CN105909289B - A kind of asymmetric roadway support structure of deep three-soft seam - Google Patents

Abstract

The invention discloses a support structure for an asymmetric roadway in deep three soft coal seams, which includes a roadway top support, a roadside side support and a roadway bottom support. The roadway top support includes a metal mesh for supporting the roadway top and a The top reinforced ladder beam, top anchor rod and top anchor cable at the roof of the roadway; the roadside support includes high-side support and low-side support, both of which include electric welded flat mesh for supporting the roadside and reinforcement The side reinforcement ladder beam and side anchor of the side of the roadway, the high side support also includes the side anchor cable; At the bottom corners on both sides formed by the side of the lane, the depression angle is 45°. The present invention adopts the joint support mode of anchor beam, net and cable, improves the stress state of the surrounding rock of the roadway through the setting of anchor rods, anchor cables, steel ladder beams, etc. Partial support, and at the same time set the floor angle anchor rod, so as to effectively control the floor heave of the roadway.

Description

A support structure for asymmetric roadway in deep three-soft coal seam

technical field

The invention relates to an asymmetric roadway support structure, in particular to an asymmetric roadway support structure in deep three soft coal seams.

Background technique

my country is a large coal-producing country, and coal is the main energy source in our country with abundant reserves. The Twelfth Five-Year Plan pointed out that until 2015, the proportion of coal in my country's energy consumption will still account for about 63%. It is difficult to change the coal-based energy structure. Since the founding of New China nearly 70 years ago, China's energy supply and consumption capacity has changed from weak to strong, and it has become the world's largest energy producer and second largest energy consumer. In recent years, the scale, output and depth of coal mining in the central and eastern regions of my country have been increasing year by year, and shallow coal resources have become less and less. In order to meet the urgent needs of economic development for coal production, coal enterprises have to turn to deep mining. According to a survey, more than 94% of coal mines in China are underground mines. The average mining depth of large and medium-sized coal mines is 456m, and the output of mines with a mining depth of more than 600m accounts for 28.5%, and the deepest reaches 1365m. Especially in recent years, the number of thousand-meter-deep wells in China has been increasing, and currently there are more than 20, but the safety hazards of deep well mining have also increased, especially the problem of roadway support in deep three-soft coal seams has become a technology that restricts the safe and efficient mining of coal mines One of the puzzles.

The three soft coal seams are encountered in coal mining: soft roof rock formation, soft main mining coal seam and soft coal seam floor rock formation. In general, the roof and floor of the coal seam with three soft features are weak rock formations, with well-developed coal seam fissures and complex structures. The roadway in the three-soft coal seam has the characteristics of soft surrounding rock, high stress, low strength, easy expansion when exposed to water, and no selectivity. With the continuous increase of mine mining depth, the original rock stress and tectonic stress continue to increase, and the stability of the surrounding rock in the third soft coal seam roadway is more difficult to control. The surrounding rock of the roadway will produce nonlinear large deformation, the roof of the roadway will sink seriously, the bottom plate will bulge, and the two sides will easily converge with asymmetric large deformation, which will bring great hidden dangers to the safe production of the mine.

At present, coal mine roadway support technology at home and abroad mainly includes material stone wall, concrete wall, truss, anchor rod, anchor cable, anchor injection, I-beam, U-shaped steel shrinkable support and high-strength concrete arc plate support, etc. In the mining roadway (coal roadway), the most important support technology is still based on bolt support (including plastic mesh, metal mesh, "W" steel belt and other combined forms). The above-mentioned support methods have their own advantages and disadvantages, but up to now, the roadway support in deep three-soft coal seams still has technical problems such as high support cost, large maintenance amount, poor support effect, and insufficient support theory and methods.

Contents of the invention

Purpose of the invention: The purpose of the present invention is to solve the problems existing in the prior art and provide an asymmetric roadway support structure in deep three soft coal seams that can effectively control the deformation of the roadway and reduce the maintenance cost of the roadway.

Technical solution: The asymmetric roadway support structure in deep three-soft coal seam according to the present invention includes roadway top support, roadside side support and roadway bottom support, and the roadway top support includes metal net and the top reinforced ladder beam, top anchor rod and top anchor cable for reinforcing the roadway roof; the roadside support includes high-side support and low-side support, both of which include electric welding flats for supporting the roadside Net and the side reinforcement ladder beams and side anchors used to reinforce the side of the roadway. The high side support also includes the side anchor cables; The pole is located at the corners on both sides formed by the bottom of the road and the side of the road, and its depression angle is 45°.

