CN111535307A - Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum - Google Patents
Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum Download PDFInfo
- Publication number
- CN111535307A CN111535307A CN202010439059.6A CN202010439059A CN111535307A CN 111535307 A CN111535307 A CN 111535307A CN 202010439059 A CN202010439059 A CN 202010439059A CN 111535307 A CN111535307 A CN 111535307A
- Authority
- CN
- China
- Prior art keywords
- drilling
- hole
- drill bit
- pile
- reef
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
- E02D5/38—Concrete or concrete-like piles cast in position ; Apparatus for making same making by use of mould-pipes or other moulds
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D13/00—Accessories for placing or removing piles or bulkheads, e.g. noise attenuating chambers
- E02D13/04—Guide devices; Guide frames
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D7/00—Methods or apparatus for placing sheet pile bulkheads, piles, mouldpipes, or other moulds
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A40/00—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production
- Y02A40/80—Adaptation technologies in agriculture, forestry, livestock or agroalimentary production in fisheries management
- Y02A40/81—Aquaculture, e.g. of fish
Abstract
The invention provides a rotary drilling bored concrete pile hole forming construction method in a reef limestone stratum, and belongs to the technical field of municipal bridge engineering construction. According to the method, the protective cylinder guide frame is installed firstly in combination with the engineering geological characteristics of the reef limestone, a seabed hard layer of the reef limestone is drilled, then the bottom sealing concrete is poured, the protective cylinder is placed, and a special anti-inclined drill bit is adopted for drilling, so that the verticality of the drilled hole can be improved, the condition that the formed hole is inclined is avoided, and the drill hole is alternatively matched by the cylindrical drill and the anti-inclined drill bit in the drilling process, so that a series of construction problems of difficult embedding of the protective cylinder, poor hole forming verticality, hole collapse, serious liquid level leakage in the hole, poor hole cleaning effect and the like in the construction process are solved, and a good effect is achieved.
Description
Technical Field
The invention relates to the technical field of municipal bridge engineering construction, in particular to a rotary drilling bored pile hole forming construction method in a reef limestone stratum.
Background
In recent years, the construction of large-span bridge projects such as river-crossing, sea-crossing and the like is developed at a rapid pace, bridge foundations generally adopt large-diameter super-long piles, and the construction process of a rotary drilling technology in the large-diameter super-long piles is generally applied. Factors influencing the hole forming of the rotary drilling bored pile are various and mainly comprise engineering geological conditions, equipment performance and the like. The reef limestone stratum is a skeleton reef which is formed by the conglutination and accumulation of calcareous remains, crustacean remains and calcareous algae of hermatypic coral and plays a supporting role, coral sand or biological weathering debris and the like are filled in reef gaps, and the engineering geological assembly which is obviously different from the conventional stratum is formed by long-time growth and consolidation. The reef limestone has engineering geological characteristics of small density, multiple pores, obvious variation in strength and the like due to uneven pores and cementation degree of substance particles, is influenced by the change of ecological environment of a coral reef growth region, has different regional attributes, is evolved by the deposition history environment and the deposition phase zone of the coral reef growth in the same reef island region, and has obvious differences in the structure, the granularity composition and the cementation degree of the coral reef. Due to the special properties of the reef limestone, the problems of hole collapse, hole inclination and the like are often encountered in the rotary drilling and hole forming process, the hole forming construction difficulty is high, and hidden dangers are brought to the engineering quality.
Disclosure of Invention
The invention aims to provide a hole forming construction method for a rotary drilling cast-in-place pile in a reef limestone stratum, which can solve a series of construction problems that a steel casing is difficult to accurately place, the hole forming verticality is poor, holes are easy to collapse, concrete oversteer is serious and the like under severe wave environments in the reef limestone stratum, and can ensure pile forming quality, shorten construction period and reduce engineering cost.
In order to achieve the above object, the present invention provides the following technical solutions:
the invention provides a rotary drilling bored concrete pile pore-forming construction method in a reef limestone stratum, which comprises the following steps:
(1) providing a rotary drilling rig, a crawler crane, an air compressor, a protective cylinder and auxiliary equipment;
(2) measuring a pile position at a position to be constructed, and determining the center of the pile position;
(3) positioning and fixing a pile casing guide frame in the center of the pile position;
(4) according to the pile position center, positioning the rotary drilling rig, adjusting the verticality of a drill rod of the rotary drilling rig, adjusting the drill bit center of the rotary drilling rig and the pile position center to be on the same axis, and drilling a reef-removing limestone seabed hard layer, wherein the deviation is less than or equal to 2 cm;
(5) in a low-level tide time period, placing a guide pipe in a drill hole obtained by drilling a reef-removing limestone seabed hard layer, enabling the guide pipe to be 300-500 mm away from the hole bottom, and pouring bottom sealing concrete;
(6) placing a pile casing on the bottom sealing concrete;
(7) drilling a reef limestone stratum by taking the protective cylinder as a reference, wherein a cylinder drill and an anti-inclined drill bit are alternately matched in the drilling process;
(8) sequentially carrying out primary hole cleaning and secondary hole cleaning on the formed holes obtained by drilling, and then carrying out concrete pouring to form piles;
the anti-deviation drill bit comprises a guide device and a pick drill bit, the guide device is a cylinder with openings at two ends, the lower part of the guide device is fixedly sleeved on the upper part of the pick drill bit and used for prolonging the length of a drill cylinder of the pick drill bit, the side wall of the guide device is provided with a plurality of water drainage holes, and the upper part of the pick drill bit is provided with a drill bit square opening.
