CN111719548A - Method for dry-method hole-forming pile foundation wet-method pouring construction - Google Patents
Method for dry-method hole-forming pile foundation wet-method pouring construction Download PDFInfo
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- CN111719548A CN111719548A CN202010417946.3A CN202010417946A CN111719548A CN 111719548 A CN111719548 A CN 111719548A CN 202010417946 A CN202010417946 A CN 202010417946A CN 111719548 A CN111719548 A CN 111719548A
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- 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
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D15/00—Handling building or like materials for hydraulic engineering or foundations
- E02D15/02—Handling of bulk concrete specially for foundation or hydraulic engineering purposes
- E02D15/04—Placing concrete in mould-pipes, pile tubes, bore-holes or narrow shafts
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- General Engineering & Computer Science (AREA)
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- Piles And Underground Anchors (AREA)
Abstract
The invention provides a method for wet-process pouring construction of a dry-process hole-forming pile foundation, which comprises the following steps of: pile foundation dry process pore-forming, installation steel reinforcement cage and pipe are downthehole to the pile foundation, through the pipe to downthehole concrete of pouring of pile foundation and with the chisel of the partial concrete pile head of surpassing pouring, before the concrete pouring, still include: pouring clear water into the pile foundation hole by means of the guide pipe, wherein the pouring height of the clear water is obtained by calculation according to the formula (1):
the clear water fills the back and pours concrete into, and the concrete is leaned on self gravity to fall to the lower floor of clear water and constantly raises the clear water, and the clear water on upper strata supports the concrete surface that presses the lower floor and makes the concrete density of lower floor, along with the pouring height increase of concrete, is discharged from pile foundation hole top by the clear water of raising. The invention has simple operation, can improve the pile foundation pouring work efficiency, pile-forming quality and green construction level, and is the same as the methodThe investment cost is reduced, the operation environment of pile foundation dry hole pouring is improved, manual vibration is not needed, and the safety of worker construction is improved.
Description
Technical Field
The invention relates to the technical field of building construction, in particular to a method for wet-process pouring construction of a dry-process hole-forming pile foundation.
Background
The conventional pile foundation pouring process at present comprises a pile foundation dry hole pouring process and a slurry dado underwater pouring process, but both the two pile foundation pouring processes have certain limitations.
In a water source protection area in a mountain area, the requirement on environmental protection is high, and meanwhile, the pile foundations of the intercommunicated ramp ring bridge are positioned in a hard rock geological area where underground water does not develop, and holes are formed by a dry method (including rotary drilling, water grinding and drilling and manual hole digging and hole forming), the dry hole pouring and the manual vibration are matched by adopting the traditional process-a conduit method, so that the pouring method has the advantages of poor working condition of operators, high safety risk, low pouring speed, large labor cost investment, large pouring quality influenced by human factors and unstable pouring quality of pile foundations; the underwater grouting process of the slurry retaining wall has serious environmental pollution of an operation site, high investment of environmental management measures in areas with strict environmental protection requirements, and great difficulty in arranging a slurry pool in narrow areas.
Disclosure of Invention
In view of the above situation, the present invention provides a method for wet-process grouting construction of a dry-process pore-forming pile foundation, which solves the technical problem that the existing dry-process grouting and wet-process grouting both have certain limitations.
In order to achieve the purpose, the invention adopts the technical scheme that: the method for the wet pouring construction of the dry-method hole-forming pile foundation comprises the following steps: dry-method hole forming of a pile foundation, detection before installation of a guide pipe, installation of a reinforcement cage and the guide pipe into the pile foundation hole, pouring concrete into the pile foundation hole, and chiseling out the super-poured concrete pile head,
before concrete pouring, the method further comprises the following steps: and pouring clear water into the pile foundation hole by means of the guide pipe, wherein the pouring height of the clear water is obtained by calculation according to a formula:
wherein H is the filling height of clear water;
ρ1is the density of the concrete;
ρ2is the density of water;
d is the depth of the conduit embedded into the concrete;
h is the distance between the bottom of the guide pipe and the bottom of the pile foundation hole;
the clear water fills the back and pours concrete into, and the lower floor that the concrete that pours into falls to the clear water by self gravity constantly raises the clear water, and the clear water on upper strata supports the concrete surface who presses the lower floor and makes the concrete density of lower floor, along with the high increase of pouring of concrete, and the clear water of being raised is followed the top in stake foundation hole is discharged.
