Karst geology steel sheet pile cofferdam grouting impact hole-forming pile foundation and construction method

Abstract

The invention relates to a karst geology steel sheet pile cofferdam grouting impact hole forming pile foundation and a construction method, a steel sheet pile cofferdam-high-pressure jet grouting-permanent steel casing combined treatment technology is adopted, a plurality of high-pressure jet grouting piles are annularly arranged on the outer side of a double-layer steel casing, and the construction safety of the pile foundation under karst geology is improved; by the adoption of the efficient backfilling device for backfilling soil in the pile casing, the construction efficiency of installation of the double-layer steel pile casing is improved, and the construction period is further guaranteed; the construction platforms are arranged at the corners of the steel cofferdam, and then the steel pipe piles are constructed and reinforced, so that the construction efficiency of local steel pipe pile reinforcement treatment is improved, and the construction quality of steel pipe pile driving is improved; according to the double-layer steel casing inner support positioning device, the double-layer steel casing inner support positioning device is adopted, the wedge-shaped block is arranged on the outer casing placing plate and used for adjusting the perpendicularity of the inner casing, the in-place accuracy of the double-layer steel casing is improved, the integrity of the double-layer steel casing is improved, and then the construction quality is improved.

Description

Technical Field

[0001] The invention belongs to the field of karst geological pile foundation construction, and in particular relates to a karst geological steel sheet pile cofferdam grouting impact hole forming pile foundation and a construction method. Background Art

[0002] Pile foundation construction under karst geological conditions often faces many technical challenges due to the complexity and particularity of the geological environment. There are many underground caves in karst areas, and the stratum stability is poor, which brings great uncertainty to the construction of pile foundations. In order to ensure the safety and stability of pile foundations, scientific and effective construction methods and technical measures must be adopted.

[0003] As a commonly used cofferdam form, steel sheet pile cofferdam has the advantages of fast construction speed, simple operation and strong adaptability, and has been widely used in pile foundation construction under karst geological conditions. Grouting technology can improve the bearing capacity and stability of the stratum by reinforcing and filling the stratum, providing strong support for the construction of pile foundation. However, the current construction technology for karst geological pile foundation still has a series of shortcomings.

[0004] Based on the actual requirements of complex construction conditions, high construction quality and tight construction period of engineering projects, an innovative karst geological steel sheet pile cofferdam grouting impact bored pile foundation and construction method with high construction efficiency, excellent construction quality and low safety risk is of great significance to improving the construction quality of karst geological bored piles. Summary of the invention

[0005] The purpose of the invention is to overcome the deficiencies in the prior art and provide a karst geological steel sheet pile cofferdam grouting impact hole pile foundation and a construction method.

[0006] The karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system includes a pile foundation, a reinforced steel pipe pile, a pile driver, a steel column, a double-layer steel casing, a construction platform, a steel cofferdam, a verticality detector and an efficient backfilling device for backfilling soil in the casing;

[0007] There are several pile foundations in the steel cofferdam, and a double-layer steel casing is set outside the pile foundation. Several high-pressure jet grouting piles are set in the circumferential direction outside the double-layer steel casing; corner reinforcement components are set at the four corners of the steel cofferdam; a pile driver is installed at one corner of the steel cofferdam through a construction platform;

[0008] The high-efficiency backfilling device for backfilling soil in casing comprises a ring-shaped lower track and an upper track, and a low hammer and a high hammer are respectively connected to the lower track and the upper track.

[0009] Preferably, a steel base is provided in the middle of the steel cofferdam, and lower struts and truss supports are provided between the steel bases on both sides, the corner reinforcement assembly includes two reinforced I-beams and right-angle steel plates, corner tensioning rods are provided on the reinforced I-beams, reinforcement plates are provided between the webs of the reinforced I-beams, mounting grooves are provided on the reinforcement plates, mounting grooves are provided on the right-angle steel plates, diagonal struts are provided in the two mounting grooves, and tensioning blocks are provided on the diagonal struts for adjusting the supporting force of the diagonal struts.

