Sealing structure for preventing seepage and leakage behind the primary support of a mined shaft and construction method thereof

Abstract

The present invention relates to a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft and a construction method thereof. The plugging structure includes a grouting bag that is used to abut between the primary support structure and the inner wall of the shaft when inflated. The grouting bag is arranged in a ring shape between the primary support structure and the inner wall of the shaft. A first water stop belt connected to the inner wall of the shaft and a second water stop belt connected to the primary support structure are provided on the grouting bag. A sealed cavity for accommodating grout is formed inside the grouting bag, and the sealed cavity is communicated with a grouting conduit passing through the primary support structure. By setting a grouting bag between the primary support structure and the inner wall of the shaft and grouting into the grouting bag, the present invention avoids the diffusion of grout during grouting. At the same time, as the grout is injected, the grouting bag expands and abuts between the primary support structure and the inner wall of the shaft, realizing a tight plugging of the gap between the primary support structure and the inner wall of the shaft, preventing the seepage and leakage of water behind the primary support, improving the construction efficiency and quality, and reducing the construction cost.

Description

Technical Field

[0001] The present invention relates to the field of construction, and particularly to a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft and a construction method thereof. Background Art

[0002] As is well known, during the construction of mined shafts in underground engineering, interlayer stagnant water in the soil mass and / or seepage and leakage of underground pipelines are often encountered. The seepage and leakage flow through the voids behind the primary support structure to the excavation face, and when encountering soil, a large amount of accumulated water and silt will appear on the excavation face, thus greatly affecting the construction efficiency and bringing great difficulties to the on-site construction.

[0003] Therefore, it is necessary to effectively fill the voids behind the primary support structure and block the seepage path of the seepage and leakage in order to ensure water-free operation on the excavation face. In response to this problem, the traditional treatment measure is to carry out backfill grouting behind the already constructed primary support structure through pre-buried back grouting pipes. Judging from the actual implementation situation on site, the effect of this grouting method is very poor because the slurry spreads everywhere uncontrollably. In addition, this grouting method requires temporary bottom sealing of the shaft before grouting (to ensure that the slurry does not flow out from the excavation face), and the above temporary bottom sealing needs to be broken again during the re-excavation. In summary, this grouting method is time-consuming, laborious, material-consuming, and the effect is very poor. Summary of the Invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft and a construction method thereof. By setting a grouting bag between the primary support structure and the inner wall of the shaft and grouting into the grouting bag, the spread of the slurry during grouting is avoided. At the same time, as the slurry is injected, the grouting bag expands and abuts between the primary support structure and the inner wall of the shaft, realizing a tight plugging of the gap between the primary support structure and the inner wall of the shaft, effectively preventing the seepage and leakage behind the primary support, greatly improving the construction efficiency and construction quality, and reducing the construction cost.

[0005] The technical solution for realizing the above purpose is as follows:

[0006] The present invention provides a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft. The plugging structure includes a grouting bag that abuts between the primary support structure and the inner wall of the shaft when bulging. The grouting bag is annularly arranged between the primary support structure and the inner wall of the shaft. The grouting bag is provided with a first water stop belt connected to the inner wall of the shaft and a second water stop belt connected to the primary support structure. A sealed cavity for accommodating the slurry is formed inside the grouting bag, and the sealed cavity is communicated with a grouting conduit passing through the primary support structure.

[0007] A further improvement of the plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in the present invention lies in that the first waterstop and the second waterstop are symmetrically arranged on both sides of the grouting package.

[0008] A further improvement of the plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in the present invention lies in that a first protrusion is provided on the side of the first waterstop in contact with the inner wall of the shaft, and a second protrusion is provided on the side of the second waterstop in contact with the primary support structure.

[0009] A further improvement of the plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in the present invention lies in that a grouting disc for fixing the grouting conduit and communicating the grouting conduit with the sealing cavity is provided on the grouting package.

