Shallow-coverage high-strength inclined bare rock chambering pile foundation and construction method

Abstract

The invention relates to a shallow-covering high-strength inclined bare rock reaming pile foundation and a construction method. The construction method comprises the following steps that a drilling covering layer is constructed; hole cleaning construction; installing a steel fence on the outer side of the cast-in-place concrete; pouring flat concrete for construction; drilling and chambering construction on the inclined rock surface; when drilling and chambering construction is carried out on an inclined rock surface, the underwater part encounters fractured rock geology, and slag digging construction needs to be carried out. The hole bottom cleaning device has the beneficial effects that the barrel is blocked by flowing-in sludge, so that the sludge is pulled out, the problem of slag discharging is effectively solved, the hole bottom cleaning effect is obvious, and the working efficiency is greatly improved; the problem of rotary excavating hole forming depth is effectively solved, the problems of over-standard reaming, generation of eccentric holes, inclined holes and the like are effectively avoided, and the filling coefficient of pile foundation concrete pouring is favorably controlled; the drilling perpendicularity can be accurately guaranteed, the hole deviation risk is reduced, frequent deviation correction is avoided, the hole forming quality and stability are greatly improved, and the pile foundation bearing capacity is enhanced.

Description

Technical Field

[0001] The invention belongs to the technical field of pile foundation engineering, and in particular relates to a shallow-cover high-strength inclined bare rock hole-enlarged pile foundation and a construction method. Background Art

[0002] In the field of construction engineering, with the continuous development of infrastructure construction, bridges, ports and other projects are increasingly facing the challenges of complex geological conditions, among which pile foundation construction in shallow cover, high-strength inclined bare rock areas is particularly difficult. Traditional pile foundation construction methods have many problems in shallow cover layers and high-strength inclined bare rock areas. For example, when the pile encounters fissured rock geology in the underwater part, it is difficult to drain slag during pile foundation construction. It is difficult to drill holes deep in the undulating inclined rock surface, and it is easy to cause problems such as over-standard hole expansion, biased holes, and inclined holes, making it difficult to guarantee the quality of the piles. Therefore, there is an urgent need for an expanded hole pile foundation and its construction method suitable for shallow cover, high-strength inclined bare rock areas to improve construction efficiency and quality and ensure the safety and reliability of the project. Summary of the invention

[0003] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a shallow-cover high-strength inclined bare rock enlarged pile foundation and a construction method.

[0004] The construction system of this shallow-cover high-strength inclined bare rock expanded hole pile foundation includes: a shallow-cover inclined rock surface pouring concrete leveling system, a retractable and lowerable rotary drilling roller barrel drill structure and a new combined slag removal barrel structure; the new combined slag removal barrel structure includes a top integral hoisting structure and a bottom semi-movable tongue-and-groove connected steel plate closing structure; there is a shallow covering layer on the large undulating inclined rock surface; the shallow-cover inclined rock surface pouring concrete leveling system includes a supporting steel frame, a rotary drilling rig, a poured concrete outer steel enclosure and a connecting rod; a rotary drilling rig is arranged above the preset position of the shallow covering layer pile foundation; a poured concrete outer steel enclosure is arranged on the inner wall of the pile foundation, the poured concrete outer steel enclosure is connected to a connecting rod, and the other end of the connecting rod is connected to the supporting steel frame; the bottom of the supporting steel frame is inserted into the large undulating inclined rock surface; concrete is poured in the pile foundation; the rotary drilling rig is connected to a retractable and lowerable rotary drilling roller barrel drill structure, and the retractable and lowerable rotary drilling roller barrel drill structure includes a three-stage roller barrel drill; the new combined slag removal barrel structure includes a steel pipe.

[0005] Preferably, the shallow covered inclined rock surface pouring concrete leveling system comprises a rotary drilling rig; the greatly undulating inclined rock surface is provided with an upslope surface and a downslope surface; supporting steel frames with pile tips are respectively driven around the preset position of the pile foundation, the rotary drilling rig is connected to the rotary drilling rig, the side wall of the outer steel enclosure of the poured concrete facing the downslope surface is connected with a connecting cross bar, the other end of the connecting cross bar is connected to the supporting steel frame, a first connecting vertical bar is connected between the connecting cross bars, the side wall of the outer steel enclosure of the poured concrete facing the upslope surface is connected with a connecting diagonal bar, the other end of the connecting diagonal bar is connected to the supporting steel frame, and a second connecting vertical bar is connected between the connecting diagonal bars.

[0006] Preferably, the retractable and lowerable rotary drilling cone barrel drill structure includes a retractable connecting shaft; the three-stage cone barrel drill includes a first-stage cone barrel drill, a second-stage cone barrel drill, and a third-stage cone barrel drill; the top of the third-stage cone barrel drill is connected to the rotary drilling rig, and the inner side of the third-stage cone barrel drill is connected to the second-stage cone barrel drill and the first-stage cone barrel drill through a retractable connecting shaft; the diameters of the first-stage cone barrel drill, the second-stage cone barrel drill, and the third-stage cone barrel drill increase in sequence.

