关键词: 涨壳式中空注浆锚杆, 锚固力, 预应力, 止浆塞, 标准化施工

Abstract: To meet the requirements of the standardized tunnel construction, it is necessary to control and to evaluate the technical parameters and construction quality of the main process measures during the tunnel construction process. Throughout the on-site and laboratory testing, the key parameters in the grouting of the ground anchors with hollow bars, such as, the anchoring loads, pre-stressed torque conversion relationship, and grout stopping are studied. The standardized construction technology and the key technical parameters of the low pre-stressed inflatable ground anchor with hollow bars are proposed. The results show that, there is a significant difference in the anchoring load of the inflatable head of the ground anchors in different soil and rock strata. For layers with poor geotechnical properties, such as the carbonaceous shale section, it is not recommended to use the inflatable ground anchor with hollow bars. The prestressing load applied to the anchor rod should not be less than 60kN, and it is recommended that the torque value should not be less than 600N · m. To ensure the construction quality, special tooling and equipment with good quality control measures must be installed; The ground anchor should be equipped with a grout stop plug with exhaust and pressure stabilization function to achieve the requirement of the grouting pressure not less than 0.5MPa and the pressure stabilization time not less than 30s.

Key words: Inflatable Ground Anchor with Hollow Bars, Ultimate Anchoring Loads, Pre-Stressing, Stopper Plug, Standardized Construction