[0010] A further improvement of the plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in the present invention lies in that the interior of the grouting disc is hollow and frustum-shaped, including a first table surface fixed to the grouting package and a second table surface fixed to the grouting conduit. A first opening communicating with the sealing cavity is provided on the first table surface, and a second opening communicating with the grouting conduit is provided on the second table surface.

[0011] A further improvement of the plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in the present invention lies in that the plugging structure includes a plurality of the grouting packages, and the plurality of grouting packages are distributed along the excavation direction of the shaft.

[0012] The present invention also provides a construction method for a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft, including the following steps:

[0013] Excavate the shaft, and closely attach a grouting package with a sealing cavity formed inside and communicating with a grouting conduit and with a first waterstop and a second waterstop respectively provided on both outer sides to the inner wall of the shaft, and connect the first waterstop to the inner wall of the shaft;

[0014] Erect the primary support framework of the primary support structure closely against the second waterstop of the grouting package, and pass the grouting conduit through the primary support framework;

[0015] Spray primary support concrete onto the primary support framework to form a primary support structure;

[0016] Inject grout into the sealing cavity to expand the grouting package and tightly press it against the space between the primary support structure and the inner wall of the shaft;

[0017] Plug the grouting conduit.

[0018] A further improvement in the construction method of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention lies in that one side of the first waterstop strip in contact with the inner wall of the shaft is provided with a first protrusion, and one side of the second waterstop strip in contact with the primary support structure is provided with a second protrusion;

[0019] When installing the grouting package, drive the first protrusion into the shaft soil body, and extend the second protrusion into the primary support framework;

[0020] When spraying the primary support concrete, anchor the second protrusion into the primary support structure.

[0021] A further improvement in the construction method of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention lies in that after the primary support framework is erected in place and before spraying the primary support concrete, an airtightness inspection is carried out on the grouting package.

[0022] A further improvement in the construction method of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention lies in that the excavation of the shaft is carried out in sections from top to bottom. After each shaft section is excavated, the grouting package is selectively set according to the water leakage condition of the current shaft section.

[0023] Beneficial effects of the plugging structure and its construction method for treating seepage water behind the primary support of an underground-excavated shaft in the present invention:

[0024] During the construction process of the underground-excavated shaft, in the present invention, by setting an annular grouting package between the primary support structure and the inner wall of the shaft and grouting into the grouting package, the diffusion of the grout during grouting is avoided. At the same time, as the grout is injected, the grouting package expands and abuts between the primary support structure and the inner wall of the shaft, realizing a tight plugging of the gap between the primary support structure and the inner wall of the shaft, effectively preventing the leakage of seepage water behind the primary support, greatly improving the construction efficiency and construction quality, and reducing the construction cost. Description of the Drawings

[0025] Figure 1 It is a longitudinal sectional view of the installation of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention.

[0026] Figure 2 It is a side view of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention.

[0027] Figure 3 It is a front view of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention.

[0028] Figure 4 It is a top view of the plugging structure for treating seepage water behind the primary support of an underground-excavated shaft in the present invention. Detailed Description of the Invention

[0029] During the construction of a dark excavated shaft, a primary support frame is erected along the inner wall of the shaft, and primary support concrete is sprayed onto the primary support frame to form a primary support structure. Small irregular gaps are inevitably present between the primary support structure formed by spraying support concrete and the inner wall of the shaft, and interlayer stagnant water in the soil and / or leakage water from underground pipelines are easily leaked through the gaps to affect the excavation surface. The present invention avoids the slurry from spreading around during grouting by setting a grouting bag between the primary support structure and the inner wall of the shaft and injecting grout into the grouting bag. At the same time, as the slurry is injected, the grouting bag expands and presses against the primary support structure and the inner wall of the shaft, thereby achieving a tight sealing of the gap between the primary support structure and the inner wall of the shaft, effectively preventing the leakage of water behind the primary support, greatly improving the construction efficiency and quality, and reducing the construction cost.

