定点定向二次注浆对锚索极限抗拔承载力的影响研究  

STUDY ON THE INFLUENCE OF DIRECTIONAL SECONDARY GROUTING ON THE ULTIMATE PULL-OUT BEARING CAPACITY OF ANCHOR CABLES

作　　者：李幸泽 李启民[1] LI Xing-ze;LI Qi-min(School of Water Resources and Environment,China University of Geosciences(Beijing),100083,Beijing,China)

机构地区：[1]中国地质大学(北京)水资源与环境学院,北京100083

出　　处：《建筑技术》2024年第S01期98-101,共4页Architecture Technology

摘　　要：锚索注浆是为了形成锚固段以提供足够的锚固力,锚索注浆质量直接影响着整个深基坑支护体系的安全。在锚索二次注浆管的特定位置安装注浆阀,使锚索二次注浆时注浆液可在注浆阀的径向定点定向高压劈裂一次注浆体和锚固段周围的岩土体,从而在注浆阀环侧形成直径更大、形状更饱满的锚固体,有利于提高锚索的极限抗拔承载力。本研究通过锚索现场抗拔试验分别获得了定点定向二次注浆锚索和传统二次注浆方式锚索的荷载位移数据,并以实测数据为基础,利用指数模型拟合了锚索的Q-s曲线,得到了锚索的极限抗拔承载力值。Grouting of anchor cables is carried out to form an anchorage segment that provides sufficient anchoring force,and the quality of grouting directly affects the safety of the entire deep excavation support system.This study proposes installing grouting valves at specific locations along the secondary grouting pipes of anchor cables,enabling the grouting fluid during secondary grouting to directionally split the primary grouted body and the surrounding rock and soil around the anchorage segment under high pressure at the fixed points of the grouting valves.This process forms a largerdiameter and more well-shaped anchor body around the grouting valve rings,which is conducive to improving the ultimate pull-out bearing capacity of the anchor cables.Through field pull-out tests on anchor cables,this study separately obtained load-displacement data for anchor cables with directional secondary grouting and those with traditional secondary grouting methods.Based on the measured data,an exponential model was used to fit the Q-s curves of the anchor cables,yielding their ultimate pullout bearing capacity values.

关 键 词：预应力锚索 定点定向注浆技术 锚索极限抗拔承载力 

分 类 号：TU44[建筑科学—岩土工程]