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

Abstract

The present application relates to a kind of karst geology steel sheet pile cofferdam grouting impact hole forming pile foundation and construction method, steel sheet pile cofferdam-high pressure jet grouting-permanent steel casing combination treatment technology is used, several high-pressure jet grouting piles are arranged in the outside ring of double-layer steel casing, the safety of pile foundation construction under karst geology is improved;Efficient backfilling device is used in the backfilling soil in casing, the construction efficiency of double-layer steel casing installation is improved, and the construction period is further guaranteed;Construction platform is set in the corner of steel cofferdam, and then construction reinforced steel pipe pile is carried out, the construction efficiency of local steel pipe pile reinforcement is improved, and the construction quality of steel pipe pile is improved;Double-layer steel casing is supported positioning device, wedge is set on the outer casing rest plate, for adjusting the perpendicularity of inner casing, the accuracy of double-layer steel casing is improved, the integrity of double-layer steel casing is improved, and then the construction quality is improved.

Description

Technical Field

[0001] This invention belongs to the field of karst geological pile foundation construction, and particularly relates to a karst geological steel sheet pile cofferdam grouting impact drilling pile foundation and construction method. Background Technology

[0002] Pile foundation construction in karst geological conditions often presents numerous technical challenges due to the complexity and unique nature of the geological environment. Karst areas are characterized by numerous underground caves and poor ground stability, introducing significant uncertainties into pile foundation construction. To ensure the safety and stability of the pile foundation, scientifically effective construction methods and technical measures must be adopted.

[0003] Steel sheet pile cofferdams, as a commonly used type of cofferdam, have advantages such as fast construction speed, simple operation, and strong adaptability, and have been widely used in pile foundation construction under karst geological conditions. Grouting technology can strengthen and fill the strata, improving their bearing capacity and stability, and providing strong support for pile foundation construction. However, current construction techniques for pile foundations in karst geological conditions still have a number of shortcomings.

[0004] Given the complex construction conditions, high construction quality, and tight construction schedule of engineering projects, this paper proposes an innovative construction method for grouting impact drilling pile foundations in karst geological areas. This method is characterized by high construction efficiency, excellent construction quality, and low safety risks, and is of great significance for improving the construction quality of bored piles in karst geological areas. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a grouting impact drilling pile foundation for karst geological steel sheet pile cofferdams and its construction method.

[0006] This karst geological steel sheet pile cofferdam grouting impact drilling pile foundation construction system includes pile foundation, reinforced steel pipe pile, pile driver, steel column, double-layer steel casing, construction platform, steel cofferdam, verticality detector and efficient backfilling device for backfill soil inside casing;

[0007] The steel cofferdam has several pile foundations inside, and a double-layer steel casing is installed on the outside of the pile foundations. Several high-pressure jet grouting piles are arranged circumferentially on the outside of the double-layer steel casing. Corner reinforcement components are installed at the four corners of the steel cofferdam. A pile driver is installed at one corner of the steel cofferdam via a construction platform.

[0008] The efficient backfilling device for the casing includes a lower track and an upper track in a ring shape, with a low hammer and a high hammer connected to the lower track and the upper track respectively.

[0009] Preferably, a steel base is installed in the middle of the steel cofferdam, and a lower strut and truss support are installed between the steel bases on both sides. The corner reinforcement assembly includes two reinforcing I-beams and a right-angle steel plate. A corner tensioning rod is installed on the reinforcing I-beam, and a reinforcing plate is installed between the webs of the reinforcing I-beam. An installation groove is provided on the reinforcing plate, and an installation groove is provided on the right-angle steel plate. Diagonal struts are installed in the two installation 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 high-efficiency backfilling device for the casing is placed on the ground. The lower track is circular and is assembled from four arc-shaped tracks. Track connecting plates are provided at both ends of the arc-shaped tracks. Inclined columns are provided on the track connecting plates. An upper track is provided on the top of the inclined columns. The upper track is circular. A sleeve is provided at the bottom of the upper track and fits on the top of the inclined columns. A high hammer sliding seat is provided on the upper track and is connected to the high hammer. A low hammer sliding seat is provided on the lower track. A low hammer telescopic rod is provided at the end of the low hammer sliding seat and is connected to the low hammer. Both the high hammer and the low hammer are driven by a motor.

[0011] As a preferred option, the construction platform is placed at the corner of the steel cofferdam, and steel columns are installed on the outside of the steel cofferdam. The steel columns are supported at the bottom of the construction platform, and 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 by steel with limiting plates.

