›› 2018, Vol. 32 ›› Issue (5): 466-469.

• 工程实录 • 上一篇    下一篇

成都卵石地层抗浮锚杆施工工艺及拉拔试验研究

唐延贵,岳大昌,李 明,闫北京   

  1. (成都四海岩土工程有限公司,成都 610094)
  • 收稿日期:2017-10-25 修回日期:2017-11-09 出版日期:2018-10-30 发布日期:2018-11-02
  • 作者简介:唐延贵(1987-),男,工程师,研究方向为岩土工程勘察、地基处理及基坑支护设计。

Pullout Tests and Construction Technique of Buoyancy Anchor in Rounded Gravels in Chengdu

TANG Yangui, YUE Dachang, LI Ming,  YAN Beijing   

  1. (Chengdu Global Geotechnical Co. Ltd., Chengdu 610094)
  • Received:2017-10-25 Revised:2017-11-09 Online:2018-10-30 Published:2018-11-02

摘要: 成都卵石层地区抗浮水位高、地下工程结构承受的浮力大,单根抗浮锚杆抗拔承载力要求高,采用增加锚固体长度提高承载力的方法受到“长度临界值”的限制,增加锚固体直径、改善锚固体与岩土间界面特性对提高承载力起关键作用。采用钻机成孔、高压旋喷注浆的工艺施工锚杆,进行多级循环拉拔试验,根据锚杆的荷载-位移曲线及现场变形破坏特征,确定抗浮锚杆破坏模式为锚固体与岩土体粘结界面破坏。试验结果证明,卵石地层高压旋喷注浆工艺锚杆比常规注浆工艺锚杆的抗拔承载力高,可为进一步试验以及工程设计、施工提供参考。

关键词: 卵石地层, 旋喷注浆, 抗浮锚杆, 抗拔承载力

Abstract: The rounded gravel soil deposits in Chengdu area usually have the characteristics of high groundwater. The underground structures will require a high design buoyancy. As a result, the single ground anchor will need to design for the higher ground anchor uplift capacity. However, the ground anchor is usually limited by the “critical length” and the increased uplift design load can be achieved throughout increasing the grouting diameter as well as improve the bond strength between soilgrout interface. The ground anchors, which were installed by conventional drill rigs, high pressure rotary jet grouting methods, were cyclic pullout loaded tested. The bond stress as well as the pullout failure modes of the uplift anchors were determined throughout the test results. The results indicate that the pullout resistance of high pressure jet grouted ground anchors in rounded gravel soil deposits have higher uplift resistance than the anchors with conventional grouting methods.

Key words: Rounded Gravel Deposits, Rotary Jet Grouted, Buoyancy Anchors, Uplift Capacity