阅读说明：本技术 一种煤矿软岩巷道或硐室底板分阶段控制方法 (Method for controlling soft rock roadway or chamber bottom plate of coal mine in stages ) 是由 潘锐 王雷 程桦 陆鹏举 刘宁 王珍 于 2021-08-30 设计创作，主要内容包括：本发明提供一种煤矿软岩巷道或硐室底板分阶段控制方法,包括以下步骤：步骤1,建立底板数值模型,得到底板围岩位移分布规律；步骤2,根据底板围岩位移分布规律,定量划分零点位移曲线和拉应变范围；根据零点位移曲线和拉应变范围确定第一阶段,第一阶段为硐室底板爆破泄压支护阶段的爆破参数与锚固参数；步骤3,监测底板围岩的变形程度与支护构件受力大小,得到底板与构件的监测数据；步骤4,根据步骤3中的底板与构件的监测数据,确定第二阶段的支护参数,第二阶段为锚注二次支护阶段。该底板分阶段控制方法主动对底板进行泄压支护,使得巷道或硐室底板的形变得到良好的控制,使得底板变形得到良好的控制,避免了底鼓现象的发生。(The invention provides a coal mine soft rock roadway or chamber bottom plate staged control method, which comprises the following steps: step 1, establishing a bottom plate numerical model to obtain a bottom plate surrounding rock displacement distribution rule; step 2, quantitatively dividing a zero displacement curve and a tensile strain range according to a bottom plate surrounding rock displacement distribution rule; determining a first stage according to the zero displacement curve and the tensile strain range, wherein the first stage is blasting parameters and anchoring parameters of a chamber bottom plate blasting pressure relief supporting stage; step 3, monitoring the deformation degree of surrounding rocks of the bottom plate and the stress of the supporting member to obtain monitoring data of the bottom plate and the supporting member; and 4, determining support parameters of a second stage according to the monitoring data of the bottom plate and the member in the step 3, wherein the second stage is an anchoring and grouting secondary support stage. The base plate staged control method actively carries out pressure relief support on the base plate, so that the deformation of the roadway or chamber base plate is well controlled, the deformation of the base plate is well controlled, and the occurrence of the bottom heave phenomenon is avoided.)

1. A coal mine soft rock roadway or chamber bottom plate staged control method is characterized by comprising the following steps:

step 1, establishing a bottom plate numerical model to obtain a bottom plate surrounding rock displacement distribution rule;

step 2, quantitatively dividing a zero displacement curve and a tensile strain range according to a bottom plate surrounding rock displacement distribution rule;

determining a first stage according to the zero displacement curve and the tensile strain range, wherein the first stage is blasting parameters and anchoring parameters of a chamber bottom plate blasting pressure relief supporting stage;

step 3, monitoring the deformation degree of surrounding rocks of the bottom plate and the stress of the supporting member to obtain monitoring data of the bottom plate and the supporting member;

and 4, determining support parameters of a second stage according to the monitoring data of the bottom plate and the member in the step 3, wherein the second stage is an anchoring and grouting secondary support stage.

2. The floor phasing control method according to claim 1, wherein a numerical model is established in step 1 by analyzing ground stress, rock formation distribution, positions of the roadway or the chamber, and geometric parameters, rock mechanical parameters and support parameters of the roadway or the chamber are analyzed on the basis of the established floor numerical model;

preferably, the roadway or the chamber is of a right-angle semicircular arch structure, a bottom plate numerical model of the right-angle semicircular arch structure is established, and the stress parameters of the bottom plate, the mechanical parameters of surrounding rock masses and the supporting parameters are substituted into the bottom plate numerical model to obtain a displacement direction sketch map and a stress range sketch map of the bottom plate.