In the embodiment of the invention, accumulated water and accumulated slag in the pile foundation hole are cleaned before the clear water is poured.
In the embodiment of the invention, before the installation of the conduit, the conduit is subjected to a watertight pressure-bearing test and a joint tensile test, and the water pressure for the watertight pressure-bearing test is not less than 1.3 times of the water depth.
In the embodiment of the invention, in the concrete pouring process, the slump, the expansion degree, the air content and the mold-entering temperature of the underwater concrete are detected according to the specified time and recorded.
In the embodiment of the invention, the quantity of the first batch of bottom-sealed concrete is calculated and controlled.
In the embodiment of the invention, the depth of the conduit embedded in the concrete is 2 m-6 m.
In the embodiment of the invention, the distance between the bottom end of the guide pipe and the bottom of the pile foundation hole is 30-40 cm.
In the embodiment of the invention, the pouring height of the clear water is not less than 8m, and the depth of the pile foundation hole is not less than 8 m.
In the embodiment of the invention, the elevation of the top of the poured pile is 0.5-1 m higher than the design elevation.
In the embodiment of the invention, the method for the wet pouring construction of the dry-method hole-forming pile foundation is suitable for geological areas where underground water does not develop hard rock.
Due to the adoption of the technical scheme, the invention has the following beneficial effects:
(1) according to the invention, clear water is poured into the pile foundation hole by means of the guide pipe, and because the density of the clear water is less than that of concrete, the concrete falls to the lower layer of the clear water when the concrete is poured, so that the clear water can generate pressure on the concrete positioned on the lower layer all the time, and the pressure action of the clear water replaces the action of manual vibration, so that the concrete on the lower layer is compact, and the problems that the pile bottom concrete at the bottom of the guide pipe is difficult to be manually vibrated and the quality of the concrete at the part of the guide pipe away from the pile bottom is easy to be defective due to the fact that the concrete cannot be vibrated to be compact are solved;
when the guide pipe is highly submerged in the concrete, the concrete can be compacted by the pressure of the concrete column for submerging the guide pipe; the height of the clear water is only about 8m, compared with the full slurry filling process in the wet filling construction in the prior art, the method saves the using amount of the slurry, and meanwhile, the clear water is adopted for filling without building a slurry pool on site, so that the environmental pollution caused by full slurry filling can be avoided, and the method conforms to the concept of high environmental protection requirement in mountainous areas.
(2) The method is simple to operate, can improve the pile foundation pouring work efficiency, pile forming quality and green construction level, simultaneously reduces the cost investment, improves the pile foundation dry hole pouring operation environment, does not need manual vibration, improves the safety of worker construction, and has remarkable social benefit.
(3) The process concept of the invention can be completely popularized to the underground water undeveloped soft rock geological area, the slurry with equivalent height is poured into the hole, the soft rock softening and hole collapse caused by the pouring of clear water is avoided, the purpose of the dry-method hole-forming pile foundation wet-method pouring construction of the underground water undeveloped soft rock geological area is realized, the benefit is ensured to be improved, and the influence on the surrounding environment and the investment of the construction cost are reduced.
Drawings
FIG. 1 is a schematic flow chart of the wet pouring construction of the dry-method hole-forming pile foundation.
Fig. 2 is a schematic diagram of the water injection arrangement of the dry hole pile foundation of the invention.
The correspondence of reference numerals to components is as follows:
a catheter 1; a pile foundation hole 2; a water injection pipe 3; and (4) water injection height A.
Detailed Description
To facilitate an understanding of the present invention, the following description is made in conjunction with the accompanying drawings and examples.
