Method for reinforcing large fault through multi-row horizontal drill hole grouting

Abstract

The invention discloses a method for reinforcing a large fault through multi-row horizontal drill hole grouting, which comprises the following steps: firstly, collecting and analyzing hydrogeological information of a fault area, designing the position of each row of drill holes, drilling a plurality of rows of drill holes in a treatment area by using a directional drilling machine according to the design, and performing multi-layer deep synchronous grouting reinforcement on the treatment area by using a ground grouting system. And forming a waterproof reinforcing layer. According to a complex water-rich structure of the large fault, by arranging multiple rows of drill holes, matching with a parallel and oblique crossing comprehensive hole arrangement mode and combining with a multi-layer grouting technology, grout is evenly diffused to form a multi-layer closed barrier, fault water is effectively prevented from leaking to an excavation area, waterproof reinforcement of the large fault is achieved, the method is simple, the effect is remarkable, and the method is suitable for large fault construction. The method has high operability, and can effectively improve the water disaster prevention and control capability of mine and tunnel engineering; as the fault is waterproof and reinforced, the thickness of the coal mine waterproof coal pillar is shortened, and the utilization rate of mineral resources is improved.

Description

Technical Field

[0001] The invention relates to the technical field of mine water hazard prevention and control, and more specifically to a method for reinforcing a large fault by grouting multiple rows of horizontal drilling holes. Background Art

[0002] In mine and tunnel projects, faults usually serve as natural water channels, especially when the fault has a large drop and sandwiches multiple layers of water-rich limestone, there is a serious threat of water damage. The traditional single-row drilling and grouting method cannot cover a large range of faults and cannot form an effective grouting barrier, increasing the risk of leakage in the project area. Existing technologies often have difficulty meeting waterproofing requirements when facing large faults with multiple aquifers and large drop. Summary of the invention

[0003] To this end, the technical problem to be solved by the present invention is to provide a method for reinforcing a large fault by multiple rows of horizontal drilling and grouting, which can effectively block the water conduction channel of the large fault and improve the safety of the project.

[0004] In order to solve the above technical problems, the present invention provides the following technical solution: a method for reinforcing a large fault by grouting multiple rows of horizontal drilling, comprising the following steps:

[0005] Step A: Collect and analyze hydrogeological information of the fault area to determine the stratigraphic structure and stratigraphic properties of the fault area;

[0006] Step B: Determine the treatment area according to the stratigraphic structure and stratigraphic properties of the fault area, design the location of each row of boreholes in the fault area, and ensure that the boreholes widely cover the water-rich layers in the upper and lower walls of the fault;

[0007] Step C: First row of drilling construction: Use a directional drill to drill from the ground to the water-rich layer at the depth position A1. After the drill reaches the depth position A1, it starts to drill horizontally into the water-rich layer to complete a borehole. Then, use the grouting system to inject grout into the current borehole to perform grouting construction;

[0008] Step D: Nth row of drilling holes: Use a directional drill to drill from the ground to the water-rich layer at the depth position A2. After the drill reaches the depth position A2, it starts to drill horizontally into the water-rich layer to complete a borehole. Then, a grouting system is used to inject grout into the current borehole to perform grouting construction;

[0009] Step E: Repeat steps C and D in sequence to perform balanced grouting of the water-rich layers in the upper plate and the lower plate until a first row of boreholes is formed in the water-rich layer at a depth of A1, and a second row of boreholes is formed in the water-rich layer at a depth of A2, thereby forming a grouting curtain to achieve reinforcement and water blocking;

[0010] Step F: During the grouting process, the grouting pressure, flow rate and slurry consumption are monitored in real time to ensure that the slurry is evenly diffused in the water-rich layer; after the construction is completed, the effect of the grouting curtain is evaluated through hydrological monitoring to confirm the water-sealing performance of the reinforcement layer; based on the monitoring data, the areas with insufficient grouting are treated with hole filling to ensure the grouting effect.

[0011] In the above method of reinforcing a large fault by grouting multiple rows of horizontal drilling, in step C, the first row of boreholes includes boreholes parallel to the fault strike and boreholes oblique to the fault strike.

[0012] In the above method of reinforcing a large fault by grouting multiple rows of horizontal drilling, in step D, the Nth row of drilling holes includes drilling holes parallel to the fault strike and drilling holes oblique to the fault strike.

[0013] In the above-mentioned method of reinforcing a large fault by using multiple rows of horizontal drilling and grouting, when drilling, some holes are first arranged parallel to the direction of the fault to ensure that the entire drilling is located in the water-rich layer, and grouting construction is carried out to construct a longitudinal closed barrier; then holes are arranged oblique to the fault direction, and grouting construction is carried out to form a multi-level grouting barrier; the hole spacing of each row of holes is less than or equal to 60m.