[0007] Preferably, the top integral hoisting structure includes a steel pipe; a plurality of stiffening ribs are evenly welded on the outer side of the steel pipe, a steel pipe top edge protection is provided at the top of the steel pipe, connecting steel plates are evenly distributed on the inner wall top of the steel pipe, and the other ends of the connecting steel plates are connected with connecting steel pipe columns; the connecting steel plates are provided with first hoisting holes, and adjacent first hoisting holes are penetrated by a first steel wire rope; the bottom of the connecting steel pipe column is connected with a first steel plate, the top of the connecting steel pipe column is connected with a second steel plate, a short column is connected to the top of the second steel plate, a second hoisting hole is arranged in the short column, the second hoisting hole is penetrated by a second steel wire rope, the second steel wire rope hangs the first steel wire rope, and the second steel wire rope is connected with a truck crane.

[0008] Preferably, the bottom semi-mobile tongue-and-groove connection steel plate closing structure includes an annular fixed steel plate; the annular fixed steel plate is welded on the inner side of the bottom of the steel pipe, the annular fixed steel plate is connected with an annular connecting shaft, the connecting movable steel plate is connected with the annular fixed steel plate through the annular connecting shaft, and tongue-and-groove connections are arranged on the opposite surfaces of adjacent movable steel plates.

[0009] The construction method of this shallow overburden high-strength inclined bare rock reaming pile foundation includes the following steps:

[0010] Step 1: Drilling the overburden construction: Support steel frames are respectively driven around the preset position of the pile foundation, and a hole is drilled to the large-undulation inclined rock surface at the preset position of the pile foundation through a rotary drilling rig.

[0011] Step 2: Hole cleaning construction: Hole cleaning construction is carried out on the shallow overburden layer of the part that has not been drilled into a hole under the large-undulation inclined rock surface.

[0012] Step 3: Installation of the steel enclosure outside the poured concrete construction: A steel enclosure outside the poured concrete is arranged on the side wall of the pile foundation, and both sides of the steel enclosure outside the poured concrete are connected and strengthened and fixed through the arranged connecting rods and support steel frames.

[0013] Step 4: Pouring the flat concrete construction: After the installation construction of the steel enclosure outside the poured concrete is completed, concrete is poured into the steel enclosure outside the poured concrete to a predetermined height through a conduit.

[0014] Step 5. Construction of shallow-covered high-strength inclined bare rock reaming: Connect the retractable lowering type rotary drilling cone barrel drill structure to the rotary drilling rig, and adjust the three-stage cone barrel drill in sequence through the retractable lowering type rotary drilling cone barrel drill structure to achieve the cyclic reaming of the first-stage reaming, second-stage reaming, and third-stage reaming of the shallow-covered high-strength inclined bare rock, and complete the construction of the shallow-covered high-strength inclined bare rock reaming;

[0015] Step 6. Sludge removal construction: When constructing the reaming of the shallow-covered high-strength inclined bare rock, in case of fractured rock geology in the underwater part, it is necessary to use a new type of combined sludge removal barrel for sludge removal construction.

[0016] Preferably, in Step 5, the retractable lowering type rotary drilling cone barrel drill structure includes a retractable connecting shaft, and the three-stage cone barrel drill includes a first-stage cone barrel drill, a second-stage cone barrel drill, and a third-stage cone barrel drill; a retractable connecting shaft is arranged inside the third-stage cone barrel drill, and the retractable connecting shaft connects the second-stage cone barrel drill and the first-stage cone barrel drill; the first-stage cone barrel drill is adjusted by controlling the retractable connecting shaft to achieve the first-stage reaming of the shallow-covered high-strength inclined bare rock, then the second-stage cone barrel drill is adjusted by controlling the retractable connecting shaft to achieve the second-stage reaming of the shallow-covered high-strength inclined bare rock, and then the third-stage cone barrel drill is adjusted by controlling the retractable connecting shaft to achieve the third-stage reaming of the shallow-covered high-strength inclined bare rock.

[0017] Preferably, in Step 6, the top integral lifting structure includes a steel pipe; a connecting steel plate is arranged on the inner wall of the steel pipe, the connecting steel plate is connected with a connecting steel pipe column, a first lifting hole is opened in the connecting steel plate, and a first steel wire rope passes through the first lifting hole; the bottom of the connecting steel pipe column is connected with a first steel plate, and the top is connected with a second steel plate; a short column is connected to the top of the second steel plate, a second lifting hole is arranged in the short column, a second steel wire rope passes through the second lifting hole, the second steel wire rope suspends the first steel wire rope, and the second steel wire rope is connected with a truck crane. Hoist the steel pipe directly above the pile foundation, then pass the second steel wire rope through the second lifting hole, connect the second steel wire rope with the truck crane, lift the steel pipe, and remove the other two second steel wire ropes, then lower the steel pipe; Bottom semi-mobile tongue-and-groove connection steel plate closed structure: Weld an annular fixed steel plate on the inner side of the bottom of the steel pipe, the annular fixed steel plate is connected with a movable steel plate through an annular connecting shaft, and the movable steel plate is connected through a tongue-and-groove. Through the top integral lifting structure and the bottom semi-mobile tongue-and-groove connection steel plate closed structure, sink into the mud by its own weight. When the mud and slag flow into the steel pipe, lift the movable steel plate upward, and use the flowing mud and slag to block the steel pipe, so that the mud and slag can be pulled out.

