CN112411613A - Underpinning beam construction method in pile foundation underpinning construction - Google Patents
Underpinning beam construction method in pile foundation underpinning construction Download PDFInfo
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- CN112411613A CN112411613A CN202011188884.XA CN202011188884A CN112411613A CN 112411613 A CN112411613 A CN 112411613A CN 202011188884 A CN202011188884 A CN 202011188884A CN 112411613 A CN112411613 A CN 112411613A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D27/00—Foundations as substructures
- E02D27/32—Foundations for special purposes
- E02D27/48—Foundations inserted underneath existing buildings or constructions
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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
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D27/00—Foundations as substructures
- E02D27/10—Deep foundations
- E02D27/12—Pile foundations
- E02D27/14—Pile framings, i.e. piles assembled to form the substructure
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- E—FIXED CONSTRUCTIONS
- E04—BUILDING
- E04G—SCAFFOLDING; FORMS; SHUTTERING; BUILDING IMPLEMENTS OR AIDS, OR THEIR USE; HANDLING BUILDING MATERIALS ON THE SITE; REPAIRING, BREAKING-UP OR OTHER WORK ON EXISTING BUILDINGS
- E04G21/00—Preparing, conveying, or working-up building materials or building elements in situ; Other devices or measures for constructional work
- E04G21/12—Mounting of reinforcing inserts; Prestressing
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2250/00—Production methods
- E02D2250/0007—Production methods using a mold
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D2600/00—Miscellaneous
- E02D2600/20—Miscellaneous comprising details of connection between elements
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- Engineering & Computer Science (AREA)
- Structural Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Civil Engineering (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Architecture (AREA)
- Mechanical Engineering (AREA)
- Piles And Underground Anchors (AREA)
Abstract
The invention discloses a construction method of a underpinning beam in pile foundation underpinning construction, which comprises the steps of firstly forming a groove on the outer side surface of a pile foundation to be underpinned, implanting a plurality of connecting steel bars, then binding the periphery of the pile foundation to be underpinned to form a steel bar framework connected with the connecting steel bars, erecting a template, and finally pouring concrete and curing to obtain the underpinning beam. By adopting the construction method, the combination degree and the connection strength of the underpinning beam and the pile foundation to be underpinned can be improved, and the integral structure strength and the stress performance of the underpinning beam and the pile foundation to be underpinned after connection are improved.
Description
Technical Field
The invention relates to the technical field of civil engineering construction, in particular to a construction method of a underpinning beam in pile foundation underpinning construction.
Background
With the vigorous development of urban construction, urban ground traffic is increasingly busy, and in order to relieve ground traffic pressure, the construction of convenient and rapid underground railways becomes a choice of a plurality of urban traffics. Because underground excavation construction underground railways have small influence on ground traffic, and the underground excavation method becomes the main construction method of urban underground railway construction along with the maturity of the underground excavation construction method, but inevitably can cross ground buildings, the pile foundation underpinning technology is needed to underpin the pile foundation of the ground buildings deeply into the tunnel, and the upper structure load born by the part of the pile foundation is transferred to the pile foundation outside the influence range of tunnel construction through the newly constructed underpinning structure.
In the underpinning construction of the pile foundation, an underpinning beam connected with an old bearing platform of an original pile foundation needs to be constructed, then the load of the original pile foundation is transmitted to an underpinning pile through the underpinning beam, in order to ensure effective and stable connection between the underpinning beam and the old bearing platform, reinforcing steel bars are usually firstly implanted into the old bearing platform during the construction of the underpinning beam, and then the reinforcing steel bars are connected with the reinforcing steel bars in the underpinning beam formed by subsequent pouring. In the existing pile foundation underpinning construction process, the steel bars are implanted into an old bearing platform, the convenience of construction is mainly considered, usually, a plurality of steel bar implanting holes are drilled in the same operation direction and the steel bars are implanted, then a plurality of steel bar implanting holes are drilled in the other operation direction and the steel bars are implanted until the steel bars are implanted into the whole pile foundation, the construction method has large influence on the structural strength and the stability of the pile foundation, and safety accidents easily occur. In addition, in the existing pile foundation underpinning construction, the positions to be optimized in the aspects of arrangement form, implantation mode, operation process and the like of all reinforcing steel bars exist, so that the defects of poor safety in the pile foundation underpinning construction process, poor overall quality after construction and the like exist.