3. The method for controlling the bottom plate in stages as claimed in claim 2, wherein in the bottom plate blasting pressure relief support stage, a blasting support integrated hole is drilled in the bottom plate;

the blasting and supporting integrated hole comprises an explosive section, a buffer section and a supporting section; the explosive section is positioned at the hole bottom of the blasting support integrated hole, and the buffer section is positioned between the explosive section and the support section;

preferably, a slit is cut between the blasting section and the buffer section, the slit being perpendicular to the axis of the hole of the blasting support body.

4. A floor staging control method according to claim 3, wherein the blasting parameters include depth of an integral hole of the blasting support, length of the buffer section, and length of the explosive section;

the anchoring parameters comprise the rod body length of the anchor rod (cable), the anchoring length and the row spacing.

5. The method of claim 4, wherein the zero displacement maximum value and the tensile strain range deepest value are determined by a displacement direction sketch map and a stress range sketch map;

the length of the supporting section is the maximum value of zero displacement;

the length of the explosive segment is the maximum value of the tensile strain minus the maximum value of zero displacement;

the length of the buffer segment is half of the length of the explosive segment.

6. The floor grading control method according to claim 4, wherein if the floor surrounding rock deformation exceeds the zero displacement value, the anchor member in the first stage is a grouting anchor rod (cable);

if the deformation of the surrounding rock of the bottom plate does not exceed the zero displacement value, the anchoring member in the first stage adopts an anchor rod (cable);

the second stage of anchor-grouting support member adopts grouting anchor rod (cable).

7. The method as claimed in claim 4, wherein in the step 3, the floor heave amount, the rod body stress and the surrounding rock stress are monitored with time after the first stage is performed.

8. The floor grading control method according to claim 7, wherein second-stage support parameters are determined according to floor heave, rod stress and surrounding rock stress change curves of the floor along with time, and the support parameters comprise grouting materials and grouting pressure.

9. The method of claim 8, wherein the grouting material is cement slurry, and the cement slurry has a water-cement ratio in a range of 0.8: 1-1.5: 1;

if a grouting anchor cable is selected, the length range of the grouting anchor cable is 5-6 m, and the grouting pressure is 2-3 MPa;

if a grouting anchor rod is selected, the length of the grouting anchor rod is 2.5m, and the grouting pressure is 1-2 MPa.

10. The method according to claim 8, wherein after the second-stage support is completed, the deformation of the floor is continuously monitored, and whether to continue the bolting and grouting support is determined according to a displacement variation curve of the floor.

Technical Field

The invention belongs to the technical field of pucking treatment, and particularly relates to a coal mine soft rock roadway or chamber floor staged control method.

Background

The control of the soft rock of the deep well is one of the major problems troubling the safe and efficient production of coal mines all the time, and under the influence of high stress, fault fracture zone, weak cementation and the like, the bottom of the tunnel or the chamber has a bottom bulging phenomenon due to the extrusion effect of rock strata along with the increase of service time in the tunnel or the chamber, so that the bottom of the tunnel or the chamber becomes uneven, the repair strength and the repair frequency of the tunnel or the chamber are increased, and the working efficiency is influenced.

At present, the soft rock roadway or chamber floor control mainly adopts an inverted arch as a main part and belongs to passive control, and because the soft rock roadway or chamber belongs to permanent buildings of a coal mine, the normal production operation of the coal mine can be seriously influenced by the repair and treatment after the floor deformation exceeds the limit, so that a simple and efficient floor control method is urgently needed.

The existing floor control methods mainly have the following disadvantages:

1. the inverted arch construction process is complex, the floor deformation is difficult to repair after exceeding the limit, the construction period is long, and the manpower and material resources are consumed greatly;

2. the inverted arch has weak influence on stress distribution of the excavated surrounding rock, and the supporting time is lagged, so that a supporting structure cannot be formed in time;

3. the inverted arch belongs to passive support, and essentially provides larger radial acting force for surrounding rocks, cannot transfer the self bearing capacity of the surrounding rocks, and is difficult to maintain the long-term stability of the surrounding rocks.