[0030] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0031] See also Figure 1 and Figure 2 , Figure 1 The longitudinal cross-sectional view of the installation of the plugging structure for treating water leakage behind the primary support of a dark-dug vertical shaft according to the present invention is shown. Figure 2 The side view of the external grouting bag for treating water leakage behind the primary support of a concealed vertical shaft of the present invention is shown. The vertical shaft is excavated and formed in the soil 10, and the primary support structure 20 is arranged around the vertical shaft 10. The blocking structure includes a grouting bag 40 for abutting between the primary support structure 20 and the inner wall of the vertical shaft when it is bulged. The grouting bag 40 is annularly arranged between the primary support structure 20 and the inner wall of the vertical shaft. The grouting bag 40 is provided with a first water stop 42 connected to the inner wall of the vertical shaft and a second water stop 43 connected to the primary support structure 20. A sealed cavity 41 for accommodating slurry is formed inside the grouting bag 40, and the sealed cavity 41 is connected to a grouting conduit 50 passing through the primary support structure 20.

[0032] In this embodiment, the grouting bag 40, the first waterstop 42 and the second waterstop 43 are all made of EVA waterproof material. The grouting bag 40 is made by hot-melt welding of EVA waterproof board, and the first waterstop 42, the second waterstop 43 and the grouting bag 40 are fixed by hot-melt welding; the grouting conduit 50 passes through the primary support structure 20 and protrudes out of the primary support structure 20 with a length of 10cm to 15cm; the grouting conduit 50 is a common waterproof material on the market.

[0033] As a preferred embodiment of the sealing structure for treating water leakage behind the primary support of a dark-dug vertical shaft according to the present invention, the first water stop 42 and the second water stop 43 are symmetrically arranged on both sides of the grouting bag 40. The grouting bag 40 is subjected to balanced force and is more stable.

[0034] As a preferred embodiment of the plugging structure for treating water leakage behind the primary support of the dark-dug vertical shaft of the present invention, combined with Figure 3 and Figure 4 As shown,Figure 3 shows the front view of the plugging structure for controlling the seepage and leakage behind the primary support of the mined shaft according to the present invention, Figure 4 shows the top view of the plugging structure for controlling the seepage and leakage behind the primary support of the mined shaft according to the present invention. On one side where the first water stop belt 42 is in contact with the inner wall of the shaft, there is a first protrusion 45, and on one side where the second water stop belt 43 is in contact with the primary support structure 20, there is a second protrusion 46.

[0035] Through the settings of the first protrusion 45 and the second protrusion 46, on the one hand, it can make the grouting pack 40, the inner wall of the shaft and the primary support structure 20 be combined more tightly and reliably. On the other hand, it can extend the seepage path of water, making it more difficult for water to seep, forming a double insurance with the grouting pack 40 that is tightly engaged with the soil body 10 and the primary support structure 20 in the filled state after grouting, thereby completely plugging the seepage path of the seepage and leakage behind the primary support and completely preventing the seepage and leakage behind the primary support from continuing to leak downward along the annular gap 30 between the primary support structure 20 and the inner wall of the shaft.

[0036] As a preferred embodiment of the plugging structure for controlling the seepage and leakage behind the primary support of the mined shaft according to the present invention, a grouting plate 44 is provided on the grouting pack 40 for fixing the grouting conduit 50 and communicating the grouting conduit 50 with the sealing cavity 41.

[0037] As a preferred embodiment of the plugging structure for controlling the seepage and leakage behind the primary support of the mined shaft according to the present invention, the inside of the grouting plate 44 is hollow and frustum-shaped, including a first table surface fixed to the grouting pack 40 and a second table surface fixed to the grouting conduit 50. A first opening communicating with the sealing cavity 41 is provided on the first table surface, and a second opening communicating with the grouting conduit 50 is provided on the second table surface. In this embodiment, a communication hole is provided at the connection between the sealing cavity 41 and the grouting conduit 50. The diameter of the grouting plate 44 is larger than the diameter of the communication hole. The first table surface of the grouting plate 40 completely covers the communication hole, and a first opening with the same size as the communication hole is provided at the position corresponding to the communication hole on the first table surface for communicating the grouting pack 40 with the inside of the grouting plate 44; a second opening for communicating the inside of the grouting plate 44 with the grouting conduit 50 is provided at the position corresponding to the grouting conduit 50 on the second table surface, and a sleeve communicating with the second opening and protruding outward is fixed at the second opening. The grouting conduit 50 is sleeved and fixed through this sleeve. Through the setting of the above grouting plate 44, the connection area between the grouting conduit 50 and the grouting pack 40 is enlarged, making the connection between the grouting conduit 50 and the grouting pack 40 more tight and stable. The grouting plate 44 is a common waterproof material in the market.