[0010] Preferably, the lower track of the efficient backfilling device for backfilling soil in the casing is placed on the ground, the lower track is annular, and is assembled from four arc-shaped tracks, track connecting plates are arranged at both ends of the arc-shaped track, inclined columns are arranged on the track connecting plates, and an upper track is arranged on the top of the inclined column, the upper track is annular, and a sleeve is arranged at the bottom of the upper track, and the sleeve is sleeved on the top of the inclined column, a high hammer sliding seat is arranged on the upper track, the high hammer sliding seat is connected to the high hammer, a low hammer sliding seat is arranged on the lower track, a low hammer telescopic rod is arranged at the end of the low hammer sliding seat, the low hammer sliding seat is connected to the low hammer, and the high hammer and the low hammer are both driven by a motor.

[0011] Preferably, the construction platform is placed at the corner of the steel cofferdam, and steel columns are provided on the outside of the steel cofferdam. The steel columns are supported on the bottom of the construction platform. The inside of the construction platform is fixed to the steel cofferdam by bolts, and the upper part of the bolts is connected to the construction platform through a steel section with a limiting plate.

[0012] Preferably, the double-layer steel casing includes an inner casing and an outer casing, the inner casing is a permanent casing, a blade angle and an outer casing placement groove are arranged at the bottom of the inner casing, a slide groove is arranged in the middle of the outer wall of the inner casing, a diamond support is arranged for sliding in the slide groove, an inner steel casing hanging ear is arranged on the top of the inner casing, an outer casing shelf plate is arranged on the inner side of the outer casing, the inner steel casing hanging ear is placed on the outer casing shelf plate on the outer casing, a wedge block is arranged on the outer casing shelf plate for adjusting the verticality of the inner casing, a limit groove is arranged on the top of the outer casing, a cross bar with a sleeve is arranged between adjacent limit grooves, a tetrahedral ball is arranged above the center of the outer casing, the tetrahedral ball is connected to the cross bar with a sleeve through an inclined rod, and a verticality detector is arranged under the tetrahedral ball.

[0013] The construction method of the karst geological steel sheet pile cofferdam grouting impact hole pile foundation comprises the following steps:

[0014] Step 1: Steel cofferdam construction: build steel cofferdams, add corner reinforcement components at the corners, and finally carry out high-pressure jet grouting pile construction around the designed position of the pile foundation;

[0015] Step 2: Double-layer steel casing production: hoist the outer casing and place it outside the inner casing to form a double-layer steel casing, and then install the double-layer steel casing;

[0016] Step 3: Backfill soil around the steel casing: Install the lower track on the ground, install the upper track through the inclined column, and use the low hammer and high hammer to automatically hammer and compact the soil while backfilling;

[0017] Step 4: Pile foundation construction: Once again adjust the verticality of the inner casing using the wedge block and then proceed with the pile foundation construction.

[0018] Step 5: Local reinforcement of steel pipe piles: Install construction platforms and pile drivers at the corners of the steel cofferdam to strengthen the steel pipe piles.

[0019] Preferably, the double-layer steel casing includes an inner casing and an outer casing, the inner casing is a permanent casing, a blade angle and an outer casing placement groove are arranged at the bottom of the inner casing, a slide groove is arranged in the middle of the outer wall of the inner casing, a diamond support is arranged for sliding in the slide groove, an inner steel casing hanging ear is arranged on the top of the inner casing, an outer casing shelf plate is arranged on the inner side of the outer casing, the inner steel casing hanging ear is placed on the outer casing shelf plate on the outer casing, a wedge block is arranged on the outer casing shelf plate for adjusting the verticality of the inner casing, a limit groove is arranged on the top of the outer casing, a cross bar with a sleeve is arranged between adjacent limit grooves, a tetrahedral ball is arranged above the center of the outer casing, the tetrahedral ball is connected to the cross bar with a sleeve through an inclined rod, and a verticality detector is arranged under the tetrahedral ball.

[0020] Preferably, in step two, the diamond support is installed on the outer casing, and then the outer casing is lifted and placed on the outside of the inner casing, the inner casing hanging ear of the inner casing is placed on the outer casing shelf plate, the bottom of the outer casing is placed in the outer casing placement groove, and then the steel casing is installed, and then the tetrahedral pyramid with a verticality tester is installed, and the verticality of the inner casing is adjusted by the wedge block.