[0018] The beneficial effects of the present invention are:

[0019] 1) In view of the problem that it is difficult to discharge slurry and remove slag during the construction of pile foundations when the underwater part of the pile encounters fractured rock geology, the present invention adopts a new type of combined slag bucket (steel pipe) structure. Through the integral hoisting structure at the top and the semi-mobile tongue-and-groove connection steel plate sealing structure at the bottom, it sinks into the slurry by its own weight. After the mud and slag flow into the barrel (steel pipe), the movable steel plate is lifted upward, and the barrel is blocked by the flowing-in mud and slag, so that the mud and slag can be pulled out, effectively solving the problem of slag discharge, with obvious hole-bottom cleaning effect and greatly improving work efficiency.

[0020] 2) For the rotary drilling to form a hole in a large-undulation inclined rock surface, the present invention adopts a concrete leveling system for pouring in a shallow-covered inclined rock surface. By using a supporting steel frame with a pile tip to fix the steel retaining wall outside the poured concrete, a flat rock mass is formed after the inclined rock surface is combined with the concrete, effectively solving the problem of the depth of the rotary drilling hole formation, effectively avoiding problems such as over-standard hole expansion, deviation hole formation, and inclined hole formation, and being beneficial to controlling the fullness coefficient of the pile foundation concrete pouring.

[0021] 3) The present invention uses a retractable and lowerable rotary drilling roller bit barrel drill structure for the construction of hole expansion in a shallow-covered high-strength inclined bare rock. Through multiple cycles of primary hole expansion, secondary hole expansion, and tertiary hole expansion, the construction of hole expansion in a shallow-covered high-strength inclined bare rock is completed, which can accurately ensure the drilling verticality, reduce the risk of deviation holes, avoid frequent hole correction, greatly improve the hole formation quality and stability, and enhance the bearing capacity of the pile foundation. Description of the Drawings

[0022] Figure 1 It is a schematic diagram of the new type of combined slag bucket structure;

[0023] Figure 2 It is a schematic diagram of the semi-mobile tongue-and-groove connection steel plate sealing structure at the bottom;

[0024] Figure 3 It is a schematic diagram of the hoisting system of the new type of combined slag bucket;

[0025] Figure 4 It is a schematic diagram of the structure of a large-undulation inclined rock surface in a shallow overburden layer;

[0026] Figure 5 It is a schematic diagram of the rotary drilling to form a hole to a large-undulation inclined rock surface;

[0027] Figure 6 It is a schematic diagram of the hole cleaning structure;

[0028] Figure 7 It is a schematic diagram of the concrete pouring and leveling structure for a shallow-covered inclined rock surface;

[0029] Figure 8 It is a schematic diagram of the retractable and lowerable rotary drilling roller bit barrel drill structure;

[0030] Figure 9 It is a schematic diagram of the structure after the primary hole expansion is completed;

[0031] Figure 10 It is a schematic diagram of the completed structure of the secondary reaming;

[0032] Figure 11 It is a schematic diagram of the completed structure of the tertiary reaming.

[0033] Description of the reference numerals in the drawings: 1 - steel pipe, 2 - stiffening rib, 3 - edge protection at the top of the steel pipe, 4 - connecting steel plate, 5 - connecting steel pipe column, 6 - first lifting hole, 7 - first steel wire rope, 8 - first steel plate, 9 - second steel plate, 10 - short column, 11 - second lifting hole, 12 - annular fixing steel plate, 13 - annular connecting shaft, 14 - movable steel plate, 15 - rabbet joint, 16 - second steel wire rope, 17 - truck crane, 18 - shallow overburden layer, 19 - large undulating inclined rock surface, 20 - rotary drilling rig, 21 - rotary bucket drill, 22 - supporting steel framework, 23 - steel retaining wall on the outside of the cast-in-place concrete, 24 - connecting cross bar, 25 - first connecting vertical bar, 26 - connecting diagonal bar, 27 - second connecting vertical bar, 28 - concrete, 29 - first-stage roller cone drill, 30 - second-stage roller cone drill, 31 - third-stage roller cone drill, 32 - telescopic connecting shaft. Detailed implementation manners

[0034] The present invention will be further described below in conjunction with embodiments. The description of the following embodiments is only for helping to understand the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several modifications can still be made to the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

