In the construction of grid structures, the installation quality of anchor bolts, as key components connecting the grid and foundation, directly affects the stability and safety of the entire grid structure. Correctly installing the anchor bolts and strictly controlling the precautions at each stage are important foundations for ensuring the smooth completion of the truss project.
Preparation before installation
Material inspection: Before installation, carefully check whether the specifications and models of the anchor bolts are consistent with the design requirements, and the appearance of the bolts should be free of defects such as cracks, scars, rust, etc. At the same time, check whether the matching nuts, washers, etc. are complete and whether the quality is qualified.
Measurement and laying out: Using high-precision measuring instruments, accurately lay out the position of the anchor bolts according to the design drawings. Mark the longitudinal and transverse axes on the basis, and determine the center position of each anchor bolt to provide accurate positioning basis for subsequent installation.
setup script
Positioning and fixation: Place the anchor bolts into the reserved holes of the foundation, use positioning templates or other positioning devices to ensure the accurate position of the anchor bolts. By adjusting, the verticality deviation of the anchor bolts should be controlled within the allowable range, and generally the verticality deviation should not exceed 1/100 of the bolt length. Then, temporarily fix the anchor bolts to prevent displacement during subsequent construction.
Pre embedded pouring: After confirming the position and verticality of the anchor bolts are correct, concrete pouring is carried out. During the pouring process, attention should be paid to avoiding direct collision of the vibrating rod with the foundation bolts to prevent bolt displacement or deformation. At the same time, it is necessary to pour and compact the foundation concrete layer by layer to ensure its strength and integrity.
Bolt tightening: After the foundation concrete reaches 75% or more of the design strength, the anchor bolts should be tightened. Use a suitable torque wrench to tighten the bolts according to the design requirements, ensuring a secure connection. When tightening, a symmetrical fastening method should be used to avoid uneven local stress.
matters needing attention
Pollution prevention: During the installation process, attention should be paid to protecting the anchor bolts to prevent them from being contaminated by mud, oil, and other substances. If the surface of the anchor bolt is contaminated with pollutants, it should be cleaned up in a timely manner to avoid affecting the fit between the bolt and nut, as well as the anti-corrosion performance of the bolt.
Regular review: During the foundation construction process, due to various factors, the anchor bolts may experience displacement. Therefore, it is necessary to regularly review the position and verticality of the anchor bolts. Once deviations are found, they should be adjusted in a timely manner.
Finished product protection: After the installation of the anchor bolts is completed, the finished product protection work should be done well. Set up clear warning signs around the foundation to prevent damage to the installed anchor bolts caused by other construction activities. At the same time, avoid welding other components on the bolts. If welding is required, effective cooling measures should be taken to prevent the bolts from affecting their mechanical properties due to high temperatures.
Record archiving: Throughout the installation process, various records should be kept, including measurement data, bolt tightening torque values, problems encountered during construction, and corresponding solutions. These records will serve as important basis for engineering acceptance and quality traceability, and must be properly preserved.
In short, the installation of anchor bolts for the grid structure is a meticulous and critical task. Only by strictly following the specifications and paying full attention to the key points of each link can the installation quality of anchor bolts be ensured, providing strong guarantees for the safety and stability of the grid structure.