Meanwhile, the jack is arranged on the underpinning pile and the underpinning beam to lift the underpinning beam, which is an important construction step in pile foundation underpinning construction. The current jacking of underpinning roof beam all is in the biggest jacking force within range of design, carries out the jacking according to synchronous jacking principle, and control to concrete jacking mode and jacking force does not have strict scheme, and its maneuverability is relatively poor, appears great error easily and leads to the safety problem, is difficult to realize improving jacking efficiency when guaranteeing jacking accuracy, jacking quality and construction safety nature.
Disclosure of Invention
The invention aims to overcome the defects in the prior art and provides a construction method of a underpinning beam in pile foundation underpinning construction.
In order to solve the technical problems, the invention adopts the following technical scheme:
a construction method of a underpinning beam in pile foundation underpinning construction comprises the following steps:
(A) forming a plurality of grooves on the outer side surface of the pile foundation to be underpinned, and implanting a plurality of connecting steel bars on the outer side surface of the pile foundation to be underpinned;
(B) binding the periphery of the pile foundation to be underpinned to form a steel bar framework connected with the connecting steel bars, and erecting a template on the periphery of the steel bar framework;
(C) and pouring concrete into the template, and curing to obtain the underpinned beam.
In the above construction method, preferably, the steel reinforcement frame has at least two annular steel reinforcement mesh layers arranged around the pile foundation and connected to the connecting steel reinforcements, and the at least two annular steel reinforcement mesh layers are sequentially sleeved from inside to outside.
In the construction method, the distance between two adjacent annular reinforcing mesh layers is preferably 400-600 mm.
In the construction method, preferably, in the step (C), each groove is cleaned before the concrete is poured, and the interface treatment agent is brushed on the inner wall of each groove within four hours before the concrete is poured.
In the above construction method, preferably, in the step (C), at least two water-through heat-radiating pipes arranged at intervals up and down are preset in the formwork before the concrete is poured, and cooling water is introduced into each water-through heat-radiating pipe after the concrete is poured for cooling maintenance.
Preferably, the construction method includes the following steps:
(a1) presetting a plurality of bar planting height layers which are sequentially arranged at intervals from top to bottom on a pile foundation to be underpinned;
(a2) drilling a plurality of bar planting holes in a bar planting height layer, wherein the bar planting holes extend from the outer side surface of a pile foundation to be underpinned to the interior of the pile foundation to be underpinned, cleaning and dedusting the bar planting holes, then injecting anchoring glue into the bar planting holes, and inserting and installing prefabricated connecting steel bars into each bar planting hole in which the anchoring glue is injected to complete bar planting of the bar planting height layer;
(a3) repeating the step (a2), and planting bars on the rest bar planting height layers one by one.
In the construction method, preferably, each of the bar-planting holes extends upwards from the outer side surface of the pile foundation to be underpinned to the inner side of the pile foundation to be underpinned in an inclined manner, and the inclined angle of the bar-planting hole relative to the horizontal plane is greater than or equal to 10 degrees.
In the construction method, preferably, the distance between any two bar planting holes on the pile foundation to be underpinned is less than or equal to 35 cm; in any horizontal section of the pile foundation to be underpinned, the number of the bar planting holes is not more than two.
In the construction method, preferably, the aperture of the rib planting hole is larger than or equal to the diameter of the connecting steel bar by +4mm, and the depth of the rib planting hole is larger than or equal to the preset implantation depth of the connecting steel bar by +15 mm.
In the construction method, preferably, in the process of drilling the bar planting hole, if the drill bit touches the steel bar inside the pile foundation to be underpinned, the drilling is stopped immediately, and the position is changed to drill the hole again.