[0035] Embodiment 1

[0036] As an embodiment, a construction system for a shallow overburden high-strength inclined bare rock reaming pile foundation is proposed. As Figures 1 to 11 shown, it includes a new combined slag cleaning barrel structure, a shallow overburden inclined rock surface cast-in-place concrete leveling system, and a telescopic lowering rotary roller cone drill structure;

[0037] The new combined slag cleaning barrel structure is characterized in that it includes: an overall lifting structure at the top and a semi-movable rabbet joint connecting steel plate closing structure at the bottom;

[0038] The described top integral hoisting structure is characterized by comprising: a steel pipe 1, stiffening ribs 2, a steel pipe top edge guard 3, connecting steel plates 4, a connecting steel pipe column 5, a first hoisting hole 6, a first steel wire rope 7, a first steel plate 8, a second steel plate 9, a short column 10, a second hoisting hole 11, a second steel wire rope 16, and a truck crane 17. A plurality of stiffening ribs 2 are evenly welded on the outer side of the steel pipe 1. A steel pipe top edge guard 3 is made at the top of the steel pipe 1. The connecting steel pipe column 5 is connected by four evenly distributed connecting steel plates 4. First hoisting holes 6 are respectively formed in the connecting steel plates 4. The four first hoisting holes 6 on the four connecting steel plates 4 are connected in series by a first steel wire rope 7. The lower part of the connecting steel pipe column 5 is connected to the first steel plate 8, and the upper part of the connecting steel pipe column 5 is connected to the second steel plate 9. A short column 10 is connected to the second steel plate 9. A second hoisting hole 11 is formed in the short column 10. The first steel wire rope 7 is hoisted by symmetrically two second steel wire ropes 16. The second steel wire ropes 16 are connected to the truck crane 17 at the upper part. The steel pipe 1 is hoisted to directly above the fractured rock geological pile foundation, and then one second steel wire rope 16 is passed through the second hoisting hole 11. The second steel wire rope 16 is connected to the truck crane 17 at the upper part to hoist the steel pipe 1, and the other two second steel wire ropes 16 are removed, and then the steel pipe 1 is lowered;

[0039] The described bottom semi - movable tongue - and - groove connecting steel plate closing structure is characterized by comprising: a steel pipe 1, an annular fixed steel plate 12, a connecting shaft 13, a movable steel plate 14, and a tongue - and - groove 15. The annular fixed steel plate 12 is welded on the inner side of the bottom of the steel pipe 1. The annular fixed steel plate 12 is connected to the movable steel plate 14 through an annular connecting shaft 13. The movable steel plate 14 is connected through the tongue - and - groove 15.

[0040] As Figures 4 to 7 As shown, the described shallow - covered inclined rock surface concrete pouring and leveling system comprises a rotary bucket drill 21; the large - undulation inclined rock surface 19 has an uphill surface and a downhill surface; around the preset position of the pile foundation, support steel frames 22 with pile tips are respectively driven. The rotary bucket drill 21 is connected to a rotary drilling rig 20. A connecting cross bar 24 is connected to the side wall of the outer steel enclosure 23 for concrete pouring facing the downhill surface and is connected to the support steel frame 22 at the other end. A first connecting vertical bar 25 is connected between the connecting cross bars 24. A connecting diagonal bar 26 is connected to the side wall of the outer steel enclosure 23 for concrete pouring facing the uphill surface and is connected to the support steel frame 22 at the other end. A second connecting vertical bar 27 is connected between the connecting diagonal bars 26.

[0041] As Figures 8 to 11As shown in the figure, the retractable downhole rotary roller bit barrel drill structure is characterized by comprising a rotary drilling rig 20, a first-stage roller bit barrel drill 29, a second-stage roller bit barrel drill 30, a third-stage roller bit barrel drill 31, and a telescopic connecting shaft 32. The third-stage roller bit barrel drill 31 is connected to the rotary drilling rig 20 above, and the inner side of the third-stage roller bit barrel drill 31 is connected to the second-stage roller bit barrel drill 30 and the first-stage roller bit barrel drill 29 through the telescopic connecting shaft 32. By controlling the telescopic connecting shaft 32, the first-stage roller bit barrel drill 29 is adjusted to achieve the first-stage reaming of shallow-covered high-strength inclined bare rock, then by controlling the telescopic connecting shaft 32, the second-stage roller bit barrel drill 30 is adjusted to achieve the second-stage reaming of shallow-covered high-strength inclined bare rock, and then by controlling the telescopic connecting shaft 32, the third-stage roller bit barrel drill 31 is adjusted to achieve the third-stage reaming of shallow-covered high-strength inclined bare rock. Through multiple cycles of first-stage reaming, second-stage reaming, and third-stage reaming, the reaming construction of shallow-covered high-strength inclined bare rock is completed.