Therefore, there is a need to provide an improved solution to the above-mentioned deficiencies of the prior art.

Disclosure of Invention

The invention aims to provide a method for controlling a soft rock roadway or a chamber floor in a coal mine in stages, which at least solves the problems of complex process, poor effect and the like of the existing floor control.

In order to achieve the above purpose, the invention provides the following technical scheme:

a coal mine soft rock roadway or chamber bottom plate staged control method comprises the following steps:

step 1, establishing a bottom plate numerical model to obtain a bottom plate surrounding rock displacement distribution rule;

step 2, quantitatively dividing a zero displacement curve and a tensile strain range according to a bottom plate surrounding rock displacement distribution rule;

determining a first stage according to the zero displacement curve and the tensile strain range, wherein the first stage is blasting parameters and anchoring parameters of a chamber bottom plate blasting pressure relief supporting stage;

step 3, monitoring the deformation degree of surrounding rocks of the bottom plate and the stress of the supporting member to obtain monitoring data of the bottom plate and the supporting member;

and 4, determining support parameters of a second stage according to the monitoring data of the bottom plate and the member in the step 3, wherein the second stage is an anchoring and grouting secondary support stage.

In the above method for controlling the floor by stages, preferably, in step 1, a numerical model is established by analyzing the ground stress, the rock stratum distribution, the position of the roadway or the chamber, and geometric parameters, rock mechanics parameters and support parameters of the roadway or the chamber are analyzed on the basis of the established numerical model of the floor;

preferably, the roadway or the chamber is of a right-angle semicircular arch structure, a bottom plate numerical model of the right-angle semicircular arch structure is established, and the stress parameters of the bottom plate, the mechanical parameters of surrounding rock masses and the supporting parameters are substituted into the bottom plate numerical model to obtain a displacement direction sketch map and a stress range sketch map of the bottom plate.

In the method for controlling the base plate in stages, preferably, in the stage of blasting, pressure relief and support of the base plate, a blasting support integrated hole is drilled in the base plate;

the blasting and supporting integrated hole comprises an explosive section, a buffer section and a supporting section; the explosive section is positioned at the hole bottom of the blasting support integrated hole, and the buffer section is positioned between the explosive section and the support section;

preferably, a slit is cut between the blasting section and the buffer section, the slit being perpendicular to the axis of the hole of the blasting support body.

The baseplate grading control method as described above, preferably, the blasting parameters include the depth of an integral hole of the blasting support, the length of the buffer section and the length of the explosive section;

the anchoring parameters comprise the rod body length of the anchor rod (cable), the anchoring length and the row spacing.

In the above-described baseplate staging control method, preferably, the zero displacement maximum value and the tensile strain range deepest value are determined by the displacement direction sketch and the stress range sketch;

the length of the supporting section is the maximum value of zero displacement;

the length of the explosive segment is the maximum value of the tensile strain minus the maximum value of zero displacement;

the length of the buffer segment is half of the length of the explosive segment.

In the floor grading control method as described above, preferably, if the deformation of the surrounding rock of the floor exceeds the zero displacement value, the anchoring member in the first stage is a grouting anchor rod (cable);

if the deformation of the surrounding rock of the bottom plate does not exceed the zero displacement value, the anchoring member in the first stage adopts an anchor rod (cable);

the second stage of anchor-grouting support member adopts grouting anchor rod (cable).

In the above method for controlling the floor in stages, preferably, in step 3, the floor heave amount, the rod body stress and the surrounding rock stress are monitored with time after the first stage is performed.

According to the baseplate grading control method, preferably, the second-stage support parameters are determined according to the floor heave amount of the baseplate, the stress of the rod body and the change curve of the surrounding rock stress along with time, and the support parameters comprise grouting materials and grouting pressure.