[0021] The beneficial effects of the present invention are:

[0022] 1) The present invention adopts a combined treatment technology of steel sheet pile cofferdam-high pressure rotary jet grouting-permanent steel casing. Several high pressure rotary jet piles are arranged in a circumferential direction on the outer side of the double-layer steel casing, thereby improving the safety of pile foundation construction under karst geology.

[0023] 2) The present invention adopts a highly efficient backfilling device for backfilling soil inside the casing, which improves the construction efficiency of the double-layer steel casing installation and further ensures the construction period.

[0024] 3) The present invention adopts a method of setting a construction platform at the corner of the steel cofferdam to further construct and strengthen the steel pipe piles, thereby improving the construction efficiency of the local steel pipe pile reinforcement treatment and improving the construction quality of the steel pipe pile driving.

[0025] 4) The present invention adopts a double-layer steel casing inner support positioning device, and a wedge block is arranged on the outer casing shelf plate to adjust the verticality of the inner casing, thereby improving the accuracy of the double-layer steel casing in position, improving the integrity of the double-layer steel casing, and thus improving the construction quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a three-dimensional schematic diagram of the construction of grouting impact-formed pile foundation for karst geological steel sheet pile cofferdam;

[0027] Figure 2 It is a schematic diagram of local steel pipe pile reinforcement;

[0028] Figure 3 It is a schematic diagram of a steel cofferdam;

[0029] Figure 4 It is a schematic diagram of the steel cofferdam support;

[0030] Figure 5 is a schematic diagram of a corner reinforcement assembly;

[0031] Figure 6 This is a schematic diagram of the installation of a highly efficient backfilling device for backfilling soil inside the casing;

[0032] Figure 7 It is a schematic diagram of a highly efficient backfilling device for backfilling soil in casing;

[0033] Figure 8 It is a schematic diagram of a double-layer steel casing;

[0034] Fig. 9 is a schematic diagram of the outer casing;

[0035] Fig.10 It is a schematic diagram of the inner casing.

[0036] Among them: 1. Pile foundation 2. Reinforced steel pipe column 3. Connecting seat 4. Steel with limit plate 5. Pile driver 6. Construction platform 7. Bolt 8. Steel column 9. Lower support rod 10. Double-layer steel casing 11. Truss support 12. Steel base 13. Corner reinforcement assembly 14. High-pressure jet grouting pile 15. Steel cofferdam 16. Corner tension rod 17. Reinforced I-beam 18. Diagonal support rod 19. Tension block 20. Installation groove 21. Reinforcement plate 22. Verticality detector 23. Inner steel casing hanger Ear 24. Wedge block 25. Crossbar with sleeve 26. Quadrangular pyramid ball 27. Limiting groove 28. Outer casing shelf plate 29. Diamond support 30. Blade corner 31. Outer casing 32. Inner casing 33. Slide groove 34. Outer casing placement groove 35. Low hammer telescopic rod 36. Height positioning plate 37. Ground 38. Lower track 39. Track connecting plate 40. Low hammer sliding seat 41. Inclined column 42. Sleeve 43. Upper track 44. High hammer sliding seat 45. High hammer 46. Low hammer. DETAILED DESCRIPTION

[0037] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0038] Embodiment 1

[0039] As an embodiment, this karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system involves a steel sheet pile cofferdam-high pressure rotary jet grouting-permanent steel casing combined treatment technology, an efficient backfilling device for backfilling soil in the casing, local steel pipe pile reinforcement placed on a steel sheet pile cofferdam steel construction platform, a double-layer steel casing internal support positioning device, etc., and mainly includes a pile foundation 1, a reinforced steel pipe pile 2, a pile driver 5, a steel column 8, a double-layer steel casing 10, a construction platform 6, a steel cofferdam 15, and a verticality detector 22.

