CN106401609A - Bottom plate pressure relief and reinforcement structure for controlling floor heave of deep roadway and construction method of bottom plate pressure relief and reinforcement structure - Google Patents

Abstract

The invention discloses a bottom plate pressure relief and reinforcement structure for controlling a floor heave of a deep roadway and a construction method of the bottom plate pressure relief and reinforcement structure. The construction method comprises the following steps: (1) excavation of a roadway and anchor mesh supporting: excavating the deep roadway, and performing the anchor mesh supporting on a surrounding rock after the surrounding rock is formed; and (2) digging of two pressure relief troughs: respectively digging a long-strip-type pressure relief trough in each of the left and right sides of a bottom plate of the roadway through an air pick along the axial direction of the roadway, wherein the cross section of each pressure relief trough is rectangular, and the pressure relief troughs take a boundary line of one side end as a symmetric line. In conclusion, a bottom plate pressure relief method is used for controlling the problems of the floor heave of the deep roadway and deformation of the surrounding rock; and on the basis of a deep roadway anchor and injection supporting technology at the present, the pressure relief effect on the surrounding rocks on the bottom plate, two ends and a top plate is improved by reasonably determining the shape, the size and the arrangement position of each pressure relief trough, the number of secondary interstices in the surrounding rocks is increased, the grouting effect on the surrounding rocks is enhanced, the problem of the floor heave of the deep roadway can be effectively controlled, and long-term stability of the surrounding rock of the deep roadway is guaranteed.

Description

A floor pressure relief and reinforcement structure for controlling the bottom of deep roadway and its construction method

technical field

The invention belongs to the field of roadway support, and in particular relates to a floor pressure relief reinforcement structure for controlling deep roadway bottom sag and a construction method thereof.

Background technique

Due to the impact of roadway excavation or coal seam mining, the stress field of the original rock is destroyed, causing the stress redistribution of the surrounding rock of the roadway. When the concentrated stress of the surrounding rock exceeds the strength of the surrounding rock, the surrounding rock undergoes plastic deformation, which is mainly manifested as the roof and floor of the roadway and the surrounding walls of the two sides. The rock moves to the roadway space, and the movement of the surrounding rock of the roadway floor to the roadway becomes the bottom rock. Under normal circumstances, the roadway floor is in a state of no support or no closure, and the support strength of the roadway floor is lower than that of the two sides and the roof of the roadway. The deformation and damage of the roadway first starts from the bottom of the roadway, that is, the bottom of the roadway, and then the two sides of the roadway converge, resulting in The roadway support is completely ineffective. Therefore, the bottom of the deep mining roadway (cavement) has always been the main factor affecting the stability of the surrounding rock of the roadway (cavement) and increasing the difficulty of roadway support. The distance is more than 80%, and the bottom of the roadway not only increases the distance of the roof and the floor, but also reduces the section size of the roadway, which affects the normal transportation, ventilation and pedestrians of the roadway. When the bottom thickness reaches 0.8~1m or more, the roadway needs undercover maintenance, and the maintenance cost is high. For chambers such as the machine head or winch room where large fixed equipment is installed, if a certain undershoot occurs in the chamber, it will cause the base of the large equipment to tilt, which will directly affect the normal operation of the equipment, and even stop production for maintenance. , is a hidden danger to normal pedestrians and safe transportation in coal mine roadways, and poses a serious threat to mine safety production. With the increase of coal mining depth, the mine enters deep mining, the geological conditions of the mine deteriorate, and the roadway surrounding rock of hard rock in shallow mining gradually transforms into deep soft rock. The approaching amount of the surrounding rock of the roadway, especially the amount of bottom sill, has increased significantly, and the problem of bottom sag has become more prominent. The field observation results of a large number of coal mine roadways show that under the condition of mining depth of 600-800m, the roadways with bottoms account for about 25%; under the condition of mining depth of 900m, the bottom roadways account for about 40%; The undercut roadway exceeds 80%, and with the increase of mining depth, the undercut amount and its proportion in the approaching amount of the roof and floor will gradually increase. The roadway with serious bottom slack causes the increase of the approach of the two sides of the roadway, the deformation of the surrounding rock of the roadway is in a rheological state, and the surrounding rock is in an unstable state. completely scrapped. Therefore, how to effectively control the bottom of the deep roadway and maintain the long-term stability of the surrounding rock of the roadway floor has important practical significance for ensuring the normal use of the deep mining coal mine roadway and mine safety production.