In the method for controlling the floor in stages, preferably, the grouting material is cement slurry, and the water-cement ratio of the cement slurry is in a range of 0.8: 1-1.5: 1;

if a grouting anchor cable is selected, the length range of the grouting anchor cable is 5-6 m, and the grouting pressure is 2-3 MPa;

if a grouting anchor rod is selected, the length of the grouting anchor rod is 2.5m, and the grouting pressure is 1-2 MPa.

In the above method for controlling the floor in stages, preferably, after the second-stage support is completed, the deformation of the floor is continuously monitored, and whether to continue to implement the bolting and grouting support is determined according to a displacement change curve of the floor.

Has the advantages that: the invention provides a staged control method for a coal mine soft rock roadway or chamber bottom plate, which comprises the steps of carrying out first-step pressure relief and support on the bottom plate through blasting and support in a first stage, wherein a blasting area is formed, so that the influence of stress deformation of surrounding rock layers on the roadway or chamber bottom plate is reduced; on the basis, a supporting section in the blasting supporting integrated hole is supported, so that the bottom plate of the roadway or the chamber has enough structural strength and cannot deform; the second stage of support further strengthens the support of the roadway or chamber floor. The deformation of the roadway or chamber bottom plate is well controlled, the bottom plate staged control method of the invention firstly actively explodes and decompresses the bottom plate, thoroughly cuts off the connection between the bottom plate and the surrounding rock stratum, and supports the bottom plate; the base plate staged control method actively carries out pressure relief support on the base plate, so that the deformation of the base plate is well controlled, and the bottom bulging phenomenon is avoided.

Drawings

FIG. 1 is a flow chart illustrating a method for controlling a backplane by stages according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a zero displacement curve and a tensile strain range determined in the baseplate grading control method in the embodiment of the invention;

FIG. 3 is a schematic diagram illustrating a first stage and a second stage of construction performed on a bottom plate in the bottom plate stage control method according to the embodiment of the present invention;

FIG. 4 is a schematic structural diagram of an integral hole of a blasting support in an embodiment of the invention;

FIG. 5 is a graph of the displacement of the base plate over time in an embodiment of the invention.

In the figure: 1. blasting and supporting an integral hole; 1-1, an explosive section; 1-2, a buffer section; 1-3, a support section; 2. anchor rods (cables).

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

In the description of the present invention, the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are for convenience of description of the present invention only and do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. The terms "connected" and "connected" used herein should be interpreted broadly, and may include, for example, a fixed connection or a detachable connection; they may be directly connected or indirectly connected through intermediate members, and specific meanings of the above terms will be understood by those skilled in the art as appropriate.

The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings. It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

According to the specific embodiment of the invention, as shown in fig. 1-5, the invention provides a coal mine soft rock roadway or chamber floor staged control method, which can be used for floor support of underground engineering such as soft rock roadway, chamber, extraction roadway and the like, and the floor staged control method comprises the following steps:

step 1, establishing a bottom plate numerical model according to engineering geological conditions of a roadway or a chamber to obtain a bottom plate surrounding rock displacement distribution rule. Specifically, a numerical model is established by analyzing the ground stress, the rock stratum distribution and the roadway or the chamber position, and the roadway or the chamber geometric parameters, the rock mass mechanics parameters and the support parameters are analyzed on the basis of the established floor stress numerical model to obtain the floor displacement distribution rule.

In this embodiment, a straight-wall semi-circular arch is taken as an example for a roadway or a chamber, the established numerical model of the roadway or the chamber bottom plate is a straight-wall semi-circular arch model, and then the stress parameters of the bottom plate, the mechanical parameters of surrounding rock masses and the supporting parameters are substituted into the numerical model to obtain a displacement direction sketch and a stress range sketch of the bottom plate.

Step 2, quantitatively dividing a zero displacement curve and a tensile strain range according to a bottom plate surrounding rock displacement distribution rule; and determining blasting parameters and anchoring parameters of a first stage, namely a bottom plate blasting pressure relief supporting stage according to the zero displacement curve and the tensile strain range.

