CN101694163B - Determination method of deep tunnel roof support forms and support depth - Google Patents

Abstract

The invention discloses a method for determining the support form and support depth of a deep roadway roof, which uses an intelligent borehole imager to measure the images and data of the inner wall lithology, crack distribution and separation layer of boreholes at different depths; Data and image editing and processing, to obtain the alternate interval occurrence and spatial distribution of the fractured zone and the complete zone in the surrounding rock of each drilling hole, and set the bolt, anchor cable or anchor cable in the case of structural zones with different thicknesses Combined support form and support depth. The present invention obtains sufficient scientific basis when designing the support depth of anchor rods and anchor cables, makes the support parameters more economical and reasonable, and achieves the best support effect under the most economical conditions. The invention can scientifically and quantitatively determine the anchoring form of the deep roadway and the length of the roof anchor rod and the anchor cable, and has important promotion value for realizing the quantitative design of the anchoring support of the deep high-stress roadway and ensuring the safety of the roof of the deep roadway.

Description

Determination Method of Roof Support Form and Support Depth in Deep Roadway

technical field

The invention relates to the technical field of roadway support in deep coal mines.

Background technique

After the coal mine roadway is excavated, the original rock stress balance state will be broken, which will lead to deformation and damage of the surrounding rock. Certain support means are needed to prevent the deformation of the surrounding rock and prevent damage. At present, there are many methods for roadway support, such as masonry Support, bolt support, anchor shotcrete support, anchor net spray support, anchor cable support, metal arch support, material stone support, reinforced concrete support and the joint support between various supports In deep mining, in addition to the above methods, roadway support also adopts anchoring and grouting support. In the above-mentioned anchor rod and anchor cable support, the length of the anchor rod and anchor cable is selected according to experience. The scientific basis Insufficient, if the selection is too long, it will be very expensive, if the selection is too short, the support effect will not be achieved. The support method related to the present invention is a bolt support method, an anchor spray support method, an anchor net spray support method, an anchor cable support method and an anchor injection support method. In these support methods, all are based on the bolt support, first arrange the boreholes on the surrounding rock of the roadway during support, and then fix the bolts in the boreholes. At present, when arranging bolts, the length of the bolts (i.e. support depth) is selected according to the standard design. The standard design comes from common experience, and the scientific basis is not sufficient. Due to the geological conditions of each section of each mine, the rock The occurrence conditions are different, so the depth of deformation and damage of surrounding rocks is different. If the bolt is selected according to the current standard design, the following disadvantages will be brought. If the choice is too long, the construction volume will be large and the bolt material will be wasted; if the choice is too short, the support effect will not be achieved, and the surrounding rock will still be deformed and damaged. So far, there has not been an accepted scientific method to quantitatively determine the length of bolt or anchor cable under different surrounding rock conditions.

With the development of science and technology, the borehole TV technology has become very mature. The so-called borehole TV technology is to use the intelligent borehole imager to observe the images of the distribution of rock formation cracks and abscission layers in the borehole, and its built-in control module collects the images, Processing, editing, displaying, storing and transmitting, so as to obtain the surrounding lithology and primary fracture distribution of the measured borehole wall. The specific working method is: use the guide rod to advance the color camera of the intelligent borehole imager along the axis of the borehole, and record the advance depth at the same time by the depth counter until the bottom of the borehole. During the advance process, the color camera probe observes the rock formation in the borehole Image, the built-in module processes and edits the image, and the video signal is transmitted to the LCD screen of the host computer by the video transmission line, and the inner wall of the borehole can be displayed on the display screen. This technology has high observation accuracy, accurate positioning, and simple on-site operation. It has been widely used in engineering geology, geological prospecting, geotechnical engineering, mining and other departments, but it has not been applied to bolt support. The adoption of these new technologies can provide reliable technical design basis for bolt support.

Contents of the invention

In order to promote the advancement of coal mine roadway bolt support technology, the applicant undertook the national 973 project "Basic Research on Mechanism and Prevention of Dynamic Disasters in Deep Coal Mining". Roof support form and method of support depth". In the above method, it includes determining whether it is the bolt support, the anchor cable support or the combined support of the bolt and cable, and the support depth. The support depth determined according to the present invention can further determine the length of the anchor rod and the length of the anchor cable.

