Before starting grouting, the mouth tube must be placed in the hole about 200mm away from the bottom of the hole; When gargling, after the mud passes through the hole, gradually draw the outlet tube and gargle continuously until there is no shrinkage hole in the hole; After the successful step, the reinforcement must be put into the hole in time and quickly, and the top of the bolt must be effectively treated with anti-corrosion.
1. Construction of anti-floating anchor
For example, there are about 2800 anti-floating bolts, different anchorage lines should be set up as soon as possible according to different geological conditions, involving the depth of the floating anchor in the mountain layer diameter in Φ130, the depth of the bottom hole is suitable for greater than the expected depth of the hole, the accurate size is about 200mm, fully ensuring that the powder in the hole reaches an adequate exit age range. There are two obvious problems in the drilling process below the design: 1) When the hole is collapsed, the treatment method is to choose the inner diameter larger than the steel tire wall Φ130, (2) when the weak middle layer is formed, the drilling pipe should be quickly raised, and the plastic pipe with the inner diameter less than Φ130 and greater than Φ80 should be inserted in time, and the length of the plastic pipe should pass through the middle layer; After the plunger is in place, slowly pull out the plastic tube.
Before starting grouting, the mouth tube must be placed in the hole about 200mm away from the bottom of the hole; When gargling, after the mud passes through the hole, gradually draw the outlet tube and gargle continuously until there is no shrinkage hole in the hole; After the successful step, the reinforcement must be put into the hole in time and quickly, and the top of the bolt must be effectively treated with anti-corrosion.
Anti-floating anchor
2. Test experiment of anti-floating anchor
Referring to the basic standards of building foundation planning, carefully check that the number of bolts is 5% of the total number of bolts, and 151 anti-float bolts are tested. According to the basic scheme initially established, the test loads of fully weathered calcareous SLATE bolt, moderately weathered calcareous SLATE bolt and strongly weathered calcareous SLATE bolt are 250, 300 and 280kn respectively. It can be seen from the results of the basic test that the bearing capacity of all the test bolts can effectively meet the original requirements of the planning.
The information required for anti-floating anchor inspection is as follows:
1. Commencement report
2. Construction organization design
3. Submit the subcontractor's qualification for examination
4. Report for approval of raw materials, mortar or concrete ratio
5. Raw materials, processing and equipment inspection batch used in ground improvement works
6. Concealed steel bars
7. Basic records of anti-floating anchor construction
8. Summary of reinforcement welding statements (including trial welding)
9. The test block of grouting or concrete should have a detailed summary table and be measured
10. As-built drawing
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