Preferably, in the step (1), the diameter of the pile casing is 200-400 mm larger than the diameter of the pile;
in the step (3), the deviation between the center of the pile casing guide frame and the pile position is not more than 2 cm;
in step (4) bore the in-process of removing reef limestone seabed crust, adopt toper reamer bit to carry out the reaming, the diameter ratio of toper reamer bit protects the diameter of a section of thick bamboo and is big 300 ~ 400 mm.
Preferably, in the step (4), the drilling and reef-removing limestone seabed hard layer is carried out until the obtained drilling depth is 500mm below the required sinking depth of the pile casing.
Preferably, in the step (5), when the bottom sealing concrete is poured, the concrete is poured firstly until the depth of the conduit embedded with the concrete is not less than 1m, and then the concrete is poured to the original sea bed elevation.
Preferably, in the step (6), after the casing is placed on the bottom sealing concrete, the top opening of the casing is centered and adjusted and is firmly welded with the casing guide frame.
Preferably, in the step (7), before drilling the reef limestone stratum, clear water is firstly adopted to drill off the bottom sealing concrete in the pile casing until the reef limestone stratum is drilled, and the anti-inclination drill bit is replaced.
Preferably, in the step (7), in the process of drilling the reef limestone stratum, when the reef limestone stratum is drilled to a stratum which is easy to collapse, the wall protecting material is thrown into the hole to fill the hole.
Preferably, in the step (7), in the drilling process, after the rotary drilling rig moves and resets every time, the drill bit is centered and checked, and the perpendicularity of the formed hole is detected every time 10m of drilling is performed until the formed hole meets the design depth requirement.
Preferably, a closing-in chamfer is arranged at the top of the guide device; an upper reinforcing circular ring is fixedly arranged on the inner wall of the guide device at the lower end of the closing-in chamfer; a lower reinforcing ring is fixedly connected to the inner side wall of the lower part of the pilot device; a plurality of drill bits are welded on the inner wall of the lower end of the pilot device at equal angles in the circumferential direction.
Preferably, the pick drill bit is internally provided with a discharge switch lengthening compression rod, and the upper end of the discharge switch lengthening compression rod extends out of the pilot.
The invention provides a rotary drilling bored concrete pile pore-forming construction method in a reef limestone stratum, which comprises the following steps: (1) providing a rotary drilling rig, a crawler crane, an air compressor, a protective cylinder and auxiliary equipment; (2) measuring a pile position at a position to be constructed, and determining the center of the pile position; (3) positioning and fixing a pile casing guide frame in the center of the pile position; (4) according to the pile position center, positioning the rotary drilling rig, adjusting the verticality of a drill rod of the rotary drilling rig, adjusting the drill bit center of the rotary drilling rig and the pile position center to be on the same axis, and drilling a reef-removing limestone seabed hard layer, wherein the deviation is less than or equal to 2 cm; (5) in a low-level tide time period, placing a guide pipe in a drill hole obtained by drilling a reef-removing limestone seabed hard layer, enabling the guide pipe to be 300-500 mm away from the hole bottom, and pouring bottom sealing concrete; (6) placing a pile casing on the bottom sealing concrete; (7) drilling a reef limestone stratum by taking the protective cylinder as a reference, wherein a cylinder drill and an anti-inclined drill bit are alternately matched in the drilling process; (8) sequentially carrying out primary hole cleaning and secondary hole cleaning on the formed holes obtained by drilling, and then carrying out concrete pouring to form piles; the anti-deviation drill bit comprises a guide device and a pick drill bit, the guide device is a cylinder with openings at two ends, the lower part of the guide device is fixedly sleeved on the upper part of the pick drill bit and used for prolonging the length of a drill cylinder of the pick drill bit, the side wall of the guide device is provided with a plurality of water drainage holes, and the upper part of the pick drill bit is provided with a drill bit square opening.
According to the method, a protective cylinder guide frame is installed firstly in combination with engineering geological characteristics of the reef limestone, a reef limestone seabed hard layer is drilled, then bottom sealing concrete is poured, a protective cylinder is placed, a special anti-inclined drill bit is adopted for drilling, the verticality of the drilled hole (the verticality deviation of the formed hole is 0.3-0.8%) can be improved, the condition that the formed hole is inclined is avoided, and the drill bit and the anti-inclined drill bit are adopted for alternately matching drilling in the drilling process, so that a series of construction problems that the protective cylinder is difficult to embed, the verticality of the formed hole is poor, the hole collapses, the liquid level in the hole is serious, the hole cleaning effect is poor and the like in the construction process are solved, and a good effect is achieved.
Drawings
Fig. 1 is a schematic view of an anti-tilting bit structure for a rotary drilling rig according to the present invention, wherein: 1. the discharging switch lengthens the pressure lever; 2. closing and chamfering; 3. an upper reinforcing ring; 4. adding a stiffening plate; 5. a pilot; 6. a stiffening plate is arranged below; 7. a water drain hole; 8. a square opening of a drill bit; 9. a lower reinforcing ring; 10. a drill bit; 11. a pick bit.