The technical solution of the present invention takes the following steps:

The first step: the determination of the measuring hole

Drilling holes are drilled in the deep part of the surrounding rock facing the vertical rock on the roof of the excavated deep roadway, and the drilling holes are arranged near the central axis of the roadway section. Because the coal mine roadway is generally no more than 5 meters in width and no more than 3 meters in height. Under this section size of the roadway, the thickness range of the roof that has a significant impact on the roadway support does not exceed 3 times the height of the roadway. At the same time, for the same roadway arranged along the coal seam, the geological conditions within the length of 80-100 meters generally represent the geological conditions of the entire roadway. Therefore, a hole is arranged at intervals of 15-20 meters along the direction of the roadway, the drilling depth is 10 meters, six holes are arranged in a row, and the length of the roadway of 100 meters is used as the measurement area.

Step 2: Probing of the Measuring Hole

An intelligent borehole imager is arranged in the roadway, and the borehole TV technology is used to detect the lithology of the borehole wall, the direction of the original crack, and the distance between the cracks. The detection process is as follows:

(1) Turn on the intelligent borehole imager, make it in the recording state, and clear it;

(2) Use the guide rod to push the camera along the drilling axis until the bottom of the hole. If the hole is deep, you can extend the length with an external guide rod;

(3) During the advancing process, the color camera probe actually measures the image of the rock formation in the borehole, and the video signal is transmitted to the host LCD by the video transmission line. Images and data of the inner wall lithology, fracture distribution and separation conditions of boreholes at different depths.

Step 3: Determination of the rupture zone

According to the data and images obtained in the second step, the computer image processing software of the intelligent borehole TV imager is used to edit and process the images, so as to obtain the alternate interval occurrence and spatial distribution of the fractured zone and the complete zone in the surrounding rock of each borehole The situation, that is, the number of layers and the thickness of the fractured zone and the intact zone in each borehole, the structural zone with a thickness greater than or equal to 30cm and no rupture is defined as the complete zone, which is called the first structural zone and the second structural zone in sequence from the hole opening. zone, the third structural zone, and so on, and then add and average the thicknesses of all drill holes in the same structural zone to obtain the average thickness of each structural zone in the survey area;

The above-mentioned structural zones include intact zones and fractured zones alternately distributed in two forms, namely:

When the first structural zone is a complete zone, the second structural zone is a fractured zone, the third structural zone is a complete zone, and so on;

When the first structural zone is a ruptured zone, the second structural zone is a complete zone, the third structural zone is a ruptured zone, and so on;

Step 4: Determine the support form and support depth

(1) When the first structural belt is a complete belt longer than 3 meters, no anchor support is needed, and other support forms such as simple scaffold support can be used;

(2) When there are only three structural zones and the first structural zone is a complete zone less than 3 meters but greater than 2 meters, use anchor cables for support, and the anchor cables should pass through the second structural zone and be anchored in the third structural zone ;

(3) When there are only two structural zones and the first structural zone is a rupture zone greater than 2 meters, anchor cables shall be used for support, and the anchoring ends of the anchor cables shall be anchored in the second structural zone;

(4) When there are only two structural zones and the first structural zone is a rupture zone less than 2 meters long, use bolts for support, and the bolts are anchored in the second structural zone;

(5) When the first structural zone is a rupture zone of less than 2 meters and there are more than two interval rupture zones, joint support of anchor rods and anchor cables is required, and the anchoring end of the anchor rod should be anchored in the second structural zone. The cable anchoring end should pass from the first construction zone until anchored in a full zone greater than 50 cm thick.

The positive effect of the present invention is: when designing the support depth of anchor rods and anchor cables, sufficient scientific basis is obtained, the support parameters are more economical and reasonable, and the best support effect is achieved under the most economical conditions. The invention can scientifically and quantitatively determine the anchoring form of the deep roadway and the length of the roof anchor rod and the anchor cable, and has important promotion value for realizing the quantitative design of the anchoring support of the deep high-stress roadway and ensuring the safety of the roof of the deep roadway.

Description of drawings:

Fig. 1 takes a coal mine as an example in the implementation of the drill hole layout cross-sectional schematic diagram.

Fig. 2 is a schematic diagram of the arrangement of boreholes along the direction of the roadway in the present application.

Fig. 3, Fig. 4, Fig. 5 and Fig. 6 are diagrams of support forms under different conditions of the structural zone respectively.

