Method and device for sealing core sampling holes in ground-connected wall joints under high water pressure conditions

Abstract

The present invention discloses a method and device for sealing core sampling holes in ground-connected wall joints under high water pressure conditions. The sealing method comprises the following steps: S1, using a reaming drill bit to continue reaming along the sampling hole into the rock and soil body, forming a hemispherical reaming hole in the stratum outside the sampling hole; S2, pushing a sealing device into the sampling hole, wherein the front end of the sealing device can be formed into a hemispherical sealing end by pressurized grouting, and then the sealing device is pulled back in reverse to form a close contact between the hemispherical sealing end and the outer wall of the ground-connected wall; S3, filling the sampling hole with a water-stopping material; S4, installing a sealing structure at the hole opening of the sampling hole to achieve hole sealing. The present invention can be used to solve the problem of water-stopping and sealing the core hole in a dynamic water environment during the core sampling process at the milling joint position of the ultra-deep ground-connected wall in a water-rich stratum, thereby ensuring that the anti-leakage performance of the ground-connected wall caused by the core sampling of the joint meets the construction requirements and avoids a series of catastrophic consequences caused by pipe bursts and sand flow.

Description

Technical Field

[0001] The present invention relates to the technical field of rock and soil underground engineering construction, and in particular to a method and device for sealing a core sampling hole in a ground-connected wall joint under high water pressure conditions. Background Art

[0002] Underground continuous walls have been widely used in deep foundation pit enclosures due to their high rigidity and strong adaptability. Especially in recent years, the "milling joint" technology developed based on double-wheel milling and other grooving equipment has greatly improved the construction depth, construction efficiency and joint anti-seepage control level of underground continuous walls compared to traditional joint treatment methods.

[0003] The use of sleeve milling joints at the joint locations between the first and second phase trench sections has a certain weakening effect on the overall mechanical performance of the ground-diaphragm wall, particularly with regard to micro-deformation control of the retaining structure of the ultra-deep circular vertical shaft excavation. This is due to the use of retaining slurry during trenching to ensure trench stability. This inevitably results in a certain width of mud and sand inclusions at the trench joint locations during the sleeve milling process. Current domestic research and engineering applications are largely based on the experience of underground diaphragm wall construction in Japan, generally assuming a 3mm trench joint width. Some joint mechanical performance tests are also conducted using laboratory specimens prepared with 3mm slurry joints. However, given domestic construction conditions and varying geotechnical conditions, it is necessary to conduct core sampling and a series of mechanical performance tests on actual ground-wall joints to improve the accuracy of structural mechanical performance evaluation and deformation control for the project, while also accumulating technical parameters for the sleeve milling joint process under typical geological conditions in my country.

[0004] The holes left in the ground-anchored wall after core sampling have minimal impact on the structural stress. Generally, for durability and anti-seepage considerations, a series of operations are used, including core hole cleaning → polyurethane wall brushing → expansive cement mortar pouring and filling. However, for the high water pressure conditions commonly faced by ultra-deep ground-anchored walls, this core hole sealing method lacks operability and reliability.

[0005] Therefore, it is necessary to design and develop a water-stopping and sealing device for dynamic water environment according to the characteristics of core sampling operation of ground-anchored wall, so as to form a sealing method for core sampling holes of ground-anchored wall sleeve milling joints under high water pressure conditions. Summary of the Invention

[0006] In response to the deficiencies in the prior art, the purpose of the present invention is to provide a method and device for sealing core sampling holes in ground-anchored wall joints under high water pressure conditions, which is used to solve the problem of water-stopping and sealing core holes in a dynamic water environment during core sampling at ultra-deep ground-anchored wall sleeve milling joints in water-rich formations, thereby ensuring that the anti-leakage performance of the ground-anchored wall caused by joint core sampling meets the construction requirements and avoids a series of catastrophic consequences caused by pipe bursts and sand flow.

[0007] To achieve the above object, the present invention is implemented through the following technical solutions:

[0008] In one aspect, the present invention provides a method for sealing a core sampling hole in a ground-wall joint under high water pressure conditions, comprising the following steps:

[0009] S1. Use the reaming drill bit to continue reaming along the sampling hole into the rock and soil, forming a hemispherical reaming hole in the stratum outside the sampling hole;

[0010] S2. Push the plugging device into the sampling hole. The front end of the plugging device can be formed into a hemispherical plugging end by pressurized grouting. Then, the plugging device is pulled back in the reverse direction so that the bottom surface of the hemispherical plugging end is in close contact with the outer wall of the ground connection wall.

[0011] S3, filling the sampling hole with water-stopping material;

[0012] S4. Install a sealing structure at the opening of the sampling hole to seal the hole.

[0013] Preferably, the bottom surface of the hemispherical expansion hole is concentrically arranged with the sampling hole, and the diameter of the bottom surface of the hemispherical expansion hole is larger than the diameter of the sampling hole.

[0014] Preferably, the water-stopping material is a rubber water-stopping core material that swells when exposed to water.

[0015] Furthermore, the sealing structure includes a rubber baffle, a steel ring plate and fixing bolts. The rubber baffle is tightly attached to the opening of the sampling hole, and the steel ring plate is tightly attached to the bottom of the rubber baffle and is fixed to the ground wall by the fixing bolts.

[0016] On the other hand, the present invention also provides a sealing device for realizing a method for sealing core sampling holes in ground-wall joints under high water pressure conditions, the sealing device comprising a grouting pipe, an exhaust pipe, a support frame and an elastic bag, the exhaust pipe being arranged inside the grouting pipe for discharging excess gas in the elastic bag to the outside; the support frame being hinged on the grouting pipe outlet; the elastic bag wraps the support frame inside and is connected to it, and the elastic bag feed port is connected to the grouting pipe outlet; in the initial stage, the support frame is in a retracted state under the elastic action of the elastic bag; in the grouting stage, the elastic bag and the support frame expand outward under the grouting pressure of the grouting pipe to form a hemispherical sealing end.

[0017] Preferably, the front end of the exhaust pipe extends upward and passes through the grouting pipe to form an exhaust portion, the front end of the exhaust portion is connected to the elastic bag, and an exhaust hole is provided on the exhaust portion.

[0018] Furthermore, the skeleton includes a plurality of radiating struts arranged radially in a circumferential pattern, the end of each radiating strut is hinged to the grouting pipe outlet, two connecting rods are hinged between each radiating strut and the exhaust part, and the two connecting rods are hinged to each other.

[0019] Furthermore, the surface of the exhaust portion is wrapped with filter gauze.

[0020] Preferably, the overall length of the blocking device needs to be greater than the sum of the lengths of the hemispherical expansion hole and the sampling hole.

[0021] Preferably, the diameter of the exhaust pipe is smaller than the diameter of the grouting pipe.

[0022] Compared with the prior art, the present invention has the following significant advantages:

[0023] The present invention aims at the quantitative analysis of the weakening effect of joints during the construction process of ground-connected walls using sleeve milling joints. Core sampling must be used for research. However, the holes left after core sampling under high water pressure and dynamic water conditions cannot be filled with conventional materials. The present invention designs a mechanical device that realizes the reverse tensioning and close sealing of the outer wall of the ground wall through a sac-type expansion movement mechanism, thereby effectively solving the problem of hole sealing and water stopping under dynamic water conditions.

[0024] Compared with the conventional water-stopping method of injecting mortar, polyurethane and other materials, the advantages of this method are: through the sealing method and device provided by the present invention, the outer wall of the ground wall can be reversely tensioned through the sac-type expansion movement mechanism to achieve close sealing, establish the first water-stopping line of defense, and through the built-in waterproof core material filling, the water flow path length is increased, the water head attenuation is effectively completed, and the second water-stopping line of defense is formed. Through the sealing plate on the inner wall of the ground-connected wall, the weak water head that may arrive can be securely sealed to form the third water-stopping line of defense; the three waterproof layers are progressive and work together; at the same time, the device can remove the sealing plate and replace the aging core material at any time to achieve rapid and reciprocating maintenance operations of hole water stopping. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the structure of the mud joints between the two phases of the ground-connected wall;

