CN105759010A - Mining influence tunnel dynamic monitoring and stability evaluation method - Google Patents

Abstract

The invention discloses a dynamic monitoring and stability evaluation method of a roadway affected by mining, which comprises the following steps: step 1, installing a high-precision microseismic monitoring system and a peeping instrument; step 2, collecting data before the impact of mining; step 3, collecting Data collection after impact: the specific implementation steps are the same as step 2; step 4, surrounding rock stability analysis: based on the location of surrounding rock rupture, the energy of surrounding rock rupture, the number of times of surrounding rock rupture and the Fragmentation degree, the increase rate of surrounding rock fracture range, the increase rate of surrounding rock fracture energy, the increase rate of unit volume density of surrounding rock rupture events, and the increase rate of surrounding rock fragmentation degree are calculated respectively; step 5, mining affects the stability of the roadway under the coal pillar Quantitative evaluation: Based on the evaluation values of each surrounding rock obtained in step 4, the weight analysis method is used to establish a quantitative evaluation index for the stability of the excavation roadway affected by mining, and the quantitative evaluation of the excavation roadway affected by mining is carried out.

Description

A method for dynamic monitoring and stability evaluation of roadway affected by mining

technical field

The invention belongs to the technical field of safety in underground engineering, and in particular relates to a method for dynamic monitoring and stability evaluation of tunnels affected by mining.

Background technique

With the depletion of shallow coal resources, coal mining gradually extends to the deep, the ground stress increases accordingly, and the roadway instability is serious, threatening the life safety of underground workers and affecting the normal production of coal mines. Therefore, the stability of the roadway has become a The key to coal mine safety and efficient production.

During the excavation of the roadway below the coal pillar, the mining pressure generated by the mining of the upper working face has an impact on the lower excavation roadway, resulting in a decrease in the strength of the surrounding rock, large deformation of the excavation roadway, and failure of supporting components. The pressure directly affects the stability of the excavation roadway below and the strength of the surrounding rock. Therefore, quantitative detection is carried out during the excavation process of the roadway under the coal pillars affected by mining, so as to guide the on-site construction and optimize the roadway support parameters.

There are following problems in prior art:

1. During the mining process of the overlying working face, the stability of the roadway under the coal pillar and the rupture range of the surrounding rock cannot be determined.

2. At present, there is no method for dynamic monitoring and stability evaluation of roadways affected by mining.

3. In actual engineering, the stress of mining on the overlying working face and the stress of excavation on the working face under the coal pillar act on the surrounding rock together. Under the complex stress state, the failure characteristics of the surrounding rock directly affect the deformation of the roadway. At present, the impact of mining at home and abroad Research on roadway dynamic monitoring and stability evaluation methods is rare.

Contents of the invention

In view of this, in order to solve the above-mentioned problems, the present invention provides a dynamic monitoring and stability evaluation method of mining-affected roadway, which accurately judges the stability of the roadway through a high-precision microseismic monitoring system and a drilling peeping instrument.

In order to achieve the above object, the present invention adopts the following technical solutions.

A mining-affected roadway dynamic monitoring and stability evaluation method, comprising the following steps:

Step 1, install a high-precision microseismic monitoring system and a peeping instrument;

Step 2, collect data before impact of mining:

The high-precision microseismic monitoring system is used to monitor the roadway under the coal pillar, and record the location, energy and frequency of surrounding rock rupture;

Use the borehole peep imaging recorder to peep, record the degree of surrounding rock fragmentation, and divide the surrounding rock into complete area, relatively complete area, relatively broken area and broken area from inside to outside;

Step 3, collect data after mining impact: the specific implementation steps are the same as step 2;

Step 4, stability analysis of surrounding rock: Based on the location of surrounding rock rupture, the energy of surrounding rock rupture, the number of times of surrounding rock rupture and the degree of surrounding rock fragmentation before and after the impact of mining, the increase rate of surrounding rock fracture range, The increase rate of surrounding rock fracture energy, the increase rate of unit volume density of surrounding rock rupture events and the increase rate of surrounding rock fragmentation degree;

Step 5. Quantitative evaluation of the stability of the excavation roadway under the coal pillars affected by mining: Based on the evaluation values of the surrounding rocks obtained in step 4, the weight analysis method is used to establish a quantitative evaluation index for the stability of the excavation roadway affected by mining, and the impact of mining on the roadway stability. Do a quantitative evaluation.