[0038] As a preferred embodiment of the plugging structure for controlling the seepage and leakage behind the primary support of the mined shaft according to the present invention, the plugging structure includes a plurality of grouting packs 40, and the plurality of grouting packs 40 are distributed along the excavation direction of the shaft.

[0039] To ensure reliable connection between the grouting pack 40, the primary support structure 20 and the inner wall of the shaft, the size of the grouting pack 40 should not be too large. Therefore, the size, quantity, and installation position of the grouting pack 40 need to be determined in combination with the construction site conditions of the shaft.

[0040] The present invention also provides a construction method for a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft, comprising the following steps:

[0041] Excavate the shaft, and closely attach the grouting pack 40, which has a sealed cavity 41 formed inside and communicating with a grouting conduit 50, and a first water stop 42 and a second water stop 43 respectively provided on both outer sides, to the inner wall of the shaft, and connect the first water stop 42 to the inner wall of the shaft;

[0042] Erect the primary support framework of the primary support structure 20 closely to the second water stop 43 of the grouting pack 40, and pass the grouting conduit 50 through the primary support framework;

[0043] Spray primary support concrete onto the primary support framework to form the primary support structure 20;

[0044] Inject grout into the sealed cavity 41 to expand the grouting pack 40 and tightly press it between the primary support structure 20 and the inner wall of the shaft;

[0045] Plug the grouting conduit 50.

[0046] In this embodiment, the length of the grouting conduit 50 extending out of the primary support structure 20 is 10 - 15 cm to facilitate grouting and plugging operations. Additionally, to ensure the tightness of the connection between the grouting conduit 50 and the grouting pack 50, a grouting plate 44 is provided at the connection between the two in this embodiment. The grouting plate 44 is fixed on the grouting pack 40, communicates with the sealed cavity 41 on one side and the grouting conduit 50 on the other side. Through the enlarged connection area of the grouting plate 44, the connection between the grouting conduit 50 and the grouting pack 40 is made more tight and stable.

[0047] As a preferred embodiment of the construction method of the plugging structure for controlling seepage and leakage behind the primary support of the mined shaft of the present invention, a first protrusion 45 is provided on the side of the first water stop 42 in contact with the inner wall of the shaft, and a second protrusion 46 is provided on the side of the second water stop 43 in contact with the primary support structure;

[0048] When installing the grouting pack 40, drive the first protrusion 45 into the soil body 10 on one side of the inner wall of the shaft, and insert the second protrusion 46 into the primary support framework;

[0049] When spraying the primary support concrete, anchor the second protrusion 46 into the primary support structure 20.

[0050] Refer to Figure 3, ribs are provided on the surfaces of the first waterstop 42 and the second waterstop 43. Through the ribs, the grouting bag 40 is tightly engaged with the uneven inner wall of the shaft and the concrete surface of the primary support structure 20. In addition, through the arrangement of the first protrusion 45 and the second protrusion 46, while strengthening the stability of the connection, the seepage path of water is effectively extended, making it more difficult for water to seep. Together with the grouting bag 40 that is tightly engaged with the soil body and the shotcrete of the primary support structure 20 in the filled state after grouting, a double insurance is formed, thereby completely blocking the seepage path of the water seeping behind the primary support and completely preventing the water seeping behind the primary support from continuing to flow downward along the back void.

[0051] As a preferred embodiment of the construction method of the plugging structure for treating the water seepage behind the primary support of the mined shaft in the present invention, before spraying the primary support concrete after the primary support framework is erected in place, an airtightness test is carried out on the grouting bag 40.

