FRACTURED ROOF 110 MINING METHOD ENTRY-SIDE ANTI-COLLAPSED STRUCTURE

Abstract

A fractured roof 110 mining method entry-side anti-collapsed structure, one working face of the 110 mining method corresponds to one roadway but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees. One working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry.

Description

TECHNICAL FIELD

This disclosure relates to a non-pillar mining technique, in particular, to an entry-side anti-collapsed structure during a non-pillar mining.

BACKGROUND

At present, in a longwall mining process, a 121 mining method, that is, one working face needs to excavate two roadways firstly and retains one coal pillar for supporting, is employed. In this structure, the coal pillar is required to be retained to cause large waste of resources. And, each working face needs to excavate two roadways to lead to low work efficiency.

In order to save coal resources, non-pillar mining technique is gradually put into practice. However, when the non-pillar mining is used, due to characteristics of a longwall beam roof pressure, periodic pressure will be generated. The periodic pressure not only has great pressure but also creates extremely huge destructing force to the coal mining working face, and even causes coalmine accident.

SUMMARY

A fractured roof 110 mining method entry-side anti-collapsed structure is used in a 110 mining method, one working face of the 110 mining method corresponds to one roadway, but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees.

In an optional embodiment, the arch is a semi-circular arch.

In an optional embodiment, the arch is a three-centered arch, which includes three sections of arcs with smooth transition.

In an optional embodiment, the roof of the roadway is supported by means of constant resistance large deformation anchor rods and/or common anchor rods and/or anchor cables.

In an optional embodiment, the roadway is supported by a composite mesh for gangue prevention on its side of releasing pressure.

In an optional embodiment, the roadway is supported by a H-shaped steel prop.

In an optional embodiment, the roadway is supported by a temporary close-standing props in front of the working face.

In an optional embodiment, the H-shaped steel prop and a close-standing single prop in the front of the working face are spaced apart from each other, and are connected with the composite mesh for gangue prevention as a whole.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of the present disclosure is taken in conjunction with the accompanying drawings.

FIG. 1 is a schematic view showing one specific application of a fractured roof 110 mining method entry-side anti-collapsed structure according to the present disclosure;

FIG. 2 is a schematic structural view of a roadway roof in the fractured roof 110 mining method entry-side anti-collapsed structure according to the present disclosure.

DETAILED DESCRIPTION

Typical embodiments embodying features and advantages of the present disclosure will be set forth in the following description. It is appreciated that the present disclosure may have various modifications in various embodiments, all without departing from scope of the invention, and the description and drawings are regarded to be illustrative in nature and not limit the present disclosure.

A longwall 110 mining method is a novel coal mining method with one working face only corresponds to one roadway, without retaining any coal pillar.

The fractured roof 110 mining method entry-side anti-collapsed structure of the present disclosure is used in a 110 mining method. As shown in FIG. 1, in the illustrative embodiment, a roadway 1 retains an entry after the previous working face implements mining top-cutting pressure release, and a roof 2 of the roadway 1 is arch-shaped.

In the illustrative embodiment, in order to reinforce supporting, constant resistance large deformation anchor rods 3 are used on the roof 2 to reinforce support strength of the roof 2, typically, 3-7 constant resistance large deformation anchor rods 3 are arranged along a cross section and arranged in an extending direction of the roadway 1 at equal intervals. In addition, common anchor rods and/or anchor cables may be used on the roof 2 in coordination to reinforce the support strength, generally, the anchor rods are smaller, but the anchor cables are longer.

In the illustrative embodiment, one side of the roadway 1 is cut. A cutting line is shown in FIG. 1, and a cutting angle α is between 15-20 degrees, to ensure that the roof of the mined-out area caved by cutting takes least effects on the roof 2 of the roadway 1.

