How to Choose a Drill Bit for Long Auger Rigs?
The construction of a long spiral drilling rig should select the drill bit based on the geological conditions on site:
(1) Stroking bedrock: equipped with a pickaxe type core drill bit - conical spiral drill bit - double bottom rotary drill bucket, or a straight spiral drill bit with a pickaxe - double bottom rotary drill bucket.
(2) For silt, weakly cohesive soil layers, sandy soil, and poorly cemented pebble layers with smaller particle sizes, double-layer bottom drilling buckets can be used.
(3) Hard cement: Choose a rotary drilling bucket with a single soil inlet (single bottom and double bottom), or a straight screw with bucket teeth.
(4) Clay: Use a single-layer bottom rotating drill bucket. If the diameter is too small, a two petal bucket or a drill bucket with a soil dumping plate can be used.
(5) Cemented pebbles, gravels, and strongly weathered rocks: conical drill bits and double-layer rotary drill buckets (large particle size single port, small particle size double port) are required
(6) Slightly weathered bedrock: Use a cone core drill bit, a conical spiral drill bit, and a double bottom rotary excavator. If the diameter is too large, a graded drilling process should be used.
(7) Frozen soil layer: For areas with low ice content, straight spiral buckets and rotary excavators can be used, while for areas with high ice content, conical drills can be used. It should be noted that the drill bit is effective for soil layers (excluding silt and silt), but they must be used in the absence of groundwater to avoid being sucked in and causing jamming.
General soil drill bits: mainly suitable for non cyclic drilling in soil layers, sand layers, dense sand layers with a small amount of clay, and sand layers with smaller particle sizes. Wear-resistant alloy bucket teeth with picks, with a straight spiral structure, divided into three types: single head single screw, double head single screw, and double head double screw. Single screw drill bits have the advantages of easy slag removal and low rotational resistance, making them suitable for drilling in well cemented pebble and clay layers.
Rock specialized spiral drill bit: mainly suitable for non cyclic drilling in weathered bedrock, well cemented cobblestone formations, and various permanent frozen soil layers on drawings. The alloy cutting teeth imported from the United States have two structures: straight thread and tapered thread. According to the soil removal performance of the formation and drill bit, it can be divided into single head single screw, double head single screw, and double head double screw.
During the construction process of CFG drilling rigs, attention should be paid to the rational use of spiral drill bits, daily maintenance, and timely replacement of drill bits after a certain period of time.