(1 国电电力发展股份有限公司, 北京 100101; 2 同济大学建筑设计研究院 (集团) 有限公司,上海 200092; 3 海南中海电力工程有限公司, 海口 570100)

摘要: 提出一种预应力扩底锚索结构,通过扩底端与围岩之间形成挤压摩擦锚固,并对钢绞线施加预拉力减小其疲劳应力幅,可代替普通岩石锚杆作为抗疲劳结构用于岩石地基基础中. 对强风化岩石地基中的预应力扩底锚索分别进行了现场疲劳试验和静力试验,共计 7 组试验. 试验结果表明,强风化岩石地基中,预应力扩底锚索可以承担 200 万次以上的疲劳荷载作用,估算疲劳应力幅为 148MPa,锚索的疲劳寿命和抗疲劳承载力较高;静力试验锚索最终发生钢绞线断丝破坏,锚头均未被拔出,扩底端的锚固性能好,能充分发挥钢绞线的抗拉强度. 经过合理设计,预应力扩底锚索可以应用于具有疲劳作用的风电结构强风化岩石地基基础中.

关键词: 预应力扩底锚索; 强风化岩石地基; 抗疲劳性能; 锚固性能

中图分类号:TU471. 6 文献标志码:A 文章编号:1002-848X(2023)12-0132-06

DOI:10. 19701 / j. jzjg. 20201445

Anti-fatigue experimental research on pre-stressed under-reamed anchor cable in highly weatheredrock foundation

QU Zhongkan1, HE Guirong2, SUN Qi3

(1 GD Power Development Co. , Ltd. , Beijing 100101, China; 2 Tongji Architectural Design (Group) Co. ,Ltd. , Shanghai 200092, China; 3 Hainan Zhonghai Power Engineering Co. , Ltd. , Haikou 570100, China)

Abstract: A type of pre-stressed under-reamed anchor cable structure was proposed, which utilized the compression andfriction between the expanded bottom and the surrounding rock to anchor, and applied pre-tension to the steel strands toreduce their fatigue stress amplitude. It can replace the ordinary anchor rod as a fatigue-resistant structure in rockfoundation. Totally seven sets of experiments were conducted on site, including fatigue experiments and static experimentson pre-stressed under-reamed anchor cable in highly weathered rock foundations. The test result shows that in heavilyweathered rock foundations, the pre-stressed under-reamed anchor cable has higher fatigue life and anti-fatigue bearingcapacity, which could withstand more than 2 million cycles of fatigue load with 148MPa of an estimated fatigue stressamplitude. In the static tests, the steel strands of anchor cable eventually broke, but the anchor heads were not pulled out,which reveals that the anchoring performance of the expanded bottom was good, and the tensile strength of the steel strandscould be fully utilized. With reasonable design, pre-stressed under-reamed anchor cables can be applied in highlyweathered rock foundations of wind power structures with fatigue effects.

Keywords: pre-stressed under-reamed anchor cable; highly weathered rock foundation; anti-fatigue property;anchoring performance

第一作者:曲忠侃,学士,高级工程师,主要从事新能源开发工作,Email:quzk@ 600795. com. cn.

[引用本文] 曲忠侃,何桂荣,孙奇. 强风化岩石地基中预应力扩底锚索抗疲劳试验研究[ J]. 建筑结构,2023,53(12):132-137. QU Zhongkan, HE Guirong, SUN Qi, et al. Anti-fatigue experimental research on pre-stressed underreamed anchor cable in highly weathered rock foundation[J]. Building Structure,2023,53(12):132-137.