Specifically, the metal mesh is laid along the inclined surface of the roadway roof, the top reinforced ladder beams are arranged outside the metal mesh, spliced along the inclined direction of the roadway roof, and distributed at intervals in the longitudinal direction of the roadway, and the top anchor rods are vertically pierced on any top reinforced ladder beam The top anchor cable is located in the middle of the roadway roof, and the ladder beam passing through the top steel bar is located between the adjacent top anchor rods, and the adjacent top anchor cables are connected through the top channel steel in the longitudinal direction of the roadway.

Preferably, there are at least two top anchor cables, and the top anchor cables and the top anchor rods are distributed at intervals on the top reinforced ladder beam.

Further, the top reinforced ladder beams are distributed equidistantly in the longitudinal direction of the roadway, and the top anchors are equidistantly distributed on the top reinforced ladder beams.

Among them, the top anchor rods at the head and end of any top reinforced ladder beam are inclined 10° to the adjacent side of the road respectively.

In the above road side support, the welded flat mesh is laid along the side of the road, and the side reinforced ladder beams are arranged on the outside of the welded flat mesh, spliced longitudinally along the roadway, and distributed vertically on the side of the side. Pierce the anchor rod vertically.

Among them, on the side of the low side support, the side anchor rods are arranged staggeredly on the vertically adjacent side reinforcement ladder beams.

Among them, on one side of the high-side support, the vertical ends of the roadway are provided with side anchor cables. The side anchor cables are distributed along the longitudinal interval of the roadway, and the adjacent side anchor cables are connected by the side channel steel in the longitudinal direction of the roadway. The side channel steel is located between two vertically adjacent side reinforcement ladder beams; on the adjacent side side channel steel and the side reinforcement ladder beam, the side anchor cable and the side anchor rod The position of the side is staggered; the positions of the side anchors on the reinforced ladder beams of the adjacent two sides are staggered in the vertical direction of the side of the lane.

Preferably, the reinforcement ladder beams at the side are distributed at equal intervals in the vertical direction of the lane, and the anchor rods at the side are distributed at equal intervals on the ladder beams with reinforcement at the side.

Further, the gang anchor rod installed on the gang reinforcement ladder beam at the uppermost end of the road gang is inclined 10° to the road top, and the gang anchor rod pierced on the gang reinforcement ladder beam at the lowermost end of the road gang is inclined toward the road bottom. Tilt 10°.

Beneficial effects: Compared with the prior art, the advantage of the present invention is that: the present invention adopts the joint support method of anchor beams, nets and cables, and installs anchor rods, anchor cables, reinforced ladder beams and other components on the roof and side of the road, and reasonably Arrange the position, quantity and arrangement of each component to achieve the effect of improving the overall anchoring force of the surrounding rock of the roadway and the stress state of the surrounding rock of the roadway; by installing the side anchor cable on the high side of the roadway, it can be realized in complex conditions such as faults and folds. The purpose of strengthening the support of the high side of the roadway during the geological structure; in addition, setting the bottom angle anchor rods at the bottom corners on both sides of the roadway bottom, and making the bottom angle anchor rods support at a certain inclination angle can effectively control the roadway Bottom drum; when the roadway support structure of the present invention is used for asymmetrical roadway support in deep three soft coal seams, it can alleviate the stress concentration of the surrounding rock of the roadway, slow down the plastic deformation of the surrounding rock of the roadway, and effectively reduce the and the displacement of the bottom of the roadway, it can quickly and effectively contain the nonlinear large deformation of the roadway.

Description of drawings

Fig. 1 is the support section schematic diagram of roadway support structure of the present invention;

Fig. 2 is the roadway top support structure schematic diagram of roadway support structure of the present invention;

Fig. 3 is the high side support structure schematic diagram of roadway support structure of the present invention;

Fig. 4 is a schematic diagram of the low profile support structure of the roadway support structure of the present invention.

detailed description

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings.

In the present invention, the longitudinal direction of the roadway is the extension direction of the roadway, and the vertical direction of the side of the roadway is the height direction of the roadway. Since the top of the roadway is an inclined surface, there must be a vertical height difference between the sideways of the two sides, and the sideways on the higher side The gang is called the high gang, and the lane gang on the lower side is called the low gang.