[0042] As Figure 1 shown in the figure, the top integral hoisting structure includes a steel pipe 1; a plurality of stiffening ribs 2 are evenly welded on the outer side of the steel pipe 1, a steel pipe top edge protection 3 is provided at the top of the steel pipe 1, connecting steel plates 4 are evenly distributed on the inner wall top of the steel pipe 1, and the other ends of the connecting steel plates 4 are connected to connecting steel pipe columns 5; first hoisting holes 6 are formed in the connecting steel plates 4, and first steel wire ropes 7 penetrate through adjacent first hoisting holes 6; a first steel plate 8 is connected to the bottom of the connecting steel pipe column 5, a second steel plate 9 is connected to the top of the connecting steel pipe column 5, a short column 10 is connected to the top of the second steel plate 9, a second hoisting hole 11 is formed in the short column 10, a second steel wire rope 16 penetrates through the second hoisting hole 11, the second steel wire rope 16 suspends the first steel wire rope 7, and the second steel wire rope 16 is connected to a truck crane 17.

[0043] The bottom semi-mobile tongue-and-groove connection steel plate closing structure includes an annular fixed steel plate 12;

[0044] The annular fixed steel plate 12 is welded to the inner side of the bottom of the steel pipe 1, the annular fixed steel plate 12 is connected to an annular connecting shaft 13, a connecting movable steel plate 14 is connected to the annular fixed steel plate 12 through the annular connecting shaft 13, and tongue-and-groove 15 connections are provided on the opposite surfaces of adjacent movable steel plates 14.

[0045] Embodiment 2

[0046] As another embodiment, this Embodiment 2 is proposed on the basis of Embodiment 1, and a more specific construction system for a pile foundation with reaming of shallow-covered high-strength inclined bare rock, as Figures 1 to 11As shown in the figure, it includes a concrete leveling system for pouring on a shallowly covered inclined rock surface, a retractable and lowerable rotary bucket drill with roller bits structure, and a new combined slag bucket structure; the new combined slag bucket structure includes an integral lifting structure at the top and a semi-mobile rabbet connection steel plate sealing structure at the bottom; there is a shallow overburden layer 18 on the large-undulation inclined rock surface 19; the concrete leveling system for pouring on a shallowly covered inclined rock surface includes a supporting steel frame 22, a rotary drilling rig 20, a steel retaining wall 23 outside the poured concrete, and a connecting rod; a rotary drilling rig 20 is provided above the preset position of the pile foundation in the shallow overburden layer 18; a steel retaining wall 23 outside the poured concrete is provided on the inner wall of the pile foundation, the steel retaining wall 23 outside the poured concrete is connected with a connecting rod, and the other end of the connecting rod is connected with a supporting steel frame 22; the bottom of the supporting steel frame 22 is inserted into the large-undulation inclined rock surface 19; concrete 28 is poured into the pile foundation; the rotary drilling rig 20 is connected with a retractable and lowerable rotary bucket drill with roller bits structure, and the retractable and lowerable rotary bucket drill with roller bits structure includes a three-stage roller bit bucket drill; the new combined slag bucket structure includes a steel pipe 1.

[0047] As Figures 4 to 7 As shown in the figure, the concrete leveling system for pouring on a shallowly covered inclined rock surface is characterized by including: a shallow overburden layer 18, a large-undulation inclined rock surface 19, a rotary drilling rig 20, a rotary bucket drill 21, a supporting steel frame 22 with a pile tip, a steel retaining wall 23 outside the poured concrete, a connecting cross bar 24, a first connecting vertical bar 25, a connecting diagonal bar 26, a second connecting vertical bar 27, and concrete 28. There is a shallow overburden layer 18 on the large-undulation inclined rock surface 19. Supporting steel frames 22 with pile tips are driven around the preset position of the pile foundation. The rotary bucket drill 21 connected by the rotary drilling rig 20 is used to drill a hole to the large-undulation inclined rock surface 19. The shallow overburden layer 18 of the part that has not been drilled into a hole at the lower part of the large-undulation inclined rock surface 19 is subjected to manual or small mechanical hole cleaning construction. The steel retaining wall 23 outside the poured concrete is installed. The lower side of the steel retaining wall 23 outside the poured concrete is fixedly connected with the supporting steel frame 22 with a pile tip through the connecting cross bar 24 and the first connecting vertical bar 25, and the upper side of the steel retaining wall 23 outside the poured concrete is fixedly connected with the supporting steel frame 22 with a pile tip through the connecting diagonal bar 26 and the second connecting vertical bar 27. Then, concrete 28 is poured through a conduit to a predetermined height.

[0048] As Figures 8 to 11 As shown in the figure, the retractable and lowerable rotary bucket drill with roller bits structure includes a telescopic connecting shaft 32; the three-stage roller bit bucket drill includes a first-stage roller bit bucket drill 29, a second-stage roller bit bucket drill 30, and a third-stage roller bit bucket drill 31; the top of the third-stage roller bit bucket drill 31 is connected to the rotary drilling rig 20, and the second-stage roller bit bucket drill 30 and the first-stage roller bit bucket drill 29 are connected to the inside of the third-stage roller bit bucket drill 31 through the telescopic connecting shaft 32; the diameters of the first-stage roller bit bucket drill 29, the second-stage roller bit bucket drill 30, and the third-stage roller bit bucket drill 31 increase in sequence.