The invention provides a method for wet-process pouring construction of a dry-process hole-forming pile foundation, which can realize compaction of concrete at the bottom of a pile without manual vibration at the initial stage of concrete pouring so as to ensure the quality of the concrete at the bottom of the pile, and simultaneously does not need a slurry retaining wall construction method so as to avoid the defects of serious environmental pollution and large later-stage treatment investment caused by the slurry retaining wall construction method.
Referring to fig. 1, the method includes the following steps: detect before pile foundation dry process pore-forming, 1 installation of pipe, installation steel reinforcement cage and pipe to pile foundation downthehole, pour into and will surpass partial concrete pile head chisel of irritating to the downthehole concrete of pile foundation through the pipe and remove, before concrete pouring, still include: pouring clear water into the pile foundation hole by means of the guide pipe, and controlling the pouring height of the clear water, wherein the pouring height of the clear water is obtained by calculation according to the formula (1):
wherein H is the filling height of clear water, and the unit is m;
ρ1is the density of the concrete, and has the unit of t/m3；
ρ2Is the density of water, in units of t/m3；
d is the depth of the conduit embedded in the concrete, and the unit is m;
h is the distance between the bottom of the guide pipe and the bottom of the pile foundation hole, and the unit is m;
the clear water fills the back poured concrete that accomplishes, and the poured concrete leans on self gravity to fall to the lower floor of clear water and constantly raises the clear water, and the clear water on upper strata supports the concrete surface who presses the lower floor and makes the concrete density of lower floor, along with the high increase of pouring of concrete, is discharged from the top in pile foundation hole by the clear water of raising. Concretely, the theoretical basis that concrete is compacted by the pressure of a slurry column at the initial stage of underwater pouring and concrete is compacted by the pressure of a concrete column of an immersed guide pipe at the later stage is obtained by carrying out comparative analysis on a pile foundation dry hole pouring process and a slurry retaining wall underwater pouring process, the height of an equivalent pressure water column (the concrete density is 2.4 t/m) is calculated by applying a pressure equivalence principle and considering a certain safety coefficient according to the requirements (the depth of the guide pipe embedded into the concrete is preferably controlled to be 2 m-6 m in the pouring process) of underwater poured concrete in technical Specification for Highway bridge and culvert construction (JTG/TF50-2011)3Water density 1t/m3Considering that the depth of the conduit embedded into the concrete is controlled to be 2 m-6 m (generally not more than 8m) and the distance between the conduit bottom and the hole bottom of the pile foundation is 0.4m, the equivalent water column height can be calculated to be 2.4 × 2/1+0.4 ═ 5.2m and 2.4 × 6/1+0.4 ═ 14.8m according to the formula (1), and the water column height can be finally determined to be an integer of 6 m-15 m for facilitating the field control; in the embodiment of the invention, the depth of the conduit embedded into the concrete is controlled to be 3m and the distance between the conduit bottom and the hole bottom of the pile foundation is 0.4m, so that the equivalent water column height is 2.4 × 3/1+0.4 to 7.6m, and finally the water column height can be determined to beAn integer of 8m, in which case the depth of the pile foundation hole is generally not less than 8 m). Water injection arrangement as shown in fig. 2, water is injected into the pile foundation hole 2 by inserting the water injection pipe 3 into the guide pipe 1, and the position A is the water injection height 8m of the invention.
Preferably, for deeper pile foundation holes, the artificial vibration risk is high, and the superiority of the method can be embodied; for shallow (less than 8m) pile foundation holes, manual vibration can be directly adopted without pouring clear water.
In the embodiment of the invention, the distance between the bottom of the guide pipe and the hole bottom of the pile foundation is not limited to 0.4m, and is generally 0.3 m-0.4 m.
