Over the last decade, many foreign mine equipment widely used in highly mechanized trackless mining, loading, transportation and unloading, etc., to develop appropriate methods have changed, the main change is to dig for trackless equipment up and down the passage of the ramp.

When there is no other lifting wellbore, the main ramp connecting the surface is mainly used for transporting ore (using trackless vehicles ). It also serves as the material for the access, ventilation and transportation of equipment for trackless equipment. When there is a lifting wellbore, the slopeway is mainly used for the entry and exit of the trackless equipment, and serves as both ventilation and auxiliary transportation. The slope road at this time is called auxiliary development roadway.

Mine-free rail device, the phase between the auxiliary ramp almost essential that it not only can be transferred scraper trackless other equipment, but also pedestrians, haul and ventilation channels, it is still secondary development roadway _.

First, the type of ramp

1 . The spiral ramp is shown in Figure 6-lla , and its geometric form is generally a cylindrical spiral or a conical gyro, which can be designed as a regular spiral or an irregular spiral depending on the specific conditions. The radius of curvature and slope of the irregular spiral ramp are varied throughout the line. The slope of the spiral ramp is generally 10% to 30 % .

2. The foldback ramp is shown in Figure 6-11b . It consists of a straight line segment and a curved segment (or a folded segment); the straight segment transforms the elevation and the curve segment changes direction to facilitate the turning of the trackless device; the slope of the curve segment Slowly or approximately horizontally, the slope of the straight section is generally not more than 15% . In the entire line, the straight line segment is long and the curved segment is short.

Second, the typical development method of the slope

1. Spiral ramp development method Figure 6-12 shows the spiral oblique tunnel of the No. 5 ore body of the Shengang original mine in Japan Pioneering law. In the side of the ore body, the spiral slope is drilled from +200m to Om , with a section of 4*3m ^{2 with a} minimum radius of curvature of 15m, an average slope of 21% (12°) and a total length of 1200m. From the top to the bottom, the roadway is connected to the spiral slope and working face. The section of the roadway is 4*3m ² and the total length is 2000 m .

After the completion of the project, the trackless equipment can enter the underground mining stage and the ground from the ground. No matter what stage is needed, the work can be transferred at any time.

Trackless equipment used are: Wagner ST-2B scraper 4, Gardner Denver • 2 sets of boring car, stay Gardner Denver • 1 mine trolley station, Wagner Taiwan people and vehicles, jeeps three.

2. Foldback ramp development method

Figure 6-13 shows a typical foldback ramp development method. The reversing ramp is located outside the movement boundary of the lower strata of the ore body. When the ramp 1 passes through a certain stage level, the reentry is carried out. At each stage of the horizontal reentry, the excavation door 2 ( or the ramp road contact) is transported to the roadway 3 . Trackless equipment can be accessed from the ground through ramps at various stages, and the ore produced at each stage is transported out of the ground by trolleys.

At present, there are still few underground mines using the ramp development method alone. In many foreign mines, when the shaft development method is adopted, auxiliary slopes connecting the surface are provided, or auxiliary slopes are connected between the transportation lanes at each stage, so that the trackless equipment can be moved from the surface to the underground stage or from one stage to another. Stage work. Figure 6-14 is a diagram of a typical development method for the lower shaft used in the Krysten Nickel Mine in Canada, supplemented by ramps .

Figure 1 is a front shaft, provided in the main processing plant wellhead 8, as the original 2 inclined auxiliary shaft, after digging helical ramps 3, the swirling up from the surface to deep deepened portion. Ramp section is 5 * 3.5m ^2, the turning radius of 7m, ramps laid concrete floor, roof supporting metal mesh of struts and gold. The trackless equipment can be driven from the ground to the ground via the ramp, and all the nuggets are connected by the segmented roadway. Later, the slope can be exploited in the deep section, and there is no need to extend the inclined shaft . The inclined shaft has been changed into the return air passage and the alternate intake well.

The ore is transported from the loading point to the main chute with trackless equipment , with a flow rejection of 150m and a productivity of I50t/h ( with ST-4 scraper ). After the ore is crushed, it is transported by the belt conveyor to the loading chamber, and then the shaft bucket is lifted to the wellhead for selection.

three. Comparison of gyro ramps and foldback ramps

1. Advantages of a spiral ramp

(1) Since there are not as many gentle slope segments as the foldback type, the spiral type is more short-circuited and the amount of pioneering work is small during the same elevation;

(2) When it is combined with vertical wells such as slides, ventilation and slagging are convenient;

(3) Suitable for the development of cylindrical ore bodies.

2. Shortcomings of spiral ramps

(1) dig into the construction requirements Gao (change of direction, the outer ultra-high);

( 2) The driver can see a small distance, so the safety is poor;

(3) Increased wear of vehicle tires and differentials;

(3) The road maintenance workload is large.

3. Advantages of the foldback ramp

( 1) Construction is easier;

(2) The driver can see a large distance and the driving is safer;

(3) The driving speed is larger than that of the spiral type, and the amount of harmful gas discharged is small;

(4) The line is convenient to maintain a fixed distance from the ore body;

( 5 ) The road is easy to maintain.

4. Disadvantages of the foldback ramp

( 1 ) Larger amount of pioneering work than spiral roads;

(2) Vertical wells and lanes for ventilation and slag need to be used for excavation.

In general, the advantages of the foldback type are many. However, if it can solve the construction difficulties of the inclined section of the tunneling, it can also be designed as a spiral type. In this way, the total tunneling capacity of the spiral ramp can be reduced by approximately 25% .

4. Selection of spiral ramps and foldback ramps

The choice of ramp type is related to the following factors:

1. Use of slopes If the main slope is used for transporting ore and the volume of transportation is large, it is advisable to use a reversing ramp; the auxiliary ramp can be a spiral ramp.

2. It is better to use a reentry type ramp for a longer service life.

3. Exploring the amount of engineering In addition to the engineering quantity of the slope road itself, it should also consider the auxiliary shaft and road engineering during the excavation (such as Wind patio, drilling, etc.) and the amount of contact roadway engineering for each segment.

4. Ventilation conditions The ramps are generally used for ventilation. The spiral ramps have a large ventilation resistance, but the lines are

Shorter.