西安黄土地区桥梁桩基侧摩阻力的合理取值

Reasonable Value of Side Friction Resistance of Bridge Pile Foundation in Xi'an Loess Area

结合西安及周边地区铁路高架桥、高速公路、市内立交3个试验区共8根不同几何尺寸试桩的静载荷试验,分析各试桩的承载特性和荷载传递规律,浸水对黄土湿陷性、桩基承载力的影响,以及各试桩极限状态下桩周土体侧摩阻力的发挥情况。结果显示,当黄土密实度为稍密时,建议桩侧阻力取值范围为60~80kPa;当黄土密实度为中密时,建议桩侧阻力取值范围为70~95kPa;当黄土密实度为密实时,建议桩侧阻力取值范围为85~110kPa。

Based on the static load tests of eight test piles of different geometric sizes in three test areas of railway viaduct,expressway and interchange in Xi’an and its surrounding areas,the bearing characteristics and load transfer rules of each test pile were analyzed,as well as the influence of water immersion on the collapsibility of loess and the bearing capacity of pile foundation,and the exertion of lateral friction of soil around the pile under the ultimate state of the test pile.The results show that when the compaction density of loess is slightly low,the recommended value of pile side resistance is 60-80 kPa;when the compaction density of loess is medium,the recommended value is 70-95 kPa;when the compaction density of loess is high,the recommended value is 85-110 kPa.