In this embodiment, taking the construction of a straight-wall semi-circular arch tunnel or chamber as an example, the clear width of the tunnel or chamber is 5000mm, the clear height is 4300mm, the elastic modulus of the surrounding rock mass is 1.6GPa, the cohesion force is 0.6MPa, and the internal friction angle is 28 °; under the action of the ground stress of 25MPa, the stress data of the bottom plate is substituted into the numerical model of the bottom plate to obtain a sketch map of the displacement direction of the bottom plate, wherein the upward direction is the bottom drum direction, the downward direction is the bottom plate sinking direction, and as shown in figure 2, the junction of the two directions is a zero displacement curve; the tensile strain range is similar to the floor displacement direction sketch.

And obtaining the zero displacement curve and the tensile strain range, wherein the zero displacement curve reaches 2.8m below the bottom plate at the deepest part, and the anchoring length is set to be the depth of the zero displacement curve, namely 2.8 m. The tensile strain range is 3.2m below the bottom plate at the deepest.

In the blasting, pressure-releasing and supporting stage of the bottom plate, a blasting and supporting integrated hole 1 is drilled in the bottom plate; the blasting support integrated hole 1 comprises an explosive section 1-1, a buffer section 1-2 and a support section 1-3; the explosive section 1-1 is positioned at the hole bottom of the blasting support integrated hole 1, and the buffer section 1-2 is positioned between the explosive section 1-1 and the support section 1-3. In the blasting support integrated hole 1, the buffer section 1-2 is arranged, so that the blasting of the explosive section 1-1 does not influence the quality of the hole wall of the support section 1-3, and the support quality is ensured.

A cutting seam is cut between the blasting section 1-1 and the buffering section 1-2 through a high-pressure water jet device, and the cutting seam is perpendicular to the axis of the blasting supporting integral hole, so that the blasting section, the buffering section and the supporting section are physically separated, the influence on the supporting section during blasting of the blasting section can be reduced, and the hole forming quality of the supporting section is ensured.

The blasting parameters comprise the depth of the blasting support integral hole 1, the length of the buffer section 1-2 and the length of the explosive section 1-1.

In the embodiment, the length of the explosive section 1-1 in the blasting support integrated hole 1 is the maximum value of tensile strain minus the maximum value of zero displacement of the deepest bottom plate, namely 3.2m-2.8m is 0.4 m; the explosive is coal mine permitted emulsion explosive and is loaded in two sections; the length of the buffer section 1-2 is half of the length of the explosive section 1-1, namely the buffer section 1-2 is 0.2m, and the buffer section 1-2 is filled with flexible filling materials such as foam concrete and the like.

The support section 1-3 adopts a grouting anchor rod (cable) as an anchoring member in the first stage according to the crushing condition of the surrounding rock of the bottom plate if the deformation of the surrounding rock of the bottom plate exceeds a zero displacement value; if the deformation of the surrounding rock of the bottom plate does not exceed the zero displacement value, the anchoring member in the first stage adopts an anchor rod (cable);

the anchoring parameters include the length of the anchor rod (cable), the anchoring length and the row spacing.

Firstly, determining construction parameters of a first stage, namely a bottom plate blasting pressure relief supporting stage according to engineering geological conditions of a roadway or a chamber; firstly, drilling a plurality of blasting support integrated holes 1 at the bottom of a roadway or a chamber, filling explosives at the lowest part of the holes for blasting, and forming a pressure relief area in a blasting area so that a bottom plate at the bottom of the lower part of the roadway or the chamber is separated from a surrounding rock layer through the pressure relief area, thereby reducing the influence of stress deformation of the surrounding rock layer on the bottom plate of the roadway or the chamber; on the basis, the support sections 1-3 in the blasting support integrated hole 1 are supported to strengthen and support the bottom plate of the roadway or the chamber into a whole, so that the bottom plate of the roadway or the chamber has enough structural strength and cannot deform.