According to the invention, clear water is poured into the pile foundation hole by means of the guide pipe, and because the density of the clear water is less than that of concrete, the concrete falls to the lower layer of the clear water when the concrete is poured, so that the clear water can generate pressure on the concrete positioned on the lower layer all the time, and the pressure action of the clear water replaces the action of manual vibration, so that the concrete on the lower layer is compact, and the problems that the pile bottom concrete at the bottom of the guide pipe is difficult to be manually vibrated and the quality of the concrete at the part of the guide pipe away from the pile bottom is easy to be defective due to the fact that the concrete cannot be vibrated to be compact are solved; when the guide pipe is highly submerged in the concrete, the concrete can be compacted by the pressure of the concrete column for submerging the guide pipe; the height of the clear water is only about 8m, compared with the full slurry filling process in the wet filling construction in the prior art, the method saves the using amount of the slurry, and meanwhile, the clear water is adopted for filling without building a slurry pool on site, so that the environmental pollution caused by full slurry filling can be avoided, and the method conforms to the concept of high environmental protection requirement in mountainous areas.
In the embodiment of the invention, a conduit detection step is carried out before the conduit is installed, specifically, the conduit of the invention adopts a quick connector conduit with the diameter of 200 mm-350 mm, a watertight pressure-bearing test and a connector tensile test are carried out before the conduit is used, and a pressure-compressing pressure test is forbidden. The water pressure for carrying out the watertight bearing test is not less than the pressure of 1.3 times of the depth of water in the pile foundation hole, and the guide pipe is preferably a seamless guide pipe.
In the embodiment of the invention, accumulated water and accumulated slag in the pile foundation hole are cleaned after the pile foundation hole is formed and before clear water is poured. Specifically, when the hole forming method adopts manual hole digging and water grinding drilling, a pile foundation hole can be manually placed to remove a hole; when the hole forming method adopts the rotary drilling drill to form the hole, the rotary drilling drill can automatically clean accumulated slag, and the pipe can be lowered to pump water when underground accumulated water is obviously much; generally, the influence of accumulated water is not great, and water is injected particularly in the later period.
In the embodiment of the invention, the adopted pouring water body can be used only after being tested and detected to be qualified, so that the water quality meets the requirement of concrete pouring, and the detection of the water quality usually detects the content of chloride ions in the water body; clear water must carry out the water injection through the pipe, prevents to erode the pore wall, leads to the emergence of pile foundation defect.
In the embodiment of the invention, in the concrete pouring process, the slump, the expansion, the air content and the mold-entering temperature of the underwater concrete are detected according to the specified time, and the record is made, and the pouring quality of the concrete is strictly controlled; the detection of the slump, the expansion degree, the gas content and the mold-entering temperature of the concrete is routine operation in the field, and special equipment is adopted for detection, and the specific detection can refer to the standard of the test method for the performance of common concrete mixtures (GB/T50080-.
In the embodiment of the invention, the quantity of the first-batch bottom sealing concrete is calculated and controlled so as to ensure certain impact energy when the concrete falls down, and enough impact energy can flush the pile bottom sediment as far as possible so as to effectively control the pile bottom sediment. The first set of closed-end concrete calculations are performed exactly as the calculations for the mud dado.
In the embodiment of the invention, before pouring concrete, water is sprayed on a concrete conveying pipeline and a collecting hopper for wetting, then an isolating bolt (the isolating bolt adopts a steel plate which is pulled by a thin steel wire rope and lifted by a truck crane) is installed in the collecting hopper, and the quantity of the first pouring concrete can meet the requirement that the first embedding depth of the guide pipe is not less than 1 m.
In the embodiment of the invention, after the first batch of concrete falls down, the concrete should be continuously poured.
In the embodiment of the invention, the elevation of the poured pile top is controlled to be higher than the designed elevation by about 0.5-1 m so as to ensure the concrete strength, and the surplus pile head is chiseled off so as to ensure that the pile head has no loose layer. After the concrete is poured, the guide pipe, the funnel and the like are cleaned and checked in time to be used for the next hole. In the process of pouring concrete, "concrete pouring record" should be filled.
In the embodiment of the invention, the dry-method hole forming of the pile foundation is suitable for the underground water undeveloped hard rock geological area, the research concept of the dry-method hole forming and the wet-method pouring is also completely suitable for the underground water undeveloped soft rock geological area, slurry with equivalent height is injected into the pile foundation hole, the soft rock softening and hole collapsing caused by the pouring of clear water are avoided, the wall protection effect can be achieved, and the construction operation of the dry-method hole forming pile foundation wet-method pouring is realized.