Contents of the invention

In order to solve the deficiencies in the prior art, the present invention provides a method for controlling deep roadway bottom swell with simple structure, convenient construction, reasonable design and effective control of roadway bottom swell.

In order to solve the above technical problems, the present invention adopts the following technical scheme: a floor pressure relief and reinforcement structure for controlling deep roadway bottom slabs, including two pressure relief grooves arranged on both sides of the roadway bottom plate and sprayed concrete sprayed on the surface of the roadway surrounding rock , there are several anchor layers in the deep rock formation around the roadway, all the anchor layers are arranged side by side along the axial direction of the roadway, and each row of anchor layers includes several anchor rods arranged uniformly along the circumference of the roadway. The anchor tail ends of the anchor rods are fixed by nuts, and there is a tray that is crimped with the sprayed concrete. The left and right sides of the roadway floor.

A construction method for controlling a bottom slab pressure-relieving reinforcement structure of a deep roadway bottom, comprising the following steps:

(1) Excavate the roadway and carry out anchor net support: the deep roadway is excavated, and after the surrounding rock is formed, implement anchor net support for the surrounding rock;

(2) Dig out two pressure relief grooves: on the left and right sides of the roadway floor along the axis of the roadway, use a pick to dig out a long strip of pressure relief grooves. The cross section of the pressure relief groove is rectangular, and the pressure relief groove Taking the boundary line of one side of the roadway as the symmetrical line, the depth of the pressure relief groove is 2000mm, and the width is 800mm. The depth of the pressure relief groove refers to the length along the height direction of the pressure relief groove, and the width of the pressure relief groove refers to the length of the pressure relief groove The length along the left and right directions, the length of the pressure relief groove is the length of the roadway;

(3) Grout the floor and fill the pressure relief groove with concrete; the pressure relief groove is excavated, and the surrounding rock of the roadway is deformed. After 10-15 days of pressure relief for the surrounding rock, the roadway floor is reinforced by grouting, and then Two pressure relief grooves are filled with sprayed concrete;

(4) Reinforce the two sides of the roadway and the inside of the roof by grouting.

3. The floor pressure relief and reinforcement structure for controlling deep roadway bottom sag and its construction method according to claim 2, characterized in that: in step (1), the specific steps of implementing anchor net support for surrounding rock are:

a) Spray a layer of shotcrete on the rough section of the roadway;

b) Then construct the first row of anchor layers along the ring direction of the roadway, and install the anchor end of the anchor on the sprayed concrete through the tray;

c) After the construction of the first row of anchor layers is completed, the second row of anchor layers and the third row of anchor layers are sequentially constructed along the axial direction of the roadway. At the same time, the anchor ends of all the anchors in each row are passed through the pallet. Installed and fixed on the sprayed concrete;

Then, the anchor tail ends of all the anchor rods are connected together by the steel wire ropes along the axial direction and the circumferential direction of the roadway, and the steel wire ropes in the axial direction and the circumferential direction of the roadway form a netted steel wire rope net.