Compared with the prior art, the invention has the advantages that:
the construction method of the underpinning beam in the underpinning construction of the pile foundation comprises the steps of firstly forming a plurality of grooves on the outer side surface of the pile foundation to be underpinned and implanting a plurality of connecting reinforcing steel bars, then binding the periphery of the pile foundation to be underpinned to form a reinforcing steel bar framework connected with the connecting reinforcing steel bars, erecting a template, pouring concrete into the template, curing to obtain the underpinning beam with a reinforced concrete structure, arranging the grooves and the connecting reinforcing steel bars on the outer side surface of the underpinning pile foundation, enabling the grooves to be better combined with the concrete poured to form the underpinning beam, enabling the connecting reinforcing steel bars to be connected with the reinforcing steel bar framework inside the underpinning beam, improving the combination degree and the connection strength of the underpinning beam and the pile foundation to be underpinned, and improving the integral structural strength and.
Drawings
Fig. 1 is a flow chart of a construction method of an underpinning beam in pile foundation underpinning construction.
Detailed Description
The invention is described in further detail below with reference to the figures and specific examples.
As shown in fig. 1, the construction method of the underpinning beam in the pile foundation underpinning construction of the embodiment includes the following steps:
(A) forming a plurality of grooves on the outer side surface of the pile foundation to be underpinned, and implanting a plurality of connecting steel bars on the outer side surface of the pile foundation to be underpinned;
(B) binding the periphery of the pile foundation to be underpinned to form a steel bar framework connected with the connecting steel bars, and erecting a template on the periphery of the steel bar framework;
(C) and pouring concrete into the template, and curing to obtain the underpinned beam.
The construction method of the underpinning beam in the underpinning construction of the pile foundation comprises the steps of firstly forming a plurality of grooves on the outer side surface of a pile foundation to be underpinned and implanting a plurality of connecting steel bars, then binding and forming a steel reinforcement framework connected with the connecting steel bars on the periphery of the pile foundation to be underpinned and erecting a set template, pouring concrete into the template, obtaining the underpinning beam of a reinforced concrete structure after curing, arranging the grooves and the connecting steel bars on the outer side surface of the underpinning pile foundation simultaneously, enabling the grooves to be combined with the concrete which is poured to form the underpinning beam better, enabling the connecting steel bars to be connected with the steel reinforcement framework inside the underpinning beam, improving the combination degree and the connection strength of the underpinning beam and the pile foundation to be underpinned, and improving the overall structure strength.
In this embodiment, framework of steel reinforcement has the two-layer more than annular reinforcing bar stratum reticulare that encircles the pile foundation setting, and the two-layer more than annular reinforcing bar stratum reticulare all links to each other with each connecting reinforcement, and the mode setting of establishing is in order to overlap from inside to outside on the more than annular reinforcing bar stratum reticulare of both sides. More than two layers of annular reinforcing steel mesh layers are close to the connecting position of the underpinning beam and the pile foundation, so that the connecting strength and the stress uniformity of the underpinning beam and the pile foundation can be greatly improved.
In this embodiment, the interval between two adjacent annular reinforcing bar stratum reticulare is 400mm ~ 600mm, under the circumstances of guaranteeing joint strength, has saved the quantity of reinforcing bar, does benefit to reduce cost and improves the efficiency of construction.
In this embodiment, in the step (C), the grooves are cleaned before concrete is poured, and the interface treatment agent is brushed on the inner walls of the grooves within four hours before the concrete is poured, so as to improve the connection strength between the concrete and the pile foundation, and further improve the connection strength between the underpinned beam formed by pouring and the pile foundation.
In this embodiment, in step (C), at least two water-through radiating pipes arranged at intervals up and down are preset in the formwork before concrete is poured, cooling water is introduced into each water-through radiating pipe after concrete is poured for cooling and maintenance, and a mode of arranging the water-through radiating pipes inside and cooling water for cooling and maintenance is adopted, so that the temperature of concrete in the underpinning beam can be reduced, cracking of the concrete caused by too large temperature difference between the inside and the outside is prevented, cracks in the concrete are reduced, and the overall quality of the underpinning beam is improved.
