Backfilling anti-seepage method for surrounding rock bottom plate of water curtain roadway of underground water-sealed cave depot

Abstract

The invention provides a backfilling anti-seepage method for a surrounding rock bottom plate of a water curtain roadway of an underground water-sealed cave depot, and relates to the technical field of underground water-sealed cave depots. A mixture formed by mixing bentonite, stone powder and water is adopted, backfilling and seepage prevention are directly conducted on the surface of a water curtain roadway surrounding rock bottom plate in a water guide crack structure area between the water curtain roadway surrounding rock bottom plate and a storage medium cavern, and the method has the advantages of being easy and convenient to construct, high in work efficiency, good in water plugging and seepage prevention effect, free of safety operation risks and high in practicability. And in addition, the comprehensive engineering construction cost is greatly saved, and meanwhile, the formed impermeable layer is stable in layer surface and structure state.

Description

Technical Field

[0001] The present invention relates to the technical field of underground water-sealed caverns, and particularly to a backfilling and anti-seepage method for the surrounding rock floor of a water curtain roadway in an underground water-sealed cavern. Background Art

[0002] The water curtain system is one of the basic safety measures for artificially replenishing water to the surrounding rock of an underground cavern group to ensure the stable and reliable groundwater water-sealing condition of an underground water-sealed cavern. It mainly consists of a water curtain roadway and long horizontal parallel and densely arranged water curtain holes provided on the side walls of the water curtain roadway and extending into the surrounding rock. All roadways and water curtain holes are arranged in parallel at a certain elevation position directly above the cavern group of the storage medium (such as crude oil or liquefied petroleum gas, etc.), and cover the lower cavern group. When the groundwater of the site needs to be replenished, during the construction stage, the water curtain roadway serves as a construction operation roadway, and the water supply in the water curtain holes is provided by a temporary water supply pipeline. After the construction is completed and the lower caverns are sealed, the water supply pipeline is removed, and water is directly supplied into the water curtain roadway, and the surrounding rock of the underground cavern group is replenished with water through the water curtain holes on the side walls of the roadway.

[0003] Due to the development of water-conducting fissure structures of varying degrees in natural surrounding rock, water seepage will occur in the caverns of the storage medium along some fissure structures. Among them, a considerable part of the fissure structures communicate to the lower storage medium caverns along the bottom plate of the water curtain roadway. However, since the water curtain roadway is not filled with water during the construction period, these water-conducting fissure structures are not discovered in time in the lower storage medium caverns, thus becoming a blind spot for grouting and water plugging of the surrounding rock in the storage medium caverns. With the sealing of the storage medium caverns, the entire water curtain roadway starts to store water, and seepage will occur in some undiscovered water-conducting fissure structures that communicate to the storage medium caverns at the bottom plate of the roadway, resulting in an increase in the amount of water seepage in the storage medium caverns. At this time, personnel can no longer enter the storage medium caverns for leak detection and water plugging operations, and this situation is common in existing projects. To solve this problem, currently in engineering, a simple comprehensive hydraulic test is carried out in the water curtain roadway before the storage medium caverns are sealed, that is, the roadway is partially filled with water (usually about 1 m high), and it is judged whether there are significant water seepage at which parts of the surrounding rock of the lower storage medium cavern corresponding to the bottom plate of the roadway, so as to determine whether there are water-conducting fissure structures at the bottom plate of the roadway. If it is confirmed that there are water-conducting fissure structures, grouting and water plugging treatment are required.