In step 1, the high-precision microseismic monitoring system includes sensors, data acquisition substations, microseismic system hosts, and ground data comprehensive processing and analysis system; 3 sensors are installed on the left side of the roadway under the coal pillar, and 3 sensors are installed on the right shoulder to collect data respectively. Surrounding rock rupture signal, each sensor converts the microseismic signal into an analog electrical signal after receiving the microseismic signal, and connects the collected electrical signal to the coal mine network substation through an optical fiber through the data acquisition substation, and transmits the signal to the microseismic system host through the coal mine network , while the ground data comprehensive processing and analysis system converts electrical signals into digital signals, and processes the digital signals to realize the positioning of microseismic events and the acquisition of event parameters.

Before the upper mining face and the lower excavation roadway overlap in the vertical direction, the sensors move forward sequentially with the excavation face, and when the upper mining face and the lower excavation face overlap in the vertical direction, the sensors follow the excavation face. The recovery of the mining work is moved backward in sequence;

Boreholes are arranged on the left side, right side, left shoulder, right shoulder and top of the roadway, and the peeping instrument is used to peek at the surrounding rock in the drilling and record the breaking of the surrounding rock.

In step 2, the formula for calculating the fracture energy of the surrounding rock before the impact of mining is D=A ₁₁ E ₁ +A ₁₂ E ₂ +A ₁₃ E ₃ +A ₁₄ E ₄ +A ₁₅ E ₅ +A ₁₆ E ₆ , where A ₁₁ , A ₁₂ , A ₁₃ , A ₁₄ , A ₁₅ , and A ₁₆ are correlation coefficients, and A ₁₁ +A ₁₂ +A ₁₃ +A ₁₄ +A ₁₅ +A ₁₆ =1, E ₁ means energy<10J, E ₂ means energy 10-100J, E ₃ means energy 100-1000J, E ₄ means energy 1000-5000J, E ₅ means energy 5000-10000J, E ₆ means energy ≥ 10000J.

In step 2, the density of surrounding rock rupture events per unit volume is calculated based on the number of surrounding rock ruptures before mining.

In step 2, the borehole peep imaging recorder unfolds the plane of the surrounding rock of the borehole wall to analyze the damage range of the surrounding rock. Based on the borehole peeping instrument, the calculation formula for the degree of fragmentation of the surrounding rock before the impact of mining can be obtained W=S ₁ +S ₂ +S ₃ +S ₄ , S ₁ , S ₂ , S ₃ , and S ₄ respectively correspond to the lengths when the surrounding rocks are complete, relatively complete, relatively broken and broken.

In step 4, the increase rate of the surrounding rock fracture range is R ₁ =(L'-L)/L; the increase rate of the surrounding rock fracture energy

R ₂ ＝(D'-D)/D; the increase rate of unit volume density of the surrounding rock rupture event R ₃ ＝(C'-C)/C; the increase rate of the surrounding rock fracture degree

R ₄ ＝(W'-W)/W, where L' and L are the range of surrounding rock fractures before and after mining; D' and D are the energy of surrounding rock fractures before and after mining respectively; C' and C are the The unit volume density of surrounding rock fracture time before and after excavation, W' and W are the fragmentation degree of surrounding rock before and after mining impact, respectively.

In step 5, the quantitative evaluation of the stability of the excavation roadway under the coal pillar affected by the mining is obtained by weighting the comprehensive evaluation index R=∑H _k R _k of the stability of the excavation roadway under the coal pillar, and the R value is compared with a certain The roadway stability under the influence of mining can be obtained by comparing the statistical standard value R0 of the roadway stability evaluation effect under the impact of specific roadway mining, _{where H k is} the weight coefficient, k=1, 2, 3, 4, where The size should be allocated according to the size of R ₁ ~ R ₄ and the reliability and accuracy of the test data, satisfying ∑H _k =1.