Detailed Description
The invention provides a rotary drilling bored concrete pile pore-forming construction method in a reef limestone stratum, which comprises the following steps:
(1) providing a rotary drilling rig, a crawler crane, an air compressor, a protective cylinder and auxiliary equipment;
(2) measuring a pile position at a position to be constructed, and determining the center of the pile position;
(3) positioning and fixing a pile casing guide frame in the center of the pile position;
(4) according to the pile position center, positioning the rotary drilling rig, adjusting the verticality of a drill rod of the rotary drilling rig, adjusting the drill bit center of the rotary drilling rig and the pile position center to be on the same axis, and drilling a reef-removing limestone seabed hard layer, wherein the deviation is less than or equal to 2 cm;
(5) in a low-level tide time period, placing a guide pipe in a drill hole obtained by drilling a reef-removing limestone seabed hard layer, enabling the guide pipe to be 300-500 mm away from the hole bottom, and pouring bottom sealing concrete;
(6) placing a pile casing on the bottom sealing concrete;
(7) drilling a reef limestone stratum by taking the protective cylinder as a reference, wherein a cylinder drill and an anti-inclined drill bit are alternately matched in the drilling process;
(8) sequentially carrying out primary hole cleaning and secondary hole cleaning on the formed holes obtained by drilling, and then carrying out concrete pouring to form piles;
the anti-deviation drill bit comprises a guide device and a pick drill bit, the guide device is a cylinder with openings at two ends, the lower part of the guide device is fixedly sleeved on the upper part of the pick drill bit and used for prolonging the length of a drill cylinder of the pick drill bit, the side wall of the guide device is provided with a plurality of water drainage holes, and the upper part of the pick drill bit is provided with a drill bit square opening.
In the present invention, the required equipment is well known to those skilled in the art, and the types of the equipment are well known to those skilled in the art, unless otherwise specified.
The invention provides a rotary drilling rig, a crawler crane, an air compressor, a protective cylinder and auxiliary equipment. In the invention, the rotary drilling rig is preferably provided with a high-strength mechanical lock drill rod. In the embodiment of the invention, the rotary drilling rig is preferably a TR360D rotary drilling rig, the air compressor is preferably a BKDY-13.6/8 air compressor, and the crawler crane is preferably a QUY85 crawler crane.
The invention measures and puts the pile position at the position to be constructed and determines the center of the pile position. In the invention, the position to be constructed is preferably the surface of a reef limestone stratum or other surfaces which are uneven in hardness and contain large-dip-angle rock surfaces and are easy to deflect and collapse holes. The invention preferably uses a GPS or a total station instrument to measure and place four orthogonal angular points which pass through the center of the pile position on a steel platform, and draws a cross line to determine the center of the pile position.
After the pile position center is determined, the pile position center positioning and fixing device positions and fixes the pile casing guide frame. The protective cylinder guide frame is preferably manufactured by double-splicing and welding H-shaped steel, the length of a vertical guide section of the protective cylinder guide frame is not less than 3.5m, and the vertical guide section and the transverse limiting frame are preferably subjected to reinforcement welding through an H-shaped steel inclined strut. According to the invention, the pile casing guide frame is positioned by the crawler crane, so that the deviation between the center of the pile casing guide frame and the pile position is not more than 2cm, and then the steel plate is firmly welded on the steel platform.
After the pile casing guide frame is positioned and fixed, the rotary drilling rig is in place according to the pile position center, the verticality of a drill rod of the rotary drilling rig is adjusted, the drill bit center of the rotary drilling rig and the pile position center are adjusted to be on the same axis, the deviation is less than or equal to 2cm, and a reef and limestone seabed hard layer is drilled. In the process of drilling the reef-removing limestone seabed hard layer, a barrel drill with the diameter of 800mm is preferably used for drilling a positioning front guide hole at a pile position until the drill bit contacts the seabed and starts drilling and rotates slowly under light pressure, when the drill bit drills to the seabed hard layer for 3-5 m, the conical hole-expanding drill bit is replaced for hole-expanding drilling, the diameter of the conical hole-expanding drill bit is preferably 300-400 mm larger than that of the protective barrel, and the drilling speed is accelerated after 1/3 of the conical hole-expanding drill bit enters the stratum, so that the impact of sea waves on the drilling tool is reduced. The process of the light-pressure slow turning and the change process of the drilling speed are not specially limited, and the process can be adjusted according to actual requirements according to experience well known in the field. In the drilling process, the same-diameter cutting bit is preferably matched and used for slag fishing; the method carries out the drilling and removing of the reef limestone seabed hard layer until the obtained drilling depth reaches 500mm below the required sinking depth (or design requirement) of the casing.
After the reef-removing limestone seabed hard layer is drilled, in the low-level tide time period, a guide pipe is arranged in a drill hole obtained by drilling the reef-removing limestone seabed hard layer, the distance between the guide pipe and the hole bottom is 300-500 mm, and bottom sealing concrete is poured. The low level tide time period is not particularly limited in the present invention and may be determined according to experience well known in the art. According to the invention, the pipe clamp is preferably firmly welded on the steel platform, then the pipe is lowered in the drilled hole of the seabed hard layer according to the tidal condition at the low and flat tide time period, so that the distance between the pipe and the hole bottom is 300-500 mm, and concrete is poured. In the present invention, the concrete used for pouring the concrete is low-grade concrete, the low-grade concrete is not particularly limited in the present invention, and the concrete capable of sealing the casing can be any concrete, and in the embodiment of the present invention, the concrete is specifically C15 or C20 concrete. When the concrete is poured for the first time, the concrete is preferably poured through the guide pipe (assisted by a large hopper) until the depth of the concrete embedded in the guide pipe is not less than 1 m. After the primary pouring of concrete is completed, the invention preferably pours the concrete to the original sea bed elevation by adopting the conventional process. After the completion of the pouring, the large hopper and the guide pipe used for pouring are removed and cleaned. According to the invention, the lower part of the pile casing is sealed by pouring the bottom sealing concrete, so that the periphery of the lower part of the pile casing is wrapped by the concrete.
