阅读说明：本技术 一种半封闭式大断面巷道软弱破碎底板加固方法 (Reinforcing method for semi-closed large-section roadway weak crushing bottom plate ) 是由 魏辉 李晓星 王凯 李全中 李�杰 于 2021-07-12 设计创作，主要内容包括：本发明公开了一种半封闭式大断面巷道软弱破碎底板加固方法,采用预制混凝土反底拱结构和灌注混凝土盖板对底板高应力进行支挡防护,方便快捷的保证软弱破碎底板的完整稳定。首先在开挖好的缓冲槽底部中间位置开挖卸压槽进行抵消高应力作用；其次在开挖的扇形区域拼插组合预制混凝土反底拱结构,混凝土反底拱结构两侧空腔填装碎矸石或炉渣；最后在巷道底板位置通过灌注混凝土形成盖板,最终形成半封闭式巷道加固结构。本方法通过卸压槽卸压、碎矸石层缓压、混凝土反底拱抗压、空心缓冲柱和充填空腔减压、混凝土盖板支挡稳固等程序,保证大断面巷道底板的完整稳定,工作顺利进行及人员安全作业。(The invention discloses a semi-closed large-section roadway weak crushing bottom plate reinforcing method, which adopts a precast concrete inverted arch structure and a poured concrete cover plate to support and protect high stress of a bottom plate, and conveniently and quickly ensures the integrity and stability of the weak crushing bottom plate. Firstly, excavating a pressure relief groove at the middle position of the bottom of an excavated buffer groove to counteract high stress action; secondly, splicing and combining the prefabricated concrete inverted arch structure in the excavated fan-shaped area, and filling crushed gangue or slag into cavities at two sides of the concrete inverted arch structure; and finally, forming a cover plate at the position of the roadway bottom plate by pouring concrete, and finally forming a semi-closed roadway reinforcing structure. According to the method, the pressure relief of the pressure relief groove, the pressure relief of the crushed gangue layer, the compression resistance of the concrete inverted arch, the pressure reduction of the hollow buffer column and the filling cavity, the stability of the concrete cover plate retaining and the like are performed, so that the completeness and the stability of the large-section roadway bottom plate are ensured, the work is smoothly performed, and the safety operation of personnel is realized.)

1. A semi-closed large-section roadway weak crushing bottom plate reinforcing method is characterized in that: the method comprises the following steps:

determining and dividing the positions and the damage ranges of a roadway bottom plate with a weak crushing bottom plate and a bottom heave damage easily generated in a large-section roadway or an underground chamber;

secondly, excavating a buffer groove on the bottom plate within the divided damage range, wherein the vertical section outline of the bottom of the buffer groove is in an arc shape;

thirdly, excavating a pressure relief groove at the bottom of the buffer groove along the central line of the roadway bottom plate;

fourthly, paving and cushioning a circular arc-shaped crushed gangue or slag layer on the bottom surface of the excavated buffer groove;

placing a prefabricated concrete inverted bottom arch in the buffer tank;

filling crushed waste rock or slag in the upper space of the concrete inverted arch, and gradually compacting and leveling;

and (seventhly), laying a reinforcing mesh on the upper surface of the crushed gangue or slag in the step (six), pouring concrete, and forming a concrete cover plate after the concrete is solidified, wherein the upper surface of the concrete is flush with the upper surface of the roadway bottom plate.

2. The reinforcing method of the semi-closed large-section roadway weak crushing bottom plate according to claim 1, characterized by comprising the following steps: and (2) in the step (II), the maximum excavation depth of the buffer groove is 1100mm, and the lowest position of the buffer groove is positioned on the central line of the roadway bottom plate.

3. The reinforcing method of the semi-closed large-section roadway weak crushing bottom plate according to claim 1, characterized by comprising the following steps: in the step (III), the size of the pressure relief groove along the width direction of the roadway is 500-.

4. The reinforcing method of the semi-closed large-section roadway weak crushing bottom plate according to claim 1 or 2, characterized by comprising the following steps: and (IV) paving the crushed gangue or slag layer on the bottom surface of the buffer tank in the step (IV), wherein the thickness of the crushed gangue or slag layer is 100 mm.