As shown in Figures 1 to 4, the asymmetrical roadway support structure in the deep three soft coal seams of the present invention includes roadway top support, roadside side support and roadway bottom support, and the roadway top support includes metal for supporting the roadway roof. Mesh 1 and the top steel ladder beam 2, top anchor bar 3 and top anchor cable 4 used to reinforce the roof of the roadway; the roadside support includes high-side support and low-side support, and both side supports include The welded flat mesh 5 of the side, the side steel ladder beam 6 and the side anchor 7 for reinforcing the side of the roadway, the high side support also includes the side anchor cable 8; Angle anchor rod 9, the base angle anchor rod 9 is located at the bottom corners on both sides formed by the bottom of the roadway and the side of the roadway, and its depression angle is 45 °.

The present invention adopts the joint support method of anchor beam, mesh and cable, on the one hand, the stress state of the surrounding rock is improved by setting the anchor rods, anchor cables, steel ladder beams, etc. The support can locally strengthen the support of the high side of the roadway when complex geological structures such as faults and folds are encountered; on the other hand, the bottom heave of the roadway can be effectively controlled by setting the position and inclination angle of the bottom angle anchor.

As shown in Figure 2, in the roof support of the roadway, the metal mesh 1 is laid on the inclined surface of the roadway roof, and the top reinforced ladder beam 2 is arranged on the outside of it, and the top reinforced ladder beam 2 is spliced along the inclined direction of the roadway roof, and after splicing, it is distributed longitudinally in the roadway , such as can be distributed at equal intervals in the longitudinal direction of the roadway.

Top anchor rods 3 are set at intervals on each top reinforced ladder beam 2, and the distance between adjacent top anchor rods 3 can be equal; The adjacent side of the road is inclined by 10°, and the other top anchor rods 3 are perpendicular to the inclined surface of the road top.

The top anchor cable 4 is located in the middle of the roadway roof, passes through the top steel bar ladder beam 2, and is located between the adjacent top anchor rods 3, and the adjacent top anchor cables 4 are connected by the top channel steel 10 in the longitudinal direction of the roadway; the top anchor cable 4 can be When there is one top anchor cable, the top anchor cable 4 is located in the middle of the roadway roof; when there are at least two top anchor cables 4, the top anchor cable 4 is located in the middle of the roadway roof, and it is connected to the top Anchor rods 3 are distributed at intervals on the top reinforced ladder beam 2 .

As shown in Fig. 3 and Fig. 4, in the support of the side of the road, the welded flat mesh 5 is laid on the surface of the side of the road, and the side reinforcement ladder beam 6 is arranged on the outside, and the side reinforcement ladder beam 6 is spliced longitudinally along the roadway, and after splicing, it is placed on the side of the side of the road. Distributed at vertical intervals, the distance between the reinforced ladder beams 6 of two vertically adjacent sides can be equal.

Any side reinforcement ladder beam 6 is pierced with side anchor rods 7 at intervals, and the distance between adjacent side part anchor rods 7 can be equal; The bar 7 is inclined 10° to the top of the lane, and the anchor rod 7 of the side on the side reinforcement ladder beam 6 at the lowermost end of the side of the lane is inclined 10° to the bottom of the lane.

As shown in Fig. 4, on the side of the low side support, the side anchor rods 7 are staggeredly arranged on the vertically adjacent side reinforcement ladder beams 6.

As shown in Figure 3, on one side of the high-side support, side anchor cables 8 are provided at both vertical ends of the roadway. The side anchor cables 8 are distributed at intervals along the longitudinal direction of the roadway. The side channel steel 11 is connected, and the side channel steel 11 is located between two vertically adjacent side reinforcement ladder beams 6; on the side side channel steel 11 and the side reinforcement ladder beam 6, the side anchor cable 8 and the side anchor rod 7 are staggered in the vertical position of the side of the road; the positions of the side anchor rods 7 on the adjacent two side part reinforced ladder beams 6 are staggered in the vertical direction of the side of the road.

Example

Taking the deep three-soft coal seam roadway of a coal mine in the Huainan mining area as an example, the roadway support structure of the present invention is used to systematically study the roadway surrounding rock control effect.