[0004] There are currently two conventional methods for grouting water control. One is to conduct post-grouting on the water outlet area in the storage medium chamber. The disadvantage of this method is that: due to the relatively high clearance of the storage medium chamber and the water outlet area often being concentrated in the upper half of the chamber, high-altitude grouting operations are required. High-altitude operations not only pose greater safety risks but also are difficult to control the grouting pressure. Because too high a pressure will cause the surrounding rock to be unstable, and too low a pressure will not achieve good results. Especially since the surface of the surrounding rock inside the chamber is generally treated with shotcrete, the shotcrete layer coverage makes it impossible to accurately find the specific location and occurrence of the water-conducting fissure structure, often resulting in a blind grouting state. The other method is to directly conduct post-grouting after finding the area of the water-conducting fissure structure on the bottom plate of the water curtain roadway. The disadvantages of this method are: one is that it is necessary to fully drain the water stored in the water curtain roadway to create a working space, so such water storage - drainage - re-water storage is time-consuming, laborious, and costly; the other is that in the area where the water-conducting fissure structure develops on the bottom plate, the rock mass is often relatively broken and the connectivity of the surrounding rock fissures is strong, and grouting is prone to slurry leakage and channeling, especially affecting the grouting effect. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention provides a backfill and anti-seepage method for the surrounding rock bottom plate of the water curtain roadway in an underground water-sealed storage cavern, which solves the problems of time-consuming, laborious, and costly anti-seepage engineering for the bottom plate of the water curtain roadway in an underground water-sealed storage cavern.

[0006] To achieve the above objectives, the present invention is realized through the following technical solutions:

[0007] A backfill and anti-seepage method for the surrounding rock bottom plate of the water curtain roadway in an underground water-sealed storage cavern, the backfill and anti-seepage method comprising:

[0008] By conducting a hydraulic test on the water curtain roadway, investigating the seepage of the surrounding rock in the storage medium chamber, and combining with geological exploration sketches, determine whether there is a water-conducting fissure structure between the surrounding rock bottom plate of the water curtain roadway and the storage medium chamber, and at the same time determine the anti-seepage area that needs to be treated for the surrounding rock bottom plate;

[0009] Set anti-seepage layer retaining walls at both ends of the anti-seepage area along the axial direction of the water curtain roadway;

[0010] By mass, mix 7 - 8 parts of bentonite with 2 - 3 parts of stone powder and add water to stir until it becomes a moist and flowable mixture;

[0011] Backfill the mixture on the surface of the surrounding rock bottom plate of the water curtain roadway in the anti-seepage area to form a backfill and anti-seepage layer.

[0012] Preferably, the anti-seepage layer retaining wall is made of ordinary bricks.

[0013] Preferably, the fineness modulus of the stone powder is between 0.5 - 1.2.

[0014] Preferably, the thickness of the backfill anti-seepage layer is not less than 600 mm.

[0015] Preferably, the height of the anti-seepage layer retaining wall is the same as the thickness of the backfill anti-seepage layer.

[0016] The present invention provides a method for backfill anti-seepage of the surrounding rock floor of a water curtain roadway in a groundwater-sealed cavern storage. Compared with the prior art, it has the following beneficial effects:

[0017] In the present invention, a mixture formed by mixing bentonite and stone powder with water is used to directly backfill and prevent seepage on the surface of the surrounding rock floor of the water curtain roadway in the water-conducting fracture structure area between the surrounding rock floor of the water curtain roadway and the storage medium cavern. It has the advantages of simple construction, high work efficiency, good water-blocking and anti-seepage effect, no safety operation risk, and greatly saves the comprehensive engineering construction cost. At the same time, the formed anti-seepage layer has a stable surface layer and structural state. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0019] Figure 1 It is a flow chart of the backfill anti-seepage method in the embodiment of the present invention.

[0020] Figure 2 It is a perspective view of the water curtain roadway after backfill anti-seepage in the embodiment of the present invention.

[0021] Figure 3 For Figure 2 The sectional view taken along A-A in

[0022] Figure 4 For Figure 2 The sectional view taken along B-B in

[0023] The reference numerals in the drawings are set as follows: water-conducting fracture structure 1, surrounding rock floor 2, anti-seepage area 3, anti-seepage layer retaining wall 4, backfill anti-seepage layer 5. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0025] By providing a backfill and anti-seepage method for the surrounding rock floor of the water curtain roadway in a groundwater-sealed cavern storage, the embodiment of the present application solves the problems of time-consuming, laborious and costly anti-seepage engineering for the floor of the water curtain roadway in the groundwater-sealed cavern storage.