5. The reinforcing method of the semi-closed large-section roadway weak crushing bottom plate according to claim 1, characterized by comprising the following steps: in the step (V), the concrete inverted arch is integrally of an arc-shaped plate structure and comprises an arc-shaped concave inverted arch and an arc-shaped convex inverted arch, the arc-shaped concave inverted arch is positioned on the left side of the arc-shaped convex inverted arch, an arc-shaped slot with an opening on the right side is formed in the lower part of the arc-shaped concave inverted arch, an arc-shaped inserting plate inserted into the arc-shaped slot is integrally arranged on the left side of the arc-shaped convex inverted arch, a hollow buffer column positioned above the arc-shaped slot is arranged on the arc-shaped concave inverted arch, the vertical section of the hollow buffer column is of an isosceles triangle structure with a narrow upper part and a wide lower part, and the vertical central line of the isosceles triangle structure penetrates through the circle center where the concrete inverted arch is positioned; the lower side arc surface of the concrete inverted arch is in full contact with the buffer slot through the crushed gangue or the slag layer, so that a large-area left gap is avoided.

6. The reinforcing method of the semi-closed large-section roadway weak crushing bottom plate according to claim 1, characterized by comprising the following steps: and (seventhly), before the concrete is poured, the roadway bottom plate extends left and right into coal (rock) bodies on two sides of the roadway in the horizontal direction, two long slotted holes with the width of 400mm are formed, the reinforcing mesh also extends into the long slotted holes, when the concrete is poured, the concrete is poured into the long slotted holes at the same time, the left side and the right side of the concrete cover plate formed after solidification form strong supports for the concrete inverted bottom arch in the long slotted holes, and the thickness of the concrete cover plate is 200 mm.

Technical Field

The invention belongs to the technical field of mining maintenance control of mine roadways, and particularly relates to a reinforcing method for a semi-closed large-section roadway weak crushing bottom plate.

Background

In the process of mining mineral resources, particularly the mining of coal resources, along with the exhaustion of easily mined resources in the shallow part, the mining of coal occupies a main position under the complex condition in the deep part. When large-section roadways, chambers and other projects are excavated under deep complex geological conditions, the width of the section of the bottom plate is large, and the bottom heave damage sometimes happens. Particularly, under the condition that a large-section roadway bottom plate contains a weak broken coal rock stratum, the influence of overlying strata vertical stress, tectonic stress and underground water is added, the coal rock mass at the bottom of the roadway is easy to break and destabilize, bottom heave damage occurs, the section of the roadway is reduced, the lifting of the bottom plate influences transportation, ventilation and personnel walking, the roadway can be closed in serious conditions, the repair engineering quantity and the maintenance cost are increased, and the normal recovery and the working progress are influenced.

At present, the method for treating the heaving floor of the large-section roadway mainly adopts modes of punching a bottom plate, grouting and anchoring, setting a closed bracket and the like. Although the prevention and control methods can prevent the tunnel bottom plate from being damaged and deformed, the construction progress is slowed down due to the defects of large engineering quantity, complex construction process, time and labor waste in the construction process and the like. Therefore, on the premise of considering the stability and safety of the service roadway, a novel roadway bottom plate reinforcing method needs to be invented, the broken bottom plate can be conveniently and conveniently treated, the phenomena of bottom heave and the like of the roadway are prevented, the construction cost is reduced or lowered, the roadway bottom plate reinforcing time is shortened, and the service life of the roadway is maintained.

Disclosure of Invention

The invention aims to provide a reinforcing method of a semi-closed large-section roadway weak and broken bottom plate, which is convenient and rapid to construct, good in roadway floor heave prevention effect and long in period, so as to solve the problems in the prior art, reduce the floor heave damage caused by the roadway bottom plate due to high stress action, and avoid roadway deformation and influence on normal roadway functions.

