Sleeve valve pipe grouting method and application thereof

Abstract

The invention relates to the technical field of sleeve valve pipe construction, in particular to a sleeve valve pipe grouting method and application thereof. Comprising the following steps: S1, establishing a three-dimensional geologic model in geological survey, judging the geology of a reinforcing area, and dividing the reinforcing area into a plurality of functional zones for hole site layout; s2, drilling equipment is moved to the hole site area, drilling operation is conducted, the hole site condition is observed, and acceptance inspection is conducted; s3, a sleeve valve pipe and an exhaust pipe are installed and lowered in a segmented mode, the upper end of the exhaust pipe is exposed out of the ground, the pipe body is fixed through a limiting device, the periphery of the sleeve valve pipe and the periphery of the exhaust pipe are filled with the mixed liquid for sealing, and initial setting is stable; s4, according to the functional partitions, filling operation is conducted through a jumping type grouting method, reinforced pouring is conducted at the last time, and grout is waited for initial setting; according to the method, the overall grouting procedure is optimized, the jumping type grouting method is adopted for grouting operation, the problems of slurry pressure concentration and uneven diffusion are effectively solved, and the construction efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of sleeve valve pipe construction, and particularly to a sleeve valve pipe grouting method and its application. Background Art

[0002] In construction, for dealing with problems such as soft foundation treatment, enhancing soil stability, and preventing water leakage, sleeve valve pipe grouting reinforcement is an excellent construction technology. At present, for the grouting method of sleeve valve pipes, pouring operations are usually carried out in a fixed sequence, which easily leads to local pressure concentration and uneven slurry diffusion, affecting the finished product quality. Moreover, serious slurry cross-infiltration occurs in adjacent hole areas, reducing the grouting efficiency, wasting slurry raw materials, and being unfavorable for actual construction production. Summary of the Invention

[0003] The technical problem to be solved by the present invention is, in view of the above-mentioned existing technical deficiencies, to provide a sleeve valve pipe grouting method and its application, optimize the overall grouting process, and adopt a skip grouting method for grouting operations, effectively solving the problems of slurry pressure concentration and uneven diffusion, and improving the construction efficiency.

[0004] To solve the above technical problems, the technical solution adopted by the present invention includes the following steps:

[0005] S1. Conduct geological exploration to establish a three-dimensional geological model, judge the geology of the reinforcement area, and divide it into several functional areas for hole layout;

[0006] S2. Move the drilling equipment to the hole position area and carry out drilling operations, observe the hole position conditions and conduct acceptance;

[0007] S3. Install and lower the sleeve valve pipe and the exhaust pipe in sections, and the upper end of the exhaust pipe is exposed above the ground. Fix the pipe body itself with a limiting device, pour the mixed liquid around the sleeve valve pipe and the exhaust pipe for sealing, and wait for initial setting and stabilization;

[0008] S4. According to the functional areas, carry out filling operations by the skip grouting method, and conduct supplementary pouring for the last time, and wait for the slurry to initially set;

[0009] S5. Slowly pull out the sleeve valve pipe and the exhaust pipe, and seal the grouting holes and exhaust holes.

[0010] Preferably, the functional areas include a dense hole area, a uniform hole area, a sparse hole area, and a boundary area distributed in a radial elliptical shape from the center, and the exhaust holes are arranged at the center.

[0011] Preferably, the mixed liquid is prepared by stirring and mixing water, ash, and a quick-setting agent, and the sealing depth is greater than 1.5 meters.

[0012] Preferably, a reinforcing material is added to the slurry, and the temperature is 20 - 30 °C.

[0013] Preferably, the initial setting time of the mixture is less than 30 minutes.

[0014] Preferably, the initial setting time of the slurry is 5 - 7 hours.

[0015] Preferably, the filling depth of the hole sealing treatment is greater than 2 meters below the ground surface.

[0016] Preferably, the inclination of the hole position is less than 1%, the bottom end of the exhaust hole is located 0.5 meters below the top of the reinforcement area, and the bottom end of the grouting hole is located 0.5 meters below the bottom of the reinforcement area. [[ID=1(]]

[0017] Preferably, for the secondary grouting operation in the hollow area, new hole positions are opened. The new hole positions are at a certain distance from the original holes and are drilled at a specified angle to a specific depth.

