CN101915108A - A method of controlling the floor drum of the dynamic pressure roadway - Google Patents

Abstract

A method for controlling the floor heave of a dynamic pressure roadway. On the roadway floor in a high-stress mining environment, the center of the roadway cross-section is used as a boundary to symmetrically drill holes with different longitudinal angles α in the direction of the two sides, and then install hydraulic expansion anchors. When the high-pressure water injection reaches 30MPa, stop the high-pressure water injection; construct row by row according to the row spacing, until the construction of the roadway floor prone to floor drum in the high-stress mining environment is completed. The anchoring force of the hydraulic expansion bolt has little change with the difference in the nature of the surrounding rock, and it is especially suitable for the support of the floor of the dynamic pressure roadway, which provides a new way for controlling the floor heave of the dynamic pressure roadway. The construction method is simple, the operation is convenient, the cost is low, the labor intensity is small, the installation efficiency is high, no pollution, and the economic benefit is remarkable.

Description

A method of controlling the floor drum of the dynamic pressure roadway

technical field

The invention relates to a method for controlling the floor heave of a roadway, in particular to a method for controlling the floor heave of a roadway in a high-stress mining environment.

Background technique

Bass drum is a dynamic phenomenon that often occurs in coal mine shafts. After the roadway is excavated, the surrounding rock changes from a three-dimensional stress state to a two-dimensional stress state. Under the influence of complex concentrated stress, the floor rock layer is stretched and destroyed to form a floor heave. A large number of measured data show that about 2/3 of the roadway deformation is reflected in the floor drum. The main hazard of the bottom drum is that it reduces the section of the roadway, which affects pedestrians, transportation, water supply and drainage, and underground ventilation.

The problem of bottom drum control in dynamic pressure roadway has always been one of the major problems plaguing the production and construction of coal mines. In recent years, many scholars and coal mine technicians at home and abroad have carried out fruitful research on the mechanism and prevention measures of roadway floor heave, and proposed many floor heave control technologies, such as reinforced floor, closed metal bracket, floor anchor rod, floor grouting , roadside filling and pressure relief coal pillars, etc. These research results have a good guiding role in controlling the roadway floor heave. However, the above-mentioned bottom drum control methods have more or less defects such as slow construction speed, complicated process, high economic cost, limited control effect, and high labor intensity. For example, although the reinforced floor can play a certain role in suppressing the bottom drum, but In the dynamic pressure roadway, the material consumption is large, the support cost is high, and the engineering volume is large; under the condition of high stress and soft floor, the closed metal support bottom beam often cannot fully exert its bearing capacity, resulting in bulging into the roadway and losing The ability to control the bottom heave; in many cases, floor anchors fail due to poor anchorage in soft floor rock formations, insufficient anchoring force, or a mismatch between the amount of extension and the amount of floor heave; floor grouting can reinforce shallower layers of the floor, such as If the grouting fails to reach the failure depth of the floor rock layer, the upper reinforced rock layer will be lifted by the lower rock layer. Therefore, the role of grouting to control the bottom heave is also limited; and the construction procedures of the roadside filling method and the pressure relief coal pillar method are complicated , the time is long, it has a great influence on the mining face, and the control effect is very limited.

Contents of the invention

Technical problem: The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for controlling the floor drum of a dynamic pressure roadway with simple application, convenient operation, low cost, low labor intensity and high installation efficiency.

Technical solution: The method for controlling the bottom drum of the dynamic pressure roadway according to the present invention, the steps are as follows:

(1) On the floor of the roadway in the environment of high mining stress, a row of drill holes is constructed symmetrically to the two sides with the center of the roadway cross section as the boundary. 2800mm, the longitudinal angle α of a row of drilling holes is 0°, 15°, 25°, 30°, 45°, 60°;

(2) Install hydraulic expansion anchor rods in each borehole after construction, and the diameter of the hydraulic expansion anchor rods is 25-30mm;

(3) Connect the liquid injection port of the hydraulic expansion anchor and the high-pressure water injection pump through the water pipe, inject high-pressure water into the hydraulic expansion anchor, and when the pressure of the high-pressure water injection pump reaches 30MPa, turn off the high-pressure water injection pump;

(4) After the high-pressure water injection pump is depressurized, the high-pressure water injection pump is removed to complete the construction of the bottom drum of the controlled dynamic pressure roadway in a section;

(5) Repeat the above steps, and construct row by row according to the row spacing, until the construction of the roadway floor prone to floor drum in the whole mining high stress environment is completed.

The spacing of a row of drilled holes in the interval construction is 500-2000 mm; the row spacing is 600-2000 mm.

