土工基础

›› 2019, Vol. 33 ›› Issue (3): 255-257.

• 工程实录 • 上一篇    下一篇

含漂石卵石地层中螺杆桩成桩工艺及效果分析

樊军让1,李 辉1,李 燚2   

  1. （1.陕西圆极岩土科技发展有限公司，陕西宝鸡 721000；2.西安建筑科技大学土木工程学院，西安 710055）
  • 收稿日期:2018-08-06 修回日期:2018-08-28 出版日期:2019-06-20 发布日期:2019-08-16
  • 作者简介:樊军让（1965-），男，工程师，研究方向为岩土工程。

Auger Cast Pile Installation in Gravelly Soils with Boulders

FAN Junrang1, LI Hui1, LI Yi2   

  1. (1.Shaanxi Yuanji Geotechnical Technology Co., Ltd., Baoji 721000;
    2.School of Civil Engineering, Xian University of Architecture and Technology, Xi'an 710055)
  • Received:2018-08-06 Revised:2018-08-28 Online:2019-06-20 Published:2019-08-16

摘要： 在含有漂石的卵石地层中进行灌注桩施工时，穿透坚硬的漂石和卵石地层以及保持孔壁稳定是成桩的关键。针对这种情况，在螺杆桩施工工艺的基础上，采用能穿透漂石的专用钻头和外挂浅螺纹螺杆桩技术，并经过二次成孔，使大部分卵石、碎石挤入桩周围土体，解决了含漂石的卵石地层中灌注桩成桩难题。桩身完整性和单桩静载荷试验表明，桩身完整且质量稳定，经过挤密作用，改善了桩身与桩周土界面性能，提高了桩侧摩阻力和单桩承载力，单桩承载性状大为改善。

关键词: 卵石地层, 螺杆桩, 挤密效应, 二次成孔

Abstract: The techniques that can penetrate the gravelly soil with large size boulders and maintain the stabilities of bore holes are key factors for the success of the castinplace reinforced concrete pile installation. This paper presents a new allflight auger drilling method with special drill bit and a shallow displacement auger. With the secondary drilling, the majority of the boulder and large size gravel soils can be pushed into the adjacent soils so that the displacement type of the cast-in-place reinforced concrete piles can be successfully formed. The concrete pile integrity and static loading test indicated that the concrete pile installed with the new method had good installation quality. Due to the compaction effect, higher axial pile capacity can be obtained.

Key words: Rounded Gravel Soils, Auger Cast Piles, Compaction Effect, Secondary Drilling