Novel treatment device suitable for shallow karst cave in pile foundation construction process

Abstract

The utility model relates to the technical field of pile foundation engineering, in particular to a novel treatment device suitable for shallow karst caves in the pile foundation construction process, which comprises a pile casing, a telescopic sleeve bolt assembly and a spring steel sheet limiting assembly. The pile casing is defined by connecting three steel plates end to end, and a plurality of pairs of fixing rings I are welded to the inner wall of the pile casing; the telescopic sleeve bolt assembly comprises a steel sleeve horizontally arranged on the inner side of the pile casing, a rotating handle is welded to the middle of the outer wall of the steel sleeve, the two ends of the steel sleeve are each in threaded connection with a bolt rod with the end provided with a hole, and each bolt rod with the end provided with a hole is rotationally connected with a pair of fixing rings I through a pin shaft; the spring steel sheet limiting assembly comprises a spring steel sheet, C-shaped steel and a pair of fixing rings II welded to the outer wall of the pile casing. The problems that according to an existing shallow karst cave treatment method, the phenomena of collapse, drill jamming and deviation are prone to occurring, the construction period is long, and meanwhile the construction quality and safety are poor are solved.

Description

Technical Field

[0001] This utility model relates to the field of pile foundation engineering technology, specifically a novel treatment device for shallow karst caves during pile foundation construction. Background Technology

[0002] Bridge pile foundations are designed to adapt to various complex geological conditions and are the "foundation" for the safe operation of highway bridge structures. Their quality directly affects the stability and safety of the entire bridge structure. Various problems can be encountered during the construction of bridge pile foundations. In particular, the construction of bridge pile foundations in karst areas requires effective treatment of karst caves to ensure the stability and strength of the bridge pile foundations.

[0003] Karst is a type of geological formation where rock strata, after being eroded by water, form voids, caves, and various cut-shaped rock masses. Limestone strata, after long-term erosion by groundwater, gradually form caves. Due to the inherent concealment of these caves, bridge pile foundation construction faces significant challenges. Furthermore, the poor bearing capacity of the rock mass in cave areas easily leads to uneven settlement of the main structure, posing safety hazards to the later bridge structure. Currently, in engineering projects, if a shallow cave (less than 3 meters high) is encountered, a backfilling and wall-building method must be used. When mud loss is observed in the casing during construction, drilling is stopped, and materials such as rubble, clay, and cement are immediately thrown into the hole for backfilling. Each layer of backfill is compacted, and the material is compacted as much as possible, until it reaches a height of 1-2 meters above the cave top. Only after the mud loss problem has completely disappeared can drilling resume.

[0004] However, practice has shown that the existing methods for treating shallow karst caves have the following problems: First, due to the irregular structure of the karst caves, it is not easy to transport the filling material into the cave, which makes the filling difficult and the construction period long; Second, because the filling material is in a loose state, the construction quality is difficult to control, and collapse, drill jamming, and deviation are likely to occur during construction, which poses a great safety risk to construction personnel.

[0005] Therefore, it is necessary to invent a new treatment device for shallow karst caves during pile foundation construction to solve the above problems. Utility Model Content

[0006] In order to solve the problems of existing methods for treating shallow karst caves, such as easy collapse, stuck drill, and deviation, as well as long construction period and poor construction quality and safety, this utility model provides a new treatment device for shallow karst caves in the process of pile foundation construction.

[0007] This utility model is achieved using the following technical solution:

[0008] A novel treatment device for shallow karst caves during pile foundation construction includes a casing, a telescopic sleeve bolt assembly, and a spring steel sheet limiting assembly.

[0009] The casing is formed by connecting three steel plates end to end, and several pairs of fixing rings I are welded to the inner wall of the casing;

[0010] The retractable sleeve bolt assembly includes a steel sleeve horizontally disposed inside the casing. A rotating handle is welded to the middle of the outer wall of the steel sleeve. Each end of the steel sleeve is threaded with a bolt rod with a hole at the end. Each bolt rod with a hole at the end is rotatably connected to a pair of fixing rings I through a pin.

[0011] The spring steel sheet limiting assembly includes a spring steel sheet, a C-shaped steel, and a pair of fixing rings II welded to the outer wall of the casing. The bottom plate of the spring steel sheet is welded to the outer wall of the casing. A pre-drilled hole is provided on the outer wall of the casing, and a tensioning strap is inserted through the pre-drilled hole. One end of the C-shaped steel is rotatably connected to the pair of fixing rings II via a pin. The other end of the C-shaped steel is tied to the outer wall of the casing via the tensioning strap, and the knot of the tensioning strap is located inside the casing. The opening of the C-shaped steel faces the outer wall of the casing, and the top plate of the spring steel sheet abuts against the inner wall of the C-shaped steel.