In this embodiment, implanting a plurality of connecting steel bars into the outer side of the pile foundation to be underpinned specifically includes the following steps:
(a1) presetting a plurality of bar planting height layers which are sequentially arranged at intervals from top to bottom on a pile foundation to be underpinned;
(a2) drilling a plurality of bar planting holes in a bar planting height layer, wherein the bar planting holes extend from the outer side surface of a pile foundation to be underpinned to the interior of the pile foundation to be underpinned, cleaning and dedusting the bar planting holes, then injecting anchoring glue into the bar planting holes, and inserting and installing prefabricated connecting steel bars into each bar planting hole in which the anchoring glue is injected to complete bar planting of the bar planting height layer;
(a3) and (a2) repeating the step, and planting the bars on the other bar planting height layers one by one.
This kind of bar planting method in pile foundation underpins construction predetermines a plurality of bar planting height layers that are located co-altitude on treating the underpinning pile foundation, adopt and carry out the mode of bar planting one by one to a plurality of bar planting height layers and implant the connecting reinforcement on treating the underpinning pile foundation, this kind sets up multilayer bar planting height layer and implants the mode of connecting reinforcement to multilayer bar planting height layer successive layer, but the influence that underpinning pile foundation structural strength and stability caused is treated to the greatly reduced bar planting in-process, the security of guarantee construction, and pile foundation underpins construction quality.
In this embodiment, each bar planting hole upwards extends towards the inside slope of waiting to underpin the pile foundation from the outside of waiting to underpin the pile foundation, and the inclination angle more than or equal to 10 in bar planting hole for the horizontal plane. Therefore, after the reinforcing mesh connected with the connecting reinforcing steel bars is arranged at the subsequent stage and concrete is poured to form the underpinning beam, the connecting reinforcing steel bars extending obliquely can provide better shearing resistance, so that the underpinning beam can better support the pile foundation
In this embodiment, the interval between two arbitrary planting muscle holes on the pile foundation is less than or equal to 35cm, and is less to the structural strength influence of pile foundation, has compromise simultaneously and has satisfied the joint strength of pile foundation with subsequent connection cushion cap. In arbitrary horizontal cross-section on the pile foundation, the quantity in bar planting hole is no longer than two, has guaranteed the structural strength and the stability of pile foundation.
In the embodiment, the aperture of the rib planting hole is larger than or equal to the diameter of the connecting steel bar by +4mm, and the depth of the rib planting hole is larger than or equal to the preset implantation depth of the connecting steel bar by +15 mm. Both be convenient for connecting reinforcement insert plant muscle hole, and do benefit to connecting reinforcement and pass through anchor glue and plant muscle hole pore wall and form good being connected, improve joint strength and steadiness.
In this embodiment, in the process of drilling the bar planting hole, if the drill bit touches the internal steel bar of the pile foundation, the drilling should be stopped immediately, and the hole is drilled again by changing the position. Further reduce the influence that the bar planting in-process led to the fact the structural strength and the stability of pile foundation, the security of guarantee construction.
The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above-described embodiments. Modifications and variations that may occur to those skilled in the art without departing from the spirit and scope of the invention are to be considered as within the scope of the invention.
Claims (10)
1. A construction method of a underpinning beam in pile foundation underpinning construction is characterized by comprising the following steps:
(A) forming a plurality of grooves on the outer side surface of the pile foundation to be underpinned, and implanting a plurality of connecting steel bars on the outer side surface of the pile foundation to be underpinned;
(B) binding the periphery of the pile foundation to be underpinned to form a steel bar framework connected with the connecting steel bars, and erecting a template on the periphery of the steel bar framework;
(C) and pouring concrete into the template, and curing to obtain the underpinned beam.
