Rotary drilling rig is the most common equipment in the current pile construction. Because the geology of each place is different, how to choose the right drill bit in the piling process becomes a key issue. Today we will talk about how to After understanding the geological characteristics of the site, a rotary drilling rig bit was selected.
Soil double bottom sand drilling bucket:
Applicable to silt, fine sand, silt, silty clay, clay, some kinds of soil soft rock, such as full, strong weathering and moderately weathered mudstone, argillaceous sandstone, etc.; it is the most widely used drill bit in the industry.
Inlaid rock double bottom sand bucket:
Applicable to eggs, gravel layers, moderately weathered soil-like soft rocks, such as moderately argillaceous sandstone, muddy conglomerate. Harder rock with a higher degree of weathering, such as full and strong weathered granite, is often used in conjunction with drum drills and auger drills when drilling hard rock.
Suitable for medium weathered sandstones with high stratification (high probability of core extraction) and circumcision of hard rock formations. In high-density soil layers, or in some soft rock formations, try to use a drum drill when selecting a friction drill pipe to cause slippage.
Rock inlaid spiral drill bit:
It is suitable for the breakage of the boulders in the hole and the hard rock formation of the orphan. For some cemented formations, the medium-density pebble soil can be drilled using a spiral drill bit when the soil double bottom sand bucket cannot be drilled.
Double tube drill:
It is suitable for drilling eggs and boulders with a particle size of 200-500mm. The double-deck drill uses a new idea of drilling to “squeeze”. The broken and pebbles of different sizes will be squeezed out of the tube and taken out of the hole. When designing, the outer cylinder diameter is designed according to the pile diameter, and the inner cylinder diameter is designed according to the average particle diameter of the pebbles, and the inner cylinder is higher than the outer cylinder. This drilling tool has been widely used in China, and its drilling efficiency and drill tooth loss are obviously superior to other drilling tools.
Soil layer single bottom sand bucket:
The drill bit has the same function as the double bottom sand drilling bucket. The advantage is that it has a side entry to the earth mouth, and there is no need to back drill the door, and the drilling efficiency for the soil layer is higher. The disadvantage is that the weight is light. For some hard soil layers, especially when used with the friction rod, there may be a phenomenon that the slip does not advance, which seriously affects the drilling efficiency.
Soil spiral drill bit:
It is only suitable for clay piles with small pile diameter and large cohesion. The advantage is that the bit height can be up to 4m, the single-row amount is large, and it can effectively avoid the problem that other drill bits are difficult to discharge in such engineering. It is recommended to use within the scope of application.
Double bottom single door drilling tool:
Generally it is a drill with a diameter of ≤1.2m. Compared with double-deck double-opening drills, it has a larger single-sided earth inlet, which is more conducive to drilling in some formations, such as pebble formation with a particle size of less than 200mm. However, since the single-door is an asymmetric structure, it has high requirements for design or production, otherwise it is prone to partial hole phenomenon. This type of drill is recommended for drilling in pebble formations with a small pile diameter of ≤1.2 m.
Classification and use of drill teeth:
The drilling tooth is the part of the rotary drilling rig system that directly contacts the working object. The correct selection of parameters such as selection, arrangement angle and arrangement spacing has a decisive effect on the construction efficiency. Good drill teeth should have: no cracks, continuous smashing, wear resistance, disassembly and assembly.
There are four common types of drill teeth:
1. Tooth: Suitable for soil drilling, sharp edge, fast cutting speed, can not be used for hard formations such as pebbles and rock formations.
2. Baochao: It is thicker and more difficult to break than the teeth. It is used for large-diameter soil buckets, suitable for small and medium-sized pebbles and soft rocks.
3. Picks: Into the rock drill teeth, wear-resistant alloy points provide greater pressure on the rock, suitable for rock fragmentation.
4. Roller teeth: suitable for super-hard rock drilling, crushing and crushing rock, the rotation of the cone reduces rock vibration, and the wear-resistant alloy knife prolongs the service life.