After the bottom sealing concrete is poured, the pile casing is placed on the bottom sealing concrete. The invention preferably selects the casing according to the pile diameter. According to the invention, the pile casing is preferably a steel pile casing, the diameter of the pile casing is preferably 200-400 mm larger than the diameter of the pile, the thickness and the length of the steel pile casing are preferably determined according to the structural strength of the pile casing in the using process and the actually required length requirement under the pile casing, and the steel pile casing can be ensured to be stable after entering a stable stratum; in an embodiment of the invention, the steel casing dimension is in particular phi 1800 x 16 mm. According to the surge period and the surge law, the crawler crane is preferably adopted to lift and adjust the vertical protection cylinder in advance, the protection cylinder is quickly placed in the bottom sealing concrete which is not initially set by utilizing the leveling time after the surge (the placing position can ensure that the protection cylinder can be fixed in the concrete and can meet the fixing effect of the concrete on the protection cylinder), then the top opening of the protection cylinder is aligned and adjusted and is firmly welded with the protection cylinder guide frame, and the verticality and the plane error of the protection cylinder meet the design and specification requirements (the deviation of the embedding plane position of the protection cylinder is controlled within 5cm, and the verticality deviation is less than or equal to 1%). The process of quickly lowering the casing is not particularly limited in the invention, and the process is carried out according to the process well known in the art.
After the protective cylinder is arranged on the bottom sealing concrete, the reef limestone stratum is drilled by taking the protective cylinder as a reference, and a cylinder drill and an anti-inclination drill bit are alternately matched in the drilling process.
In the invention, the drill bit for drilling is preferably an anti-inclination drill bit, and the structural schematic diagram of the anti-inclination drill bit is shown in FIG. 1; the anti-deviation drill bit comprises a pilot 5 and a pick bit 11, the pilot 5 is a cylinder with openings at two ends, and the lower part of the pilot 5 is fixedly sleeved at the upper part of the pick bit 11 and used for prolonging the length of a drill cylinder of the pick bit 11, so that the verticality of formed holes can be ensured, and the condition that the formed holes are inclined is avoided; the side wall of the guide device 5 is provided with a plurality of drainage holes 7, the upper part of the cutting pick drill bit 11 is provided with a drill bit square opening 8, the drainage holes 7 are used for draining slurry in the guide device 5, the number of the drainage holes 7 is preferably four, the drainage holes are circumferentially and uniformly distributed on the side wall of the guide device 5, and the length of each drainage hole 7 is preferably 350mm, and the height of each drainage hole 7 is preferably 250 mm; the drill bit square opening 8 is used for being connected with a drill rod of a rotary drilling rig, and is inserted into the drill bit square opening 8 through a pin shaft, so that the drill rod and the anti-inclination drill bit for the rotary drilling rig are connected, and the rotary drilling rig is convenient to use.
Leading 5 tops of ware to be provided with binding off chamfer 2, setting up like this, can avoid the drill bit to scrape the pore wall when lifting. An upper reinforcing ring 3 is fixedly arranged on the inner wall of the guide device 5 at the lower end of the closing-in chamfer 2 and used for improving the structural strength of the guide device 5. The anti-inclination drill bit for the rotary drilling rig further comprises four reinforcing plates 4, the end faces of the side ends of the four reinforcing plates 4 are welded to the inner wall of the guide device 5, the upper end faces of the four reinforcing plates 4 are welded to the lower surface of the upper reinforcing circular ring 3, so that the connecting strength between the guide device 5 and the upper reinforcing circular ring 3 can be enhanced, and the upper reinforcing plates 4 and the upper reinforcing circular ring 3 are preferably steel plates with the thickness of 20 mm. A plurality of drill bits 10 are welded on the inner wall of the lower end of the pilot device 5 at equal angles in the circumferential direction and are used for preventing the pilot device 5 from being worn. The height of the cutting pick drill barrel is preferably 1.6m, the diameter of the cutting pick drill barrel is preferably 1.4m, and the outer diameter of the cutting pick drill barrel is preferably 1.5m after cutting pick is added to the bottom of the drill barrel. The lower reinforcing ring 9 is fixedly connected to the inner side wall of the lower part of the guide device 5 and used for improving the structural strength of the guide device 5. The anti-inclination drill bit for the rotary drilling rig further comprises four lower stiffening plates 6, the side end faces of the lower stiffening plates 6 are welded to the lower portion of the inner side wall of the guide device 5, the upper end faces of the lower stiffening plates 6 are welded to the lower surface of the lower reinforcing circular ring 9 and used for reinforcing the welding strength between the inner side wall of the guide device 5 and the lower reinforcing circular ring 9, the lower ends of the lower stiffening plates 6 are welded to the upper end of the cutting pick drill bit 11, and steel plates with the thickness of 20mm are preferably adopted for the lower stiffening plates 6 and the lower reinforcing circular ring 9. The cutting pick drill bit 11 is internally provided with a discharging switch lengthening compression bar 1, the working principle of the discharging switch compression bar is the same as that of a discharging switch compression bar which is widely applied in the prior art, the discharging switch can be opened to finish discharging by pressing the discharging switch lengthening compression bar 1, the upper end of the discharging switch lengthening compression bar 1 extends out of a guide device 5, the discharging switch lengthening compression bar 1 is higher than the guide device 5 by 300mm, and a user can press the discharging switch lengthening compression bar conveniently. The guide 5 is made of a steel pipe with a diameter of 1.5m, a height of 1.6m and a wall thickness of 20 mm.
In the present invention, the method of using the deviation prevention drill is preferably: the drill rod square head of the rotary drilling rig penetrates through the upper reinforcing ring 3 from the top of the anti-inclination drill guide 5, is inserted into the drill bit square opening 8 of the cutting pick drill bit 11, then is fixed by inserting a pin, connection of the drill rod and the drill bit is realized, and an installer can observe and guide through the drain hole 7 in the installation process. When the drill bit provided by the invention is used for drilling, the drill bit is drilled at a low rotating speed, and the drilling depth of each time is strictly limited to exceed the height of a drilling bucket of the cutting bit 11.
