Location (Province): Zhejiang Province
Location (City): Quzhou
Drilling Rig Model: HDL-180D1
Drilling Tool Configuration: 146 casing + 89 drill pipe
Construction Process: Casing + drill pipe double-tube drilling
Stratum Conditions: 6 meters of unsupported loose small gravel, medium gravel, large gravel, and cobble layer. 6-10 meters is a sand-gravel layer of medium and small gravel. No soil. Equipment improvement feedback: In this stratum, the original protrusion of the drill pipe bit beyond the casing bit by 10 cm was shortened to 3 cm. Features: 1. Excessive protrusion causes the front end of the casing to form a sweeping hole, and when encountering slightly larger cobbles, it is easy to deviate. 2. Prevent large particles from entering the casing, making them difficult to remove, and reduce hole cleaning time.
Other feedback: 5.5KW sewage pump, 15KW booster pump. 146 casing with 146-156 bit, 89 drill pipe, 89-115 drill pipe bit
Construction process: Double-tube impact drilling in cobble stratum.
1. Position the drilling rig over the hole (mast perpendicular to the working surface and aligned with the previous hole) to facilitate the production of the next waist beam.
2. Fix the machine with 4 outriggers slightly lifted; in difficult strata, do not let the tracks hang in the air (use lifting, mast raising, and sliding to adjust to a suitable position). Keep the casing center position and rotary impact to enter the required position, then use the lower clamp to grip and remove the thread, continue adding casing and impact to the required depth of 10m.
3. Add 89 inner rod, turn on the water pump for impact and slag discharge, repeat this operation until 10m depth.
4. Move the sliding cylinder up until the lower clamp cannot grip the casing thread, and use the upper and lower clamps to remove the drill pipe.
5. First insert the grouting pipe into the bottom of the casing for grouting—then lower the rebar.
6. When pulling out the casing, replenish grout at the casing mouth every 4 meters until the casing is completely removed. Process features: For about 10 meters, containing a small amount of soil, mainly sand-gravel layer. If conventional double-tube construction is used, two people are required to assemble drilling tools, hole cleaning time is long, and hole deviation is easy.