[0026] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the specification drawings and specific implementation manners.

[0027] Embodiment:

[0028] As Figures 1-4 shown, the present invention provides a backfill and anti-seepage method for the surrounding rock floor of the water curtain roadway in a groundwater-sealed cavern storage, and the backfill and anti-seepage method includes:

[0029] S1. After a simple comprehensive hydraulic test of the water curtain roadway, conduct a seepage investigation on the surrounding rock of the storage medium cavern, and in combination with the geological exploration sketch, determine whether there is a water-conducting fracture structure 1 between the surrounding rock floor of the water curtain roadway and the storage medium cavern, and at the same time preliminarily determine the anti-seepage area 3 that needs to be treated for anti-seepage on the surrounding rock floor 2;

[0030] S2. Set a common brick-built anti-seepage layer retaining wall 4 at both ends of the anti-seepage area 3 along the axis direction of the water curtain roadway, and the wall height is the same as that of the anti-seepage layer;

[0031] S3. By mass, mix 7-8 parts of bentonite and 2-3 parts of stone powder with water and stir to a wet and flowable state of the mixture, wherein the fineness modulus of the stone powder is between 0.5 and 1.2;

[0032] S4. Backfill the mixture on the surface of the surrounding rock floor of the water curtain roadway in the anti-seepage area 3 to form a backfill anti-seepage layer 5 with a thickness of not less than 600 mm.

[0033] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0034] In the embodiment of the present invention, a mixture formed by mixing bentonite and stone powder with water is used to directly backfill and prevent seepage on the surface of the surrounding rock floor of the water curtain roadway in the water-conducting fracture structure area between the surrounding rock floor of the water curtain roadway and the storage medium cavern, which has the advantages of simple construction, high work efficiency, good water-blocking and anti-seepage effect, no safety operation risk, and greatly saves the comprehensive project construction cost. At the same time, the formed anti-seepage layer has a stable layer surface and structure state.

[0035] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0036] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for backfilling and seepage prevention of the surrounding rock floor of a water curtain roadway in an underground water-sealed cavern depot, characterized in that, The backfill and anti-seepage method includes: Through the hydraulic test of the water curtain roadway and the investigation of seepage water in the surrounding rock of the storage medium chamber, combined with the geological exploration sketch, determine whether there is a water-conducting fissure structure (1) between the bottom plate of the surrounding rock of the water curtain roadway and the storage medium chamber, and at the same time determine the anti-seepage area (3) of the bottom plate of the surrounding rock (2) that needs to be treated for anti-seepage; Set anti-seepage layer retaining walls (4) at both ends of the anti-seepage area (3) along the axis direction of the water curtain roadway; Mix 7-8 parts of bentonite and 2-3 parts of stone powder by mass and add water to stir until it becomes a moist and flowable mixture; Backfill the mixture on the surface of the bottom plate of the surrounding rock of the water curtain roadway in the anti-seepage area (3) to form a backfill anti-seepage layer (5).

2. The anti-seepage backfilling method for the surrounding rock floor of the water curtain roadway in the groundwater-sealed cavern storage as described in claim 1, characterized in that The anti-seepage layer retaining wall (4) is built with ordinary bricks.

3. The backfilling and anti-seepage method for the surrounding rock floor of the water curtain roadway in the groundwater-sealed cavern storage as claimed in claim 1, wherein The fineness modulus of the stone powder is between 0.5 and 1.

2.

4. The anti-seepage backfilling method for the surrounding rock floor of the water curtain roadway in the groundwater-sealed cavern storage according to claim 1, characterized in that, The thickness of the backfill anti-seepage layer (5) is not less than 600 mm.

5. The anti-seepage backfilling method for the surrounding rock floor of the water curtain roadway in the groundwater-sealed cavern storage according to claim 1, characterized in that, The height of the anti-seepage layer retaining wall (4) is the same as the thickness of the backfill anti-seepage layer (5).

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