2. The construction method according to claim 1, wherein the steel reinforcement cage has two or more annular steel reinforcement mesh layers provided around the pile foundation and connected to the respective connecting reinforcements, and the two or more annular steel reinforcement mesh layers are provided so as to be sequentially fitted from inside to outside.
3. The construction method according to claim 2, wherein the distance between two adjacent annular reinforcing mesh layers is 400-600 mm.
4. The construction method according to claim 1, wherein in the step (C), each groove is cleaned before the concrete is poured, and the interface treatment agent is brushed on the inner wall of the groove within four hours before the concrete is poured.
5. The construction method according to claim 1, wherein in the step (C), at least two water-through heat-radiating pipes are arranged in the form at intervals up and down in advance before the concrete is poured, and cooling water is introduced into each water-through heat-radiating pipe after the concrete is poured for cooling maintenance.
6. The construction method according to any one of claims 1 to 5, wherein the step of implanting a plurality of connecting steel bars on the outer side of the pile foundation to be underpinned specifically comprises the steps of:
(a1) presetting a plurality of bar planting height layers which are sequentially arranged at intervals from top to bottom on a pile foundation to be underpinned;
(a2) drilling a plurality of bar planting holes in a bar planting height layer, wherein the bar planting holes extend from the outer side surface of a pile foundation to be underpinned to the interior of the pile foundation to be underpinned, cleaning and dedusting the bar planting holes, then injecting anchoring glue into the bar planting holes, and inserting and installing prefabricated connecting steel bars into each bar planting hole in which the anchoring glue is injected to complete bar planting of the bar planting height layer;
(a3) repeating the step (a2), and planting bars on the rest bar planting height layers one by one.
7. The construction method according to claim 6, wherein each tendon-planting hole extends obliquely upwards from the outer side surface of the pile foundation to be underpinned to the interior of the pile foundation to be underpinned, and the inclination angle of the tendon-planting hole relative to the horizontal plane is greater than or equal to 10 degrees.
8. The construction method according to claim 6, wherein the distance between any two bar planting holes on the pile foundation to be underpinned is less than or equal to 35 cm; in any horizontal section of the pile foundation to be underpinned, the number of the bar planting holes is not more than two.
9. The construction method according to claim 6, wherein the diameter of the bar planting hole is larger than or equal to the diameter of the connecting steel bar by +4mm, and the depth of the bar planting hole is larger than or equal to the preset implantation depth of the connecting steel bar by +15 mm.
10. The construction method as claimed in claim 6, wherein during drilling the bar-planting holes, if the drill bit hits the steel bars inside the pile foundation to be underpinned, the drilling is stopped immediately, and the position is changed to drill the holes again.
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CN202011188884.XA CN112411613A (en) | 2020-10-30 | 2020-10-30 | Underpinning beam construction method in pile foundation underpinning construction |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115126016A (en) * | 2022-07-28 | 2022-09-30 | 中铁四局集团第二工程有限公司 | Construction method for connecting underpinned beam and existing pier |
CN116356880A (en) * | 2023-04-12 | 2023-06-30 | 中交第四航务工程局有限公司 | Construction method for pipe ditch joist replacement |
-
2020
- 2020-10-30 CN CN202011188884.XA patent/CN112411613A/en active Pending
Non-Patent Citations (2)
Title |
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杨正华: ""地铁隧道下穿异型连续梁桩基托换设计"", 《铁道标准设计》 * |
薛保国: ""深圳福田站桩基托换技术研究"", 《科技创新导报》 * |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN115126016A (en) * | 2022-07-28 | 2022-09-30 | 中铁四局集团第二工程有限公司 | Construction method for connecting underpinned beam and existing pier |
CN116356880A (en) * | 2023-04-12 | 2023-06-30 | 中交第四航务工程局有限公司 | Construction method for pipe ditch joist replacement |
CN116356880B (en) * | 2023-04-12 | 2023-11-21 | 中交第四航务工程局有限公司 | Construction method for pipe ditch joist replacement |
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Application publication date: 20210226 |