[0052] Generally, an airtightness test has been carried out on the grouting bag 40 before the grouting bag 40 is provided. However, since the primary support framework is generally made of steel bars, when the primary support framework is erected close to the grouting bag 40, the grouting bag 40 may be scratched due to improper operation. In order to prevent the air leakage of the grouting bag 40 caused by scratching from affecting the subsequent construction effect, in this embodiment, an airtightness test is carried out on the grouting bag 40 again before spraying the primary support concrete after the primary support framework is erected in place. After passing the test, the primary support concrete is sprayed. If it is unqualified, a new grouting bag 40 is replaced.

[0053] As a preferred embodiment of the construction method of the plugging structure for treating the water seepage behind the primary support of the mined shaft in the present invention, the excavation of the shaft is carried out in sections from top to bottom. After each shaft section is excavated, the grouting bag 40 is selectively set according to the water leakage condition of the current shaft section.

[0054] In this embodiment, if the problem of water seepage in the annular gap 30 can be solved by setting the grouting bag 40 in one shaft section, then the grouting bag 40 may not be set in the construction of the next section. Of course, during the process of the shaft construction downward, if new leakage is found, the grouting bag 40 can be set again at the current shaft section to intercept water.

[0055] The following specifically describes the construction method of the plugging structure for treating the water seepage behind the primary support of the mined shaft in the present invention:

[0056] The shaft is formed by excavation and its cross-section is square. The construction process of the shaft is to first excavate downward for a certain section (generally, the excavation step is 50 cm) to form a shaft section, and then erect the primary support framework along the inner wall of the shaft section. Preferably, the primary support framework is made of steel grids. Connecting bars are inserted into the primary support framework to connect adjacent primary support frameworks and strengthen the structural strength of the primary support framework. The connection method is straight thread sleeve connection. After the steel grids and connecting bars are installed, the steel mesh is installed, and the steel mesh is tied to the steel grids with binding wire. The vertical lap distance of the steel mesh is 15 cm. Thus, the installation of the primary support framework corresponding to one shaft section is completed. Then, concrete is sprayed onto the primary support framework, and the sprayed concrete connects the primary support framework with the inner wall of the shaft section. The primary support framework and the sprayed concrete constitute the primary support structure. Continue to excavate downward to form the next shaft section, and then construct the primary support structure of this shaft section. Repeat this step until the required depth of the shaft is reached.

[0057] When the shaft is constructed to a certain depth, the interlayer stagnant water in the soil body and / or the leakage water of the underground pipeline will stay at the bottom of the current shaft section, that is, on the current excavation surface, along the above leakage path, thus affecting the construction of the shaft. When constructing the primary support structure at the position where there is interlayer stagnant water and / or leakage water of the underground pipeline, the grouting package is pasted on the inner wall of the shaft of the current shaft section, and the first protrusion of the first water stop belt is driven into the soil body on the inner wall of the shaft on the side connected to it to fix the grouting package. Then, the primary support framework is erected against the grouting package (so that the second protrusion of the second water stop belt extends into the primary support framework). After the primary support framework of this shaft section is erected in place, the grouting conduit for grouting the grouting package is passed through the primary support framework and extends out of the primary support framework. Then, concrete is sprayed to form the primary support structure, and the second protrusion is also anchored into the concrete of the primary support structure. Through the above connection method of the grouting package, when the interlayer stagnant water and / or the leakage water of the underground pipeline leaks along the annular gap, most of the water is intercepted by the grouting package on its upper surface. A small part of the water may leak downward along the water stop belts on both sides of the grouting package. However, due to the extension of the leakage path by the protrusions provided on the water stop belt, before the small part of the water leaks out, the concrete of the primary support structure has already reached the initial setting state. At this time, the grouting package is grouted through the grouting conduit. It is recommended that the grouting pressure does not exceed 0.5 MPa, so that the grouting package expands and clamps between the primary support structure and the inner wall of the shaft. Then, the grouting conduit is blocked, so that the small part of the water is also completely intercepted, realizing a tight seal.

