循环剪切荷载作用下加锚节理岩体抗剪特性研究

The cyclic shear deformation at the rock joints would cause serious damage to the anchoring structures under the conditions of cyclic shear loading and seismic loading. However, the current research is limited to direct shear loading condition, and the influence of cyclic shear loading and seismic loading on the bolted rock joints has never been studied. This project is focused on the shear characteristics of bolted rock joints under cyclic shear loading and seismic loading conditions. Firstly, cyclic shear tests would be conducted on the bolted rock joints under various conditions. The damage mechanism and key influencing factors of bolting structure under cyclic shear condition would be revealed. The evolution rules of shear characteristics for various types of rock bolts would be clarified, providing the basis for bolting system design. Secondly, seismic test of the bolted rock mass under the dynamic loading of the vibrating table would be carried out. The seismic behavior of bolted rock joints would be revealed. The similarities and differences of shearing characteristics of bolted rock joints under cyclic shear load and seismic load would be analyzed. Finally, the shear strength model of bolted rock joint would be established considering the cyclic shear damage factor. A numerical platform for shear tests of bolted rock joints would be established based on the DEM software. The shear properties of the conventional rock bolts and the new rock bolts would be analyzed, which provides a theoretical basis for the anti-shear design and disaster prevention of jointed rock masses.

在循环剪切荷载、地震动荷载等条件下，节理岩体循环剪切错动可能会导致贯穿其中的锚固结构产生严重破坏。目前,针对加锚节理岩体剪切特性的研究局限在单向直接剪切条件下，未充分研究循环剪切荷载和地震动荷载的影响。本项目拟深入研究循环剪切荷载和地震动荷载作用下加锚节理岩体的剪切特性。首先，对传统锚杆和新型大变形锚杆进行加锚节理岩体循环剪切试验，阐明循环剪切作用下锚固结构损伤破坏机理和关键影响因素，揭示各类锚杆抗剪特性演化规律。其次，通过振动台动载作用下加锚节理岩体抗剪试验，揭示地震动荷载作用下加锚节理岩体抗剪特性演化规律，分析地震动荷载与循环剪切荷载作用下加锚节理岩体剪切特性的异同点。考虑循环剪切损伤因子，建立循环剪切荷载和地震动荷载作用下加锚节理岩体抗剪理论模型，进行离散元程序二次开发建立加锚节理岩体抗剪演算数值模型，分析传统锚杆和新型大变形锚杆抗剪特性，为节理岩体抗剪设计和灾害防治提供理论依据。

在地震、煤矿回采等条件下，节理/裂隙循环剪切错动可能会对锚固结构产生严重破坏。然而，目前针对加锚节理剪切特性的研究却局限在直接剪切条件下，忽略了循环剪切荷载的作用，导致锚固设计存在重大安全隐患。本项目对循环剪切荷载作用下加锚节理抗剪特性进行了深入的研究。具体研究内容详述如下。 . 首先，对无锚节理岩体进行了加卸载试验，探讨岩石节理剪切刚度在剪切过程中的演化规律，并提出了加卸载条件下岩石节理峰值剪切强度的数学模型，考虑峰值剪切强度随剪应变衰减的影响，通过该模型推导出加卸载剪切试验中剪切刚度的数学模型，为相关理论研究和工程实践提供一定参考。进而，制作不同节理粗糙度的无锚试件、传统螺纹锚杆试件和吸能锚杆试件进行室内直剪试验，阐明剪切作用下锚固结构损伤破坏机理和关键影响因素，揭示各类锚杆抗剪特性演化规律，为抗剪锚固设计提供基础依据。最后，通过室内循环剪切试验，研究了不同节理粗糙度条件下节理岩体及锚杆的循环剪切特性，基于剪切试验结果，提出剪切能量损失率，定量评价节理和锚杆在循环剪切荷载作用下抗剪性能。. 项目研究成果对提高循环剪切荷载下锚固结构的安全性和可靠性，具有重要的理论指导意义和工程实践价值。. 2020 年至 2022 年间，项目组共发表论文 12 篇(其中 SCI/EI 收录 10 篇），授权发明专利 5 项，授权实用新型专利 3 项。