[0018] Preferably, the specified angle is 15 - 30 degrees, and the adjustment range of the specific depth is ±0.5 meters.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. By introducing the secondary grouting process, it is possible to perform fixed-point grouting operations on the vacant areas, ensuring the reliability of reinforcement and stabilizing the finished product structure;

[0021] 2. Adopting the skip - type sequential grouting control, compared with the traditional sequential grouting operation, it avoids the occurrence of slurry cross - flow between adjacent hole positions, disperses the grouting pressure, and improves the utilization rate of raw materials;

[0022] 3. According to different geological conditions, the layout of the hole positions is optimized. Compared with the traditional hole - layout method, it is more flexible and diverse, can dynamically adjust the hole - layout position and density, improve the grouting effect, and avoid the problem of local weak areas;

[0023] 4. The mixture seals the area around the pipe orifice, which can effectively improve the internal tightness, avoid the situation of slurry back - flow during the grouting operation, and enhance the stability of grouting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of functional zoning;

[0025] Figure 2 It is a schematic diagram of the layout of new hole positions.

[0026] In the figure: 1. Hole position; 2. Dense - hole area; 3. Uniform - hole area; 4. Sparse - hole area; 5. Boundary area; 6. New hole position; 7. Exhaust pipe. DETAILED DESCRIPTION OF THE INVENTION

[0027] To make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0028] Specific Embodiment 1: As shown in Figure 1-2 A sleeve valve pipe grouting method includes the following steps: S1. Use a RAMAC GPR system of a certain company with a working frequency of 25 MHz to 1 GHz. For shallow detection (0 - 5 meters), a higher frequency (such as 400 MHz) can achieve a resolution of several centimeters; for deep detection (more than 5 meters), a lower frequency (such as 100 MHz) is selected, and the detection depth can reach more than 30 meters. Cooperate with borehole sampling to complete geological exploration, and use Autodesk Revit or Bentley Systems' MicroStation to create a 3D model. By importing geological radar scanning data and borehole sampling results, establish an accurate underground structure model, and then judge the geology of the reinforcement area and divide it into several functional zones for the layout of Hole 1; S2. Move the drilling equipment to the area of Hole 1. According to the design requirements, use an XY-3 type core drill to drill a hole. The hole diameter is generally 5% - 10% larger than the outer diameter of the sleeve valve pipe. The drilling depth is determined according to the position of the reinforcement layer and usually does not exceed 100 meters. Observe the situation of Hole 1 and conduct acceptance; S3. Install and lower the sleeve valve pipe and the exhaust pipe 7 in sections, and use a laser rangefinder (such as Leica DISTO D810 with a measurement accuracy of ±1 mm) to regularly check whether the actual depth of the sleeve valve pipe meets the design requirements. Perform depth calibration every 5 meters to ensure that the error does not exceed ±5 mm, and the upper end of the exhaust pipe 7 is exposed above the ground. Use a limiting device to fix the pipe body itself, pour the mixture around the sleeve valve pipe and the exhaust pipe 7 for sealing, and wait for initial setting and consolidation; S4. According to the functional zones, carry out filling operations using a skip grouting method, and perform reinforcement pouring for the last time, and wait for the slurry to initially set; S5. Slowly pull out the sleeve valve pipe and the exhaust pipe 7, and seal the grouting holes and exhaust holes; wherein, the limiting device uses a steel bar bracket or a fixture to fix the pipe body to prevent displacement.

[0029] Preferred embodiment, as shown in Figure 1As shown in the figure, the functional zones include a dense-hole zone 2, a uniform-hole zone 3, a sparse-hole zone 4, and a boundary zone 5 that are distributed in a radiating elliptical shape from the center. The exhaust hole is arranged at the center. The dense-hole zone is arranged in geological structures where slurry loss is fast and filling is difficult, with at least 8 holes distributed in the zone. The sparse-hole zone is applicable to medium geological structures with controllable diffusion, with at least 6 holes distributed in the zone. The sparse-hole zone is applicable to geological structures where slurry absorption is slow and resistance is high, with at least 4 holes distributed in the zone. The boundary zone is arranged along the boundary line with a small hole spacing for boundary sealing. At the same time, another hole arrangement method is provided, that is, there are 8 - 10 hole positions in each circle of the dense-hole zone, 6 - 8 hole positions in each circle of the uniform-hole zone, and 4 - 6 hole positions in each circle of the sparse-hole zone, which is more flexible in adjustment and can be planned and arranged according to the size of the zone.