[0012] Preferably, the double-layer steel casing includes an inner casing and an outer casing. The inner casing is a permanent casing. The bottom of the inner casing is provided with a cutting edge and an outer casing placement groove. A sliding groove is provided in the middle of the outer wall of the inner casing, and a diamond-shaped support is slidably provided in the sliding groove. An inner steel casing hanging lug is provided at the top of the inner casing. An outer casing support plate is provided on the inner side of the outer casing. The inner steel casing hanging lug is placed on the outer casing support plate on the outer casing. A wedge block is provided on the outer casing support plate for adjusting the verticality of the inner casing. A limiting groove is provided at the top of the outer casing. A sleeved crossbar is provided between adjacent limiting grooves. A four-corner conical ball is provided above the center of the outer casing. The four-corner conical ball is connected to the sleeved crossbar by a diagonal rod. A verticality detector is provided below the four-corner conical ball.

[0013] This construction method for grouting and impact drilling pile foundations for steel sheet pile cofferdams in karst geological conditions includes the following steps:

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

[0015] Step 2, Double-layer steel casing fabrication: The outer casing is lifted and placed outside the inner casing to form a double-layer steel casing, and then the double-layer steel casing is installed;

[0016] Step 3: Backfilling around the steel casing: Install the lower track on the ground and the upper track through the inclined columns. The low hammer and high hammer will automatically compact the soil while backfilling.

[0017] Step 4, Pile Foundation Construction: After adjusting the verticality of the inner casing once again using wedge blocks, proceed with the pile foundation construction.

[0018] Step 5: Local steel pipe pile reinforcement: Install construction platforms and pile drivers at the corners of the steel cofferdam to carry out reinforcement construction of 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. The bottom of the inner casing is provided with a cutting edge and an outer casing placement groove. A sliding groove is provided in the middle of the outer wall of the inner casing, and a diamond-shaped support is slidably provided in the sliding groove. An inner steel casing hanging lug is provided at the top of the inner casing. An outer casing support plate is provided on the inner side of the outer casing. The inner steel casing hanging lug is placed on the outer casing support plate on the outer casing. A wedge block is provided on the outer casing support plate to adjust the verticality of the inner casing. A limiting groove is provided at the top of the outer casing. A sleeved crossbar is provided between adjacent limiting grooves. A four-corner conical ball is provided above the center of the outer casing. The four-corner conical ball is connected to the sleeved crossbar by a diagonal bar. A verticality measuring instrument is provided below the four-corner conical ball.

[0020] Preferably, in step two, the diamond-shaped support is installed on the outer casing, and then the outer casing is lifted and placed outside the inner casing. The inner casing lugs of the inner casing are placed on the outer casing support plate, and the bottom of the outer casing is placed in the outer casing placement groove. Then the steel casing is installed, and then the four-corner cone ball with a verticality measuring instrument is installed. The verticality of the inner casing is adjusted by the wedge block.

[0021] The beneficial effects of this invention are:

[0022] 1) This invention adopts a combined treatment technology of steel sheet pile cofferdam-high pressure jet grouting-permanent steel casing. Several high pressure jet grouting piles are arranged circumferentially on the outer side of the double-layer steel casing, which improves the safety of pile foundation construction under karst geology.

[0023] 2) This invention uses an efficient backfilling device for backfilling soil inside the casing, which improves the construction efficiency of double-layer steel casing installation and further ensures the construction period.

[0024] 3) This invention adopts a construction platform set at the corner of the steel cofferdam, and then constructs reinforced steel pipe piles, which improves the construction efficiency of local steel pipe pile reinforcement and the construction quality of steel pipe pile driving.

[0025] 4) This invention employs a double-layer steel casing inner support positioning device, with wedge blocks set on the outer casing support plate to adjust the verticality of the inner casing, thereby improving the accuracy of the double-layer steel casing positioning, improving the overall integrity of the double-layer steel casing, and thus improving the construction quality. Attached Figure Description

[0026] Figure 1 This is a three-dimensional schematic diagram of the construction of steel sheet pile cofferdam grouting impact drilling pile foundation in karst geological conditions;

[0027] Figure 2 This is a schematic diagram of localized steel pipe pile reinforcement;

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

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

[0030] Figure 5 This is a schematic diagram of the corner reinforcement component;

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

[0032] Figure 7 This is a schematic diagram of an efficient backfilling device for the casing.

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

[0034] Figure 9 This is a schematic diagram of the outer casing;

[0035] Figure 10 This is a schematic diagram of the inner casing.