[0049] It should be noted that the parts that are the same as or similar to those in the first embodiment in this embodiment can be referred to each other and will not be elaborated in this application.

[0050] Embodiment III

[0051] As another embodiment, this embodiment III is proposed on the basis of Embodiment II. A construction method for a shallow - covered high - strength inclined bare - rock reamed pile foundation using a construction system for a shallow - covered high - strength inclined bare - rock reamed pile foundation is as Figures 1 to 11 shown, and includes the following steps:

[0052] Step 1: Drilling construction in the overburden layer: Support steel frames 22 are respectively driven around the preset position of the pile foundation, and a hole is drilled to the large - undulation inclined rock surface 19 at the preset position of the pile foundation by a rotary drilling rig 20.

[0053] Step 2: Hole - cleaning construction: Hole - cleaning construction is carried out on the shallow overburden layer 18 of the part that is not drilled into a hole under the large - undulation inclined rock surface 19.

[0054] Step 3: Construction of installing the outer steel retaining wall for pouring concrete: An outer steel retaining wall 23 for pouring concrete is arranged on the side wall of the pile foundation, and both sides of the outer steel retaining wall 23 for pouring concrete are connected and strengthened and fixed to the support steel frame 22 by setting connecting rods.

[0055] Step 4: Construction of pouring leveling concrete: After the installation construction of the outer steel retaining wall 23 for pouring concrete is completed, concrete 28 is poured into the outer steel retaining wall 23 for pouring concrete through a conduit to a predetermined height.

[0056] Step 5: Shallow - covered high - strength inclined bare - rock reaming construction: The retractable and lowerable rotary drag bit barrel drill structure is connected to the rotary drilling rig 20, and the three - stage drag bit barrel drill is adjusted in sequence through the retractable and lowerable rotary drag bit barrel drill structure to realize the first - stage reaming, second - stage reaming, and third - stage reaming cycle reaming of the shallow - covered high - strength inclined bare rock, and the shallow - covered high - strength inclined bare - rock reaming construction is completed.

[0057] Step 6: Sludge - cleaning construction: When carrying out the shallow - covered high - strength inclined bare - rock reaming construction, when encountering fractured rock geology in the underwater part, a new type of combined sludge - cleaning barrel is required for sludge - cleaning construction.

[0058] In Step 3, the lower side of the outer steel retaining wall 23 for pouring concrete is fixedly connected and strengthened to the support steel frame 22 with a pile tip through a connecting cross - bar 24 and a first connecting vertical bar 25, and the upper side of the outer steel retaining wall 23 for pouring concrete is fixedly connected and strengthened to the support steel frame 22 with a pile tip through a connecting diagonal bar 26 and a second connecting vertical bar 27.

[0059] In Step 5, as Figures 8 to 11As shown in the figure, the third-stage cone barrel drill 31 is connected to the rotary drilling rig 20 above. The inner side of the third-stage cone barrel drill 31 is connected to the second-stage cone barrel drill 30 and the first-stage cone barrel drill 29 through a telescopic connecting shaft 32. By controlling the telescopic connecting shaft 32, the first-stage cone barrel drill 29 is adjusted to achieve primary reaming of shallow-covered high-strength inclined bare rock. Then, by controlling the telescopic connecting shaft 32, the second-stage cone barrel drill 30 is adjusted to achieve secondary reaming of shallow-covered high-strength inclined bare rock. Then, by controlling the telescopic connecting shaft 32, the third-stage cone barrel drill 31 is adjusted to achieve tertiary reaming of shallow-covered high-strength inclined bare rock. And through multiple cycles of primary reaming, secondary reaming, and tertiary reaming, the construction of reaming for shallow-covered high-strength inclined bare rock is completed.

[0060] In step six, as Figures 1 to 3 shown, when reaming the inclined rock surface during drilling construction, if fissured rock geology is encountered in the underwater part, slag removal construction needs to be carried out: Use a new combined slag removal barrel for slag removal construction. The structure of the new combined slag removal barrel includes: a top integral lifting structure and a bottom semi-mobile rabbet-connected steel plate closed structure. Top integral lifting structure: A plurality of stiffening ribs 2 are evenly welded on the outer side of the steel pipe 1. A steel pipe top edge protection 3 is made at the top of the steel pipe 1. The connecting steel pipe column 5 is connected through four evenly distributed connecting steel plates 4. First lifting holes 6 are respectively opened on the four connecting steel plates 4. The four first lifting holes 6 on the four connecting steel plates 4 are connected in series through a first steel wire rope 7. The lower part of the connecting steel pipe column 5 is connected to the first steel plate 8, the upper part of the connecting steel pipe column 5 is connected to the second steel plate 9, a short column 10 is connected to the second steel plate 9, and a second lifting hole 11 is arranged in the short column 10. The first steel wire rope 7 is hoisted by symmetrically two second steel wire ropes 16. The second steel wire rope 16 is connected to the truck crane 17. The steel pipe 1 is hoisted to directly above the fissured rock geology pile foundation. Then, one second steel wire rope 16 is passed through the second lifting hole 11, the second steel wire rope 16 is connected to the truck crane 17 above, the steel pipe 1 is hoisted, and the other two second steel wire ropes 16 are removed. Then, the steel pipe 1 is lowered; Bottom semi-mobile rabbet-connected steel plate closed structure: An annular fixed steel plate 12 is welded on the inner side of the bottom of the steel pipe 1. The annular fixed steel plate 12 is connected to the movable steel plate 14 through an annular connecting shaft 13. The movable steel plate 14 is connected through a rabbet 15. Through the top integral lifting structure and the bottom semi-mobile rabbet-connected steel plate closed structure, it sinks into the mud by its own weight. When the mud and slag flow into the steel pipe 1, the movable steel plate 14 is jacked up, and the steel pipe 1 is blocked by the flowing mud and slag, so that the mud and slag are pulled out.

