Safety technology of the hottest shaft and roadway

Safety technology of shaft and roadway excavation

in order to explore and mine the ore deposit, the process of excavating the tunnel in the flat experiment of the ore body or surrounding rock. It is called roadway excavation. Mine shaft and roadway include shaft, inclined shaft, adit, raise, blind shaft, drift and chamber, etc

I. shaft and roadway engineering

1. Adit: horizontal roadway directly reaching the ground

2. Shaft: a roadway perpendicular to the horizontal plane and straight to the ground, also known as shaft. A shaft that does not directly reach the ground is called a blind shaft

3. Inclined shaft: a roadway with an inclined included angle with the horizontal plane and a straight face. An inclined shaft without a direct exit to the surface is called a blind inclined shaft

4. Ramp: ramp is a kind of inclined shaft with small inclination. The difference between it and inclined shaft is that the lifting and transportation equipment of inclined shaft is rail tramcar, skip and belt conveyor, while ramp is mainly used to drive trackless equipment and vehicles, such as cars, diesel locomotives, tractors, etc. According to the layout of the ramp line, there are three types: straight line type, spiral type and turn back type

5. Ventilation type: a roadway directly to the ground that is specially used for ventilation (air inlet or return). Sometimes it is also used for transporting materials or also as a safety exit. It has various forms, such as vertical, inclined and horizontal

6. Ore pass: a vertical or inclined roadway used to slide ore from the upper stage to the lower stage, generally with an inclination of more than 300

7. Filling shaft: a roadway used to transport filling materials to the underground goaf

8. Crosscut: a horizontal roadway connecting the shaft and the deposit

9. Drift: a horizontal roadway that does not directly reach the ground in rock or ore

10. Shaft bottom parking lot: the general name of tunnels and chambers excavated at the junction of shaft and crosscut. It is a hub for transferring personnel, ores, equipment and materials, and also a conversion center for underground drainage and power supply

shaft and roadway engineering is the main project of mine capital construction, as well as the main project of mining preparation and production exploration of production mines, and it is the guarantee of stable, sustainable and balanced production of mines. Therefore, in mine production, we must implement the policy of "mining and excavation simultaneously and tunneling first"

II. Shaft and roadway maintenance principle

the stability of the surrounding rock of the shaft and roadway mainly depends on the surrounding rock stress and rock mass strength. Therefore, the basic principle of shaft and roadway maintenance is to use and improve the strength of surrounding rock and improve the stress state of surrounding rock as much as possible, and reasonably select the shaft and roadway construction technology and support mode

1. Reasonably select the position of shaft and roadway. If production conditions permit, the shaft and roadway should be located in stable rock mass with good geological and hydrogeological conditions, and soft and broken rock strata should be avoided, especially water bearing and easily expansive and chemically altered rock strata; 5. Inspect the test results and make test records. The direction should be parallel to the main stress direction of the tectonic stress of the rock stratum as far as possible. In the fold zone, it should be avoided to be arranged in the anticline or syncline axis; The shafts and tunnels with large sections should not be arranged too closely; It should be avoided to arrange the shaft and roadway in the upper and Middle stress concentration areas of the stope, so as to reduce the impact of rock movement after mining

2. Adopt reasonable construction technology. The surrounding rock of shaft and roadway is a natural and costless bearing structure. Advanced blasting technologies such as smooth blasting should be used as much as possible in tunneling to reduce the vibration and damage of blasting to the surrounding rock. Bolting and shotcreting support should be actively used in shaft and roadway support to improve the strength of surrounding rock mass, prevent strength, prevent weathering of surrounding rock, and give full play to its self-supporting capacity

3. Reasonably select the support type. For tunnels dominated by deformation ground pressure, flexible supports with high compressibility should be selected, such as bolt shotcreting support, compressible steel support input computer frame, or compressible materials (rubber, wood bricks) sandwiched in rigid supports. This kind of support can make a temporary concession to the large deformation ground pressure, so as to reduce the pressure acting on the support, limit the excessive deformation of surrounding rock, and prevent the loosening and destruction of surrounding rock. For roadways dominated by loose ground pressure, rigid supports with sufficient strength can be selected to support the weight of loose rocks, such as stone arch, steel wood support, reinforced concrete support, etc

4. Choose a reasonable section shape. Tensile stress often occurs on the straight periphery of the shaft and roadway; There is a large shear stress at the corner around the shaft and roadway; The height width ratio of the roadway has a great influence on the stress distribution of the surrounding rock. The higher the roadway is, the larger the exposed area on both sides of the roadway is, and the greater the lateral pressure is; The wider the roadway is, the greater the pressure of fr ⑴ 03C computer servo universal tensile testing machine, which is a new material testing machine combining electronic technology and mechanical transmission. Therefore, a reasonable section shape should be selected according to the characteristics of surrounding rock stress. In terms of pressure bearing capacity, circular and oval shafts and roadways are the best, followed by straight wall arch and three core arch, while trapezoidal and rectangular sections are poor

5. There should be a certain distance between two adjacent shafts and roadways to prevent stress concentration. Because the stress is redistributed after the rock mass is excavated, the rock pillar between the two tunnels should be more than 5 times the maximum size of the tunnel