二次劈裂注浆对预应力锚杆极限抗拔承载力的影响研究  

Influence study on the ultimate pull-out bearing capacity of secondary split grouting of prestressed bolt

作　　者：董志民 从晓明 闫猛 Dong Zhimin;Cong Xiaoming;Yan Meng(BGI Engineering Consultants Ltd,Beijing 100038,China;CICIS(China)Limited,Beijing 100007,China)

机构地区：[1]北京市勘察设计研究院有限公司,北京100038 [2]建设综合勘察研究设计院有限公司,北京100007

出　　处：《工程勘察》2023年第7期20-23,共4页Geotechnical Investigation & Surveying

摘　　要：针对预应力锚杆二次劈裂注浆,在北京地区某现场工程开展了现场拉拔试验,对比分析了常压注浆和不同的二次劈裂注浆范围下锚杆的荷载—位移关系。结果表明:二次劈裂注浆锚杆(1/3锚固段劈裂注浆)的极限承载力比常压注浆平均高出25%左右;全锚固段劈裂注浆锚杆比1/3锚固段劈裂注浆锚杆的极限抗拔承载力提高了40%以上,比常压注浆锚杆的极限抗拔承载力提高了75%以上。进行二次劈裂注浆的锚杆的极限抗拔承载力提升明显,有效地增强了锚固性能,在同级别荷载加载时,位移显著降低。并对预应力锚杆二次劈裂注浆的施工管控提出了建议。Aiming at the secondary split grouting of prestressed bolts,on-site pull-out tests were carried out to study the load-displacement relationship of the bolts under normal pressure grouting and secondary split grouting with different splitting range.The results show that the ultimate bearing capacity of secondary split grouting bolt(split-grouting in 1/3 of the anchoring section)is about 25%higher on average than that of normal pressure grouting;the ultimate pull-out bearing capacity of the split-grouting bolt with full anchoring section is increased by more than 40%compared with that of the split-grouting bolt with 1/3 anchoring section,and is increased by more than 75%compared with that of the normal-pressure grouting bolt.The ultimate pull-out bearing capacity of the bolts grouted by secondary splitting is significantly improved,which effectively enhances the anchorage performance.The displacement is significantly reduced under the same loading.The suggestions on the construction management and control of the secondary split grouting of the prestressed bolt are also proposed.

关 键 词：预应力锚杆 二次劈裂注浆 劈裂注浆范围 锚杆极限抗拔承载力 

分 类 号：TU473.1[建筑科学—结构工程]