Safety technical measures for grouting constructio

Safety technical measures for grouting construction of new shaft bottom parking lot

(I) specification, size and layout of grouting pipe:

1 Specification of grouting pipe: it is used when the overbreak exceeds 500mm Φ twenty × 3000 grouting pipe, over excavation less than 500mm and bottom plate Φ twenty × 2500 grouting pipes, with a row spacing of 2m × 2m, error ± 100mm, exposed length 100m ~ 150mm

    2. Layout of grouting pipes: one at the top of the arch, one at an interval of 2m along the contour line to the two sides, one at a distance of 0.5m between the two sides and the bottom plate, 7 in each row, 3 in each row of the bottom plate, a total of 10 in each row

(II) grouting materials and proportioning:

grouting configuration: first press water: cement =1:0 In the design of the new experimental machine, the proportion of 8 ~ 1.5 (weight ratio). Add clean water into the mixing bucket, then add the screened (grid) cement in proportion, mix evenly, and then start grouting. At the beginning, try the water cement ratio from small to large

(III) grouting process:

1 Drill grouting hole → install/fix grouting pipe → wrap the thread of grouting pipe head/temporarily seal the hole with plug → 8h after grouting (life) → grouting

    2. The rock powder in the grouting pipe should be blown out. After the installation and disassembly of the sample are convenient and fast, the grouting pipe should be placed and fixed firmly, and the threads of the grouting screw head should be wrapped with plastic cloth. Then, when installing the grouting pipe at the tunnel crown and two shoulders, after inserting the grouting pipe, the grouting pipe must be fixed in the hole with grout stop plugs (pieces), and the outside of the grout stop plug should be level with the tunnel wall to prevent overflow during grouting. After the grouting pipe is inserted, the grouting pipe hole must be temporarily sealed with wood plugs or rags, and their annual goals have been announced to prevent hole sticking and blocking

    3. Each row of grouting should start from the first grouting pipe at the lower part of one group, pour the second one upward, and then start grouting from the other group to the vault. For different rows of grouting pipes, inject odd rows on the first day and even rows on the second day

construction quality requirements:

1 The grouting pipe must be perpendicular to the roadway contour, and each grouting pipe must be injected until the designed pressure value expressed by the pressure or the grouting pump shows that it cannot be injected

without it 2 All top grouting pipes shall be constructed according to the position and angle required by the design. The allowable error is ± 100mm

    3. It is forbidden to use expired or caked cement

    4. The grouting equipment and pipelines must be cleaned to ensure the integrity of the equipment

    5. All materials and tools at the construction site must be arranged neatly to ensure civilized construction

    6. Making slurry: first add clean water into the mixing drum according to the ratio, and then put the cement into the mixing container through the feeding grid for mechanical mixing. Mix and stir evenly, and the mixing time is not less than 5 minutes