[0014] In the above method of reinforcing a large fault by multiple rows of horizontal drilling and grouting, in step C and step D, the drilling depth extends to 50 meters outside the treatment boundary to ensure the grout injection effect.

[0015] In the above-mentioned method of reinforcing a large fault by using multiple rows of horizontal drilling and grouting, the first row of holes and the second row of holes are arranged in the upper and lower plates of the fault respectively, and the grouting construction is carried out simultaneously from the upper and lower plates of the fault to balance the grouting pressure and diffusion range, forming a symmetrical grouting curtain.

[0016] In the above method for reinforcing a large fault by grouting with multiple rows of horizontal drilling holes, the grouting construction adopts grouting in stages, and includes the following steps:

[0017] Step a: initial grouting: the grouting system performs grouting at low pressure and small flow rate, the grouting pressure is 3-6Mpa, the flow rate is 200-250L / min, the slurry enters the water guide path and diffuses along the water guide path to form the first layer of foundation barrier and close the initial water guide path;

[0018] Step b: Secondary grouting: After the initial grouting solidifies, the ground grouting system performs grouting at high pressure and large flow rate. The grouting pressure is 2.5 times the hydrostatic pressure of the receiving layer, and the flow rate is 500L / min. The slurry diffuses deep along the fault plane to form a multi-layer curtain.

[0019] Step c: Tertiary grouting: Supplementary grouting is carried out on the remaining water-conducting paths in the treatment area to form a continuous waterproof barrier.

[0020] In the above-mentioned method of reinforcing a large fault by multiple rows of horizontal drilling and grouting, in step A, the hydrogeological information includes the fault drop, aquifer thickness, water content and bedding structure of the limestone layer, and the water richness and permeability of the limestone layer and the stratigraphic properties of the two sides of the fault are determined based on the hydrogeological information.

[0021] In the above-mentioned method of reinforcing large faults by grouting with multiple rows of horizontal drilling, cement-based slurry or silicate-based slurry is used as the grouting slurry; during grouting, the pump volume is adjusted to 60L / min, and the grouting construction is completed when the grouting pressure reaches the designed final pressure and stabilizes for 30 minutes.

[0022] In the above method for reinforcing a large fault by multiple rows of horizontal drilling and grouting, in step C and step D, the first row of boreholes and the Nth row of boreholes are drilled from the upper wall surface and / or the lower wall surface of the fault.

[0023] The technical solution of the present invention achieves the following beneficial technical effects:

[0024] The present invention aims at the complex water-rich structure of large faults. By arranging multiple rows of drill holes, coordinating the parallel and oblique comprehensive hole layout mode, and combining the multi-level grouting process, the slurry is evenly diffused to form a multi-level closed barrier, which effectively prevents the fault water from leaking into the mining area and realizes the waterproof reinforcement of the large fault. The method is simple, the effect is significant, and it has high operability. It can effectively improve the water hazard prevention and control capabilities of mines and tunnel projects. Since the faults are waterproofed and reinforced, the thickness of the waterproof coal pillar of the coal mine is shortened, thereby improving the utilization rate of mineral resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A cross-sectional schematic diagram of the arrangement of the grouting pipes in Example 1 of the present invention;

[0026] Figure 2 A schematic plan view of the arrangement of grouting pipes in Example 1 of the present invention;

[0027] Figure 3 A cross-sectional schematic diagram of the arrangement of the grouting pipes in Example 2 of the present invention;

[0028] Figure 4 A schematic plan view of the arrangement of grouting pipes in Example 2 of the present invention.

[0029] The reference numerals in the figure are as follows: 1-the first row of holes; 2-the Nth row of holes. DETAILED DESCRIPTION

[0030] Example 1

[0031] In this embodiment, the method of reinforcing a large fault by grouting multiple rows of horizontal holes is as follows: Figure 1-2 As shown, construction is carried out on the surface of the upper wall and the lower wall of the fault, respectively, including the following steps:

[0032] Step A: Collect and analyze the hydrogeological information of the fault area, including the fault drop, aquifer thickness, water content and bedding structure of the limestone layer, and combine the relevant information to determine the water-richness and permeability of the limestone layer in the fault area and the stratigraphic properties of the two sides of the fault;

[0033] Step B: Determine the treatment area according to the stratigraphic structure and stratigraphic properties of the fault area, design the location of each row of boreholes in the fault area, and ensure that the boreholes widely cover the water-rich layers in the upper and lower walls of the fault;

[0034] Step C: First row of drilling construction: Use a directional drill to drill from the ground to the water-rich layer at the depth position A1. After the drill reaches the depth position A1, it starts to drill horizontally into the water-rich layer to complete a borehole. The depth of the borehole extends to 50 meters outside the treatment boundary to ensure the slurry injection effect. Then, use the grouting system to inject grout into the current borehole for grouting construction;