[0026] Figure 2 This is a schematic diagram of the hole structure left in the ground-connected wall after the core sampling is completed;

[0027] Figure 3 This is a schematic diagram of the structure after hole enlargement in step S1 of the method of the present invention;

[0028] Figure 4 Schematic diagram of the structure of the plugging device in step S2 of the method of the present invention;

[0029] Figure 5 This is a schematic diagram of the structure of starting grouting in step S2 of the method of the present invention;

[0030] Figure 6 This is a schematic structural diagram of the reverse stretching and plugging device after grouting in step S2 of the method of the present invention;

[0031] Figure 7 Schematic diagram of the structure of filling water-stopping material in step S3 of the method of the present invention;

[0032] Figure 8 This is a schematic diagram of the structure after the sealing structure is installed in step S4 of the method of the present invention;

[0033] Figure 9 for Figure 8 Detailed structural diagram at A in the middle;

[0034] Figure 10 This is a schematic diagram of the structure of the plugging device of the present invention after jacking (folded state);

[0035] Figure 11 This is a schematic structural diagram of the plugging device of the present invention after jacking (in the expanded state);

[0036] Figure 12 This is a schematic diagram of the bottom surface structure of the hemispherical plugging end of the plugging device of the present invention after being stretched.

[0037] In the figure: 1. Rock and soil mass; 2. First-phase wall width; 3. Second-phase wall width; 4. Sampling hole; 5. Hemispherical expansion hole; 6. Sealing device; 61. Grouting pipe; 62. Exhaust pipe; 621. Exhaust part; 63. Support frame; 631. Radial strut; 632. Connecting rod; 633. Hinge; 64. Elastic bag; 7. Hemispherical sealing end; 8. Water-stop material; 9. Sealing structure; 91. Rubber baffle; 92. Steel ring plate; 93. Fixing bolt. DETAILED DESCRIPTION

[0038] To help those skilled in the art better understand the technical solutions of the present invention, the preferred embodiments of the present invention are described below in conjunction with specific examples. However, it should be understood that the drawings are for illustrative purposes only and are not to be construed as limiting this patent. To better illustrate this embodiment, some components in the drawings may be omitted, enlarged, or reduced, and do not represent the dimensions of actual products. For those skilled in the art, the omission of certain well-known structures and their descriptions in the drawings is understandable. The positional relationships described in the drawings are for illustrative purposes only and are not to be construed as limiting this patent.

[0039] like Figure 1As shown in the figure, due to the influence of the ground-connected wall construction process, mud wall protection is adopted during the ground-connected wall construction process, and the sleeve milling joint process is adopted. There must be a certain width of mud joint between the first phase wall section and the second phase wall section. Figure 2 As shown, to study the weakening effect of joints on the overall ground-connected wall, core sampling of the concrete specimens at the joint locations was necessary for subsequent mechanical property determination through experiments. The holes left by core sampling must be watertightened; conventional polyurethane or mortar fillings are ineffective in high-pressure and dynamic water environments.

[0040] Based on this, the present invention provides a method for sealing core sampling holes in ground-wall joints under high water pressure conditions, comprising the following steps:

[0041] S1. Use a reaming drill bit to continue reaming along the sampling hole 4 into the rock mass 1, and form a hemispherical reaming hole 5 in the stratum outside the sampling hole 4; wherein the bottom surface of the hemispherical reaming hole 5 is concentric with the sampling hole 4, and the diameter of the bottom surface of the hemispherical reaming hole 5 is larger than the diameter of the sampling hole 4, such as Figure 3 shown.

[0042] S2. Insert the plugging device 6 into the sampling hole 4. The front end of the plugging device 6 can be formed into a hemispherical plugging end 7 by pressurized grouting. Then, the plugging device 6 is pulled back in the opposite direction to make the hemispherical plugging end 7 form a close contact with the outer wall of the ground-connected wall. At this time, although it is impossible to completely block the occurrence of seepage, it can effectively curb the dynamic water conditions under the external high water pressure, thereby converting the high-pressure dynamic water plugging problem into a low-pressure seepage plugging problem. Figure 4-6 shown.