While the present invention has been described in detail and with reference to the accompanying drawings and examples, it will be apparent to one skilled in the art that various changes and modifications can be made therein. Therefore, certain details of the embodiments are not to be interpreted as limiting, and the scope of the invention is to be determined by the appended claims.
Claims (10)
1. A method for wet pouring construction of a dry-method hole-forming pile foundation comprises the following steps: dry-method hole forming of pile foundation, installation of reinforcement cage and conduit into pile foundation hole, pouring concrete into pile foundation hole through conduit, and chiseling out concrete pile head of over-poured part,
before concrete pouring, the method further comprises the following steps: and pouring clear water into the pile foundation hole by means of the guide pipe, wherein the pouring height of the clear water is obtained by calculation according to the formula (1):
wherein H is the filling height of clear water;
ρ1is the density of the concrete;
ρ2is the density of water;
d is the depth of the conduit embedded into the concrete;
h is the distance between the bottom of the guide pipe and the bottom of the pile foundation hole;
the clear water fills the back and pours concrete into, and the lower floor that the concrete that pours into falls to the clear water by self gravity constantly raises the clear water, and the clear water on upper strata supports the concrete surface who presses the lower floor and makes the concrete density of lower floor, along with the high increase of pouring of concrete, and the clear water of being raised is followed the top in stake foundation hole is discharged.
2. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein accumulated water and accumulated slag in the pile foundation hole are cleaned before the clear water pouring.
3. The method for the wet pouring construction of the dry-method hole-forming pile foundation according to the claim 1, wherein before the installation of the guide pipe, the guide pipe is subjected to a watertight bearing test and a joint tensile test, and the water pressure for the watertight bearing test is not less than 1.3 times of the water depth.
4. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein in the concrete pouring process, the slump, the expansion degree, the air content and the mold-entering temperature of the underwater concrete are detected according to the specified time and recorded.
5. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, further comprising calculating and controlling the amount of the first sealing concrete.
6. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein the depth of the conduit embedded in the concrete is 2m to 6 m.
7. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein the distance between the bottom end of the guide pipe and the bottom of the pile foundation hole is 30 cm-40 cm.
8. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein the pouring height of the clear water is not less than 8m, and the depth of the pile foundation hole is not less than 8 m.
9. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein the height of the poured pile top is 0.5m to 1m higher than the design height.
10. The method for the wet pouring construction of the dry hole-forming pile foundation according to the claim 1, wherein the method for the wet pouring construction of the dry hole-forming pile foundation is suitable for underground water undeveloped hard rock geological areas.
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| CN202010417946.3A CN111719548A (en) | 2020-05-18 | 2020-05-18 | Method for dry-method hole-forming pile foundation wet-method pouring construction |
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2097489C1 (en) * | 1996-03-04 | 1997-11-27 | Александр Юрьевич Смирнов | Process of placing concrete into cast-in-place piles and installation for its implementation |
| CN106498935A (en) * | 2016-11-09 | 2017-03-15 | 中冶建工集团有限公司 | A kind of bored pile underwater concrete casting method |
-
2020
- 2020-05-18 CN CN202010417946.3A patent/CN111719548A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| RU2097489C1 (en) * | 1996-03-04 | 1997-11-27 | Александр Юрьевич Смирнов | Process of placing concrete into cast-in-place piles and installation for its implementation |
| CN106498935A (en) * | 2016-11-09 | 2017-03-15 | 中冶建工集团有限公司 | A kind of bored pile underwater concrete casting method |
Non-Patent Citations (3)
| Title |
|---|
| 中铁电气化局集团有限公司: "《铁路工程（桥涵）施工作业操作手册》", 31 December 2014, 中国铁道出版社 * |
| 支建设: "浅谈梨香溪特大桥灌注桩施工技术及质量控制", 《科技与创新》 * |
| 杜勤卫等: "浅谈桥梁工程人工挖孔桩清水灌注砼技术", 《建筑工程技术与设计》 * |
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