[0035] Step D: Nth row of drilling holes: Use a directional drill to drill from the ground to the water-rich layer at the depth position A2. After the drill reaches the depth position A2, it starts to drill horizontally into the water-rich layer to complete a borehole. Then, a grouting system is used to inject grout into the current borehole to perform grouting construction;

[0036] Step E: Repeat steps C and D in sequence to perform balanced grouting of the water-rich layers in the upper plate and the lower plate until a first row of boreholes 1 is formed in the water-rich layer at a depth of A1, and a second row of boreholes 2 is formed in the water-rich layer at a depth of A2, thereby forming a grouting curtain to achieve reinforcement and water blocking;

[0037] Step F: During the grouting process, the grouting pressure, flow rate and slurry consumption are monitored in real time to ensure that the slurry is evenly diffused in the water-rich layer; after the construction is completed, the effect of the grouting curtain is evaluated through hydrological monitoring to confirm the water-sealing performance of the reinforcement layer; based on the monitoring data, the areas with insufficient grouting are treated with hole filling to ensure the grouting effect.

[0038] Grouting construction adopts staged grouting, including the following steps:

[0039] Step a: initial grouting: the grouting system performs grouting at low pressure and small flow rate, the grouting pressure is 3-6Mpa, the flow rate is 200-250L / min, the slurry enters the water guide path and diffuses along the water guide path to form the first layer of foundation barrier and close the initial water guide path;

[0040] Step b: Secondary grouting: After the initial grouting solidifies, the ground grouting system performs grouting at high pressure and large flow rate. The grouting pressure is 2.5 times the hydrostatic pressure of the grouting layer, the orifice pressure is usually above 10Mpa, the flow rate is 500L / min, and the slurry diffuses deep along the fault plane to form a multi-layer curtain. When the pump volume is adjusted to 60L / min, the grouting pressure reaches the designed final pressure and stabilizes for 30 minutes, the grouting construction is completed;

[0041] Step c: Tertiary grouting: Supplementary grouting is carried out on the remaining water-conducting paths in the treatment area to form a continuous waterproof barrier.

[0042] Preferably, the first row of boreholes 1 and the second row of boreholes 2 are arranged in the upper and lower plates of the fault, respectively, and the grouting construction is carried out synchronously from the upper and lower plates of the fault to balance the grouting pressure and diffusion range to form a symmetrical grouting curtain.

[0043] In step C and step D, the first row of boreholes 1 and the Nth row of boreholes 2 both include boreholes parallel to the fault strike and boreholes oblique to the fault strike. When drilling, firstly, some boreholes are arranged parallel to the fault strike to ensure that the boreholes are located in the water-rich layer throughout, and grouting construction is carried out to construct a longitudinal closed barrier; then, boreholes oblique to the fault strike are arranged, and grouting construction is carried out to form a multi-level grouting barrier; the hole spacing between adjacent boreholes in each row of boreholes is less than or equal to 60m, and in areas with more complex geological structures, the hole spacing between adjacent boreholes is 40 to 50m.

[0044] Due to the action of the fault, a certain water-rich limestone layer is lifted, and some water-rich layers are close to the coal seam, which will pose a certain threat. Conventional single-row grouting cannot effectively cover the fault on a large scale. In this embodiment, two rows of upper and lower drill holes are used to cover the water-rich layers of the fault respectively. The spacing between the upper and lower rows of drill holes is designed according to the target layer for treatment, that is, the larger the distance between the treatment layers, the larger the spacing between the upper and lower rows of holes will be. Grouting reinforcement is performed on the water-rich layer to achieve large-scale coverage and form an effective grouting curtain.

[0045] Preferably, at least two drilling points are taken on the upper plate surface and the lower plate surface, and the individual holes in each row of holes can be interwoven in the spatial direction to form a mesh structure, and the upper and lower adjacent rows of holes form a denser interwoven structure, thereby improving the reinforcement and waterproofing effects.

[0046] In some other embodiments, when the site space is insufficient, it is also possible to drill holes at a single point on the upper plate surface and the lower plate surface, and then drill in all directions after reaching the specified depth. The degree of interweaving is reduced, but during subsequent grouting, combined with geological conditions, increasing the grouting time, or using higher strength grouting materials, it is still possible to achieve the effect of reinforcement and waterproofing.