Using the above technical scheme, on the basis of the current deep roadway anchoring and grouting support technology, the floor pressure relief method is used to control the bottom of the deep roadway. By arranging double rectangular pressure relief grooves with reasonable positions and reasonable sizes on the bottom of the deep roadway, after 10 ~ After 15 days of pressure relief, the surrounding rock of the roadway deforms, the high stress in the two sides of the roadway and the roof and floor transfers to the deep surrounding rock, and the stress of the surrounding rock in the shallow part of the roadway decreases, which can significantly improve the stress field of the surrounding rock in the roadway; The bearing capacity of the deep surrounding rock reduces the support resistance of the shallow confining pressure, thereby reducing the difficulty of roadway support. When the deformation of the surrounding rock tends to be stable, the surrounding rock of the roadway floor, two sides and the roof shall be reinforced by grouting to ensure the long-term stability of the roadway floor, two sides and the roof surrounding rock. After excavating the deep roadway and exposing the surrounding rock for anchor net support, two rectangular pressure relief grooves with a width of 800mm and a depth of 2000mm were manually excavated on both sides of the roadway floor at a distance of about 5m from the head. The pressure relief groove is located at the bottom of the two sides of the roadway and the bottom of the roadway floor, and the boundary line of the two sides of the roadway is the symmetry line of the pressure relief groove; when the broken rock in the pressure relief groove is taken out, two "weak structures" are formed on the roadway floor, which is the roadway A certain deformation space is reserved for the bottom; after the pressure is relieved, the high stress of the shallow floor of the roadway is transferred to the deep rock formation. When the broken rock in the pressure relief groove at the bottom corner of the roadway is compacted and compacted, and the deformation of the surrounding rock of the floor is absorbed, it shows that the "weak structure" has effectively released the high stress of the roadway floor, two sides and the roof, and improved the roadway. The surrounding rock stress distribution of the floor, two sides and the roof. Usually 10 to 15 days after the excavation of the pressure relief groove, the stress of the shallow roof and floor of the roadway and the surrounding rock of the two sides are fully released, which is mainly manifested by deformation and movement of the surrounding rock. During the formation process of the floor pressure relief groove and the process of pressure relief, the primary cracks in the roadway roof, two sides and the surrounding rock stratum of the roof further open, expand and extend, and new secondary cracks appear at the same time, resulting in the development of cracks in the surrounding rock, which is It is conducive to the pressure relief of the two sides of the roadway and the roof rock layer, and is also conducive to the grouting reinforcement of the roadway floor, the two sides and the surrounding rock of the roof in the later stage. After the bottom plate pressure relief groove is relieved, the surrounding rock of the roadway bottom plate is first grouted and reinforced, and then the double bottom plate pressure relief groove is filled with sprayed concrete to form two “strong structures” in the roadway bottom plate surrounding rock. The "strong-weak-strong" support structure of the roadway floor can effectively support and control the bottom of the roadway. Finally, when the deformation of the two sides of the roadway and the sinking speed of the roof are stable, the two sides of the roadway and the roof are reinforced by grouting. After grouting, it is beneficial to improve the strength of the surrounding rock, and at the same time increase the support performance of the anchor net support. Therefore, the present invention takes measures from two aspects of improving the supporting strength of the surrounding rock of the deep roadway and reducing the stress of the surrounding rock of the roadway, so as to ensure that the surrounding rock of the deep roadway and the anchoring and grouting support system tend to be balanced, and achieve the purpose of stabilizing the surrounding rock of the deep roadway for a long time ;

The pressure relief effect of the pressure relief groove on the floor of the roadway can be expressed by the range of the stress reduction area and the stress value of the shallow rock formation on the floor, and the strength of the shallow rock formation on the floor. The former is related to the size of the pressure relief groove, including the depth and It is related to the width, and the latter is related to the grouting reinforcement of the bottom plate. Under the current technical conditions of using pneumatic picks to implement the pressure relief construction of the bottom plate, the depth of the pressure relief groove directly affects the difficulty of the pressure relief construction and the pressure relief effect. When the pressure relief groove is shallow, it will affect the pressure relief effect, and if it is deep, it will directly increase the difficulty of construction. In recent years, pressure relief-strengthening grooves have been carried out on-site in the horizontal roads and upper (lower) mountain roadways of Pingdingshan Tianan Coal Industry Co., Ltd. in Pingdingshan Mining Area, Henan Province. sex test, the effect is remarkable. Therefore, on the basis of field tests in the Pingdingshan mining area, combined with numerical calculation results, the present invention studies the floor pressure relief-strengthening grooves to control the bottom of the deep roadway and its construction method, and determines the position of the deep roadway floor pressure relief groove, the pressure relief groove Reasonable size can effectively improve the stress distribution state of the surrounding rock of the deep roadway, improve the effect of traditional anchoring and grouting support, reduce the support and maintenance costs of the deep roadway, and ensure the long-term stability of the surrounding rock of the deep roadway and the normal production of the coal mine .