The beneficial effects of the present invention are as follows:

The present invention uses a high-precision microseismic monitoring system and a borehole peeping instrument to evaluate the dynamic monitoring and stability of the roadway affected by mining, and comprehensively compares and analyzes multiple indicators, avoiding erroneous judgments caused by a single index, and ensuring the stability of the roadway The accuracy of the judgment can comprehensively and accurately judge the stable state of the roadway, and then guide the design and implementation of the specific support scheme of the roadway in different periods.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are For some embodiments of the present invention, those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the flow chart of mining influence roadway dynamic monitoring and stability evaluation method of the present invention;

Fig. 2 is a schematic diagram of the layout of the monitoring sensors of the high-precision microseismic monitoring system of the present invention;

Fig. 3 is a schematic cross-sectional view of the layout of the monitoring sensors of the high-precision microseismic monitoring system of the present invention;

Fig. 4 is the schematic diagram of the degree of fragmentation of surrounding rock shown by the drilling peep instrument of the present invention;

Among them, 1 is the No. 1 sensor of the left side of the excavation roadway, 2 is the No. 2 sensor of the left side of the excavation roadway, 3 is the No. 3 sensor of the left side of the excavation roadway, 4 is the No. 4 sensor of the right shoulder of the excavation roadway, and 5 is the excavation roadway No. 5 sensor on the right shoulder, 6 is the No. 6 sensor on the right shoulder of the excavation roadway, S ₁ is the length of complete surrounding rock, S ₂ is the length of relatively complete surrounding rock, S ₃ is the length of relatively broken surrounding rock, and S ₄ is the length of broken surrounding rock length.

detailed description

The present invention is described in detail below in conjunction with accompanying drawing:

The present invention is based on the high-precision microseismic monitoring system and the technical research means of the borehole peeping instrument, analyzes and obtains the increase rate of the surrounding rock rupture range, the increase rate of the surrounding rock rupture energy, the increase rate of the unit volume density of the surrounding rock rupture event, and the surrounding rock breakage before and after the impact of mining. Through the weight analysis method, comprehensive quantitative analysis on the stability of the roadway affected by mining is carried out, and the quantitative evaluation index of the effect of mining on the stability of the roadway is established, which can scientifically and reasonably evaluate the stability of the roadway affected by mining.

To achieve the above object, the present invention adopts the following technical solutions:

Step 1: Design of roadway surrounding rock monitoring scheme before and after mining impact

According to the mine development method, the geological conditions of the roadway, and the size of the section, the roadway surrounding rock monitoring plan before and after the impact of mining is designed, and the layout parameters of the high-precision microseismic monitoring system are determined. As shown in Figure 1 and Figure 2, 6 sensors are arranged in the roadway, 3 sensors are arranged on the left side, and 3 sensors are arranged on the right shoulder; specifically: No. 1 sensor 1 at the left side of the tunnel, and No. 2 sensor at the left side of the tunnel 2. No. 3 sensor 3 on the left side of the excavation roadway, No. 4 sensor 4 on the right shoulder of the excavation roadway, No. 5 sensor 5 on the right shoulder of the excavation roadway, No. 6 sensor 6 on the right shoulder of the excavation roadway, S ₁ is the complete surrounding rock length, S ₂ is the length of relatively complete surrounding rock, S ₃ is the length of relatively broken surrounding rock and S ₄ is the length of broken surrounding rock.

The six sensors respectively collect the surrounding rock rupture signal, each sensor converts it into an analog electrical signal after receiving the microseismic signal, and connects the collected electrical signal to the coal mine network substation through an optical fiber through the data acquisition substation, and transmits the signal through the coal mine network It is transmitted to the host of the microseismic system, and the ground data comprehensive processing and analysis system converts the electrical signal into a digital signal, and processes the digital signal to realize the positioning of the microseismic event and the acquisition of event parameters.

Arrange 6 drill holes in the left side, left shoulder, top, right shoulder and right side of the roadway. The depth of the drill holes is 6m. The peeping instrument is used to collect the surrounding rock fragments sequentially from the shallow part to the deep part of the drilling holes. Condition.