In the invention, before the final setting of the bottom sealing concrete is finished for 1h, the protective cylinder is placed within 12h, the invention preferably adopts a cutting tooth drill bit (the diameter is preferably 1.8m) to carry out clear water drilling, the bottom sealing concrete in the protective cylinder is drilled and removed, the anti-inclination drill bit is replaced until the bottom sealing concrete is drilled to the reef limestone stratum, the square head of a drill rod of the rotary drilling rig penetrates through the upper reinforcing ring from the top of a guider of the anti-inclination drill bit and is inserted into the square opening of the cutting tooth drill bit, then a pin is inserted and fixed, and a constructor can observe and command through the drainage opening to continue drilling. According to the method, the drilling process is preferably observed according to an investigation report or the drilled core sample drilling slag until the drilling reaches the reef limestone stratum; the present invention is not particularly limited as to the extent of drilling into the reef limestone formation, as may be known in the art. In the drilling process, the barrel drill and the anti-inclination drill bit are alternately matched for drilling; the barrel drill and the anti-inclination drill bit are both arranged on the rotary drilling rig, and the drill bit is preferably replaced according to the actual drilling condition. In the invention, the barrel drill (the diameter is preferably 1.5m) is used for cutting the original reef ash layer in a circular mode, and the inclination prevention drill bit is used for cutting the internal rock layer in the circular mode and realizing drilling and hole sweeping.
The invention has no special limit on the drilling speed of the whole process, and can be adjusted according to the actual requirements according to the process well known in the field.
In the drilling process, when the drill hole is drilled into a stratum which is easy to collapse, the liquid level in the hole is easy to quickly lose, and the invention preferably puts wall protection materials into the drill hole to fill the hole, so as to maintain the stability of the hole wall. In the invention, the wall protecting material is preferably bagged cement or common grouting material. After the wall protecting material is thrown in, the method preferably uses a cylinder to drill the hole and stir for not less than 10min to uniformly mix the materials, and then carries out normal drilling.
In the drilling process, after the rotary drilling rig moves and resets every time, the drill bit centering and checking are preferably carried out, and the perpendicularity of the formed hole is detected every 10m of drilling until the formed hole meets the design depth requirement. The invention preferably utilizes a hole inspection instrument to detect the hole forming verticality, and when the verticality deviation is overlarge, the hole scanning and correcting are carried out.
In the drilling process, the liquid level condition in the hole is preferably observed at any time, and when the liquid level is near the orifice, water is timely supplemented into the hole, so that underground water is sealed, and the collapse of the hole wall is prevented by pressure; meanwhile, the abrasion conditions of the drill rod and the drilling tool are checked in time, and the drill rod and the drilling tool are repaired or replaced in time.
After the drilling is finished, the invention carries out primary hole cleaning and secondary hole cleaning on the formed holes obtained by drilling in sequence, and then carries out concrete pouring to form the pile. After drilling is finished (namely, holes meet the design depth requirement), the obtained formed holes are preferably kept stand for not less than 3 hours, then a rotary drilling rig (a flat drill bit) is put in place again and returns to the formed holes to draw out hole bottom sediment, after the hole depth is measured, a guide pipe is put down, full-section one-time hole cleaning is carried out through the guide pipe, the hole cleaning time is not less than 1 hour until the sediment in the holes meets the design requirement, and the obtained drilling slag and waste slurry in the holes are stored in a slurry box and are cleaned in time.
After the primary hole cleaning is finished and before concrete pouring is carried out, the steel bar cage is preferably hoisted by the crawler crane to enter the holes to be in butt joint.
After the steel reinforcement cage is placed, the method preferably performs hole bottom sediment thickness detection again, if sediment exceeds the standard, an air compressor is used for performing air lift reverse circulation process secondary hole cleaning, and after the thickness of the hole bottom sediment meets the specification and design requirements, concrete pouring and pile forming are performed.
The specification and design requirement of the invention refer to the specification and design requirement actually required by different projects.
The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
In the pile foundation engineering of a certain sea-crossing bridge, rotary drilling is adopted for pouring piles, the diameter of each pile is 1500mm, and the length of each pile is 27-50 m. The surface layer of the sea area or the bottom of the artificial filling layer of the construction area is mainly hard reef limestone with the thickness of about 2-6 m, and the lower stratum is a gravel-sand mixed block layer irregularly distributed with the reef limestone, so that the construction area has the characteristics of light density, multiple pores, remarkable strength variation in all directions and the like. In the sea area, a steel casing is vibrated on a construction platform to a seabed position, and then cast-in-situ bored pile construction is carried out. Besides local wind waves are formed in a construction area under the influence of monsoon and a small amount of typhoon, the influence of the swell on a sea area is large, the swell is relatively large in winter and spring, the swell is relatively small in summer and autumn, the general period of the local wind waves is 3-8 s, and the swell period is 14-20 s.
(1) Preparing equipment: the hole forming equipment adopts a TR360D rotary drilling rig, the hole cleaning adopts a BKDY-13.6/8 air compressor gas lift reverse circulation slag cleaning process, one QUY85 crawler crane and other auxiliary equipment.
(2) Pile position measurement and release: and measuring four orthogonal angular points passing through the center of the pile position on the steel platform by using a total station, and drawing a cross line to determine the center of the pile position.