[0030] In a preferred embodiment, the mixed liquid is made by stirring and mixing water, ash, and a quick-setting agent. After the sleeve valve pipe is installed, the edge position is sealed, and the sealing depth is greater than 1.5 meters. The water-cement ratio is 0.8:1, and an appropriate amount of quick-setting agent, such as water glass, is added, and the dosage is 3% - 5% of the weight of the cement to improve the sealing effect.

[0031] In a preferred embodiment, an enhancing material, such as bentonite, is added to the slurry, which can improve the performance of the consolidated body to meet the use in high-permeability areas, and the slurry temperature is between 20 - 30 °C to maintain its own fluidity.

[0032] In a preferred embodiment, the initial setting time of the mixed liquid is less than 30 minutes, which can ensure the sealing strength.

[0033] In a preferred embodiment, the initial setting time of the slurry is 5 - 7 hours, preferably 6 hours. Under the condition of ensuring the structural stability, the removal operation of the sleeve valve pipe and the exhaust pipe 7 can be realized.

[0034] In a preferred embodiment, for the hole sealing treatment after the sleeve valve pipe and the exhaust pipe are pulled out, the filling depth of the hole sealing treatment is greater than 2 meters below the ground surface to ensure the structural stability, and the hole sealing material preferably uses M20 cement mortar.

[0035] In a preferred embodiment, the inclination of the hole position 1 is less than 1%. The bottom end of the exhaust hole is 0.5 meters below the top of the reinforcement area, and the bottom end of the grouting hole is 0.5 meters below the bottom of the reinforcement area, ensuring that the depth and verticality of the hole position 1 meet the standards and avoiding potential problems such as hole collapse and necking.

[0036] In a preferred embodiment, in combination with Figure 2 As shown in the figure, for the secondary grouting operation in the hollow area, new hole positions are opened. The new hole position 6 is at a certain distance from the original hole and is drilled to a specific depth at a specified angle, improving the overall grouting effect and project quality.

[0037] For the preferred embodiment, the specified angle is selected within the range of 15 - 30 degrees, and the specific depth adjustment range is preferably ±0.5 m; the specific layout of the newly added hole positions is as follows:

[0038] By setting an offset angle, it can be ensured that the new hole will not be directly above or below the original hole position 1, thus avoiding repeated injection into the same geological structure and improving the effectiveness of slurry diffusion. For example, if the original hole position 1 is located at the coordinate (0, 0), the newly added hole position 6 can be selected to be arranged at an offset angle of 15° at a distance of 1.5 m. For the depth part, according to the geological exploration data and the feedback of the initial grouting effect, if it is found that there are problems of insufficient consolidation in certain depth ranges, the depth of the new hole can be adjusted deeper or shallower to specifically solve these problems. For example, the depth of the original hole position 1 is 20 m, but voids or highly permeable areas are found between 18 m and 20 m that have not been fully filled, then the newly added hole position 6 can be adjusted to a depth between 19 m and 21 m at the same horizontal position to optimize the regional filling effect;

[0039] According to the geological columnar section and the results of the advanced drilling, understand the formation properties at different depths (such as soft interlayers, fracture-developed areas, etc.), and adjust the depth of the newly added hole position 6 accordingly. For example, if the formation in a certain depth range is particularly loose and has a large slurry absorption capacity, multiple newly added hole positions 6 can be added near this depth, or the depth can be set deeper to ensure that this area is fully reinforced;

[0040] According to the monitoring data during the initial grouting (such as pressure changes, slurry absorption rate, etc.), analyze the actual diffusion path of the slurry, judge which areas may have weak points, and arrange new holes for these areas. If it is found during the initial grouting process that the pressure in a certain section of the formation rises too fast, it indicates that this area may be saturated or a local blockage has formed. At this time, new holes can be arranged near this area and secondary grouting can be carried out at a lower pressure to achieve a better reinforcement effect.

[0041] After the sleeve valve pipe and the exhaust pipe 7 are lowered, a double plugging mechanism can also be adopted. First, use bentonite slurry (with a water content of about 20% - 30%) for preliminary plugging, and then cover it with a layer of high-strength cement mortar (with a water-cement ratio of about 0.4 - 0.5) to form a solid sealing layer. The compressive strength of the cement mortar should be between 20 MPa and 40 MPa; and the plugging effect can be judged by injecting a small amount of water into the hole and observing whether there is leakage, and a portable ultrasonic leak detector (such as the D-Mask series of Sonatest, with a sensitivity of up to 0.01 mm / s) can also be used to assist in the detection.

