What are the procedures for horizontal roadway excavation? how to proceed?
The main processes are: drilling, blasting, rock loading and support; auxiliary processes include: pumice stone , ventilation, track laying, and long pipelines. First, rock drilling in the roadway excavation is the first process. Rock drilling is usually carried out with a gas-legged rock drill or a rock drilling trolley. The diameter of the blasthole is 38 to 46 mm, the depth is 1.2 to 2.5 m, and the blasthole is between 20 and 40. Second, the blasting of the charge in the roadway is the second process. The explosives generally use the ammonium explosives and the fuse line detonation method. The charge depth of each blasthole is 2/5~2/3 of the depth of the eye. It is 15% to 20% more than other blastholes. In order to reduce the unevenness of the roadway surface, reduce the excessive damage to the surrounding rock, reduce the support cost, and achieve the smooth requirements, the site now uses smooth blasting, that is, densely arranged peripheral eyes, reducing the charge of the peripheral eye. Quantity, strict control of the detonation of the eye, for the detailed related technology of smooth blasting, see the relevant page. 3. Ventilation work must be carried out in time after blasting, so that the harmful gases and dust on the working face can be quickly eliminated. The general ventilation time is about 20 minutes, which is completed by the axial flow type fan. The schematic diagram is shown in Figure 1. Figure 1 Schematic diagram of local ventilation 4. The rock loading work should be carried out immediately after the end of the ventilation work. The rock loading work accounts for 35% to 50% of the excavation cycle, so it is very important, and the machinery is particularly important in this process. At present, the widely used rock- loading machines include: bucket rear unloading rock loader, bucket type rock loader, and grab-type continuous rock loader. The first one is used more. The rock loader has both pneumatic and electric, and Figure 2 shows its working mechanism. Figure 2 Schematic diagram of rock loading in the bucket loading machine 1-shovel to shovel rock; 2-shovel to unload rock Other mines now use the shuttle type mine car in the mechanization of the roadway. This type of mine car is a large-capacity mine car with a conveyor at the bottom. The mine car is gradually filled by the movement of the transport machine. 3 is shown. Figure 3 Schematic diagram of shuttle car operation 1-Activity herringbone plate; 2-Loading plate transported with the transporter; 3-Minestone moving direction; 4-loading machine; 5-turn sprocket; 6-chain conveyor When a large amount of blasting is used, the shuttle ore group can also be used to load the ore. 5. After the completion of the rock loading work, roadway support should be carried out. Support means taking measures in the roadway to stabilize the roadway and ensure normal production needs. The alley support is divided into temporary brackets and permanent brackets. Permanent supports mainly include: timber supports, concrete supports, stone supports, anchors and shotcrete supports; temporary supports are relatively simple. Seucrity Patrol Drone,Rescure Drone with Searching Light, Bouy Drop Drone ,Wireless Megaphone Drones Seucrity Patrol Drone,Rescure Drone with Searching Light, Bouy Drop Drone ,Realtime Video Drone shenzhen GC Electronics Co.,Ltd. , https://www.jmrdrone.com