In summary, the present invention adopts the bottom plate pressure relief method to control the deformation of the deep roadway bottom and surrounding rock. On the basis of the current deep roadway anchoring support technology, the shape, size and layout of the pressure relief groove are reasonably determined position, improve the pressure relief effect of the surrounding rock of the bottom plate, two sides and the roof, increase the secondary cracks in the surrounding rock, improve the grouting effect of the surrounding rock, effectively control the problem of deep roadway bottom sag, and ensure the long-term stability of the deep roadway surrounding rock .

Description of drawings

Fig. 1 is the sectional view of the anchor shotcrete support roadway of the present invention;

Fig. 2 is a schematic diagram of roadway layout of the present invention;

Fig. 3 is an axial sectional view of the roadway of the present invention.

detailed description

As shown in Figures 1-3, a floor pressure relief and reinforcement structure for controlling deep roadway bottom slabs according to the present invention includes two pressure relief grooves 3 arranged on both sides of the roadway bottom plate 2 and sprayed concrete sprayed on the surface of the roadway surrounding rock 4. Several anchor layers are arranged in the deep rock formation around the roadway, and all the anchor layers are evenly arranged side by side along the axial direction of the roadway. The anchor tail ends of the anchor rods 1 are fixed by bolts and provided with a tray 5 that is press-fitted with the sprayed concrete 4, the anchor rods 1 and the surface of the sprayed concrete 4 are vertically arranged, and the anchor tail ends of adjacent anchor rods 1 are connected by wire ropes; Two pressure relief grooves 3 are symmetrically arranged on the left and right sides of the roadway bottom plate 2 .

A construction method for controlling a bottom slab pressure-relieving reinforcement structure of a deep roadway bottom, comprising the following steps:

(1) Excavate the roadway and carry out anchor net support: the deep roadway is excavated, and after the surrounding rock is formed, implement anchor net support for the surrounding rock;

(2) Dig out two pressure relief grooves; after the roadway is supported by the anchor net, in order to control the bottom of the roadway floor 2, a long strip is dug out on both sides of the roadway floor 2 along the length direction of the roadway with a pick. The pressure relief groove 3, the cross section of the pressure relief groove 3 is rectangular, the pressure relief groove 3 takes the boundary line of the side of the roadway as the symmetrical line, the depth of the pressure relief groove 3 is 2000mm, and the width is 800mm, of which the depth of the pressure relief groove 3 Refers to the length along the height direction of the pressure relief groove 3, the width of the pressure relief groove 3 refers to the transverse length of the pressure relief groove 3, and the length of the pressure relief groove 3 is the length of the roadway.

(3) Grout the bottom plate 2 and fill the pressure relief groove 3 with concrete; after 10-15 days of pressure relief, when the broken rock in the pressure relief groove 3 of the roadway bottom plate 2 is compressed and compacted, the deformation of the surrounding rock of the bottom plate 2 will be absorbed , indicating that the "weak structure" formed by the pressure relief groove 3 effectively releases the high stress in the roadway floor 2 and improves the stress distribution of the roadway surrounding rock. The pressure groove 3 is filled with concrete, so that the surrounding rock of the roadway floor 2 forms two "strong structures". The "strong-weak-strong" support structure of the roadway floor 2 effectively controls the roadway bottom.

(4) Carry out grouting reinforcement to the two sides of the roadway and the roof; when the deformation of the two sides of the roadway and the sinking speed of the roof are stable, the two sides of the roadway and the roof should be reinforced by grouting in time to ensure that the surrounding rock of the roadway is in a stable state for a long time.