[0042] Add an appropriate amount of nano-silica to the grouting slurry (such as LUDOX HS-40 of Cabot, with an addition amount of 0.5%-1%) to improve the early strength of the slurry. At the same time, use biodegradable polymers (such as the Biopolymers series products of Novozymes) to improve the fluidity. The initial consistency of the slurry is controlled at 50 mm to 100 mm (Vicat test), and the final consistency should not exceed 150 mm. At least three slurry performance tests need to be carried out before each grouting to ensure that it meets the design requirements.

[0043] During skip grouting, number the hole positions 1 in each area, such as A1, B1, C1, etc. Only activate one functional group for grouting in each round, and switch to another ungrouted functional group in the next round. In the first round, it is A1, B3, C2; in the second round, it is A2, B4, C1; in the third round, it is A3, B1, C3. After circulating N times for reinforcement, through the skip grouting sequence, the mutual interference between adjacent holes is avoided, the grouting efficiency is improved, the slurry can spread more evenly in the formation, the formation of local weak areas is reduced, and it is applicable to foundation reinforcement projects under various complex geological conditions such as soft interlayers, fracture-developed areas, karsts, cavities, and loose sand layers. And through secondary densification of hole layout and supplementary grouting, it can carry out supplementary reinforcement for the areas that could not be completely covered by the primary grouting, significantly improving the overall reinforcement effect. Moreover, by optimizing the grouting sequence and parameter settings, material waste is reduced and the construction cost is lowered. Specific Embodiment 2

[0045] Application of a sleeve valve pipe grouting method in karst cave construction;

[0046] The foundation of a certain expressway bridge is located in a typical karst development area. Geological exploration found that there are multiple hidden karst caves within the bridge site range, with the maximum cavity height reaching 8 meters. The groundwater is rich in some areas, and there are risks of ground collapse and foundation instability. To ensure the safety and long-term stability of the bridge pile foundation construction, it is necessary to carry out grouting reinforcement treatment for the karst caves;

[0047] According to the geological exploration report, the stratigraphic structure of this area is the surface soil layer, silty clay, with a thickness of about 3-5 meters, relatively dense structure, a middle sand layer, loose medium-coarse sand, high water content, strong permeability, underlying bedrock, limestone, with developed fissures, and a karst cave development area is seen. The characteristics of the karst caves are uneven distribution, some are empty, some are in a semi-filled state, the maximum cavity height is 8 meters, with characteristics such as uneven distribution and large differences in cavity sizes, which increases the difficulty of foundation reinforcement. In addition, the presence of groundwater may cause slurry leakage during the grouting process. The construction technical scheme of "multi-level zoning - adaptive optimized hole layout + skip-by-sequence grouting control" is adopted. The entire reinforcement area is divided into four functional zones. Zone A, karst cave cavity zone (unfilled), with densified hole layout, 8-10 holes per circle, in a radial + eccentric ellipse hole layout form, and priority grouting and filling. Zone B, semi-filled karst cave zone, with normal hole layout, 6-8 holes per circle, in a radial hole layout form, and grouting with controlled pressure. Zone C, fissure development zone, with sparse hole layout, 4-6 holes per circle, in a radial sparse hole layout form, and skip-by grouting. Zone D, boundary sealing zone, with 6-8 holes per circle, in a circular densified hole layout form, with holes densified along the boundary line, first grouting for sealing the edge, and at the same time all holes are distributed asymmetrically radially around the central exhaust hole to avoid slurry intermixing between adjacent holes; the hole diameter is uniformly 110mm, and the verticality deviation does not exceed 1%; the exhaust hole is arranged at the center of the reinforcement area to release gas and prevent gas blockage;

[0048] The XY-1 type hydraulic drill is used in combination with a 110mm diamond bit for drilling. For the loose sand layer section, casing is advanced to support the wall to prevent cave-ins. The exhaust hole is drilled to 0.5 meters below the top of the karst cave; the grouting hole is drilled to 0.5 meters below the bottom of the karst cave, and a high-strength PVC sleeve valve pipe is lowered to the target depth, with each sleeve valve pipe having a length of 12 meters; an exhaust pipe is installed 7 meters to 0.5 meters below the top of the karst cave; double-fluid slurry (water-cement ratio 0.8:1, admixing 3%-5% water glass) is used for sealing and fixing the pipe, and the sealing depth is not less than 1.5 meters;