In the figure: 1-intelligent drilling imager, 2-roadway, 3-roof, 4-guide rod, 5-color camera, 6-drilling hole, 7-bolt rod, 8-anchor cable, I-the first structural belt , II-second structural zone, III-third structural zone, IV-fourth structural zone;

Detailed ways

Now in conjunction with the accompanying drawings and taking a certain mine as an example, the technical scheme of the present invention will be described in detail.

1. Firstly, according to the layout of the boreholes shown in Fig. 1 and Fig. 2, the images in the boreholes are actually measured and calculated to determine the structural belt conditions, as follows:

(1) Determine the 100-meter survey area along the direction of the roadway 2. On the roof 3 axis, drill a borehole 6 every 20m, and drill six boreholes 1#, 2#, and 3# in the 100m survey area , 4#, 5#, 6# (as shown in Figure 2), the depth of the borehole 6 is 10.5m, the diameter is 43mm, and the intelligent borehole imager 1 is arranged in the roadway 2.

(2) Turn on the intelligent borehole imager 1, make it in the recording state, and clear it;

(2) Utilize the guide rod 4 to advance the color camera 5 along the axis of the borehole 6 until it reaches the bottom of the borehole 6. If the borehole 6 is deep, the guide rod can be extended externally;

(3) During the advancing process, the color camera 5 actually measures the image of the rock formation in the borehole 6, and the video signal is transmitted to the host liquid crystal display of the intelligent borehole imager 1 by the video transmission line, and the depth counter of the intelligent borehole imager 1 simultaneously Record the advancing depth of the color camera 5. The construction situation in the depth range of the borehole 6 is displayed on the display screen.

(4) According to the obtained data and images, use the computer image processing software of the intelligent borehole imager 1 to edit and process the images to obtain the situation of the structural zone, and stipulate that when the rock with a thickness of more than 30cm has no fracture, it is a complete zone, and there is The fractured zone is the fractured zone, and the average thickness of each structural zone in the survey area is obtained by adding and averaging the thicknesses of the six boreholes in the same layer of the structural zone, so as to obtain the alternate interval distribution of the fractured zone and the intact zone, that is, The thickness of each band and the number of layers to construct the band. Counting from the orifice, it is called the first structural zone, the second structural zone, the third structural zone, and so on;

The above-mentioned structural zones include intact zones and fractured zones alternately distributed in two forms, namely:

When the first structural zone is a complete zone, the second structural zone is a fractured zone, the third structural zone is a complete zone, and so on;

When the first structural zone is a ruptured zone, the second structural zone is a complete zone, the third structural zone is a ruptured zone, and so on;

2. Determine the support form and support depth according to the thickness and distribution of each structural zone mentioned above. A few examples are given below for illustration based on FIG. 3 , FIG. 4 , FIG. 5 and FIG. 6 .

The distribution of structural zones shown in Figure 3 is: the first structural zone I is a complete zone with a thickness of 2.1 meters; the second structural zone II is a broken zone with a thickness of 2.5 meters; the third structural zone III is a complete zone with a thickness greater than 4.6 meters ; It belongs to the complete belt situation that the first structural zone is less than 3 meters and greater than 2 meters, so 8 anchor cables are used for support, and the anchor ends of the anchor cables 8 are anchored in the third structural zone III, and the support depth is 2.5+2.1=4.6 meters , the anchor cable length is 4.6+0.8 (anchor length)+0.1 (exposed length)=5.5 meters.

The distribution of the structural zones shown in Figure 4 is: the first structural zone I is a rupture zone with a thickness of 2.5 meters, the second structural zone II is a complete zone greater than 2.5 meters, and there are only two structures belonging to the first structural zone I. 3.0 meters is greater than 2.0 meters, so 8 anchor cables are used for support, and the anchor cables 8 anchor ends are anchored in the second structural zone II, the support depth is 2.5 meters, and the anchor cable length is 2.5+0.8(anchor length)+0.1( exposed length) = 3.4 meters.

The distribution of structural zones shown in Figure 5 is: the first structural zone I is a rupture zone with a thickness of 1.5 meters, and the second structural zone II is a complete zone greater than 8.5 meters, which belongs to only two structural zones and the first structural zone I In the case of the rupture zone less than 2.0 meters, the anchor rod 7 is used for support. The anchor end of the anchor rod 7 should be anchored in the second structural zone II, the support depth is 1.5 meters, and the length of the anchor rod 7 is 1.5+0.4 (anchor length) +0.1 (exposed length) = 2.0 meters.

The distribution of structural zones shown in Figure 6 is: the first structural zone I is a 1.5-meter-thick rupture zone, the second structural zone II is a 0.4-meter-thick complete zone, the third structural zone III is a 0.45-meter-thick rupture zone, and the second structural zone II is a 0.4-meter-thick rupture zone. The fourth structural zone IV is a complete zone greater than 7.65 meters, belongs to the first structural zone I is a ruptured zone less than 2.0 meters, and there are more than two separated ruptured zones, so the joint support of the anchor rod 7 and the anchor cable 8 is used. The anchor rod 7 is anchored in the second construction zone II, the length of the anchor rod 7 is 1.5+0.4+0.1=2.0 meters, and the anchor cable 7 should be anchored through the first construction zone I, the second construction zone II, and the third construction zone III In the fourth belt IV, the anchor cable length is 1.5+0.4+0.45+0.8 (anchor depth)+0.1 (exposed)=3.25 meters.

Claims (1)

1. definite method of the deep tunnel roof support form and the supporting degree of depth is characterized in that it may further comprise the steps:

The first step: the confirming of measured hole

Vertical scar is to the hole of drilling, country rock deep on the deep tunnel roof that has tunneled; Drill holes drift section near the axis on, move towards every interval 15-20 rice along the tunnel and arrange a hole, 10 meters of drilling depths; Arrange continuously six holes, with 100 meters tunnel length as measurement zone;

Second step: the detection of measured hole

In the tunnel, arrange intelligence boring imager, adopt the borehole television technology that direction, the gap length distance of borehole wall lithology, initial fissure are surveyed, its detection process is:

(1) open intelligence boring imager, make it be in recording state, and zero clearing;

(2) utilize guide rod to advance camera along the boring axle center, up to foot of hole, if boring is dark, outer guide rod lengthening;

(3) rock stratum image in colored camera probe actual measurement is holed in progradation; By video transmission line with video signal transmission to the main frame LCDs; Be advanced to the degree of depth of boring by depth counter recording colour camera, on display screen, demonstrate different depth boring inwall lithology, the crack distributes and the image and the data of absciss layer situation;

The 3rd step: the confirming of the zone of fracture

Go on foot data and the image that obtains according to second; Utilize the Computer Image Processing software of intelligent drilling television imager that image is carried out editing and processing; Thereby obtain each boring country rock implosion band and complete tape alternation occurrence and spatial distribution situation at interval, promptly the number of plies and the thickness thereof of each boring implosion band and complete band stipulate more than or equal to the non-cracked structural belt of 30cm thickness to be complete band; Count from the aperture and to be called first structural belt, second structural belt successively; The 3rd structural belt, the rest may be inferred, and the thickness that again all borings is in same layer structural belt addition respectively on average obtains surveying the average thickness of each structural belt in the district;

Above-mentioned structural belt comprises the alternatively distributed complete band and the zone of fracture, and distribution form has two kinds, that is:

When first structural belt was complete band, second structural belt was the zone of fracture, and the 3rd structural belt is complete band, and the rest may be inferred;

When first structural belt was the zone of fracture, second structural belt was complete band, and the 3rd structural belt is the zone of fracture, and the rest may be inferred;

The 4th step: confirm the support form and the supporting degree of depth

(1) when first structural belt be during greater than 3 meters complete band, without anchoring support, only adopt simple frame supporting;

(2) when three structural belts and first structural belt only being arranged for the time less than 3 meters but greater than 2 meters complete band, the employing cable bolting, anchor cable should pass second structural belt and be anchored in the 3rd structural belt;

(3) when two structural belts and first structural belt only being arranged for greater than 2 meters the zone of fracture time, adopt cable bolting, the anchorage cable anchoring end should be anchored in second structural belt;

(4) when two structural belts and first structural belt only being arranged for the time, adopt bolt support less than 2 meters the zone of fracture, anchor rod anchored in second structural belt;

(5) when first structural belt is less than 2 meters zone of fractures and has the zone of fracture, plural interval; Need anchor pole, anchor cable combined supporting; Anchor rod anchored end should be anchored in second structural belt, and the anchorage cable anchoring end should pass until being anchored at the complete band thick greater than 50cm from first structural belt.

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