In order to solve the technical problems, the invention adopts the following technical scheme: a semi-closed large-section roadway weak crushing bottom plate reinforcing method comprises the following steps:

determining and dividing the positions and the damage ranges of a roadway bottom plate with a weak crushing bottom plate and a bottom heave damage easily generated in a large-section roadway or an underground chamber;

secondly, excavating a buffer groove on the bottom plate within the divided damage range, wherein the vertical section outline of the bottom of the buffer groove is in an arc shape;

thirdly, excavating a pressure relief groove at the bottom of the buffer groove along the central line of the roadway bottom plate;

fourthly, paving and cushioning a circular arc-shaped crushed gangue or slag layer on the bottom surface of the excavated buffer groove;

placing a prefabricated concrete inverted bottom arch in the buffer tank;

filling crushed waste rock or slag in the upper space of the concrete inverted arch, and gradually compacting and leveling;

and (seventhly), laying a reinforcing mesh on the upper surface of the crushed gangue or slag in the step (six), pouring concrete, and forming a concrete cover plate after the concrete is solidified, wherein the upper surface of the concrete is flush with the upper surface of the roadway bottom plate.

And (2) in the step (II), the maximum excavation depth of the buffer groove is 1100mm, and the lowest position of the buffer groove is positioned on the central line of the roadway bottom plate.

In the step (III), the size of the pressure relief groove along the width direction of the roadway is 500-.

And (IV) paving the crushed gangue or slag layer on the bottom surface of the buffer tank in the step (IV), wherein the thickness of the crushed gangue or slag layer is 100 mm.

In the step (V), the concrete inverted arch is integrally of an arc-shaped plate structure and comprises an arc-shaped concave inverted arch and an arc-shaped convex inverted arch, the arc-shaped concave inverted arch is positioned on the left side of the arc-shaped convex inverted arch, an arc-shaped slot with an opening on the right side is formed in the lower part of the arc-shaped concave inverted arch, an arc-shaped inserting plate inserted into the arc-shaped slot is integrally arranged on the left side of the arc-shaped convex inverted arch, a hollow buffer column positioned above the arc-shaped slot is arranged on the arc-shaped concave inverted arch, the vertical section of the hollow buffer column is of an isosceles triangle structure with a narrow upper part and a wide lower part, and the vertical central line of the isosceles triangle structure penetrates through the circle center where the concrete inverted arch is positioned; the lower side arc surface of the concrete inverted arch is in full contact with the buffer slot through the crushed gangue or the slag layer, so that a large-area left gap is avoided.

And (seventhly), before the concrete is poured, the roadway bottom plate extends left and right into coal (rock) bodies on two sides of the roadway in the horizontal direction, two long slotted holes with the width of 400mm are formed, the reinforcing mesh also extends into the long slotted holes, when the concrete is poured, the concrete is poured into the long slotted holes at the same time, the left side and the right side of the concrete cover plate formed after solidification form strong supports for the concrete inverted bottom arch in the long slotted holes, and the thickness of the concrete cover plate is 200 mm.

By adopting the technical scheme, when the bottom plate of the weak crushing roadway is stressed to generate bottom heave, the pressure relief groove excavated firstly can weaken part of stress and energy; secondly, a crushed gangue or slag layer laid between the buffer groove of the excavated arc bottom and the precast concrete inverted arch can dissipate part of energy to play a role in buffering; thirdly, most of stress and energy can be dispersed and relieved through rigid blocking of the prefabricated concrete inverted arch and flexible buffering action of the hollow buffering columns; and finally, the concrete cover plate formed by pouring can support and block the residual stress action, so that the stability and the integrity of the roadway bottom plate are ensured.

The concrete inverted arch is spliced and inserted into the arc-shaped slot on the right side of the arc-shaped concave inverted arch through the arc-shaped inserting plate on the left side of the arc-shaped convex inverted arch during construction, the operation is convenient in the mode, and the split assembly structure of the concrete inverted arch is convenient to prefabricate in a factory.