[0047] Example 2

[0048] The method of reinforcing a large fault by multiple rows of horizontal drilling and grouting in this embodiment is different from that in Embodiment 1 in that when the construction site is further reduced and the site conditions make it impossible to drill holes in the upper plate and the lower plate respectively, Figure 3-4 As shown, drilling can also be carried out at one position. After the drill bit drills to the corresponding depth, it turns and drills multiple holes at the depth layer. The drill bit is then lifted up and drills further downward on the basis of the original vertical hole. When a deeper position is reached, it turns to horizontal drilling at the depth position to form two rows of holes above and below. This can meet the situation of insufficient space on the construction site. The rest is the same as Example 1.

[0049] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. A method for reinforcing a large fault by grouting multiple rows of horizontal holes, characterized in that: The following steps are involved: Step A: Collect and analyze hydrogeological information of the fault area to determine the stratigraphic structure and stratigraphic properties of the fault area; Step B: Determine the treatment area according to the stratigraphic structure and stratigraphic properties of the fault area, and design the location of each row of boreholes in the fault area to ensure that the boreholes widely cover the water-rich layers in the upper and lower walls of the fault; Step C: First row of drilling construction: Use a directional drill to drill from the ground to the water-rich layer at the depth position A1. After the drill reaches the depth position A1, it starts to drill horizontally into the water-rich layer. After the drilling is completed, the grouting system is used to inject grout into the current borehole to carry out grouting construction; Step D: Nth row of drilling holes: Use a directional drill to drill from the ground to the water-rich layer at the depth position A2. After the drill reaches the depth position A2, it starts to drill horizontally into the water-rich layer. After the drilling is completed, the grouting system is used to inject grout into the current borehole to perform grouting construction; Step E: Repeating steps C and D in turn, performing balanced grouting in the water-rich layers in the upper plate and the lower plate, until a first row of boreholes (1) is formed in the water-rich layer at a depth of A1, and a second row of boreholes (2) is formed in the water-rich layer at a depth of A2, forming a grouting curtain to achieve reinforcement and water blocking; Step F: During the grouting process, the grouting pressure, flow rate and slurry consumption are monitored in real time to ensure that the slurry is evenly diffused in the water-rich layer; after the construction is completed, the effect of the grouting curtain is evaluated through hydrological monitoring to confirm the water-sealing performance of the reinforcement layer; based on the monitoring data, the areas with insufficient grouting are treated with hole filling to ensure the grouting effect.

2. A method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: In step C, the first row of boreholes (1) includes boreholes parallel to the fault strike and boreholes oblique to the fault strike.

3. A method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 2, characterized in that: In step D, the Nth row of boreholes (2) includes boreholes parallel to the fault strike and boreholes oblique to the fault strike.

4. A method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 3, characterized in that: When drilling, first arrange some holes parallel to the fault direction to ensure that the entire hole is located in the water-rich layer, and carry out grouting construction to construct a longitudinal closed barrier; then arrange holes oblique to the fault direction, and carry out grouting construction to form a multi-level grouting barrier; the hole spacing of each row of holes is less than or equal to 60m.

5. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: In step C and step D, the drilling depth extends to 50 meters outside the treatment boundary to ensure the slurry injection effect.

6. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: The first row of boreholes (1) and the second row of boreholes (2) are arranged on the upper plate and the lower plate of the fault respectively, and the grouting construction is carried out synchronously from the upper plate and the lower plate of the fault, balancing the grouting pressure and the diffusion range to form a symmetrical grouting curtain.

7. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: Grouting construction adopts staged grouting, including the following steps: Step a: initial grouting: the grouting system performs grouting at low pressure and small flow rate, the grouting pressure is 3-6Mpa, the flow rate is 200-250L / min, the slurry enters the water guide path and diffuses along the water guide path to form the first layer of foundation barrier and close the initial water guide path; Step b: Secondary grouting: After the initial grouting solidifies, the ground grouting system performs grouting at high pressure and large flow rate. The grouting pressure is 2.5 times the hydrostatic pressure of the receiving layer, and the flow rate is 500L / min. The slurry diffuses deep along the fault plane to form a multi-layer curtain. Step c: Tertiary grouting: Supplementary grouting is carried out on the remaining water-conducting paths in the treatment area to form a continuous waterproof barrier.

8. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: In step A, the hydrogeological information includes the fault drop, aquifer thickness, water content and bedding structure of the limestone layer. The water-richness and permeability of the limestone layer and the stratigraphic properties of the two sides of the fault are determined based on the hydrogeological information.

9. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: The grouting slurry adopts cement-based slurry or silicate-based slurry; during grouting, the pump volume is adjusted to 60L / min, and the grouting construction is completed when the grouting pressure reaches the designed final pressure and stabilizes for 30 minutes.

10. The method for reinforcing a large fault by multiple rows of horizontal drilling and grouting according to claim 1, characterized in that: In step C and step D, the first row of boreholes (1) and the Nth row of boreholes (2) are drilled from the hanging wall surface and / or the foot wall surface of the fault.

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