[0061] It should be noted that the same or similar parts in this embodiment and Embodiment 2 can be referred to each other, and will not be elaborated in this application.

[0062] In this specification, each embodiment is described in a progressive manner. The key points of each embodiment are the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other.

Claims

1. A construction system for shallow-cover high-strength inclined bare rock expanded pile foundation, characterized in that: include: A shallow covering inclined rock surface pouring concrete leveling system, a retractable lowering rotary drilling cone drill structure and a new combined slag removal barrel structure; the new combined slag removal barrel structure includes a top integral hoisting structure and a bottom semi-movable tongue-and-groove connected steel plate enclosed structure; there is a shallow covering layer on the large undulating inclined rock surface; The shallow covering inclined rock surface pouring concrete leveling system comprises a supporting steel frame, a rotary drilling rig, a poured concrete outer steel enclosure and a connecting rod; a rotary drilling rig is arranged above the preset position of the shallow covering layer pile foundation; an poured concrete outer steel enclosure is arranged on the inner wall of the pile foundation, the poured concrete outer steel enclosure is connected with a connecting rod, and the other end of the connecting rod is connected to the supporting steel frame; the bottom of the supporting steel frame is inserted into the undulating inclined rock surface; concrete is poured in the pile foundation; the rotary drilling rig is connected with a retractable lowering type rotary drilling tricone barrel drill structure, and the retractable lowering type rotary drilling tricone barrel drill structure comprises a three-stage rotary drilling tricone barrel drill; the new combined slag removal barrel structure comprises a steel pipe.

2. The construction system of shallow-cover high-strength inclined bare rock expanded pile foundation according to claim 1 is characterized in that: The shallow covered inclined rock surface pouring concrete leveling system comprises a rotary drilling auger; the greatly undulating inclined rock surface is provided with an upslope surface and a downslope surface; supporting steel frames with pile tips are respectively driven around the preset positions of the pile foundation, the rotary drilling auger is connected to the rotary drilling rig, the side wall of the outer steel enclosure of the poured concrete facing the downslope surface is connected with a connecting cross bar, the other end of the connecting cross bar is connected to the supporting steel frame, the first connecting vertical bar is connected between the connecting cross bars, the side wall of the outer steel enclosure of the poured concrete facing the upslope surface is connected with a connecting diagonal bar, the other end of the connecting diagonal bar is connected to the supporting steel frame, and the second connecting vertical bar is connected between the connecting diagonal bars.

3. The construction system of shallow-cover high-strength inclined bare rock expanded-hole pile foundation according to claim 1 is characterized in that: The telescopic lowerable rotary drilling roller barrel drill structure comprises a telescopic connecting shaft; the three-stage roller barrel drill comprises a first-stage roller barrel drill, a second-stage roller barrel drill and a third-stage roller barrel drill; the top of the third-stage roller barrel drill is connected to the rotary drilling rig, and the inner side of the third-stage roller barrel drill is connected to the second-stage roller barrel drill and the first-stage roller barrel drill through a telescopic connecting shaft; the diameters of the first-stage roller barrel drill, the second-stage roller barrel drill and the third-stage roller barrel drill increase in sequence.

4. The construction system of shallow-cover high-strength inclined bare rock expanded-hole pile foundation according to claim 1 is characterized in that: The top integral lifting structure includes a steel pipe; a plurality of stiffening ribs are evenly welded on the outside of the steel pipe, a steel pipe top edge guard is provided on the top of the steel pipe, connecting steel plates are evenly distributed on the top of the inner wall of the steel pipe, and the other end of the connecting steel plate is connected to a connecting steel pipe column; the connecting steel plate is provided with a first lifting hole, and a first steel wire rope is passed through the adjacent first lifting hole; the bottom of the connecting steel pipe column is connected to the first steel plate, the top of the connecting steel pipe column is connected to the second steel plate, the top of the second steel plate is connected to a short column, the short column has a second lifting hole, the second lifting hole passes through the second steel wire rope, the second steel wire rope hangs the first steel wire rope, and the second steel wire rope is connected to a car crane.