1. Basic situation of roadway

Occurrence conditions of the three soft coal seams in the deep part of the mine: the roof and floor are composed of mudstone and clay rock, and partly composed of fine sandstone and siltstone, and there is a mudstone interlayer of about 1.2m in the middle of the coal seam. The roof mudstone is 1m thick and has low strength, and the siltstone is 7m thick and is medium-hard rock. The roof mudstone is 3.5m thick and the claystone is 1.8m thick, both of which are typical soft rocks. The roof and floor are all soft rock, and the coal seam is a typical three-soft coal seam.

The buried depth of the three-soft coal seam roadway is -650m, the vertical self-weight stress of the roadway is about 15.5MPa, and the maximum horizontal concentrated stress is 31MPa, which is in the range of 25-50MPa. According to the classification of soft rock, it can be judged that the surrounding rock of the roadway is of high stress soft rock. The roof of the roadway has developed cracks, and the rock mass structure is relatively broken. After the roadway was excavated, high ground pressure, large deformation, and difficult support appeared.

2. Deformation of roadway

Select two measuring points to observe the deformation of the surrounding rock of the roadway: within the 48-day observation period, the cumulative approach of the two sides of the roadway at measuring point 1 is 784mm, the maximum deformation speed is 80mm/d, and the average is 16.3mm /d, the sinking amount of the roof of the roadway is 369mm, the maximum deformation speed is 39mm/d, the average is 7.6mm/d, the bottom heave of the roadway is 386mm, the maximum deformation speed is 30mm/d, the average is 8.0mm/d; The accumulative approach of the two sides of the roadway in 2 is 783mm, the maximum deformation speed is 68mm/d, the average is 16.3mm/d, the sinking amount of the roadway roof is 375mm, the maximum deformation speed is 37mm/d, the average is 7.8mm/d, The bottom heave of the roadway is 391mm, the maximum deformation speed is 33mm/d, and the average is 8.1mm/d. From these two measuring points, it can be seen that the surrounding rock of the roadway is greatly deformed, and the effective section of the roadway is significantly reduced, especially the two sides and the floor of the roadway, which have seriously affected the normal use of the roadway.

3. Support scheme and support effect of the present invention

Adopt roadway support structure of the present invention to support this roadway below:

First, according to the rock mechanical parameters of the roof and floor of the three soft coal seams, the parameters such as the number of bolts, anchor cables and other components, row spacing, anchoring force, torque force and other parameters are determined; Be explained:

As shown in Figure 1, a total of 12 anchor rods and 4 anchor cables are arranged on the entire section, of which 3 top anchor rods and 2 top anchor cables are arranged on the top of the roadway, and the top anchor rods on both sides are inclined 10° to the side; 5 side anchors, 2 side anchor cables, 4 side anchors on the right low side, and the upper and lower side anchors are inclined 10° to the roadway top or bottom; the top and side anchors are both Use left-handed rebar without longitudinal reinforcement with a diameter of 22mm and a length of 2400mm. The row spacing between the top anchors and the side anchors is 700×700mm, the anchoring force is not less than 18MPa, and the torque force is not less than 100N m.

The material and parameters of the floor anchors are the same as those of the top anchors and side anchors, and they are arranged at the bottom corners on both sides of the roadway floor, with a depression angle of 45°. Both the top anchor cable and the side anchor cable are steel strands with a diameter of 17.8mm and a length of 7000mm. Connected by 16# channel steel. The metal mesh used on the roof of the lane is a metal rhombic mesh with a size of 4.0m×1.0m and a mesh size of 100mm×100mm; the welded flat mesh used for the two gangs has a size of 2.0m×1.0m and a mesh size of 100mm×100mm. The specifications of the top reinforced ladder beam and the side reinforced ladder beam are welded round steel with a diameter of Ф12mm, the net length is 4m, and the width is 50mm.

The support effect is as follows:

(1) Vertical stress and horizontal stress distribution

Stress concentration occurs in the vertical stress of the roadway surrounding rock, but the range is small, and the maximum degree of stress concentration is 1.8 times the stress of the original rock. The horizontal stress of the roadway surrounding rock is basically maintained at the stress level of the original rock, and there is no large stress concentration.

(2) Distribution of plastic zone in roadway surrounding rock

The anchoring effect of anchor rod and anchor cable is better, and the plastic zone of roadway surrounding rock is small.