[0040] Several pile foundations 1 are arranged in the steel cofferdam 15, a double-layer steel casing 10 is arranged outside the pile foundation 1, and several high-pressure rotary jet piles 14 are arranged circumferentially outside the double-layer steel casing 10; corner reinforcement components 13 are arranged at the four corners of the steel cofferdam 15; a pile driver 5 is installed at one corner of the steel cofferdam 15 through a construction platform 6;

[0041] The high-efficiency backfilling device for backfilling soil in casing comprises a ring-shaped lower track 38 and an upper track 43 , and a low hammer 46 and a high hammer 45 are connected to the lower track 38 and the upper track 43 respectively.

[0042] Specifically, the combined treatment technology of steel sheet pile cofferdam-high pressure jet grouting-permanent steel casing is used. Figure 4 and Figure 5 As shown, a double-layer steel casing 10 is arranged on the outside of the pile foundation 1, and a high-pressure rotary jet pile 14 is arranged on the outside of the double-layer steel casing. A steel cofferdam 15 is arranged on the outermost layer, and corner reinforcement components 13 are arranged at the four corners of the steel cofferdam 15. A steel base 12 is arranged in the middle, and a lower support rod 9 and a truss support 11 are arranged on the steel base. The corner component is surrounded by two reinforced I-beams 17 and a right-angle steel plate. A corner tensioning rod 16 is arranged on the reinforced I-beam, and a reinforcement plate 21 is arranged between the webs of the reinforced I-beam 17. A mounting groove 20 is arranged on the reinforcement plate 21, and a mounting groove is arranged on the right-angle steel plate. Diagonal support rods are arranged in the two mounting grooves, and tensioning blocks 19 are arranged on the diagonal support rods to adjust the supporting force of the support rods.

[0043] Embodiment 2

[0044] As another embodiment, this embodiment 2 proposes, based on the embodiment 1, a more specific karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system:

[0045] like Figure 6 and Figure 7As shown, the lower track 38 of the efficient backfilling device for backfilling soil in the casing is placed on the ground 37, the lower track 38 is assembled from four pieces, a track connecting plate 39 is arranged on the edge, an inclined column is arranged on the track connecting plate 39, an upper track 43 is arranged on the top of the inclined column, a sleeve 42 at the bottom of the upper track 43 is placed on the inclined column 41, a high hammer sliding seat 44 is arranged on the upper track, the high hammer sliding seat 44 is connected to the high hammer 45, a low hammer sliding seat 40 is arranged on the lower track, a low hammer telescopic rod 35 is arranged at the end of the low hammer sliding seat 40, the low hammer sliding seat is connected to the low hammer 46, the high hammer and the low hammer are both driven by a motor, and the device improves the compaction efficiency of backfill soil through electric high and low hammers.

[0046] like Figure 2 As shown, the pipe pile reinforcement is placed on the steel sheet pile cofferdam. The steel construction platform is placed at the corner of the steel cofferdam 15, a steel column 8 is arranged on the outside, a connecting plate is arranged on the inside, and is fixed to the steel cofferdam 15 by bolts 7, a steel 4 with a limiting plate is arranged on the upper part, a construction platform is arranged on the steel column 8 and the steel with a limiting plate, a pile driver is arranged on the construction platform, and a reinforced steel pipe pile 2 is arranged on one side of the platform.

[0047] like Figures 8 to 10 As shown, the double-layer steel casing 10 is composed of an inner casing 32 and an outer casing 31. The inner casing 4 is a permanent casing. A blade angle 30 and an outer casing placement groove 34 are set at the bottom, and a slide groove 33 is set in the middle position. The diamond support 29 on the outer casing slides in the slide groove of the inner casing to facilitate the removal of the outer casing. An inner steel casing hanging ear 23 is set at the top of the inner casing. The inner steel casing hanging ear is placed on the outer casing shelf plate 28 on the outer casing. A wedge block 24 is set on the outer casing shelf plate 28 for adjusting the verticality of the inner casing. A limiting groove 27 is set at the top of the outer casing. A cross bar 25 with a sleeve is set in the limiting groove. The inclined rod of the tetrahedral sphere is placed in the sleeve, and a verticality detector 22 is set under the tetrahedral sphere.