[0058] In actual implementation, if the problem of water leakage in the annular gap can be solved by setting a grouting package at one shaft section, then a grouting package may not be set in the construction of the next section. Of course, during the process of the shaft construction downward, if new leakage situations are found, a grouting package can be set at the current shaft section to intercept water.

[0059] The present invention has been described in detail above in conjunction with the embodiments with reference to the accompanying drawings. Those of ordinary skill in the art can make various variations of the present invention according to the above description. Therefore, certain details in the embodiments should not constitute a limitation to the present invention, and the protection scope of the present invention will be defined by the scope defined in the appended claims.

Claims

1. A plugging structure for controlling seepage and leakage behind the primary support of a mined shaft, characterized in that The plugging structure includes a grouting bag that abuts between the primary support structure and the inner wall of the shaft when inflated. The grouting bag is annularly arranged between the primary support structure and the inner wall of the shaft. The grouting bag is provided with a first water stop belt connected to the inner wall of the shaft and a second water stop belt connected to the primary support structure. A sealed cavity for accommodating slurry is formed inside the grouting bag, and the sealed cavity is communicated with a grouting conduit passing through the primary support structure; One side of the first water stop belt connected to the inner wall of the shaft is provided with a first protrusion, and one side of the second water stop belt connected to the primary support structure is provided with a second protrusion; The plugging structure includes a plurality of the grouting bags, and the plurality of grouting bags are distributed along the excavation direction of the shaft.

2. The plugging structure for controlling seepage and leakage behind the primary support of the mined shaft as claimed in claim 1, wherein The first water stop belt and the second water stop belt are symmetrically arranged on both sides of the grouting bag.

3. The plugging structure for controlling seepage and leakage behind the primary support of a mined shaft as claimed in claim 1, wherein The grouting bag is provided with a grouting disc for fixing the grouting conduit and communicating the grouting conduit with the sealed cavity.

4. The plugging structure for controlling seepage and leakage behind the primary support of the mined shaft as claimed in claim 3, wherein The inside of the grouting disc is hollow and frustum-shaped, including a first table surface fixed to the grouting bag and a second table surface fixed to the grouting conduit. A first opening communicating with the sealed cavity is formed on the first table surface, and a second opening communicating with the grouting conduit is formed on the second table surface.

5. A construction method of a plugging structure for controlling seepage and leakage behind the primary support of a mined shaft in a concealed excavation, characterized in that, It includes the following steps: Excavate the shaft, closely attach the grouting bag with a sealed cavity formed inside and communicating with the grouting conduit and with a first water stop belt and a second water stop belt respectively arranged on both outer sides to the inner wall of the shaft, and connect the first water stop belt to the inner wall of the shaft; Erect the primary support framework of the primary support structure close to the second water stop belt of the grouting bag, and pass the grouting conduit through the primary support framework; Spray primary support concrete onto the primary support framework to form a primary support structure; Inject slurry into the sealed cavity to expand the grouting bag and tightly abut it between the primary support structure and the inner wall of the shaft; Plug the grouting conduit.

6. The construction method of the plugging structure for controlling seepage and leakage behind the primary support of the mined shaft as described in claim 5, characterized in that, One side of the first water stop belt connected to the inner wall of the shaft is provided with a first protrusion, and one side of the second water stop belt connected to the primary support structure is provided with a second protrusion; When installing the grouting bag, drive the first protrusion into the shaft soil body, and extend the second protrusion into the primary support framework; When spraying the primary support concrete, anchor the second protrusion into the primary support structure.

7. The construction method of the plugging structure for controlling seepage and leakage behind the primary support of the mined shaft as claimed in claim 5, characterized in that, After the primary support framework is erected in place and before spraying the primary support concrete, conduct an airtightness test on the grouting bag.

8. The construction method of the plugging structure for controlling seepage water behind the primary support of the mined shaft as claimed in claim 5, characterized in that, The excavation of the shaft is carried out in sections from top to bottom; after each shaft section is excavated, the grouting bag is selectively set according to the water leakage condition of the current shaft section.

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