Choosing the suitable under reamers hole openers according to the characteristics of the stratum during construction is the main way to improve construction efficiency.
In order to adapt to different formations, the structure of the reamer is also different. At present, there are mainly types of squeezing, runner, cutting and rock reamer.
1. Extrusion-expanding reamer realizes expansion by squeezing the stratum, so it is often used in soft soil.
2. The runner type reamer has a certain cutting and chip removal effect while squeezing the ground. It has a wide range of applicability and can be used in most soil layers.
3. The cutting type reamer mainly realizes the reaming by cutting the stratum, with good chip removal effect, especially suitable for dense sandy soil.
4. Rock reamer hole opener can be divided into cone reamer and hob reamer. The cone can be subdivided into two types: insert teeth and steel teeth (milling teeth). Generally steel teeth are used for soft rock and hard soil layers, insert teeth are mainly used for hard rock construction, and hob reamers are mainly used for hard rock or long-distance rock reaming construction.
Precautions for reaming construction:
1. During the reaming process, it is necessary to strengthen the communication between the operator and the drill pipe loading and unloading personnel at the excavation site to prevent the staff from causing personal injury accidents due to the sudden rotation of the drill pipe when the drill pipe is connected. To ensure construction safety, it is recommended to use a transfer case to connect the reamer and the drill rod.
2. During the reaming construction, it is necessary to pump enough mud into the hole, and the drilling cuttings in the hole are taken out of the hole through the mud circulation to keep the hole clean. This is also whether the final pipeline dragging can proceed smoothly. Important premise.
3. In the process of graded reaming, if abnormalities such as torque and pulling force are found to be too large, the necessary hole washing operations can be carried out after the current level of reaming construction is completed to ensure the safety of subsequent reaming construction. Particular attention is needed during construction.