微型抗滑群桩受力特性模型试验

Stress Model Test of Anti-Sliding Micropile Groups

通过模型箱试验,对微型抗滑群桩工作受力性状和桩顶连梁的作用进行了分析。分析结果表明:微型桩各排桩最大剪力在滑裂面附近,且从前排向后排依次减小,最大剪力截面位置依次上移。滑坡推力在微型桩上近似呈三角形分布,桩身中下部滑坡推力较大。桩身变形经历了一个整体弯曲到滑裂面附近的局部剪弯的过渡,抗滑合力下移,各排桩承担滑坡推力比例为1.00∶0.64∶0.44。桩顶连梁使极限承载力提高了11%,并且减小了坡体位移和桩身整体弯矩。连梁使前排桩上拔,后排桩下压,且能增大桩前桩间土压力,减小桩前桩身土压力。

The model test was carried out to analyze the stress performance of anti-sliding micropile groups and the function of connecting beam. The results shows that the maximum shearing force of the piles occurs around the slip surface and decreases from the front to the back row with maximum shearing force section moving upwards. Landslide thrust on micropiles is distributed in a approximate triangle shape with a greater thrust in the middle lower pile. The pile body deformation undergoes a transition from an integral bend to a partly shear around slip surface with anti-sloding resultant force lowering. The ratio of sliding thrust undertaken by every row of piles is 1. 00∶ 0. 64∶ 0. 44. The maximum load is enhanced 11%. Slope displament and bending moment of micropiles are reduced via connecting beam. The connecting beam enables the front row of pile pulled out and back row pressed down. Connecting beam also increases the soil pressure between piles in the front and reduces pile body pressure.