Step 3, monitoring the deformation degree of the surrounding rock of the bottom plate and the stress of the supporting member; and monitoring the bottom plate bottom bulging amount, the rod body stress and the surrounding rock stress after the first stage is implemented.

The second stage is to further strengthen the support of the bottom plate to ensure that the bottom plate has sufficient structural strength without deformation.

And 4, determining support parameters of a second stage according to the monitoring data in the step 3, wherein the second stage is an anchor grouting secondary support stage.

And determining second-stage support parameters including grouting materials and grouting pressure according to the bottom heave amount of the bottom plate, the stress of the rod body and the change curve of the surrounding rock stress along with time. The anchor-grouting support component of the second stage adopts a grouting anchor rod (cable) 2.

The second stage is a supporting stage which is carried out after the bottom plate is deformed after a certain time; the grouting anchor rod (cable) 2 is used in the second stage, on one hand, after the soft rock roadway or the chamber is used for a period of time, the phenomena of crushing, bottom bulging and the like of surrounding rocks of the bottom plate are gradually shown, and the grouting anchor rod (cable) 2 can fill the crushed cracks of the surrounding rocks through grouting to reinforce the surrounding rocks, improve the strength and the bearing capacity of the surrounding rocks and inhibit the bottom plate from further deforming and damaging; on the other hand, compared with passive measures such as inverted arch and the like, the control method adopts active bolting-grouting support after blasting pressure relief, the construction process is simple, the efficiency is higher, and the deformation of the bottom plate can be better controlled by adopting active support in the control method.

In this embodiment, the grouting material in the second stage is cement slurry, and the water cement ratio ranges from 0.8: 1-1.5: 1; if a grouting anchor cable is selected, the length range of the grouting anchor cable is 5-6 m, and the grouting pressure is 2-3 MPa; if a grouting anchor rod is selected, the length of the grouting anchor rod is 2.5m, and the grouting pressure is 1-2 MPa.

And after the second-stage support is finished, continuously monitoring the deformation condition of the bottom plate, and judging whether to continuously implement the bolting-grouting support according to the displacement change curve of the bottom plate. If the deformation of the bottom plate is large, a plurality of grouting anchor rods (cables) 2 are continuously constructed on the bottom plate, and if the deformation of the bottom plate is small, the bottom plate does not need to be reinforced and supported.

In conclusion, according to the staged control method for the coal mine soft rock roadway or chamber bottom plate, the pressure relief and support are carried out on the bottom plate in the first step through the blasting and support in the first stage, a pressure relief area is formed in a blasting area, and the influence of stress deformation of surrounding rock layers on the roadway or chamber bottom plate is reduced; on the basis, a supporting section in the blasting supporting integrated hole is supported, so that the bottom plate of the roadway or the chamber has enough structural strength and cannot deform; the second stage of support further strengthens the support of the roadway or chamber floor.

The deformation of the roadway or chamber bottom plate is well controlled, and as can be seen from the attached figure 5, in the blasting pressure relief area, the stress on the bottom plate is larger, at the moment, the bottom plate is deformed greatly, the connection between the bottom plate and the surrounding rock strata is cut off through blasting pressure relief, the strength of the bottom plate is enhanced through further support, and after the second stage of support, the deformation area of the bottom plate is stable; namely, the staged control method of the bottom plate firstly actively explodes and decompresses the bottom plate, thoroughly cuts off the connection between the bottom plate and the surrounding rock stratum and supports the bottom plate; the base plate staged control method actively carries out pressure relief support on the base plate, so that the deformation of the base plate is well controlled, and the bottom bulging phenomenon is avoided.

The above description is only exemplary of the invention and should not be taken as limiting the invention, as any modification, equivalent replacement, or improvement made within the spirit and principle of the invention is intended to be covered by the appended claims.