Beneficial effects: by using hydraulic expansion bolts to reinforce the roadway floor, preventing the development of the plastic zone of the roadway floor and controlling post-peak crushing and shearing deformation of the roadway floor rock mass, the purpose of controlling the bottom heave of the roadway under dynamic pressure is achieved. Compared with other bonded anchors, the hydraulic expansion bolt is used to control the bottom heave of the roadway with significant advantages: the hydraulic expansion bolt is full-length anchored, which can limit the expansion and deformation of the surrounding rock within the entire length of the rod body; the hydraulic expansion bolt It is frictional anchoring with the anchored body (coal, rock mass), and the residual coal (rock) powder and sewage in the drill hole will not affect the anchoring force of the bolt. The anchoring force of the hydraulic expansion bolt does not change much with the difference in the nature of the surrounding rock, and it is especially suitable for the support of the bottom plate of the dynamic pressure roadway, which provides a new way for controlling the floor heave of the dynamic pressure roadway. The construction method is simple, the operation is convenient, the cost is low, the labor intensity is small, the installation efficiency is high, no pollution, and the economic benefit is remarkable.

Description of drawings

Fig. 1 is a schematic diagram of the drilling position of the bottom drum of the present invention.

Fig. 2 is a schematic diagram of the construction and connection of the hydraulic expansion bolt of the present invention.

In the figure: 1-roadway, 2-drilling, 3-hydraulic expansion bolt, 4-bottom plate, 5-two gangs, 6-liquid injection port, 7-water pipe, 8-high pressure water injection pump.

Detailed ways

An embodiment of the present invention will be further described below in conjunction with accompanying drawing:

As shown in Figure 1, the rectangular roadway 1 is taken as an example. The method of controlling the bottom drum of the dynamic pressure roadway in a certain mine is based on the actual situation on site. Install the hydraulic expansion bolt 3 on the roadway floor 4 according to different longitudinal clamps α, and then inject water. In order to prevent the development of the plastic zone of the floor and control the post-peak fracture expansion and shear displacement deformation of the rock mass of the floor, realize the control of the floor heave of the dynamic pressure roadway. Specific steps are as follows:

1. Drilling: On the floor 4 of the roadway where the roadway bottom drum is prone to occur in the high-stress environment of mining, the longitudinal angle α in the direction of the two sides 5 is symmetrically bounded by the center of the cross-section of the roadway 1. 45°, construct a row of boreholes 2 at intervals of 500-2000mm downward on the roadway floor 4, the diameter of the boreholes 2 is 28-42mm, and the length of the boreholes 2 is 1200-2800mm. According to the actual situation on site, a row of boreholes The longitudinal angle α of 2 can be selected from 0°, 15°, 25°, 30°, 45°, 60° in ascending order;

2. Install hydraulic expansion anchors: install hydraulic expansion anchors 3 in each borehole 2 after construction, and send hydraulic expansion anchors 3 to the bottom of borehole 2. The diameter of hydraulic expansion anchors 3 is 25-30mm;

3. Inject high-pressure water: connect the liquid injection port 6 of the hydraulic expansion anchor 3 and the high-pressure water injection pump 8 through the water pipe 7, inject high-pressure water into the hydraulic expansion anchor 3, the injection pressure is not less than 30MPa, and the injection time is greater than 5min. And ensure that the initial anchor force is above 100kN; when the pressure of the high-pressure water injection pump 8 reaches 30MPa, turn off the high-pressure water injection pump 8;

4. After the pressure of the high-pressure water injection pump 8 is released, the high-pressure water injection pump 8 is removed to complete the construction of the bottom drum of the roadway with controlled dynamic pressure in a section;

5. Repeat the above steps, and construct row by row according to the row spacing of 600-2000mm, until the construction of the roadway floor 4 prone to floor drum in the whole mining high-stress environment is completed.

Claims (3)

1. method of controlling floor heave of dynamic pressure tunnel, it is characterized in that: step is as follows:

(1) on the roadway floor in adopting high stress environment (4), with tunnel (1) cross-section center is that bound pair claims to help (5) direction gang drill hole (2) of constructing at interval to two, the aperture of boring (2) is 28～42mm, the length of boring (2) is 1200～2800mm, and the longitudinal angle α in a gang drill hole (2) is 0 °, 15 °, 25 °, 30 °, 45 °, 60 °;

(2) in each boring (2) that construction is finished hydraulic expansion anchor pole (3) is installed respectively, hydraulic expansion anchor pole (3) diameter is 25～30mm;

(3) by the liquid injection port (6) and the high pressure water-injection pump (8) of water pipe (7) connection hydraulic expansion anchor pole (3) afterbody, in hydraulic expansion anchor pole (3), annotate water under high pressure, when the pressure meter of high pressure water-injection pump (8) reaches 30MPa, close high pressure water-injection pump (8);

(4) treat high pressure water-injection pump (8) release after, unload high pressure water-injection pump (8), finish the construction of a section district inner control floor heave of dynamic pressure tunnel;

(5) repeat above-mentioned steps, construct by row, the construction in pucking tunnel easily takes place until finishing the whole roadway floor of adopting in the high stress environment (4) by array pitch.

2. the method for control floor heave of dynamic pressure tunnel according to claim 1 is characterized in that: the construct spacing in a gang drill hole (2) of described interval is 500～2000mm.

3. the method for control floor heave of dynamic pressure tunnel according to claim 1 is characterized in that: described array pitch is 600～2000mm.

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