[0012] Furthermore, the steel plate is a corrugated steel plate.

[0013] Furthermore, each steel plate has mounting holes I, II, and III distributed vertically at both ends of its edges, and each mounting hole II has a limit end groove. Adjacent steel plates are connected and fixed by bolts that pass through mounting holes I, II, and III respectively.

[0014] Furthermore, the number of the spring steel sheet limiting components is greater than or equal to one.

[0015] Furthermore, the flange at the connection end between the C-shaped steel and the fixing ring II is arc-shaped.

[0016] Furthermore, the number of fixed rings I is 6 pairs, the number of telescopic sleeve bolt assemblies is 3, and the 3 telescopic sleeve bolt assemblies are arranged horizontally in a triangle on the inner side of the protective sleeve.

[0017] Furthermore, the top end of the spring steel sheet is rolled.

[0018] This utility model features a reasonable and reliable structural design, simple on-site assembly, and effectively improved construction efficiency and reduced construction period. Simultaneously, large-scale factory production of corrugated steel plates reduces production costs, resulting in significant economic benefits. Furthermore, the corrugated steel plates can be flexibly customized according to the size of the karst cave, adapting to various geological conditions and effectively addressing irregular karst cave structures. The coordinated operation of the telescopic sleeve bolt assembly and the spring steel plate limiting assembly achieves precise positioning and stable support of the karst cave, ensuring the structural safety of the pile foundation and effectively avoiding the collapse, drill jamming, and misalignment phenomena that are prone to occur in existing shallow karst cave treatment methods, as well as the problems of poor construction quality and safety. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the structure of this utility model.

[0020] Figure 2 This is a top view of the installation of the protective sleeve structure of this utility model.

[0021] Figure 3 This is a schematic diagram of the connection structure between two adjacent steel plates of this utility model.

[0022] Figure 4 This is a top view of the installation of the telescopic sleeve bolt assembly of this utility model.

[0023] Figure 5 This is a structural schematic diagram of mounting holes I, II, and III on the steel plate of this utility model.

[0024] Figure 6 This is a schematic diagram of the connection structure between the bolt rod with a hole at the end and the fixing ring I of this utility model.

[0025] Figure 7 This is a structural schematic diagram of the retractable sleeve bolt assembly of this utility model.

[0026] Figure 8 This is a schematic diagram of the structure of the spring steel sheet limiting assembly of this utility model. Figure 1 .

[0027] Figure 9 This is a schematic diagram of the structure of the spring steel sheet limiting assembly of this utility model. Figure 2 .

[0028] Figure 10 This is a schematic diagram of the structure of the spring steel sheet of this utility model.

[0029] In the diagram: 1-steel plate, 2-fixing ring I, 3-steel sleeve, 4-rotating handle, 5-bolt rod with end hole, 6-spring steel sheet, 7-C-shaped steel, 8-fixing ring II, 9-tension band, 10-mounting hole I, 11-mounting hole II, 12-mounting hole III. Detailed Implementation

[0030] A novel treatment device for shallow karst caves during pile foundation construction, as shown in the attached... Figure 1 ~Appendix Figure 10 As shown, it includes a protective sleeve, a telescopic sleeve bolt assembly, and a spring steel sheet limiting assembly;

[0031] The casing is formed by connecting three steel plates 1 end to end, and several pairs of fixing rings I2 are welded to the inner wall of the casing;

[0032] The retractable sleeve bolt assembly includes a steel sleeve 3 horizontally disposed inside the protective sleeve. A rotating handle 4 is welded to the middle of the outer wall of the steel sleeve 3. A bolt rod 5 with a hole at the end is threaded to each end of the steel sleeve 3. Each bolt rod 5 with a hole at the end is rotatably connected to a pair of fixing rings I2 through a pin.

[0033] The spring steel sheet limiting assembly includes a spring steel sheet 6, a C-shaped steel 7, and a pair of fixing rings II 8 welded to the outer wall of the casing. The bottom plate of the spring steel sheet 6 is welded to the outer wall of the casing. A pre-drilled hole is provided on the outer wall of the casing, and a tensioning strap 9 is inserted through the pre-drilled hole. One end of the C-shaped steel 7 is rotatably connected to the pair of fixing rings II 8 through a pin. The other end of the C-shaped steel 7 is tied to the outer wall of the casing through the tensioning strap 9, and the binding knot of the tensioning strap 9 is located inside the casing. The opening of the C-shaped steel 7 faces the outer wall of the casing, and the top plate of the spring steel sheet 6 abuts against the inner wall of the C-shaped steel 7.