The invention can more conveniently and quickly reinforce the roadway bottom plate in the maintenance work of the large-section roadway of the deep mine. When the roadway bottom plate is in a broken soft lithology condition, the bottom plate bulges into the roadway due to the vertical stress, the structural stress and the water reason of the overlying strata, and the integrity and the stability of the roadway are damaged. After the tunnel bottom plate breaks the soft rock stratum and is stressed, the pressure relief groove excavated firstly can dissipate and relieve part of stress and energy, and the deformation of the bottom plate is delayed; secondly, when the pressure relief groove loses the effect, the laid crushed gangue or slag layer can further buffer stress and energy, and the effect of the stress on the bottom plate is reduced; thirdly, the arc-shaped concave inverted bottom arch and the arc-shaped convex inverted bottom arch are spliced and inserted into a complete precast concrete inverted bottom arch to serve as a main stress structure for maintaining the integrity of the roadway bottom plate, most of stress can be prevented from damaging the bottom plate by the rigidity and the strength of the concrete structure, in addition, a hollow buffer column is arranged in the precast concrete inverted bottom arch, and when the concrete inverted bottom arch is damaged, the hollow buffer column can slow down the upward transmission of the stress and the energy again; finally, the garrulous waste rock that fills the intracavity and fills up and fill the concrete apron that forms of garrulous waste rock that hollow buffering post left side, the concave anti-bottom arch of arc top and hollow buffering post right side, the convex anti-bottom arch of arc top can exert its cushioning effect and prop up and keep off the effect, accomplishes the reinforcement protection to the bottom plate, more convenient and fast, labour saving and time saving's the integrality of assurance tunnel bottom plate.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

FIG. 1 is an overall schematic diagram of an embodiment of the present invention;

FIG. 2 is a schematic overall view of a precast concrete inverted arch;

FIG. 3 is a schematic diagram of a prefabricated concrete inverted arch after detachment;

fig. 4 is a top view of a precast concrete inverted arch.

In the figure: 1-roadway or chamber, 2-bottom plate, 3-buffer groove, 4-bottom plate center line, 5-pressure relief groove, 6-crushed gangue or slag layer, 7-concrete inverted arch, 8-arc concave inverted arch, 9-arc convex inverted arch, 10-crushed gangue filling cavity, 11-concrete cover plate, 12-coal (rock) body, 13-hollow buffer column, 14-crushed gangue or slag, 15-arc slot and 16-arc inserting plate.

Detailed Description

As shown in fig. 1-4, the method for reinforcing the weak crushing bottom plate of the semi-closed large-section roadway comprises the following steps:

determining and dividing positions and damage ranges of a roadway bottom plate 2 with a weak crushing bottom plate and a bottom heave damage easily occurring in a large-section roadway or chamber 1;

secondly, excavating a buffer groove 3 on the bottom plate 2 within the divided damage range, wherein the outline of the vertical section at the bottom of the buffer groove 3 is arc-shaped;

thirdly, excavating a pressure relief groove 5 at the bottom of the buffer groove 3 along the central line 4 of the roadway bottom plate;

fourthly, paving an arc-shaped crushed gangue or slag layer 6 on the bottom surface of the excavated buffer groove 3;

fifthly, placing a prefabricated concrete inverted bottom arch 7 in the buffer tank 3;

filling crushed gangue or slag 14 in the upper space of the concrete inverted arch 7, and gradually compacting and leveling;

and (seventhly), laying a reinforcing mesh on the upper surface of the crushed gangue or slag 14 in the step (six), pouring concrete, wherein the upper surface of the concrete is flush with the upper surface of the roadway bottom plate 2, and forming a concrete cover plate 11 after solidification.

In the step (II), the maximum excavation depth of the buffer groove 3 is 1100mm, and the lowest position of the buffer groove 3 is positioned on the center line 4 of the roadway bottom plate.

In the step (III), the size of the pressure relief groove 5 along the width direction of the roadway is 500-600mm, and the depth of the pressure relief groove 5 is 600-800 mm.

And (IV) the thickness of the crushed gangue or slag layer 6 paved on the bottom surface of the buffer tank 3 in the step (IV) is 100 mm.