[0036] The components include: 1. Pile foundation; 2. Reinforced steel pipe column; 3. Connecting seat; 4. Steel section with limiting 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. Tensioning block; 20. Installation groove; 21. Reinforcing plate; 22. Verticality measuring instrument; 23. Inner steel casing hanger. 24. Ear; 25. Wedge block; 26. Crossbar with sleeve; 27. Four-cornered cone ball; 28. Limiting groove; 29. ​​Outer protective sleeve support plate; 30. Rhomboid support; 31. Blade angle; 32. Outer protective sleeve; 33. Inner protective sleeve; 34. Slide groove; 35. Outer protective sleeve placement groove; 36. Low hammer telescopic rod; 37. Height positioning plate; 38. Ground; 39. Lower rail; 40. Rail connecting plate; 41. Low hammer sliding seat; 42. Inclined column; 43. Sleeve; 44. Upper rail; 45. High hammer sliding seat; 46. High hammer; 47. Low hammer. Detailed Implementation

[0037] The present invention will be further described below with reference to embodiments. The description of the embodiments below is only for the purpose of helping to understand the present invention. It should be noted that those skilled in the art can make several modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0038] Example 1

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

[0040] The steel cofferdam 15 has several pile foundations 1 inside, and a double-layer steel casing 10 is installed on the outside of the pile foundations 1. Several high-pressure jet grouting piles 14 are arranged circumferentially on the outside of the double-layer steel casing 10. Corner reinforcement components 13 are installed at the four corners of the steel cofferdam 15. A pile driver 5 is installed at one corner of the steel cofferdam 15 through the construction platform 6.

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

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

[0043] Example 2

[0044] As another embodiment, this second embodiment proposes a more specific grouting impact drilling pile foundation construction system for karst geological steel sheet pile cofferdams, based on the first embodiment:

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

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

[0047] like Figures 8 to 10 As shown, the double-layer steel casing 10 consists of an inner casing 32 and an outer casing 31. The inner casing 32 is a permanent casing with a cutting edge 30 at the bottom and an outer casing placement groove 34. A sliding groove 33 is provided in the middle. The diamond-shaped support 29 on the outer casing slides in the sliding groove of the inner casing to facilitate the removal of the outer casing. An inner steel casing hanging ear 23 is provided at the top of the inner casing. The inner steel casing hanging ear is placed on the outer casing support plate 28 on the outer casing. A wedge block 24 is provided on the outer casing support plate 28 to adjust the verticality of the inner casing. A limiting groove 27 is provided at the top of the outer casing. A crossbar 25 with a sleeve is provided in the limiting groove. The inclined rod of the four-corner conical ball is placed in the sleeve. A verticality detector 22 is provided under the four-corner conical ball.

[0048] It should be noted that the parts in this embodiment that are the same as or similar to those in Embodiment 1 can be referred to each other, and will not be repeated in this application.

[0049] Example 3

[0050] As another embodiment, this third embodiment, based on embodiments one and two, proposes a construction method for grouting impact drilling pile foundations for steel sheet pile cofferdams in karst geological conditions, comprising the following steps:

[0051] Steel cofferdam construction: Construct a steel cofferdam 15, install a steel base 12 in the middle, then install lower struts 9 and truss supports 11, and add corner reinforcement components 13 at the corners. Specifically, weld reinforcing plates 21 onto the web of the reinforcing I-beams 17, install diagonal struts 18 with tensioning blocks 19 on the mounting grooves 20 on the reinforcing plates and the corner mounting grooves, then adjust the tensioning blocks 19, and finally construct high-pressure jet grouting piles 14.

[0052] Double-layer steel casing fabrication: Install the diamond-shaped support 29 on the outer casing 31, then lift the outer casing and place it outside the inner casing. Place the inner casing lug 23 on the outer casing support plate 28, and place the bottom of the outer casing in the outer casing placement groove. Then, install the steel casing, and then install the four-corner cone ball with a verticality measuring instrument. Adjust the verticality of the inner casing by using wedge blocks.

[0053] Backfilling around the steel casing: Install the lower track 38 on the ground 37. The four tracks are connected 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, turn on the motors of the high and low hammers so that they can automatically hammer and compact the soil while backfilling.

