Construction is a process of forming project entity and an important stage of forming final product. So quality control of construction phrase is the key point of whole engineering project.
During process of construction stage, to ensure construction quality, construction tools and devices should be carried out quality inspection and control.
The target of quality control is to eliminate unqualified or dissatisfied factors and reach quality requirement, then obtain economic benefits by adopting quality operation technology. As for anchor bolt(Perno de anclaje
), quality control mainly reflects on following aspects:
1. Control of anchor bolt. Anchor bolt should be controlled strictly to meet designed standard requirements, especially for anchor bolt’s material, size and specification.
2. Control of borehole. Before drilling holes, technicians should position and confirm location of borehole, carry out along radial direction and length of borehole should not be short than designed requirement.
3. Control of prestress. Exerting prestress before grouting and then tightening nuts to reach designed torque.
4. Control of cement grout proportion. Testers should command and prepare cement slurry on the spot according to certain standard.
5. Control of grouting pressure. Before grouting next anchor bolt, grouting pressure of the first one should be guaranteed.
Through grouting, anchor bolt fills cracks fully and a multi-layered compound arch will be formed, which will not only improve lithology of surrounding rocks, but also prevent deformation and enhance supporting structure’s integrity and bearing capacity.