In the illustrative embodiment, a gangue prevention prop 5, a log 6 and a composite mesh for gangue prevention 7 are used for comprehensive three-dimensional support to prevent scattered broken rocks from falling into the roadway 1. If necessary, the collapsed portion may be protected by grouting. In other embodiments, the roadway is supported by using a H-shaped steel prop, and also by using a temporary close-standing props in front of the working face. In one embodiment, the H-shaped steel prop and the close-standing single prop in the front of the working face are spaced apart from each other, and are connected with a composite mesh for gangue prevention as a whole.

In the illustrative embodiment, the shape of the roof 2 of the roadway 1 is shown in FIG. 2. Wherein, the roof 21 is a semi-circular arch, having a center point O and a radius R, wherein the center point O is in the middle of the roadway 1, and the radius R is a half of the width of the roadway 1 and has a height point A. The roof 22 is a three-centered arch, which includes three sections of arcs with smooth transition, as shown in the figures, the first section of arcs has a center point O1 and a radius r1, the second section of arcs has a center point O2 and a radius r2, and the third section of arcs has a center point O3 and a radius r3, and the height point of the roof 22 is B. It can be seen from the figures that the height point B of the roof 22 is lower than the height point A of the roof 21, and thereby the roof 22 with the three-centered arch is safer and more reliable. It may be appreciated that FIG. 2 shows an embodiment of the roof 21 being semi-circular arch, and also shows an embodiment of the roof 22 being the three-centered arch, wherein both the roof 21 and the roof 22 are the roof 2 in FIG. 1.

Advantageous effects of the present disclosures are presented as follows: as compared with the prior art, one working face corresponds to one roadway but without retaining any coal pillar when underground mining is conducted, which can save resources and improve recovery rate of mining. And, the roof of the roadway of the retained entry is arch-shaped, which can improve safety and ensure safety of the coal mining working face. In addition, a cutting angle is 15-20 degrees, which can effectively determine a roof caving direction after top-cutting and reduce affect to the retained entry caused by the roof caving to the maximum extent.

The technical solution of the present disclosure has already described through some exemplary embodiments. It is apparent that those skilled in the art can make modifications and variations to the invention without departing from the scope of the invention. The invention is intended to cover the modifications and variations provided that they fall in the scope of protection defined by the following claims or their equivalents.

Claims

1. A fractured roof 110 mining method entry-side anti-collapsed structure, wherein, the structure is used in a 110 mining method, one working face of the 110 mining method corresponds to one roadway, but without retaining any coal pillar, the roadway retains an entry after the previous working face implements mining top-cutting pressure release, and a roof of the roadway is arch-shape, directional cutting is conducted on one side of the roadway, and the cutting angle is between 15-20 degrees.

2. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 1, wherein, the arch is a semi-circular arch.

3. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 1, wherein, the arch is a three-centered arch, which comprises three sections of arcs with smooth transition.

4. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 1, wherein, the roof of the roadway is supported by means of constant resistance large deformation anchor rods and/or common anchor rods and/or anchor cables.

5. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 1, wherein, the roadway is supported by a composite mesh for gangue prevention on its side of releasing pressure.

6. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 5, wherein, the roadway is supported by a H-shaped steel prop.

7. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 6, wherein, the roadway is supported by a temporary close-standing props in front of the working face.

8. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 7, wherein, the H-shaped steel prop and a close-standing single prop in the front of the working face are spaced apart from each other, and are connected with the composite mesh for gangue prevention as a whole.

9. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 2, wherein, the roof of the roadway is supported by means of constant resistance large deformation anchor rods and/or common anchor rods and/or anchor cables.

10. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 3, wherein, the roof of the roadway is supported by means of constant resistance large deformation anchor rods and/or common anchor rods and/or anchor cables.

11. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 2, wherein, the roadway is supported by a composite mesh for gangue prevention on its side of releasing pressure.

12. The fractured roof 110 mining method entry-side anti-collapsed structure according to claim 3, wherein, the roadway is supported by a composite mesh for gangue prevention on its side of releasing pressure.