(3) An anti-backup drill with a diameter of 1.5m was made as shown in fig. 1. The anti-deviation drill bit mainly comprises a pilot 5 and a cutting pick drill bit 11. The guiding device 5 is made of a steel pipe, 4 water drainage holes 7 are uniformly formed in the pipe wall at a position 150mm away from the bottom opening of the guiding device 5, a plurality of drill bits 10 are uniformly embedded and welded on the cylinder wall of the bottom opening of the guiding device 5, a reinforcing ring 3 and an upper stiffening plate 4 are welded on the upper portion of a steel plate inside the guiding device 5, and a closing chamfer 2 is formed in the top of the guiding device 5. The guide device 5 is sleeved on the top of the cutting pick drill bit 11 in a ring mode, the length of the guide device is about 150mm, and the guide device is firmly welded with the cutting pick drill bit 11 through the lower reinforcing circular ring 9 and the lower stiffening plate 6. The discharging switch lengthening pressure rod 1 extends upwards to be 300mm higher than the guide device 5.
(4) Manufacturing a steel casing guide frame: the protective cylinder guide frame is manufactured by double-spliced welding of I-shaped steel, the length of a vertical guide section of the guide frame is 3.5m, the side length of the inner side of a transverse limiting frame is 1.86m, the vertical guide section and the transverse limiting frame are welded in a reinforcing mode through an I-shaped steel inclined strut, and the deviation in position is not larger than 2 cm.
(5) Fixing the steel protection cylinder guide frame: and hoisting the guide frame by using a crawler crane to ensure that the deviation between the center of the guide frame and the pile position is not more than 2cm, and firmly welding the guide frame on a steel platform by using a steel plate.
(6) Drilling a reef-removing limestone seabed hard layer: and (3) positioning the rotary drilling rig according to the pile position center, adjusting the verticality of the drill rod, and adjusting the drill bit center and the pile position center to be on the same axis, wherein the deviation is not more than 2 cm. According to tide conditions, a positioning front guide hole is drilled at a pile position by using a barrel drill with the diameter of 800mm in a low level tide period, when a drill bit contacts a seabed and is slightly pressed to rotate slowly, when the drill bit drills to a seabed hard layer of 3.5m, a conical expanding drill bit with the diameter of 2.0m is replaced to perform expanding drilling, the cutting pick drill bit with the diameter of 2.0m is used for drilling and slag removal in a matched mode, and the drilling speed is increased after 1/3 of the conical expanding drill bit enters a stratum until the drill bit drills to the same depth of a front guide hole.
(7) Pouring bottom sealing concrete: firmly welding a conduit clamp on a steel platform, placing a conduit in a drilled seabed hard layer drill hole in a low-level tide time period, wherein the distance between the conduit and the bottom of the drill hole is 300-500 mm, and pouring C15 concrete; and (3) ensuring that the depth of the conduit embedded into the concrete is not less than 1m when the concrete is poured for the first time until the concrete is poured to the original sea bed elevation, and timely dismantling and cleaning the large hopper and the conduit after the pouring is finished.
(8) Placing a protective cylinder: the size of the steel pile casing is phi 1800 multiplied by 16mm, the surge period and the surge rule are observed, the pile casing is lifted and adjusted in advance, the pile casing is quickly placed in the flat recovery time after the surge, the pile casing is placed in the bottom sealing concrete which is not initially set, the top opening of the pile casing is aligned and adjusted and is firmly welded with the guide frame after the pile casing is placed, the verticality deviation of the pile casing is not more than 1%, and the deviation of the center of the pile casing and the pile position is not more than 2 cm.
(9) Drilling and removing the inner back cover concrete of the pile casing: and (3) performing full-section breaking on the bottom sealing concrete in the casing by using a cutting pick drill bit with the diameter of 1.8m within 12 hours after the casing is lowered (the rotating speed of the drill bit is controlled to be 6-8 r/min).
(10) Drilling the reef limestone section by forming holes: after entering a reef limestone stratum, an anti-inclination drill bit with the diameter of 1.5m is replaced, a barrel with the diameter of 1.5m is used for drilling in a matched mode to carry out clear water drilling, and the drilling speed is controlled to be 1-2 m/h. When entering a gravel-containing mixed block layer of the easy-to-collapse hole, cement slurry is timely put into the hole, and the hole is stirred by using a barrel drilling method and is slowly drilled.
In the drilling process, the hole detector is used for detecting the hole once every 10m of drilling, the inclination of the drilled hole is found, and hole sweeping and deviation rectifying are carried out in time.
(11) Primary hole cleaning: after the drilling is carried out to the designed hole depth, the drilling is lifted and the drilled hole is kept stand for 3 hours, then the rotary drilling rig flat-bottom drill bit is utilized to carry out back drilling and clearing on sediments at the bottom of the hole, and the ultrafine reef limestone powder is subjected to primary hole clearing in a mode of replacing slurry in the hole.
(12) And (4) lowering a reinforcement cage: and hoisting the manufactured reinforcement cage through a crawler crane, and butting and placing the reinforcement cage in the holes.
(13) Secondary hole cleaning: after the steel reinforcement cage is laid, a guide pipe qualified through pressure testing is timely placed to conduct air-lift reverse circulation secondary hole cleaning, hole cleaning effects are judged through hole cleaning of sampling sediments, hole cleaning time is generally 1-3 h, after sediment at the bottom of a hole is measured to meet design requirements, obtained drilling slag and waste slurry in the hole are stored in a slurry box and are timely cleaned, and concrete pouring and pile forming are conducted.
By adopting a conventional method, the perpendicularity of the formed hole of the cast-in-situ bored pile manufactured by the construction method of the embodiment is detected, and the result shows that the deviation of the perpendicularity of the formed hole is 0.5%, and the standard and design requirements (not more than 1%) are met.
According to the embodiment, the hole forming construction method for the rotary drilling cast-in-place pile in the reef limestone stratum is provided, a series of construction problems of difficult pile casing burying, poor hole forming verticality, hole collapse, serious liquid level leakage in the hole, poor hole cleaning effect and the like in the construction process are solved, and a good effect is achieved.