In step (1), the specific steps for implementing anchor net support to the surrounding rock are as follows:

a) Spray a layer of shotcrete 4 on the rough section of the roadway;

b) Then construct the first row of anchor layers along the ring direction of the roadway, and install the anchor tail end of the anchor 1 on the sprayed concrete 4 through the tray 5;

c) After the construction of the first row of anchor layers is completed, the second row of anchor layers and the third row of anchor layers are sequentially constructed along the axial direction of the roadway. At the same time, the anchor ends of all the anchor rods 1 are passed through the tray 5 Installed on the sprayed concrete 4;

d) Next, the anchor ends of all the anchor rods 1 are connected together by steel wire ropes along the axial and circumferential directions of the roadway, and the steel wire ropes in the axial and circumferential directions of the roadway form a netted steel wire rope net.

This embodiment does not impose any formal restrictions on the shape, material, structure, etc. of the present invention. All simple modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention belong to the protection of the technical solution of the present invention. scope.

Claims (3)

1. a kind of base plate release ruggedized construction controlling deep tunnel bottom distension it is characterised in that：Including being arranged in roadway floor two The twice pressure relief groove of side and the jetting cement being injected in roadway surrounding rock surface, the within the rock in tunnel-surrounding deep is provided with some anchor poles Layer, all of anchor pole layer is uniformly arranged side by side along the axial direction in tunnel, and often row's anchor pole layer includes some along tunnel-surrounding ring To the anchor pole being evenly arranged, the anchor tail end of anchor pole is fixed with pallet, anchor pole and spray with jetting cement press fit by nut Penetrate concrete surface to be vertically arranged, connected by steel wire rope between the adjacent anchor tail end of anchor pole；Twice pressure relief groove is symmetricly set on lane The left and right sides of road base plate.

2. the construction method of a kind of base plate release ruggedized construction controlling deep tunnel bottom distension according to claim 1, its It is characterised by：Comprise the following steps：

（1）Digging laneway simultaneously carries out bolting with wire mesh：Deep tunnel excavates, and after country rock molding, implements bolting with wire mesh to country rock；

（2）Dig out twice pressure relief groove：In the roadway floor left and right sides along the axis direction in tunnel, dig out one respectively using pneumatic pick The pressure relief groove of strip, the cross section of pressure relief groove is rectangle, pressure relief groove with the boundary line of tunnel one lateral wall as line of symmetry, release The depth of groove is 2000mm, and the depth of width 800mm, wherein pressure relief groove refers to the length along pressure relief groove short transverse, pressure relief groove Width refer to pressure relief groove length in left-right direction, the length of pressure relief groove is the length in tunnel；

（3）Base plate is carried out with slip casting and concrete filling is carried out to pressure relief groove；Pressure relief groove excavates, and roadway surrounding rock deforms, through 10- After country rock release in 15 days, grouting and reinforcing is carried out to roadway floor, afterwards twice pressure relief groove is carried out with jetting cement filling and enriches；

（4）Carry out grouting and reinforcing to inside roadway's sides and top board.

3. a kind of base plate release ruggedized construction controlling deep tunnel bottom distension according to claim 2 and its construction method, It is characterized in that：Step（1）In to country rock implement bolting with wire mesh concretely comprise the following steps：

One layer of jetting cement is sprayed on the rough section in tunnel；

Then along tunnel ring construction first row anchor pole layer, and by pallet, the anchor tail end of anchor pole is arranged on jetting cement；

The axis direction that the construction of first row anchor pole layer finishes tailing edge tunnel is constructed second row anchor pole layer, the 3rd row's anchor pole successively The anchor tail end of all of for each row anchor pole is fixed on jetting cement while construction by layer ... by pallet；

Then pass through and axially with the steel wire rope of ring, the anchor tail end of all of anchor pole link together along tunnel, tunnel axially and The webbed wire rope net of steel wire rope shape of ring.