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

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

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

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

Claims

1. A grouting impact drilling pile foundation for steel sheet pile cofferdams in karst geological conditions, characterized in that, This includes pile foundations, reinforced steel pipe piles, pile drivers, steel columns, double-layer steel casings, construction platforms, steel cofferdams, verticality measuring instruments, and efficient backfilling devices for backfilling soil inside the casings. The steel cofferdam has several pile foundations inside, and a double-layer steel casing is installed on the outside of the pile foundations. Several high-pressure jet grouting piles are arranged circumferentially on the outside of the double-layer steel casing. Corner reinforcement components are installed at the four corners of the steel cofferdam. A pile driver is installed at one corner of the steel cofferdam via a construction platform. The high-efficiency backfilling device for backfilling soil inside the casing includes a lower track and an upper track in a ring shape, with a low hammer and a high hammer respectively connected to the lower track and the upper track; A steel base is installed in the middle of the steel cofferdam, and lower struts and truss supports are installed between the steel bases on both sides. The corner reinforcement assembly includes two reinforcing H-beams and right-angle steel plates. Corner tensioning rods are installed on the reinforcing H-beams, and reinforcing plates are installed between the webs of the reinforcing H-beams. Mounting grooves are provided on the reinforcing plates and right-angle steel plates. Diagonal struts are installed in the two mounting grooves, and tensioning blocks are provided on the diagonal struts to adjust the supporting force of the diagonal struts. The lower track of the high-efficiency backfilling device for the casing is placed on the ground. The lower track is circular and is assembled from four arc-shaped tracks. Track connecting plates are set at both ends of the arc-shaped tracks. Inclined columns are set on the track connecting plates. The upper track is set on the top of the inclined columns. The upper track is circular. A sleeve is set at the bottom of the upper track. The sleeve is fitted onto the top of the inclined columns. A high hammer sliding seat is set on the upper track. The high hammer sliding seat is connected to the high hammer. A low hammer sliding seat is set on the lower track. A low hammer telescopic rod is set at the end of the low hammer sliding seat. The low hammer sliding seat is connected to the low hammer. Both the high hammer and the low hammer are driven by a motor. The double-layer steel casing includes an inner casing and an outer casing. The inner casing is a permanent casing. The bottom of the inner casing is provided with a cutting edge and an outer casing placement groove. A sliding groove is provided in the middle of the outer wall of the inner casing, and a diamond-shaped support is slidably installed in the sliding groove. An inner steel casing hanging lug is provided at the top of the inner casing. An outer casing support plate is provided on the inner side of the outer casing. The inner steel casing hanging lug is placed on the outer casing support plate on the outer casing. A wedge block is provided on the outer casing support plate to adjust the verticality of the inner casing. A limiting groove is provided at the top of the outer casing. A sleeved crossbar is provided between adjacent limiting grooves. A four-corner conical ball is provided above the center of the outer casing. The four-corner conical ball is connected to the sleeved crossbar by a diagonal bar. A verticality measuring instrument is provided below the four-corner conical ball.

2. The grouting impact drilling pile foundation for karst geological steel sheet pile cofferdams according to claim 1, characterized in that, The construction platform is located at the corner of the steel cofferdam. Steel columns are installed on the outside of the steel cofferdam and supported at the bottom of the construction platform. The inside of the construction platform is fixed to the steel cofferdam with bolts, and the upper part of the bolts is connected to the construction platform with steel sections with limit plates.

3. The construction method for grouting and impact drilling pile foundations for karst geological steel sheet pile cofferdams according to claim 1, characterized in that, Includes the following steps: Step 1: Steel cofferdam construction: Construct a steel cofferdam, add corner reinforcement components at the corners, and finally carry out high-pressure jet grouting pile construction around the designed pile foundation location; Step 2, Double-layer steel casing fabrication: The outer casing is lifted and placed outside the inner casing to form a double-layer steel casing, and then the double-layer steel casing is installed; Step 3: Backfilling around the steel casing: Install the lower track on the ground and the upper track through the inclined columns. The low hammer and high hammer will automatically compact the soil while backfilling. Step 4, Pile Foundation Construction: After adjusting the verticality of the inner casing once again using wedge blocks, proceed with the pile foundation construction. Step 5: Local steel pipe pile reinforcement: Install construction platforms and pile drivers at the corners of the steel cofferdam to carry out reinforcement construction of steel pipe piles.

4. The construction method for grouting and impact drilling pile foundations for karst geological steel sheet pile cofferdams according to claim 3, characterized in that, In step two, the diamond-shaped support is installed on the outer casing. Then, the outer casing is lifted and placed outside the inner casing. The inner casing lugs of the inner casing are placed on the outer casing support plate. The bottom of the outer casing is placed in the outer casing placement groove. Then, the steel casing is installed. Then, the four-corner cone ball with a verticality measuring instrument is installed. The verticality of the inner casing is adjusted by the wedge block.

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