Step 2: Data collection before mining impact

A. Surrounding rock rupture monitoring before mining impact. A high-precision microseismic monitoring system is used to collect in real time the location, energy and frequency of surrounding rock ruptures during roadway excavation before mining impacts.

The high-precision microseismic monitoring system collects the signals of the surrounding rock rupture through six sensors arranged in the roadway, and the data processing system processes the collected signals of the surrounding rock rupture to realize the location of the surrounding rock rupture event and determine the location of the surrounding rock rupture , the energy generated during the rupture and the number of times the surrounding rock ruptures.

The energy generated by the rupture of surrounding rocks is divided into ₆ levels, E1 is energy <10J, _E2 is energy _10-100J , E3 is energy 100-1000J, E4 is energy _1000-5000J , _E5 is energy 5000-10000J, E ₆ is energy ≥ 10000J; the energy of surrounding rock fracture is D=A ₁₁ E ₁ +A ₁₂ E ₂ +A ₁₃ E ₃ +A ₁₄ E ₄ +A ₁₅ E ₅ +A ₁₆ E ₆ , where A ₁₁ , A ₁₂ , A ₁₃ , A ₁₄ , A ₁₅ , and A ₁₆ are correlation coefficients, and A ₁₁ +A ₁₂ +A ₁₃ +A ₁₄ +A ₁₅ +A ₁₆ =1;

Analyze the distribution of the collected signals and determine the range L of surrounding rock rupture before the impact of mining. The determination method is as follows:

Six sensors are arranged to collect the cracking signal of the surrounding rock, and the data processing system processes and analyzes the cracking signal to realize the location of the cracking event of the surrounding rock and determine the cracking condition of the surrounding rock. The distance between is to determine the surrounding rock rupture range L before the impact of mining;

The number of surrounding rock rupture signals is counted, and the density of surrounding rock rupture events per unit volume is obtained as C=N/V, where N is the number of surrounding rock ruptures, and V is the volume within the range of surrounding rock ruptures.

The surrounding rock rupture signal collected by the sensor before the impact of mining is imported into the ground data processing system to locate the surrounding rock rupture and obtain the data of the surrounding rock rupture event, including the number and energy of the surrounding rock rupture.

V=L×B×H, where L is the crack range of the surrounding rock before the impact of mining, B is the crack width of the surrounding rock before the impact of mining, the B value is the distance between the two farthest rupture points of the roadway, and H is the mining impact. The height of surrounding rock rupture before the impact, H value is the distance between the highest point and the lowest point of surrounding rock rupture in the roadway.

B. Borehole peeping instrument detection before mining influence: use borehole peeping instrument to detect in the surrounding rock, and get the three-dimensional histogram of the surrounding rock, the degree of fragmentation of the surrounding rock W=S ₁ +S ₂ +S ₃ +S ₄ , S ₁ , S ₂ , S ₃ , and S ₄ respectively correspond to the lengths when the surrounding rock is complete, relatively complete, relatively broken and broken, as shown in Figure 3;

Step 3: Data collection after mining impact

C. Surrounding rock rupture monitoring after mining impact. A high-precision microseismic monitoring system is used to collect in real time the position, energy and frequency of surrounding rock ruptures during the excavation process of the roadway affected by mining.

The fracture energy of surrounding rock is D'=A' ₁₁ E' ₁ +A' ₁₂ E' ₂ +A' ₁₃ E' ₃ +A' ₁₄ E' ₄ +A' ₁₅ E' ₅ +A'_'6E' ₆ , where A' _1k (k=1, 2, 3, 4, 5, 6) is the correlation coefficient, and A' ₁₁ +A' ₁₂ +A' ₁₃ +A' ₁₄ +A' ₁₅ +A' ₁₆ = 1. Among them, E' ₁ is energy <10J, E' ₂ is energy 10~100J, E' ₃ is energy 100~1000J, E' ₄ is energy 1000~5000J, E' ₅ is energy 5000~10000J, E' ₆ means energy ≥ 10000J;

Analyze the distribution of surrounding rock fractures and determine the range L' of surrounding rock fractures after the impact of mining. The determination method is as follows:

The 6 sensors arranged to collect the rupture signal of the surrounding rock are analyzed and analyzed by the microseismic monitoring software to realize the location of the rupture event of the surrounding rock and determine the rupture of the surrounding rock. The distance, that is, the range L' of the surrounding rock fracture after the impact of mining is determined;

The number of surrounding rock rupture signals is counted to obtain the surrounding rock rupture event density per unit volume C'=N'/V', where N' is the number of surrounding rock ruptures, and V' is the volume within the range of surrounding rock ruptures.

