Technical practical operation points of anchor rods

Before drilling anchor rods and prestressed anchor cables, drilling tools, anchor rods, steel hinge wires, towing plates, cushion plates, anchoring agents, etc. should be prepared in advance before gradually drilling holes. At present, the first step is to examine the roof and solve the problem of live debris (coal) in the roof landslide. After determining the safety, the specifications and models of the coal roadway should be checked to see if they meet the design requirements. If there are any discrepancies, they should be resolved before drilling.

The hole position of anchor rod and prestressed anchor cable shall be accurately positioned and identified according to the design scheme under drilling, and the coal (rock) wall ground near the hole position shall be leveled to ensure that the towing pan and the coal (rock) wall are in close contact. Appropriate Fried Dough Twists drills shall be used to ensure the effective matching of the hole diameter, rod diameter and cartridge diameter, so as to prevent the situation of inappropriate specifications.

According to the design scheme, orientation and perspective of anchor rods and prestressed anchor cables, fix the drilling machine according to the eye position and gradually drill holes. Drilling must be carried out under reasonable temporary anchor rod support. First, slowly adjust the hole position to ensure normal drilling. Strictly follow the perspective of the eyes during construction, and properly mark the drilling tools to ensure that the depth of the drilling hole is not less than the reasonable length of the anchor rod, and not more than 30mm beyond the reasonable length of the anchor rod.

During the drilling period, it is necessary for three people to cooperate with each other. One person should actually operate the drilling machine, one person should observe the top and replace the drill rod, and one person should provide feng shui learning lines. It is forbidden to stand in front of the drilling machine to prevent injury caused by broken drill rods. The punching sequence should be carried out with an outward facing personality (orientation of the workbench), starting from the middle and then expanding towards the two sides.

After preparing the eyes, gently blow the smoke and lava inside the eyes with compressed air, insert anchor rods and pre-stressed anchor cables into the eye holes, check the eye diameter, depth, and viewing angle, and install them when they meet the design scheme or technical specifications.

Generally speaking, the difference in the position of the anchor rod hole should not exceed -4-10 centimeters. After drilling by the construction team, it is necessary to use high-pressure water to clean it clean, and then use high-pressure air to blow out the water inside and evaporate to dry. For mechanical anchor bolt holes, the difference in hole depth should be controlled within -1 to 1 centimeter. When professional technicians drill deep into the design scheme, if they encounter crushed geotechnical engineering barriers or relatively soft rock layers, the position and depth of the anchor rod should be changed.