[0043] S3, fill the sampling hole 4 with water-stop material 8; wherein the water-stop material 8 is a rubber water-stop core material that swells when exposed to water, such as Figure 7 shown.

[0044] S4. Install a sealing structure 9 at the opening of the sampling hole 4 to seal the hole; wherein the sealing structure 9 includes a rubber baffle 91, a steel ring plate 92 and a fixing bolt 93. The rubber baffle 91 is tightly attached to the opening of the sampling hole 4, and the steel ring plate 92 is tightly attached to the bottom of the rubber baffle 91 and fixed to the ground wall by fixing bolts 93. Figure 8-9 shown.

[0045] There are many design methods for the blocking device 6. The present invention provides a design scheme with high feasibility. The blocking device 6 includes a grouting pipe 61, an exhaust pipe 62, a support frame 63 and an elastic bag 64. The exhaust pipe 62 is arranged inside the grouting pipe 61 to discharge the excess gas in the elastic bag 64 to the outside; the support frame 63 is hinged on the discharge port of the grouting pipe 61; the elastic bag 64 wraps the support frame 63 inside and is connected to it, and the feed port of the elastic bag 64 is connected to the discharge port of the grouting pipe 61; in the initial stage, the support frame 63 is in a retracted state under the elastic action of the elastic bag 64, such as Figure 10 grouting stage, the elastic bag 64 and the support frame 63 in the grouting pipe 61 under the action of grouting pressure, expand outward to form a hemispherical plugging end 7, as Figure 11 As shown, slurry is gradually injected into the elastic bag 64 at the end of the blocking device 6 under pressure, causing the elastic bag 64 to expand in volume under the pressure, driving the support frame 63 to deform together. At the same time, under the constraint of the support frame 63, the bag eventually forms a hemispherical blocking end.

[0046] Specifically, the front end of the exhaust pipe 62 extends upward through the grouting pipe 61 to form an exhaust portion 621. The front end of the exhaust portion 621 is connected to the elastic bag 64. The exhaust portion 621 is provided with an exhaust hole. The exhaust hole is used to discharge the gas in the elastic bag 64 during the grouting process. In order not to affect the exhaust effect of the exhaust hole, a layer of filter gauze can be wrapped on the surface of the exhaust portion 621 to prevent the slurry from blocking the exhaust hole. The skeleton includes eight radial struts 631 arranged radially around the circumference. The end of each radial strut 631 is hinged to the discharge port of the grouting pipe 61. Two connecting rods 632 are hinged between each radial strut 631 and the exhaust portion 621 through a hinge 633. The two connecting rods 632 are hinged to each other through a hinge 633. After the grouting is completed, the two connecting rods 632, the radial struts 631, and the exhaust portion 621 form a right triangle structure. The purpose of the radial struts 631 is to ensure that the elastic bag 64 can expand in the form of an umbrella-shaped mushroom head during the grouting and expansion process, so that the bottom surface of the hemispherical blocking end remains flush with the outer wall during the pullback process. Figure 12 shown.

[0047] Compared with the conventional water-stopping method of injecting mortar, polyurethane and other materials, the advantages of this method are: through the sealing method and device provided by the present invention, the outer wall of the ground wall can be reversely tensioned through the sac-type expansion movement mechanism to achieve close sealing, establish the first water-stopping line of defense, and through the built-in waterproof core material filling, the water flow path length is increased, the water head attenuation is effectively completed, and the second water-stopping line of defense is formed. Through the sealing plate on the inner wall of the ground-connected wall, the weak water head that may arrive can be securely sealed to form the third water-stopping line of defense; the three waterproof layers are progressive and work together; at the same time, the device can remove the sealing plate and replace the aging core material at any time to achieve rapid and reciprocating maintenance operations of hole water stopping.

