth pressure generated by the rear row of micropiles to bear a large proportion in the leading row of micropiles,with the trial,the leading row micropiles will gradually increase the proportion of soil pressure bearing,at the end of test,the ratio of soil pressure acting on the micropiles,in the model with pile spacing of 2.0 cm,between the leading row and rear row is 1∶0.8,and the ratio is 1∶0.6 in the model with pile spacing of 3.0 cm,the greater the pile spacing,the earth pressure on the leading row micropiles assumed greater.The bending moment on the pile is complicated nonlinear relationship with time,the bending moment value decreases monotonically from positive to negative,the changes in the gradient moment decreases with time;the max positive bending moment on the leading row micropiles is 9.5 cm of piles,the maximum negative moment occurs at the bottom of 12.5 cm position,the max positive bending moment and maximum negative moment on the rear row micropiles occurs at the 7.5 cm,5.0 cm.The bending moment range 5.0~10.0 cm depth creates a rapid change within the soil as the slope of the sliding band.