As an essential support structure in underground engineering, rock bolt support has a simple and fast construction method and good support effect, and its stability is of vital significance to ensuring the safety of the project. With the development of rock bolt support technology, it has also been widely applicable. However, the effect of rock bolt support is affected by many factors. No matter which link encounters problems, it may lead to the failure of the rock bolt support, posing significant risks to the project. This article will comprehensively analyze how to prevent rock bolt support failure from aspects such as the design, construction, and maintenance of rock bolt support to improve the safety and stability of underground projects.
Rock bolt support design
Rock bolt support design is the primary link in preventing its failure. Unreasonable selection of rock bolting design parameters, changes in geological conditions, unqualified support materials, and construction quality that does not meet design requirements are all factors that cause rock bolt failure. Therefore, during the design process, it is necessary to fully consider the geological conditions, project scale, support structure form, and other factors to ensure the rationality of rock bolting.
Geological conditions analysis
Before designing, a detailed analysis of the geological conditions of the project site must be carried out. Through exploration, testing, and other means, we can understand the lithology, structure, groundwater, and other conditions of the formation to provide accurate geological data for design.
Project scale and support structure form selection
Select the appropriate supporting structure form based on factors such as project scale and underground space layout. For large underground projects, priority should be given to the use of high-strength support structures such as prestressed rock bolting.
Parameter design
The design of rock bolt support parameters includes rock bolt type selection, geometric parameters, mechanical parameters, density (between anchors, row spacing), installation angle, drilling diameter, hole depth, anchoring method and anchoring length, anchor tightening torque, etc. The design of these parameters should be based on the geological conditions, engineering requirements, the form of support structure, and other factors to ensure the bearing capacity and stability of rock bolt support.
Rock bolt support construction
Rock bolt support construction is a critical link in preventing anchor support failure. During the construction, to ensure the construction quality, it should be operated in strict accordance with the design requirements.
Preparation before construction
Before construction, the construction personnel should conduct a detailed investigation of the construction site to understand the underground pipelines, obstacles, and other conditions. At the same time, prepare the required construction equipment, materials, and personnel to ensure that the construction proceeds smoothly.
Drilling and grouting
Drilling is an essential part of rock bolt support construction. During the drilling process, parameters such as the diameter, depth, and inclination of the drill hole should be strictly controlled to ensure the accurate installation of rock bolts. Grouting is another essential link in rock bolt support construction. The selection of grouting materials and the control of the grouting process have a significant impact on the load-bearing capacity and stability of rock bolts. During the grouting process, the staff should ensure that the quality of materials, pressure, volume, and other parameters meet the design requirements.
Installation and tensioning
Installation and tensioning are the final stages of rock bolt support construction. During the installation process, it should be ensured that the location, direction, inclination, and other parameters of the rock bolt are consistent with the design requirements. During the tensioning process, it’s pivotal to adhere to the specified tensioning force and sequence to ensure that the rock bolt’s prestressed force meets the design requirements.
In the construction of rock bolt support, there are many human factors, such as the angle of the rock bolt, the depth of the rock bolt hole, and the matching of rock bolt support. The construction deviation of each process has a greater impact on the quality of the rock bolt support.
Therefore, by providing accurate technical training and education, we can enhance the skills of construction personnel and mitigate the impact of the aforementioned human factors. Provide pre-job technical training to construction personnel so that they are familiar with every process of rock bolt construction, master the techniques of rock bolt construction, rationally design construction process drawings, and make good use of the inherent properties of rock bolts, is of significant importance to improve the effect of rock bolt support.
Rock bolt support maintenance
Maintenance is an important guarantee to prevent rock bolt support failure. During use, the staff should carry out regular monitoring and maintenance to ensure the stability and safety of the rock bolt support.
Monitoring and evaluation
Regularly monitor the rock bolt support to understand the support effect of the rock bolt and the dynamic changes of the surrounding rock. By analyzing the monitoring data, we can assess the stability and safety of rock bolt support, promptly identify potential issues, and implement necessary measures accordingly.
Maintenance and reinforcement
Any problems discovered should be maintained and reinforced promptly. At the same time, it’s crucial to enhance the daily maintenance of rock bolt supports to ensure their proper functionality and usability.
Conclusion
The prevention of rock bolt support failure is a systematic project. Ensuring effective support of the surrounding rock mass with rock bolts requires attention to various aspects including design, construction, and maintenance. Through detailed analysis of geological conditions, reasonable selection of support structure forms, strict construction quality control, regular monitoring and maintenance, and other measures, and the implementation of all-around control, it is possible to effectively prevent rock bolt support failure issues. At the same time, with the continuous advancement of science and technology and the continuous accumulation of engineering practice, rock bolt support technology will continue to be improved and developed, providing a more reliable guarantee for the safety and stability of underground projects.