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A rotary drilling bored concrete pile pore-forming construction method in a reef limestone stratum is characterized by comprising the following steps:
(1) providing a rotary drilling rig, a crawler crane, an air compressor, a protective cylinder and auxiliary equipment;
(2) measuring a pile position at a position to be constructed, and determining the center of the pile position;
(3) positioning and fixing a pile casing guide frame in the center of the pile position;
(4) according to the pile position center, positioning the rotary drilling rig, adjusting the verticality of a drill rod of the rotary drilling rig, adjusting the drill bit center of the rotary drilling rig and the pile position center to be on the same axis, and drilling a reef-removing limestone seabed hard layer, wherein the deviation is less than or equal to 2 cm;
(5) in a low-level tide time period, placing a guide pipe in a drill hole obtained by drilling a reef-removing limestone seabed hard layer, enabling the guide pipe to be 300-500 mm away from the hole bottom, and pouring bottom sealing concrete;
(6) placing a pile casing on the bottom sealing concrete;
(7) drilling a reef limestone stratum by taking the protective cylinder as a reference, wherein a cylinder drill and an anti-inclined drill bit are alternately matched in the drilling process;
(8) sequentially carrying out primary hole cleaning and secondary hole cleaning on the formed holes obtained by drilling, and then carrying out concrete pouring to form piles;
the anti-deviation drill bit comprises a guide device and a pick drill bit, the guide device is a cylinder with openings at two ends, the lower part of the guide device is fixedly sleeved on the upper part of the pick drill bit and used for prolonging the length of a drill cylinder of the pick drill bit, the side wall of the guide device is provided with a plurality of water drainage holes, and the upper part of the pick drill bit is provided with a drill bit square opening.
2. The construction method according to claim 1, wherein in the step (1), the diameter of the casing is 200-400 mm larger than the diameter of the pile;
in the step (3), the deviation between the center of the pile casing guide frame and the pile position is not more than 2 cm;
in step (4) bore the in-process of removing reef limestone seabed crust, adopt toper reamer bit to carry out the reaming, the diameter ratio of toper reamer bit protects the diameter of a section of thick bamboo and is big 300 ~ 400 mm.
3. The construction method according to claim 1 or 2, wherein in the step (4), the drilling and reef-removing limestone seabed hard layer is carried out until the obtained drilling depth reaches 500mm below the required sinking depth of the casing.
4. The construction method according to claim 1, wherein in the step (5), when the bottom sealing concrete is poured, the concrete is poured to a depth of not less than 1m of the conduit embedded concrete, and then the concrete is poured to the original sea bed elevation.
5. The construction method according to claim 1, wherein in the step (6), after the pile casing is placed on the bottom-sealing concrete, the top opening of the pile casing is centered and adjusted to be firmly welded with the pile casing guide frame.
6. The construction method according to claim 1, wherein in the step (7), before drilling the reef limestone stratum, clear water is adopted to drill the bottom sealing concrete in the pile casing until the drilling reaches the reef limestone stratum, and the inclination prevention drill bit is replaced.
7. The construction method according to claim 1 or 6, wherein in the step (7), during drilling of the reef limestone formation, when drilling into the easily collapsed formation, a wall protecting material is poured into the hole to fill the hole.
8. The construction method according to claim 7, wherein in the step (7), in the drilling process, after the rotary drilling rig moves and resets each time, drill bit centering checking is carried out, and the perpendicularity of the drilled hole is detected every time 10m is drilled until the obtained drilled hole meets the design depth requirement.
9. The construction method according to claim 1, wherein a closing-in chamfer is arranged at the top of the pilot; an upper reinforcing circular ring is fixedly arranged on the inner wall of the guide device at the lower end of the closing-in chamfer; a lower reinforcing ring is fixedly connected to the inner side wall of the lower part of the pilot device; a plurality of drill bits are welded on the inner wall of the lower end of the pilot device at equal angles in the circumferential direction.
10. The construction method according to claim 1, wherein a discharge switch lengthening pressure rod is arranged inside the cutting pick drill bit, and the upper end of the discharge switch lengthening pressure rod extends out of the pilot.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010439059.6A CN111535307B (en) | 2020-05-22 | 2020-05-22 | Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010439059.6A CN111535307B (en) | 2020-05-22 | 2020-05-22 | Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111535307A true CN111535307A (en) | 2020-08-14 |
| CN111535307B CN111535307B (en) | 2022-09-06 |
Family
ID=71968138
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010439059.6A Active CN111535307B (en) | 2020-05-22 | 2020-05-22 | Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111535307B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113445916A (en) * | 2021-08-11 | 2021-09-28 | 中冀建勘集团有限公司 | Construction method for correcting hole sweeping deviation of small-diameter deep well bedrock section |
| CN113944456A (en) * | 2021-09-26 | 2022-01-18 | 浙江省工程勘察设计院集团有限公司 | Drilling depth measuring method and system, drilling machine and storage medium |
| CN115977549A (en) * | 2023-03-17 | 2023-04-18 | 福建省冉氏机械科技有限公司 | Dig rig soon and fall and unload native mechanism of making an uproar |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122131A (en) * | 2007-08-14 | 2008-02-13 | 蓝冰 | Foundation pit supporting pile using pipe casting pile embedding in rock |