(3) Deformation of roadway surrounding rock

The field industrial test results show that: the cumulative maximum deformation of the two sides of the roadway is 91mm, the maximum convergence speed of the two sides is 12mm/d, the average is 3.9mm/d, the maximum bottom drum is 60mm, and the maximum bottom drum speed is 4.5mm/d , the average is 1.6mm/d, the maximum sinking amount of the roof is 40mm, the maximum sinking speed is 4.5mm/d, and the average is 0.9mm/d. On the 40th day of observation, the deformation of the roadway basically tends to be stable, and the deformation of the surrounding rock of the roadway The control effect is remarkable.

Claims (5)

1. a kind of asymmetric roadway support structure of deep three-soft seam, it is characterised in that including lane topmast shield, roadside support and lane Bottom supporting, the lane topmast shield include being used for the wire netting (1) for supporting lane to push up and the top rebars ladder beam for reinforcing lane top (2), roll bolt (3) and top anchor cable (4)；The roadside support includes high side supporting and low side supporting, and two help supporting to wrap The electric welding plain net (5) for supporting lane side and portion of side reinforcing bar ladder beam (6) and side portion's anchor pole (7) for reinforcing lane side are included, The high side supporting also includes side portion's anchor cable (8)；Lane bottom supporting includes the FLOOR ANCHOR along the longitudinally asymmetric setting in tunnel (9), the FLOOR ANCHOR (9) is located at the both sides base angle that lane bottom is formed with lane side, and its angle of depression is in 45 °；

The electric welding plain net (5) is laid along lane side, portion of the side reinforcing bar ladder beam (6) on the outside of electric welding plain net (5), along tunnel Longitudinal spliced and be vertically spaced apart in lane side, interval vertical wears side portion's anchor pole (7) on any portion of side reinforcing bar ladder beam (6)；

The low side supporting side, side portion's anchor pole (7) are staggered on of vertically-adjacent portion of side reinforcing bar ladder beam (6)；It is described High side supporting side, the vertical both ends of lane side are provided with side portion's anchor cable (8), and side portion's anchor cable (8) is adjacent along tunnel longitudinally spaced distributions Side portion's anchor cable (8) is vertical upwardly through side portion's channel-section steel (11) connection in tunnel, and side portion's channel-section steel (11) is positioned at of vertically-adjacent two Between portion of side reinforcing bar ladder beam (6)；On adjacent side portion's channel-section steel (11) and portion of side reinforcing bar ladder beam (6), side portion's anchor cable (8) and side Stagger position of the portion's anchor pole (7) on lane side is vertical；Adjacent two help side portion's anchor pole (7) on portion's reinforcing bar ladder beam (6) in lane side Stagger position on vertical；

Portion of the side reinforcing bar ladder beam (6) is equidistantly spaced apart on lane side is vertical, and side portion's anchor pole (7) is in portion of side reinforcing bar ladder beam (6) equidistantly it is spaced apart on；

Side portion's anchor pole (7) on portion of the side reinforcing bar ladder beam (6) of lane side the top is arranged in 10 ° of lane top rake, is arranged in lane Side portion's anchor pole (7) on portion of the side reinforcing bar ladder beam (6) of bottom is helped to 10 ° of lane slanted floor.

2. three-soft seam asymmetric roadway support structure in deep according to claim 1, it is characterised in that the wire netting (1) laid along lane top rake face, the top rebars ladder beam (2) is spelled on the outside of wire netting (1), along lane top rake direction Connect and interval vertical wears roll bolt (3) in tunnel longitudinally spaced distributions, any top rebars ladder beam (2)；The top Portion's anchor cable (4) is located at lane top middle part and is located at adjacent top anchor pole (3) through top rebars ladder beam (2), adjacent top Anchor cable (4) is vertical upwardly through top channel-section steel (10) connection in tunnel.

3. three-soft seam asymmetric roadway support structure in deep according to claim 2, it is characterised in that the top anchor Rope (4) is at least two, and top anchor cable (4) is spaced apart with roll bolt (3) on top rebars ladder beam (2).

4. three-soft seam asymmetric roadway support structure in deep according to claim 2, it is characterised in that the top steel Muscle ladder beam (2) is equidistantly spaced apart on the longitudinal direction of tunnel, roll bolt (3) equi-spaced apart on top rebars ladder beam (2) Distribution.

5. three-soft seam asymmetric roadway support structure in deep according to claim 2, it is characterised in that any top steel Head end and the roll bolt of end (3) tilt 10 ° to its neighbouring lane side respectively on muscle ladder beam (2).