5. The construction system of shallow-cover high-strength inclined bare rock expanded pile foundation according to claim 1 is characterized in that: The bottom semi-movable tongue-and-groove connected steel plate closed structure includes an annular fixed steel plate; the annular fixed steel plate is welded to the inner side of the bottom of the steel pipe, the annular fixed steel plate is connected with an annular connecting shaft, the connecting movable steel plate is connected to the annular fixed steel plate through the annular connecting shaft, and the opposite surfaces of adjacent movable steel plates are provided with tongue-and-groove connections.

6. A method for constructing a shallow-covered high-strength inclined bare-rock expanded-hole pile foundation using the construction system for the shallow-covered high-strength inclined bare-rock expanded-hole pile foundation according to claim 1, characterized in that: The following steps are involved: Step 1: Drilling the overburden: Set up supporting steel frames around the preset position of the pile foundation, and use a rotary drilling rig to drill holes to the large undulating and inclined rock surface at the preset position of the pile foundation; Step 2: Hole cleaning: Hole cleaning is carried out in the shallow overburden layer of the lower part of the rock surface with large fluctuations and inclinations where no hole has been drilled; Step 3: Installation of cast concrete outer steel enclosure: Cast concrete outer steel enclosure is installed on the side wall of the pile foundation, and the two sides of the cast concrete outer steel enclosure are connected by connecting rods and supporting steel frames for reinforcement and fixation; Step 4: pouring and leveling concrete construction: After the installation and construction of the outer steel enclosure of the pouring concrete is completed, pour concrete to a predetermined height through a conduit in the outer steel enclosure of the pouring concrete; Step 5: Shallow-cover high-strength inclined bare rock hole expansion construction: connect the retractable lowering rotary drilling cone barrel drill structure to the rotary drilling rig, and adjust the three-stage cone barrel drill in sequence through the retractable lowering rotary drilling cone barrel drill structure to realize the shallow-cover high-strength inclined bare rock hole expansion of the first-stage hole expansion, the second-stage hole expansion and the third-stage hole expansion cycle, and complete the shallow-cover high-strength inclined bare rock hole expansion construction; Step 6: Slag removal construction: When shallow-cover high-strength inclined bare rock hole expansion construction is carried out, if fractured rock geology is encountered in the underwater part, a new type of combined slag removal barrel is required for slag removal construction.

7. The construction method of shallow-cover high-strength inclined bare rock expanded pile foundation according to claim 6, characterized in that: In step five, the retractable lowerable rotary drilling roller drill structure includes a retractable connecting shaft, and the three-stage roller drill includes a first-stage roller drill, a second-stage roller drill and a third-stage roller drill; a retractable connecting shaft is provided on the inner side of the third-stage roller drill, and the retractable connecting shaft connects the second-stage roller drill and the first-stage roller drill; the first-stage roller drill is adjusted by controlling the retractable connecting shaft to realize the first-level hole expansion of shallow coverage and high-strength inclined bare rock, and then the second-stage roller drill is adjusted by controlling the retractable connecting shaft to realize the second-level hole expansion of shallow coverage and high-strength inclined bare rock, and then the third-stage roller drill is adjusted by controlling the retractable connecting shaft to realize the tertiary hole expansion of shallow coverage and high-strength inclined bare rock.

8. The construction method of shallow-cover high-strength inclined bare rock expanded-hole pile foundation according to claim 6, characterized in that: In step six, the top integral hoisting structure includes a steel pipe; a connecting steel plate is provided on the inner wall of the steel pipe, the connecting steel plate is connected to a connecting steel pipe column, the connecting steel plate is provided with a first hoisting hole, the first hoisting hole is penetrated by a first steel wire rope; the bottom of the connecting steel pipe column is connected to the first steel plate, and the top is connected to the second steel plate; the top of the second steel plate is connected to a short column, the short column has a second hoisting hole, the second hoisting hole is penetrated by a second steel wire rope, the second steel wire rope suspends the first steel wire rope, and the second steel wire rope is connected to a car crane. The steel pipe is hoisted to the top of the pile foundation, and then the second steel wire rope is passed through the second hoisting hole, the second steel wire rope is connected to the car crane, the steel pipe is hoisted, and the other two second steel wire ropes are removed, and then the steel pipe is lowered; the bottom semi-movable tongue-and-groove connecting steel plate closed structure: an annular fixed steel plate is welded on the inner side of the bottom of the steel pipe, the annular fixed steel plate is connected to the movable steel plate through an annular connecting shaft, and the movable steel plate is connected through a tongue-and-groove connection. Through the top integral lifting structure and the bottom semi-movable tongue-and-groove connected steel plate closed structure, it sinks into the mud by its own weight. When the mud residue flows into the steel pipe, the movable steel plate is pushed upward, and the steel pipe is blocked by the flowing mud residue, so that the mud residue can be pulled out.

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