[0034] The three steel plates 1 connected end-to-end in this invention allow for rapid assembly of the casing body, simplifying on-site assembly and effectively improving construction efficiency. The fixed ring I2 serves as the rotating connection point for the retractable sleeve bolt assembly, facilitating stable casing construction within the borehole wall of the pile foundation and simplifying disassembly of the retractable sleeve bolt assembly after construction. The retractable sleeve bolt assembly is adjusted by rotating the handle 4, causing the steel sleeve 3 to drive the perforated bolt rod 5 at its end to expand the steel plate 1 until it is in close contact with the borehole wall, forming a stable casing structure. This completes the positioning and fixation of the casing within the pile foundation borehole, achieving effective control of the internal space of the karst cave. The rapid adaptation and closure ensure the flexibility and precision of the construction process, while avoiding the problems of collapse, drill jamming, and deviation that often occur with the backfill wall construction method, as well as the long construction period and poor construction quality and safety. The structural design of the spring steel plate limiting component allows the elastic restoring force of the spring steel plate 6 to push the C-shaped steel 7 outward after construction is completed. It forms a stable support structure between the casing and the borehole wall of the pile foundation through a certain angle, thereby enhancing the overall stability and load-bearing capacity of the casing and ensuring the safety of pile foundation construction. The structural design of the tension band 9 is used to temporarily fix the C-shaped steel 7 in the early stage of construction and is cut off and released after construction is completed, simplifying on-site operations.

[0035] The steel plate 1 is a corrugated steel plate.

[0036] The corrugated steel plate structure provides the necessary rigidity to withstand soil pressure while maintaining a certain degree of flexibility to adapt to irregular karst shapes and reduce stress concentration.

[0037] As attached Figure 1 Appendix Figure 5 As shown, each steel plate 1 has mounting holes I10, II11, and III12 distributed vertically at both ends of its edges. Each mounting hole II11 has a limiting end groove. Adjacent steel plates 1 are connected and fixed by bolts that pass through the mounting holes I10, II11, and III12 respectively.

[0038] The structural design of mounting holes I10, II11, III12, and the limiting end groove ensures that after the casing expands to form a stable circular structure, the bolts in each mounting hole II11 can naturally fall into the limiting end groove, thereby completing the stable fixation of the casing's own structure.

[0039] The number of spring steel sheet limiting components is greater than or equal to 1.

[0040] As attached Figure 9 As shown, the flange at the connection end of the C-shaped steel 7 and the fixing ring II 8 is arc-shaped.

[0041] The arc-shaped wing plate at the connection end of C-shaped steel 7 and fixed ring II 8 ensures the relative rotation between C-shaped steel 7 and the outer wall of the casing.

[0042] As attached Figure 4 As shown, there are 6 pairs of fixed rings I2 and 3 telescopic sleeve bolt assemblies, which are arranged horizontally in a triangle on the inner side of the casing.

[0043] The three retractable sleeve bolt assemblies are arranged in a triangular horizontal configuration on the inner side of the casing, which facilitates the rapid and stable support of the three corrugated steel plates to form a circular casing structure.

[0044] As attached Figure 8 Appendix Figure 10 As shown, the top plate end of the spring steel sheet 6 is rolled.

[0045] The rolled edge design of the top plate of the spring steel sheet 6 can reduce the friction between it and the inner wall of the C-shaped steel 7, so that when the top plate of the spring steel sheet 6 springs up, it can smoothly lift the C-shaped steel 7 and keep the C-shaped steel 7 at a certain support angle to abut against the hole wall of the pile foundation borehole.

[0046] The installation and use of this utility model are achieved through the following steps:

[0047] Step 1: Drilling and cleaning. Drilling work is carried out to the location of the known karst cave. At this time, it is necessary to check and clean any loose soil or rock blocks that may exist in the borehole to ensure the safety of subsequent construction. At the same time, the residual soil and debris in the hole should be removed.

[0048] Step Two: Assemble the casing. On-site, pre-assemble the three corrugated steel plates as shown in the attached diagram. Figure 1 Appendix Figure 2 The casing shown has adjacent corrugated steel plates connected and fixed by bolts passing through mounting holes I10, II11, and III12 respectively. Mounting hole II11 is designed with a limiting end groove for subsequent fixing. Simultaneously, six pairs of fixing rings I2 are welded to the inner wall of the casing at designed positions, as shown in the attached diagram. Figure 4 As shown, and ensuring that the height of the 6 pairs of fixing rings I2 is consistent, the three telescopic sleeve bolt assemblies are connected to the corresponding fixing rings I2 through pins, so that the three telescopic sleeve bolt assemblies are arranged horizontally in a triangle on the inner side of the casing, and the casing is kept in a loose state. Then, the spring steel sheet limiting assembly is pre-welded and installed on the outer wall of the casing, ensuring that the binding knot of the tensioning strap 9 is located on the inner side of the casing.

