高纬度低海拔岛状多年冻土桩基回冻前后承载力的试验研究

发布时间：2018-06-02 01:00

  本文选题：岛状多年冻土 + 桩基础　； 参考：《岩土力学》2015年S2期

【摘要】：冻土与普通的土体相比具有独特的工程性质。在冻土地区进行桩基础施工后,桩和周围土体在冻土地温及大气温度的作用下逐渐回冻,回冻过程中在冰的胶结作用下桩与周围土体联结成整体共同承受外荷载作用。为了研究回冻前后桩基的承载力变化及变形性质,在大兴安岭地区浇筑了2根15 m试验桩,试验桩中布设了温度监测系统,采集了桩基回冻过程中的温度数据。根据温度监测结果在桩基回冻前后进行了自平衡静载试验,研究了回冻前后桩基承载力、各土(岩)层的侧摩阻力及桩端阻力。研究结果表明,桩基回冻后冻土地温保持在-1.9℃桩基的承载力是回冻前承载力的1.42倍;端阻力是回冻前的1.49倍为964 k N,占桩基承载力的12.98%;各土(岩)层的侧摩阻力均有所增长,平均增长率为40.3%。研究结果可为类似冻土条件下的桩基设计及施工提供理论依据。
[Abstract]:Frozen soil has unique engineering properties compared with ordinary soil. After pile foundation construction is carried out in frozen soil area, the pile and surrounding soil are frozen gradually under the action of frozen soil temperature and atmospheric temperature. During the freezing process, the pile is connected with the surrounding soil to bear the external load under the action of ice cementation. In order to study the change of bearing capacity and deformation property of pile foundation before and after refreezing, two 15m test piles were built in Daxing'anling area. The temperature monitoring system was set up in the test pile, and the temperature data of the pile foundation during the freezing process were collected. Based on the temperature monitoring results, the self-equilibrium static load tests were carried out before and after the pile foundation was frozen. The bearing capacity of the pile foundation, the lateral friction of each soil (rock) layer and the pile tip resistance were studied before and after the refreezing. The results show that the bearing capacity of the pile foundation maintained at -1.9 鈩，

本文编号：1966557