In the step (V), the concrete inverted arch 7 is integrally of an arc-shaped plate structure, the concrete inverted arch 7 comprises an arc-shaped concave inverted arch 8 and an arc-shaped convex inverted arch 9, the arc-shaped concave inverted arch 8 is positioned on the left side of the arc-shaped convex inverted arch 9, an arc-shaped slot 15 with an opening on the right side is formed in the lower part of the arc-shaped concave inverted arch 8, an arc-shaped inserting plate 16 inserted into the arc-shaped slot 15 is integrally arranged on the left side of the arc-shaped convex inverted arch 9, a hollow buffer column 13 positioned above the arc-shaped slot 15 is arranged on the arc-shaped concave inverted arch 8, the vertical section of the hollow buffer column 13 is of an isosceles triangle structure with a narrow top and a wide bottom, and the vertical center line of the isosceles triangle structure penetrates through the circle center where the concrete inverted arch 7 is positioned; the lower side arc surface of the concrete inverted arch 7 is in full contact with the buffer tank 3 through the crushed gangue or the slag layer 6, so that a large-area left gap is avoided.

And (seventhly), before the concrete is poured, the concrete extends into the coal (rock) bodies 12 on the two sides of the roadway from left to right in the horizontal direction of the roadway bottom plate 2, two slotted holes with the width of 400mm are formed, the reinforcing mesh also extends into the slotted holes, when the concrete is poured, the concrete is poured into the slotted holes at the same time, the left side and the right side of the concrete cover plate 11 formed after solidification form strong support for the concrete inverted bottom arch 7 in the slotted holes, and the thickness of the concrete cover plate 11 is 200 mm.

When the bottom plate 2 of the weak crushing roadway is stressed to generate bottom heave of the bottom plate 2, the pressure relief groove 5 excavated firstly can weaken part of stress and energy; secondly, a crushed gangue or slag layer 6 laid between the buffer groove 3 with the arc-shaped bottom and the precast concrete inverted arch 7 after excavation can dissipate part of energy to play a role in buffering; thirdly, most of stress and energy can be dispersed and relieved through rigid blocking of the prefabricated concrete inverted arch 7 and flexible buffering action of the hollow buffering columns 13; finally, the poured concrete cover plate 11 can support and block the residual stress action, and the stability and the integrity of the roadway bottom plate 2 are ensured.

The concrete inverted arch 7 is spliced and inserted into the arc-shaped slot 15 on the right side of the arc-shaped concave inverted arch 8 through the arc-shaped inserting plate 16 on the left side of the arc-shaped convex inverted arch 9 during construction, the operation is convenient in the mode, and the split assembly structure of the concrete inverted arch 7 is convenient to prefabricate in a factory.

The invention can more conveniently and quickly reinforce the roadway bottom plate 2 in the maintenance work of the large-section roadway of the deep mine. When the roadway bottom plate 2 is in a broken soft lithology condition, the bottom plate 2 bulges into the roadway due to the vertical stress, the structural stress and the water reason of the overlying strata, and the integrity and the stability of the roadway are damaged. After the tunnel bottom plate 2 breaks the soft rock stratum and is stressed, the pressure relief groove 5 excavated firstly can dissipate and relieve part of stress and energy, and delay the deformation of the bottom plate 2; secondly, after the pressure relief groove 5 loses the effect, the laid crushed gangue or slag layer 6 can further buffer stress and energy, and the effect of the stress on the bottom plate 2 is reduced; thirdly, the arc-shaped concave inverted bottom arch 8 and the arc-shaped convex inverted bottom arch 9 are spliced and inserted into the complete precast concrete inverted bottom arch 7 to serve as a main stress structure for maintaining the integrity of the roadway bottom plate 2, most of stress can be prevented from damaging the bottom plate 2 by the rigidity and the strength of the concrete structure, in addition, a hollow buffer column 13 is arranged in the precast concrete inverted bottom arch 7, and when the concrete inverted bottom arch 7 is damaged, the hollow buffer column 13 can slow down the upward transmission of the stress and the energy again; finally, the garrulous waste rock that fills in the garrulous waste rock filling cavity 10 of hollow buffer column 13 left side, the concave anti-bottom arch of arc 8 top and hollow buffer column 13 right side, the protruding anti-bottom arch of arc 9 top and pour into the concrete apron 11 that forms can exert its cushioning effect and prop up the fender effect, accomplish the reinforcement protection to bottom plate 2, more convenient and fast, labour saving and time saving's the integrality of assurance tunnel bottom plate 2.

The present embodiment is not intended to limit the shape, material, structure, etc. of the present invention in any way, and any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention are within the scope of the technical solution of the present invention.