[0049] Step 4: Lowering the casing. After lowering the assembled device to the location of the karst cave in the pile foundation borehole, the construction personnel enter the casing and operate the three rotating handles 4 to drive the corresponding three steel sleeves 3 to rotate in the forward direction. This causes the six bolt rods 5 with holes at the ends to push the three corrugated steel plates to slowly expand towards the borehole wall of the pile foundation borehole and gradually fit into the borehole wall, thus forming a stable circular casing structure. At this time, the bolts in each installation hole II11 naturally fall into the limiting end groove to complete the fixing.

[0050] Step 5: Fix the casing, rotate the three rotating handles 4 in the opposite direction, and after each telescopic sleeve bolt assembly is loosened from the pin connecting the corresponding fixing ring I2, remove the 6 pins and take out the three telescopic sleeve bolt assemblies. Then, cut the tension band 9 from the inside of the casing, allowing the top plate of the spring steel sheet 6 to spring up, while lifting the C-shaped steel 7 to maintain a certain support angle against the hole wall of the pile foundation borehole, ensuring that the casing is stably supported at the karst cave location;

[0051] Step Six: After the casing is stabilized, continue drilling until the design elevation is reached. Then, install the reinforcing cage and pour concrete to form the pile, thus completing the pile foundation construction. This completes the installation and use of the device. It overcomes the problems of existing shallow karst cave treatment methods, such as easy collapse, stuck drill, and deviation, as well as long construction period and poor construction quality and safety.

[0052] In the description of this utility model, it should be understood that the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this utility model and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0053] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A novel treatment device for shallow karst caves during pile foundation construction, characterized in that: Includes casing, retractable sleeve bolt assembly, and spring steel sheet limit assembly; The casing is formed by connecting three steel plates (1) end to end, and several pairs of fixing rings I (2) are welded to the inner wall of the casing. The retractable sleeve bolt assembly includes a steel sleeve (3) horizontally disposed on the inner side of the sleeve. A rotating handle (4) is welded to the middle of the outer wall of the steel sleeve (3). A bolt rod (5) with a hole at the end is threaded to each end of the steel sleeve (3). Each bolt rod (5) with a hole at the end is rotatably connected to a pair of fixing rings I (2) through a pin. The spring steel sheet limiting assembly includes a spring steel sheet (6), a C-shaped steel (7), and a pair of fixing rings II (8) welded to the outer wall of the casing. The bottom plate of the spring steel sheet (6) is welded to the outer wall of the casing. A reserved hole is provided on the outer wall of the casing, and a tensioning strap (9) is inserted through the reserved hole. One end of the C-shaped steel (7) is rotatably connected to the pair of fixing rings II (8) through a pin. The other end of the C-shaped steel (7) is tied to the outer wall of the casing through the tensioning strap (9), and the binding knot of the tensioning strap (9) is located inside the casing. The opening of the C-shaped steel (7) faces the outer wall of the casing, and the top plate of the spring steel sheet (6) abuts against the inner wall of the C-shaped steel (7).

2. The novel treatment device for shallow karst caves during pile foundation construction according to claim 1, characterized in that: The steel plate (1) is a corrugated steel plate.

3. A novel treatment device for shallow karst caves during pile foundation construction, as described in claim 1, characterized in that: Each steel plate (1) has mounting holes I (10), II (11) and III (12) distributed vertically at both ends of its edges. Each mounting hole II (11) is provided with a limit end groove. Two adjacent steel plates (1) are connected and fixed by bolts that pass through the mounting holes I (10), II (11) and III (12) respectively.

4. A novel treatment device for shallow karst caves during pile foundation construction according to claim 1, characterized in that: The number of spring steel sheet limiting components is greater than or equal to 1.

5. A novel treatment device for shallow karst caves during pile foundation construction according to claim 1, characterized in that: The flange at the connection end of the C-shaped steel (7) and the fixing ring II (8) is arc-shaped.

6. A novel treatment device for shallow karst caves during pile foundation construction according to claim 1, characterized in that: The number of fixed rings I (2) is 6 pairs, the number of telescopic sleeve bolt assemblies is 3, and the 3 telescopic sleeve bolt assemblies are arranged in a triangle horizontally on the inner side of the casing.

7. A novel treatment device for shallow karst caves during pile foundation construction according to claim 1, characterized in that: The top end of the spring steel sheet (6) is rolled.

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