[0048] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0049] Embodiment 3

[0050] As another embodiment, this embodiment 3 proposes, based on the embodiments 1 and 2, that the construction method of the karst geological steel sheet pile cofferdam grouting impact hole pile foundation comprises the following steps:

[0051] Steel cofferdam construction: build the steel cofferdam 15, install the steel base 12 in the middle, then install the lower support rod 9 and the truss support 11, and add the corner reinforcement assembly 13 at the corner. The specific operation is: weld the reinforcement plate 21 on the web of the reinforced I-beam 17, install the diagonal support rod 18 with the tension block 19 on the installation groove 20 on the reinforcement plate and the corner installation groove, then adjust the tension block 19, and finally carry out the high-pressure jet grouting pile 14 construction

[0052] Double-layer steel casing production: install the diamond support 29 on the outer casing 21, then lift the outer casing and place it on the outside of the inner casing, place the inner casing hanging ear 23 of the inner casing on the outer casing shelf 28, place the bottom of the outer casing in the outer casing placement groove, and then install the steel casing, and then install the four-cornered pyramid ball with a verticality detector, and adjust the verticality of the inner casing through the wedge block.

[0053] Backfill soil around the steel casing: install the lower track 38 on the ground 37, connect the four tracks by bolts, then place the low hammer sliding seat 40 of the low hammer 46 on the track, then install the upper track 43 with sleeve on the upper part of the inclined column, and place the high hammer sliding seat 44 at the same time. When backfilling soil, turn on the motors of the high and low hammers to automatically hammer and compact while backfilling soil.

[0054] Pile foundation construction: After adjusting the verticality of the inner casing by the wedge block again, pile foundation construction is carried out.

[0055] Local reinforcement of steel pipe piles: install steel columns 8 on the outside of the steel cofferdam, then install the base of steel with limit plate 4 on the reinforced I-beam 17, fix it with bolts 7, then install the construction platform and pile driver 5, and finally carry out local reinforcement construction of steel pipe piles 2.

[0056] It should be noted that the parts in this embodiment that are the same or similar to those in Embodiments 1 and 2 can be referenced to each other and will not be described in detail in this application.

[0057] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system, characterized in that: It includes pile foundation, reinforced steel pipe pile, pile driver, steel column, double-layer steel casing, construction platform, steel cofferdam, verticality detector and high-efficiency backfilling device for backfill soil in casing; There are several pile foundations in the steel cofferdam, and a double-layer steel casing is set outside the pile foundation. Several high-pressure jet grouting piles are set in the circumferential direction outside the double-layer steel casing; corner reinforcement components are set at the four corners of the steel cofferdam; a pile driver is installed at one corner of the steel cofferdam through a construction platform; The high-efficiency backfilling device for backfilling soil in casing comprises a ring-shaped lower track and an upper track, and a low hammer and a high hammer are respectively connected to the lower track and the upper track.

2. The karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system according to claim 1 is characterized in that: A steel base is arranged in the middle of the steel cofferdam, and lower struts and truss supports are arranged between the steel bases on both sides. The corner reinforcement assembly includes two reinforced I-beams and right-angle steel plates. Corner tensioning rods are arranged on the reinforced I-beams, reinforcement plates are arranged between the webs of the reinforced I-beams, mounting grooves are arranged on the reinforcement plates, mounting grooves are arranged on the right-angle steel plates, diagonal struts are arranged in the two mounting grooves, and tensioning blocks are arranged on the diagonal struts to adjust the supporting force of the diagonal struts.

3. The karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system according to claim 1 is characterized in that: The lower track of the efficient backfilling device for backfilling soil in the casing is placed on the ground, the lower track is annular, and is assembled from four arc-shaped tracks, track connecting plates are arranged at both ends of the arc-shaped track, inclined columns are arranged on the track connecting plates, and an upper track is arranged on the top of the inclined column, the upper track is annular, and a sleeve is arranged at the bottom of the upper track, and the sleeve is sleeved on the top of the inclined column, a high hammer sliding seat is arranged on the upper track, and the high hammer sliding seat is connected to the high hammer, a low hammer sliding seat is arranged on the lower track, a low hammer telescopic rod is arranged at the end of the low hammer sliding seat, and the low hammer sliding seat is connected to the low hammer, and the high hammer and the low hammer are both driven by a motor.