[0049] Only one functional group is activated in each round to avoid slurry intermixing interference between adjacent holes and ensure full diffusion of the slurry. In the first round, A1, B3, C2, D1; in the second round, A2, B4, C1, D2; in the third round, A3, B1, C3, D3; in the fourth round, return to the first group for further reinforcement; after the grouting is completed, methods such as core drilling sampling, water pressure test, and radar scanning are used to detect the grouting effect. It is found that the grouting in a certain section in the middle of Zone A is not dense, and it is decided to carry out secondary densified hole layout;

[0050] The new hole position A1b, with an offset angle of 20°, and the depth is adjusted by +0.5 meters; the skip-by grouting is re-executed, and low water-cement ratio cement slurry (0.6:1) is selected, and the grouting pressure is controlled within 2.0MPa to ensure that the new holes avoid the existing diffusion paths and effectively supplement the un-reinforced area;

[0051] After the grouting is completed, wait for about 6 hours until the grout starts to set, and then slowly pull out the sleeve valve pipe and the exhaust pipe 7. Conduct secondary hole sealing treatment on the grouting holes and exhaust holes, and use M20 cement mortar for pouring and filling. The filling depth shall not be less than 2 meters below the ground surface, and the surface shall be restored to its original appearance to facilitate subsequent pile foundation construction.

[0052] It should be understood that the above specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation on the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all variations and modifications that fall within the scope and boundaries of the appended claims, or equivalent forms of such scope and boundaries.

Claims

1. A sleeve valve pipe grouting method, characterized in that, It includes the following steps: S1. Conduct geological exploration to establish a three-dimensional geological model, judge the geology of the reinforcement area, and divide it into several functional zones for hole layout; S2. Move the drilling equipment to the hole area and conduct drilling operations, observe the hole conditions and conduct acceptance; S3. Install and lower the sleeve valve pipe and the exhaust pipe in sections, with the upper end of the exhaust pipe exposed above the ground, fix the pipe body itself with a limiting device, pour the mixed liquid around the sleeve valve pipe and the exhaust pipe for sealing, and wait for initial setting and stabilization; S4. According to the functional zones, carry out filling operations by the skip grouting method, and conduct reinforcement pouring for the last time, and wait for the slurry to initially set; S5. Slowly pull out the sleeve valve pipe and the exhaust pipe, and seal the grouting holes and the exhaust holes.

2. The sleeve valve pipe grouting method according to claim 1, characterized in that: The functional zones include a dense hole area, a uniform hole area, a sparse hole area, and a boundary area distributed in a radial elliptical shape from the center, and the exhaust holes are arranged at the center.

3. A sleeve valve pipe grouting method according to claim 1, characterized in that: The mixed liquid is prepared by stirring water, ash, and a quick-setting agent, and the sealing depth is greater than 1.5 meters.

4. A sleeve valve pipe grouting method according to claim 3, characterized in that: Reinforcing materials are added to the slurry, and the temperature is 20 - 30 °C.

5. A sleeve valve pipe grouting method according to claim 1, characterized in that: The initial setting time of the mixed liquid is less than 30 minutes.

6. A sleeve valve pipe grouting method according to claim 1, characterized in that: The initial setting time of the slurry is 5 - 7 hours.

7. A sleeve valve pipe grouting method according to claim 1, characterized in that: The sealing depth of the hole sealing treatment is greater than 2 meters below the ground surface.

8. A sleeve valve pipe grouting method according to claim 1, characterized in that: The inclination of the hole is less than 1%, the bottom end of the exhaust hole is 0.5 meters below the top of the reinforcement area, and the bottom end of the grouting hole is 0.5 meters below the bottom of the reinforcement area.

9. A sleeve valve pipe grouting method according to claim 1, characterized in that: Conduct secondary grouting operations on the hollow area, open new holes, with a certain distance between the new holes and the original holes, and drill to a specific depth at a specified angle.

10. A sleeve valve pipe grouting method according to claim 9, characterized in that: The specified angle is 15 - 30 degrees, and the adjustable range of the specific depth is ±0.5 meters.

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