黄土地基中抗拔桩与抗压桩对比试验研究

通过对4根相同桩长、桩径、位于同一场地的灌注桩在竖向的拔力和压力作用下的对比试验,研究分析黄土地基中的抗拔桩和抗压桩的承载能力和位移特性,并对抗拔桩桩周地表的变形进行分析。结果表明,在相同的桩顶荷载作用下,抗拔桩桩顶上拔量大于抗压桩桩顶沉降量,当抗拔桩的上拔荷载大于1 100 kN后,侧阻力迅速退化。随着荷载的增加,抗拔桩上部侧摩阻力变化较小,而在桩身下部,侧阻增长较快。抗拔桩在2 900 kN的上拔荷载下,在距试桩中心3.667倍桩径处,地表仍有0.2 mm的隆起变形。

COMPARATIVE TEST RESEARCH ON UPLIFT PILE AND COMPRESSIVE PILE IN LOESS GROUND

Based on the vertical-compressive load and uplift load test of four bored piles with same diameter and length in the same ground,the bearing capacity and displacement behavior of uplift piles and compressive piles in loess ground were discussed.The results indicated that the displacement of the uplift piles was large than that of the compressive piles.The lateral friction was weakened rapidly when the uplift load was large than 1 100 kN.The lateral friction on the upside of compressie pile rarely changed while that of the lower part increased rapidly.There was still deformation of 0.2 mm on the ground at the place 3.667 times pile’s diameter away from the pile axis when the uplift load reached 2 900 kN.