The surrounding rock rupture signal collected by the sensor before the impact of mining is imported into the ground data processing system to locate the surrounding rock rupture and obtain the data of the surrounding rock rupture event, including the number and energy of the surrounding rock rupture.

V'=L'×B'×H', where L' is the range of surrounding rock rupture after mining, B' is the width of surrounding rock rupture after mining, and the value of B' is the distance between the two farthest rupture points of the roadway H' is the height of surrounding rock rupture after mining, and H' is the distance between the highest and lowest surrounding rock rupture points in the roadway.

D. Borehole peeping instrument detection after mining impact: Use the borehole peeping instrument to detect in the surrounding rock, obtain the three-dimensional histogram of the surrounding rock, and record the degree of fragmentation of the surrounding rock W'=S' ₁ +S' ₂ +S' ₃ +S' ₄ , S' ₁ , S' ₂ , S' ₃ , and S' ₄ respectively correspond to the lengths when the surrounding rock is complete, relatively complete, relatively broken and broken. As shown in Figure 3;

When the fissure width of the surrounding rock is less than 1mm, it is considered as complete surrounding rock; if the fissure width in surrounding rock is 1-5mm, it is relatively complete; if the fissure width is 5-10mm, it is relatively broken; if the fissure width is greater than 10mm, it is considered broken.

Step 4: Analysis of mining impact on roadway stability under coal pillars

According to the data obtained in the second and third steps, the increase rate of the surrounding rock fracture range can be obtained R ₁ =(L'-L)/L; the increase rate of the surrounding rock fracture energy R ₂ =(D'-D) /D; the increase rate of the unit volume density of the surrounding rock rupture event R ₃ =(C'-C)/C; the increase rate of the surrounding rock fragmentation degree R ₄ =(W'-W)/W.

Among them, L and L are the range of surrounding rock rupture before and after mining impact, which are determined by the above calculation values; D and D' are the surrounding rock rupture energy before and after mining impact respectively, and C and C' are the surrounding rock rupture time before and after mining respectively The unit volume density, W and W' are the fragmentation degree of the surrounding rock before and after the impact of mining, respectively.

Step 5: Quantitative evaluation of the stability of the excavation roadway under the coal pillar affected by mining

According to the processing and analysis of the surrounding rock monitoring data before and after the impact of mining in the fourth step, the final evaluation index R=∑H _k R _k for the stability of the mining-affected roadway can be obtained by weighting, and the R value is related to the stability of a specific roadway affected by mining By comparing the statistical standard value R ₀ of performance evaluation effect, the stability of the roadway affected by mining can be obtained. Among them, H _k is the weight coefficient, k=1, 2, 3, 4, and its size should be based on the size of R ₁ ~ R ₄ and The reliability and accuracy of the test data are allocated to satisfy ∑H _k =1.

It can be known from common technical knowledge that the present invention can be realized through other implementations without departing from its essence or essential features, and therefore, in every respect, it is just an illustration and not the only one. All changes within the scope of the present invention or within the scope equivalent to the present invention are embraced by the present invention.

Claims (9)

1. a mining influence tunnel dynamic monitoring and Stability Assessment method, it is characterised in that comprise the following steps:

Step 1, installs high accuracy Microseismic monitoring system and endoscope；

Step 2, data before collection mining influence:

Adopt high accuracy Microseismic monitoring system that digging laneway below coal column is monitored, position, energy and the number of times that record country rock breaks；

Utilize boring to spy on record by imaging instrument to spy on, the degree of record rock crusher, country rock is in turn divided into from inside to outside complete section, more complete district, relatively fracture area and fracture area；

Step 3, data acquisition after gathering mining influence: be embodied as step identical with step 2；

Step 4, Stability Analysis of The Surrounding Rock: number of times that the energy that breaks based on the forward and backward described country rock rupture location of mining influence, country rock, country rock break and rock crusher degree, calculates respectively and obtains country rock and break scope increase rate, country rock energy of rupture increase rate, country rock Surface Rupture Events bulk density increase rate and rock crusher degree increase rate；

Step 5, digging laneway stability quantitative assessment below mining influence coal column: each surrounding rock evaluation value obtained based on step 4, exploitation right weight analysis method, set up mining influence digging laneway stability quantitative assessing index, mining influence digging laneway is carried out quantitative assessment.

2. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that in step 1, high accuracy Microseismic monitoring system includes sensor, data acquisition substation, microseismic system main frame and ground data integrated treatment and analyzes system；The left side of digging laneway and the multiple sensor of each installation of right shoulder below coal column, gather country rock destruction signals respectively, by data acquisition substation, the signal of sensor acquisition is connected with colliery Network Outstation Used by optical fiber, microseismic system main frame is transmitted a signal to by colliery network, and ground data integrated treatment is analyzed system and the signal of telecommunication is changed into digital signal, and to digital signal processed, to realize the location to microseismic event, the acquisition of event argument.

3. mining influence tunnel dynamic monitoring as claimed in claim 2 and Stability Assessment method, it is characterized in that, top stope with lower section digging laneway before vertical direction is overlapping, sensor moves forward successively along with driving face layout, and when top stope with lower section driving face after vertical direction is overlapping, sensor moves layout successively afterwards along with the back production of actual mining.

4. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that boring is laid at left side, right side, left shoulder, right shoulder and top in tunnel, utilizes endoscope to spy on country rock in the borehole, records the broken of country rock.

5. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that in step 2, before described mining influence, country rock energy of rupture computing formula is D=A₁₁E₁+A₁₂E₂+A₁₃E₃+A₁₄E₄+A₁₅E₅+A₁₆E₆, wherein A₁₁、A₁₂、A₁₃、A₁₄、A₁₅、A₁₆For correlation coefficient, and A₁₁+A₁₂+A₁₃+A₁₄+A₁₅+A₁₆=1, E₁For energy < 10J, E₂For energy 10～100J, E₃For energy 100～1000J, E₄For energy 1000～5000J, E₅For energy 5000～10000J, E₆For for energy >=10000J.

6. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that break number of times based on adopting front country rock in step 2, unit of account volume country rock Surface Rupture Events density, its formula is C=N/V, and wherein N is that country rock breaks number of times, and V is that country rock breaks scope volume.

7. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterized in that, described boring spies on record by imaging instrument by the wall of a borehole country rock planar development, for analyzing surrounding rock failure scope, obtain country rock degree of crushing computing formula W=S before mining influence based on inspection instrument for borehole₁+S₂+S₃+S₄, S₁、S₂、S₃、S₄Length when country rock corresponding respectively is complete, more complete, relatively broken and broken.

8. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that in step 4,

Described country rock scope increase rate of breaking is R₁=(L '-L)/L；

Described country rock energy of rupture increase rate R₂=(D '-D)/D；

Described country rock Surface Rupture Events bulk density increase rate R₃=(C '-C)/C；

Described rock crusher degree increase rate R₄=(W '-W)/W, wherein before and after L ', L respectively mining influence, country rock breaks scope；Country rock energy of rupture before and after D ', D respectively mining influence, C ', C respectively adopt front and back country rock rupture time bulk density, country rock degree of crushing before and after W ', W respectively mining influence.

9. mining influence tunnel dynamic monitoring as claimed in claim 1 and Stability Assessment method, it is characterised in that

Digging laneway stability quantitative assessment below described mining influence coal column, is weighted by obtaining the comprehensive evaluation index R=∑ H of digging laneway stability below mining influence coal column_kR_k, and by R value and Drift stability evaluation effect statistical standard value R under certain concrete tunnel mining influence₀Relatively, the Drift stability of driving under mining influence can be obtained, wherein, H_kFor weight coefficient, k=1,2,3,4, its size should according to R₁～R₄Size and reliability and the accuracy of test data be allocated, meet ∑ H_k=1.