摘要
螺旋外观的锚杆通常配合树脂黏结剂和机械式锚具进行使用,由于其可施加高预应力、锚固效率高等优势,逐渐被应用在高强度、高延伸率的锚杆设计中,目前关于机械式锚具和螺旋外观锚杆的锚固机理研究较少。基于一种高抗拉强度(950 MPa)、高延伸率(30%)的螺旋外观NPR锚杆,使用力学解析、数值模拟和试验的方式,对机械式锚具预应力施加机理、使用机械式锚具时锚杆的荷载传递以及使用树脂黏结时的黏结机理进行了分析研究。结果表明:使用机械式锚具配合前卡式千斤顶和限位板可有效地对NPR锚杆施加100kN的预紧力;在锚具作用区,锚杆表面峰值米塞斯应力出现在离加载段较近的位置,高于拉伸强度约50MPa。静力拉伸试验表明锚固效率大于95%。相比常见的矿用锚杆,螺旋肋NPR锚杆具有更好的树脂黏结性能,原因在于螺旋肋的外观设计为肋与树脂之间提供更大的接触面积,在20mm直径、1mm肋高的条件下,NPR锚杆黏结强度是左旋锚杆的1.28倍,肋与树脂的有效接触面积是1.30倍。
The bolt with spiral appearance is usually used with resin binder and mechanical-type anchorage.Because of its advantages of high prestress and high anchorage efficiency,it is gradually applied in the design of bolt with high strength and high elongation.At present,there are few studies on the anchorage mechanism of mechanical anchorage and spiral appearance bolt.Based on a spiral-shaped NPR bolt with high tensile strength(950 MPa)and high elongation(30%),this paper analyzes and studies the prestressed installation mechanism,the load transfer of the bolt when using mechanical-type anchorage,and the bonding mechanism and performance when using resins,and mechanical analysis,numerical simulation and test methods are used.The results show that the pre-tightening force of 100 kN can be effectively applied to the NPR bolt by using the mechanical-type anchorage with the front clamping jack and the limit plate.In the anchorage zone,the peak Mises stress on the surface of the bolt appears near the loading section,which is about 50 MPa higher than the tensile strength.The static tensile test shows that the anchorage efficiency is greater than 95%.Compared with common mining bolts,the spiral rib appearance of NPR bolt has better resin bonding performance.The reason is that the design of spiral rib provides a larger contact area between rib and resin.Under the condition of 20 mm diameter and 1 mm rib height,the bonding strength of NPR bolt is 1.28 times that of left-handed bolt,and the contact area between rib and resin is 1.30 times.
作者
杨军
詹家旺
边文辉
王科学
董美强
YANG Jun;ZHAN Jia-wang;BIAN Wen-hui;WANG Ke-xue;DONG Mei-qiang(State Key Laboratory for Tunnel Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;School of Mechanics and Civil Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China)
出处
《中国公路学报》
北大核心
2026年第2期202-214,共13页
China Journal of Highway and Transport
基金
深地国家科技重大专项项目(2024ZD1000704)
国家自然科学基金项目(42377148)。
关键词
隧道工程
锚固体系
力学解析
NPR锚杆
预应力支护
tunnel engineering
anchorage system
mechanical analysis
NPR anchor bolt
prestressed support