[0048] Based on the description and drawings of the present invention, those skilled in the art can easily manufacture or use the method and device for sealing core sampling holes in ground-wall joints under high water pressure conditions of the present invention, and can produce the positive effects described in the present invention.

[0049] Unless otherwise specified, in the present invention, if there are terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicating orientation or positional relationships, they are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the orientation or positional relationships in the present invention are only used for illustrative purposes and cannot be understood as limiting this patent. For ordinary technicians in this field, they can understand the specific meanings of the above terms in conjunction with the drawings and according to specific circumstances.

[0050] Unless otherwise specified or limited, the terms "disposed," "connected," and "connected" in this disclosure should be interpreted broadly. For example, they may refer to fixed connections, detachable connections, or integral connections; they may refer to direct connections, indirect connections through an intermediary, or internal connections between two components. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A method for sealing core sampling holes in ground-wall joints under high water pressure conditions, characterized in that: The steps include: S1, using a reaming drill bit, continuing to reaming the hole along the sampling hole (4) into the rock and soil body (1), forming a hemispherical reaming hole (5) in the stratum outside the sampling hole (4); S2, inserting the plugging device (6) into the sampling hole (4), the front end of the plugging device (6) can be formed into a hemispherical plugging end (7) by pressurized grouting, and then the plugging device (6) is pulled back in the reverse direction so that the bottom surface of the hemispherical plugging end (7) is closely attached to the outer wall of the ground connection wall; S3, filling the sampling hole (4) with water-stopping material (8); S4, installing a sealing structure (9) at the opening of the sampling hole (4) to achieve sealing of the opening; The blocking device (6) comprises a grouting pipe (61), an exhaust pipe (62), a support frame (63) and an elastic bag (64), wherein the exhaust pipe (62) is arranged inside the grouting pipe (61) and is used to discharge excess gas in the elastic bag (64) to the outside; the support frame (63) is hinged to the discharge port of the grouting pipe (61); the elastic bag (64) wraps the support frame (63) inside and is connected to it, and the feed port of the elastic bag (64) is connected to the discharge port of the grouting pipe (61); in the initial stage, the support frame (63) is in a retracted state under the elastic action of the elastic bag (64); in the grouting stage, the elastic bag (64) and the support frame (63) expand outward under the grouting pressure of the grouting pipe (61) to form a hemispherical blocking end (7); The front end of the exhaust pipe (62) extends upward and passes through the grouting pipe (61) to form an exhaust portion (621). The skeleton includes a plurality of radiating struts (631) arranged in a circumferential radial pattern. The end of each radiating strut (631) is hinged to the discharge port of the grouting pipe (61). Two connecting rods (632) are hinged between each radiating strut (631) and the exhaust portion (621), and the two connecting rods (632) are hinged to each other.

2. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 1 is characterized by: The bottom surface of the hemispherical expansion hole (5) is concentrically arranged with the sampling hole (4), and the diameter of the bottom surface of the hemispherical expansion hole (5) is larger than the diameter of the sampling hole (4).

3. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 1 is characterized by: The water-stop material (8) is a rubber water-stop core material that swells when exposed to water.

4. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 2, characterized in that: The sealing structure (9) comprises a rubber baffle (91), a steel ring plate (92) and fixing bolts (93), wherein the rubber baffle (91) is closely attached to the opening of the sampling hole (4), and the steel ring plate (92) is closely attached to the bottom of the rubber baffle (91) and is fixed to the ground wall via the fixing bolts (93).

5. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 1 is characterized by: The front end of the exhaust portion (621) is connected to the elastic bag (64), and an exhaust hole is provided on the exhaust portion (621).

6. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 5, characterized in that: The surface of the exhaust portion (621) is wrapped with filter gauze.

7. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 1, characterized in that: The overall length of the blocking device (6) must be greater than the sum of the lengths of the hemispherical expansion hole (5) and the sampling hole (4).

8. The method for sealing core sampling holes in ground-wall joints under high water pressure conditions according to claim 1 is characterized by: The diameter of the exhaust pipe (62) is smaller than the diameter of the grouting pipe (61).

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