4. The karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system according to claim 1 is characterized in that: The construction platform is placed at the corner of the steel cofferdam. Steel columns are arranged on the outside of the steel cofferdam. The steel columns are supported on the bottom of the construction platform. The inside of the construction platform is fixed to the steel cofferdam by bolts. The upper part of the bolts is connected to the construction platform through steel with limiting plates.

5. The karst geological steel sheet pile cofferdam grouting impact hole pile foundation construction system according to claim 1 is characterized in that: The double-layer steel casing comprises an inner casing and an outer casing. The inner casing is a permanent casing. A blade angle and an outer casing placement groove are arranged at the bottom of the inner casing. A slide groove is arranged in the middle of the outer wall of the inner casing. A diamond support is arranged for sliding in the slide groove. An inner steel casing hanging ear is arranged on the top of the inner casing. An outer casing shelf plate is arranged on the inner side of the outer casing. The inner steel casing hanging ear is placed on the outer casing shelf plate on the outer casing. A wedge block is arranged on the outer casing shelf plate for adjusting the verticality of the inner casing. A limiting groove is arranged on the top of the outer casing. A cross bar with a sleeve is arranged between adjacent limiting grooves. A tetrahedral ball is arranged above the center of the outer casing. The tetrahedral ball is connected to the cross bar with a sleeve through an inclined rod. A verticality detector is arranged under the tetrahedral ball.

6. The construction method of karst geological steel sheet pile cofferdam grouting impact hole pile foundation according to claim 1 is characterized in that: The following steps are involved: Step 1: Steel cofferdam construction: build steel cofferdams, add corner reinforcement components at the corners, and finally carry out high-pressure jet grouting pile construction around the designed position of the pile foundation; Step 2: Double-layer steel casing production: hoist the outer casing and place it outside the inner casing to form a double-layer steel casing, and then install the double-layer steel casing; Step 3: Backfill soil around the steel casing: Install the lower track on the ground, install the upper track through the inclined column, and use the low hammer and high hammer to automatically hammer and compact the soil while backfilling; Step 4: Pile foundation construction: Once again adjust the verticality of the inner casing using the wedge block before proceeding with the pile foundation construction. Step 5: Local reinforcement of steel pipe piles: Install construction platforms and pile drivers at the corners of the steel cofferdam to strengthen the steel pipe piles.

7. The construction method of karst geological steel sheet pile cofferdam grouting impact hole pile foundation according to claim 6 is characterized in that: The double-layer steel casing includes an inner casing and an outer casing. The inner casing is a permanent casing. A blade angle and an outer casing placement groove are arranged at the bottom of the inner casing. A slide groove is arranged in the middle of the outer wall of the inner casing. A diamond support is arranged for sliding in the slide groove. An inner steel casing hanging ear is arranged on the top of the inner casing. An outer casing shelf plate is arranged on the inner side of the outer casing. The inner steel casing hanging ear is placed on the outer casing shelf plate on the outer casing. A wedge block is arranged on the outer casing shelf plate for adjusting the verticality of the inner casing. A limit groove is arranged on the top of the outer casing. A cross bar with a sleeve is arranged between adjacent limit grooves. A tetrahedral ball is arranged above the center of the outer casing. The tetrahedral ball is connected to the cross bar with a sleeve through an inclined rod, and a verticality detector is arranged under the tetrahedral ball.

8. The construction method of karst geological steel sheet pile cofferdam grouting impact hole pile foundation according to claim 7 is characterized in that: In step two, the diamond support is installed on the outer casing, and then the outer casing is lifted and placed on the outside of the inner casing, the inner casing hanging ear of the inner casing is placed on the outer casing shelf plate, the bottom of the outer casing is placed in the outer casing placement groove, and then the steel casing is installed, and then the four-cornered pyramid ball with a verticality tester is installed, and the verticality of the inner casing is adjusted by the wedge block.

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