| CN102966110A (en) * | 2012-12-14 | 2013-03-13 | 上海市建工设计研究院有限公司 | Vertically-combined type impermeable waterproof curtain structure and construction method thereof |
| CN104153352A (en) * | 2014-07-31 | 2014-11-19 | 广西科技大学 | Karst geology rotary-drilling bored concrete pile hole forming process |
| CN106013092A (en) * | 2016-06-08 | 2016-10-12 | 深圳市宏业基基础工程有限公司 | Cast-in-situ bored pile construction method |
| CN106638547A (en) * | 2016-10-17 | 2017-05-10 | 重庆大学 | Pile-forming method for cast-in-place pile in coral sand foundation |
| CN109469053A (en) * | 2018-10-24 | 2019-03-15 | 中国海洋大学 | Rotating steel tube stake and its application method suitable for coral island geology |
-
2020
- 2020-05-22 CN CN202010439059.6A patent/CN111535307B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101122131A (en) * | 2007-08-14 | 2008-02-13 | 蓝冰 | Foundation pit supporting pile using pipe casting pile embedding in rock |
| CN102966110A (en) * | 2012-12-14 | 2013-03-13 | 上海市建工设计研究院有限公司 | Vertically-combined type impermeable waterproof curtain structure and construction method thereof |
| CN104153352A (en) * | 2014-07-31 | 2014-11-19 | 广西科技大学 | Karst geology rotary-drilling bored concrete pile hole forming process |
| CN106013092A (en) * | 2016-06-08 | 2016-10-12 | 深圳市宏业基基础工程有限公司 | Cast-in-situ bored pile construction method |
| CN106638547A (en) * | 2016-10-17 | 2017-05-10 | 重庆大学 | Pile-forming method for cast-in-place pile in coral sand foundation |
| CN109469053A (en) * | 2018-10-24 | 2019-03-15 | 中国海洋大学 | Rotating steel tube stake and its application method suitable for coral island geology |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113445916A (en) * | 2021-08-11 | 2021-09-28 | 中冀建勘集团有限公司 | Construction method for correcting hole sweeping deviation of small-diameter deep well bedrock section |
| CN113944456A (en) * | 2021-09-26 | 2022-01-18 | 浙江省工程勘察设计院集团有限公司 | Drilling depth measuring method and system, drilling machine and storage medium |
| CN113944456B (en) * | 2021-09-26 | 2024-04-16 | 浙江省工程勘察设计院集团有限公司 | Drilling depth measurement method, drilling depth measurement system, drilling machine and storage medium |
| CN115977549A (en) * | 2023-03-17 | 2023-04-18 | 福建省冉氏机械科技有限公司 | Dig rig soon and fall and unload native mechanism of making an uproar |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111535307B (en) | 2022-09-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110230309B (en) | Karst area bridge karst cave pile foundation construction method | |
| CN111535307B (en) | Hole forming construction method for rotary drilling cast-in-place pile in reef limestone stratum | |
| CN113445498A (en) | Construction process of karst hole pile foundation in complex geology | |
| CN104747088B (en) | A kind of leafy hosqe bit of cast-in-situ bored pile list waist and drilling construction method | |
| CN108797587A (en) | A kind of novel sinking construction technology of static pressed pile | |
| CN112392400B (en) | Hole forming construction process for slope protection pile in complex geological environment | |
| CN106917409A (en) | A kind of rock lid weight consolidation grouting construction method | |
| CN106988302A (en) | A kind of high inclination-angle competent bed rotary digging pile driving construction engineering method | |
| CN110700248A (en) | Miniature steel pipe pile for grouting small and medium-sized span bridge, pile foundation and construction method | |
| CN110629747A (en) | Full-casing full-rotation construction process for pile foundation under complex geological conditions | |
| CN113235601A (en) | Deep foundation pit construction risk control structure and method for collapsible loess adjacent building | |
| CN111119195A (en) | Foundation pit soil nail shotcrete support construction method | |
| CN111236215A (en) | Rock-socketed construction process of large-diameter steel pipe inclined pile of offshore wind power high-rise pile cap foundation | |
| CN113404040A (en) | Construction method of bored pile foundation | |
| CN110593254A (en) | Construction method of cast-in-situ bored pile in stratum with karst cave in joint zone | |
| CN117107749A (en) | Construction method of large-diameter punched bored pile under influence of sea water seepage in sea-filling land-building area | |
| CN113216215A (en) | Deep groove support reverse construction method in complex environment | |
| CN112144514A (en) | Simple method for forming hole and pile in sand and pebble stratum easy to collapse during rotary drilling machine | |
| CN209891202U (en) | Anti-floating anchor rod | |
| CN111962507A (en) | Pile foundation hole forming method | |
| CN108035357B (en) | Filling pile construction scheme and its funnel | |
| Baker Jr et al. | Caisson construction problems and correction in Chicago | |
| CN110714459A (en) | Construction method of cast-in-situ bored pile | |
| CN114855776A (en) | End-bearing type cast-in-situ bored pile construction method for dry-process pore forming through powder sand layer | |
| CN103790148A (en) | Combined treatment construction method for collapsible loess foundation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB02 | Change of applicant information |
Address after: 050277 No. 555 Huai'an West Road, Luquan District, Shijiazhuang City, Hebei Province Applicant after: China Hebei Jiankan Group Co.,Ltd. Address before: 050227 No. 555, Huaian West Road, Shijiazhuang City, Hebei Province Applicant before: HEBEI CONSTRUCTION AND INVESTIGATION RESEARCH INSTITUTE Co.,Ltd. |
|
| CB02 | Change of applicant information | ||
| CB03 | Change of inventor or designer information |
Inventor after: Nie Qingke Inventor after: Li Huawei Inventor after: Yang Haipeng Inventor after: Sun Yunqing Inventor after: Song Pengbo Inventor after: Xia Wenchao Inventor after: Ma Ruxing Inventor before: Nie Qingke Inventor before: Li Huawei Inventor before: Yang Haipeng Inventor before: Sun Yunqing Inventor before: Song Pengpo Inventor before: Xia Wenchao Inventor before: Ma Ruxing |
|
| CB03 | Change of inventor or designer information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |