Finishing-free concrete pile head structure

Abstract

The utility model relates to the field of building construction, and discloses a finishing-free concrete pile head structure which is characterized in that a plurality of reinforcement cages are arranged and are annularly distributed, the upper portion of the surface of the outer ring of each reinforcement cage is sleeved with an isolation sleeve, the multiple isolation sleeves are sleeved with an isolation film, and the isolation film is sleeved with a plurality of reinforcement cages. A pouring hole is formed in the inner ring of the isolating membrane, concrete is poured on the multiple reinforcement cages and the isolating membrane to form a concrete pile head, the upper portion and the lower portion of the concrete pile head are divided into a pile head portion and an over-pouring portion through the isolating membrane, and the isolating membrane is designed on the pile top to separate the concrete of the over-pouring portion of the pile top. An over-grouting part of a pile top is separated in advance to form a weak section, the characteristics that solidified concrete is uniform and can point to brittle fracture along a weak part are utilized, the concrete is firstly molded and isolated, then a steel wedge or an excavator is adopted to simply and quickly cut (fold) and break a pile head to form a neat section, and the procedure of finishing the pile head is omitted.

Description

Technical Field

[0001] The utility model relates to the field of building construction, in particular to a concrete pile head structure free of repair. Background Art

[0002] Through the research and analysis of the technical level of pile head breaking of rotary bored piles in various regions across the country, it is found that the common point of most of the methods for breaking the over-filled part of the pile top in China is that the traditional method of breaking the over-filled part of the concrete is adopted after the concrete reaches a certain strength to retain the effective pile body. The breaking methods can be divided into overall pile head breaking and partial overall pile head breaking. Overall pile head breaking: pre-embed the steel bar isolation sleeve, then cut the ring, and then use mechanical or manual methods to separate the pile head along the ring cut; partial breaking: omitting the process of burying the isolation sleeve, first peeling off the steel bar wrapped concrete, and then using mechanical or manual methods to ring-break and separate the over-filled part of the pile top. However, these methods all have the common disadvantages of low efficiency and high labor and mechanical costs. For this reason, we designed a concrete pile head structure that does not require finishing. Summary of the invention

[0003] In order to solve the technical problems of low efficiency in breaking and separating the overfilled part of the pile top and high labor and machinery costs, the utility model provides a concrete pile head structure that does not require repair.

[0004] The utility model is implemented by the following technical scheme: a repair-free concrete pile head structure, including a steel cage, a plurality of the steel cages are provided, and the plurality of the steel cages are distributed in a ring shape, an isolation sleeve is sleeved on the outer ring surface of each steel cage, an isolation membrane is sleeved on the plurality of isolation sleeves, an inner ring opening of the isolation membrane is designed to form a pouring hole, concrete is poured on the plurality of steel cages and the isolation membrane to form a concrete pile head, and the upper and lower parts of the concrete pile head are separated into a pile head part and an over-pouring part by the isolation membrane.

[0005] As a further improvement of the above scheme, an elastic rubber ring is provided in the inner circle of the pouring hole, and a steel wire ring is provided in the outer edge membrane of the isolation membrane. The isolation membrane is tightened by the elastic rubber ring and the steel wire ring, which is convenient for the installation and fixation of the isolation membrane. The open design of the pouring hole also makes it easy to place the catheter therein, thereby facilitating the subsequent pouring of concrete.

[0006] As a further improvement of the above scheme, the isolation membrane includes two layers of geomembranes, the outer edge of the isolation membrane is designed with hot-melt sealing, and a geotextile is sandwiched between the two layers of the geomembrane, and the geotextile adopts a specification of 300-500g, wherein the geomembrane adopts a double-sided impermeable geomembrane, and the isolation membrane separates the upper invalid pile head to form a ring defect, thereby achieving the purpose of quickly breaking the invalid pile head.

[0007] As a further improvement of the above solution, a plurality of ring-shaped steel bar through-holes are provided on the isolation membrane, and the size of the steel bar through-holes matches the size of the isolation sleeve, so as to facilitate the installation and fixation of the steel bar cage and the isolation sleeve.

[0008] As a further improvement of the above scheme, the isolation membrane is divided into an outer weak ring and an inner weak ring by a plurality of steel cages, and the isolation membrane is located between the pile head part and the over-pouring part. The isolation membrane is used to separate the upper invalid pile head to form a ring defect and to layer the concrete. The pile head can be simply and quickly cut (broken) by a steel wrench or an excavator to form a neat cross-section, eliminating the process of trimming the pile head.

[0009] As a further improvement of the above scheme, the isolation sleeve is an EPE foam tube, and the upper and lower ends of the isolation sleeve are fixed to the steel cage by cable ties. There is a 5-8 cm spacing between the upper cable tie and the top of the steel cage, and there is a 5-8 cm spacing between the lower cable tie and the bottom of the isolation sleeve. A material with a lateral strength much lower than that of concrete is embedded in the concrete for filling. The principle that the fixed point of the end of a homogeneous rod fixed at one end is subjected to the largest torque when subjected to shear force, and the principle that a homogeneous rod fixed at one end is subjected to shear force and stress concentration is generated at the defect of the rod, can be used to break the pile head. When the pile head is broken, the excavator bucket can be used to apply a sufficiently large force (or impact force) perpendicular to the pile body at the pile end to break the pile head.

[0010] Compared with the prior art, the beneficial effects of the present invention are:

[0011] 1. The utility model designs an isolation membrane at the top of the pile to separate the over-filled part of the concrete at the top of the pile. By pre-embedding and sparse concrete materials in the early stage to separate the concrete, the over-filled part of the pile top is separated in advance to form a weak section. It utilizes the characteristics of the solidified concrete, which is homogeneous and can be directed along the weak part to brittle fracture, and the principle that the fixed point of the end of the homogeneous rod fixed at one end is subjected to the maximum moment, and the principle that the uniform rod fixed at one end is subjected to shear force and stress concentration occurs at the defect of the rod. The essence is to pre-shape the isolation concrete, and then use a steel wedge or an excavator to simply and quickly cut (break) the pile head to form a neat cross section, eliminating the process of trimming the pile head, and achieving the effect of reducing costs and increasing efficiency.

[0012] 2. The upper invalid pile head is separated by an isolation membrane to form an annular defect, so as to achieve the purpose of quickly breaking the invalid pile head. The pile head can be broken by applying a sufficiently large force (or impact force) perpendicular to the pile body at the pile end by an excavator bucket. When breaking a large pile diameter, the gap of the pre-buried isolation membrane of the present invention can be used to directly nail the steel wedge into the cracked pile head. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 The utility model provides a schematic diagram of the overall structure of a concrete pile head structure that does not require any repair;

[0014] Figure 2 for Figure 1 Schematic diagram of isolation sleeve and isolation membrane;

[0015] Figure 3 for Figure 2 Schematic diagram of the isolation membrane plane;

[0016] Figure 4 Schematic diagram of the force analysis of the broken pile head by an excavator.

[0017] Description of main symbols:

[0018] 1. Concrete pile head; 2. Steel cage; 3. Isolation sleeve; 4. Cable tie; 5. Isolation membrane; 51. Steel perforation; 52. Casting hole; 6. Steel wire ring; 7. Elastic rubber ring. DETAILED DESCRIPTION

[0019] The present invention is further described below in conjunction with the accompanying drawings and specific implementation methods. It should be noted that, under the premise of no conflict, the various embodiments or technical features described below can be arbitrarily combined to form a new embodiment. Example

[0020] Please combine Figure 1-Figure 4 A repair-free concrete pile head structure of the present embodiment includes a steel cage 2, a plurality of steel cages 2 are provided, and the plurality of steel cages 2 are distributed in a ring shape, an isolation sleeve 3 is sleeved on the outer surface of each steel cage 2, an isolation membrane 5 is sleeved on the plurality of isolation sleeves 3, and an inner opening of the isolation membrane 5 is designed to form a pouring hole 52, concrete is poured on the plurality of steel cages 2 and the isolation membrane 5 to form a concrete pile head 1, and the upper and lower parts of the concrete pile head 1 are separated into a pile head part and an over-pouring part by the isolation membrane 5.

[0021] An elastic rubber ring 7 is provided in the inner circle of the pouring hole 52, and a wire ring 6 is provided in the outer edge membrane of the isolation membrane 5. The isolation membrane 5 is tightened by the elastic rubber ring 7 and the wire ring 6, which is convenient for the installation and fixation of the isolation membrane 5. The open design of the pouring hole 52 also makes it convenient to place the catheter therein, thereby facilitating the subsequent pouring of concrete.

[0022] The isolation membrane 5 includes two layers of geomembranes, the outer edge of the isolation membrane 5 is designed with hot-melt sealing, and a geotextile is sandwiched between the two layers of geomembranes. The geotextile adopts a specification of 300-500g, and the geomembrane adopts a double-sided impermeable geomembrane. The isolation membrane 5 separates the upper invalid pile head to form a ring defect, thereby achieving the purpose of quickly breaking the invalid pile head.

[0023] The isolation membrane 5 is provided with a plurality of annularly distributed steel bar through-holes 51 , the size of which matches the size of the isolation sleeve 3 , so as to facilitate the installation and fixation of the steel bar cage 2 and the isolation sleeve 3 .

[0024] The isolation membrane 5 is divided into an outer weak ring and an inner weak ring by a plurality of steel cages 2, and the isolation membrane 5 is located between the pile head part and the over-filled part. The isolation membrane 5 is used to separate the upper invalid pile head to form a ring defect and to layer the concrete. The pile head can be simply and quickly cut (broken) by a steel wedge or an excavator to form a neat cross-section, eliminating the process of trimming the pile head.

[0025] The isolation sleeve 3 is an EPE foam tube, and the upper and lower ends of the isolation sleeve 3 are fixed to the steel cage 2 by cable ties 4. There is a 5-8cm gap between the upper cable tie 4 and the top of the steel cage 2, and there is a 5-8cm gap between the lower cable tie 4 and the bottom of the isolation sleeve 3. A material with a lateral strength much lower than that of the concrete is embedded in the concrete for filling. The principle that the fixed point of the end of the homogeneous rod fixed at one end is subjected to the largest torque, and the principle that the homogeneous rod fixed at one end is subjected to shear force and stress concentration is generated at the defect of the rod, when breaking the pile head, the excavator bucket can be used to apply a sufficiently large force (or impact force) perpendicular to the pile body at the pile end to break the pile head.

[0026] The implementation principle of a repair-free concrete pile head structure in the embodiment of the present application is as follows: first, an isolation sleeve 3 is installed for the longitudinal reinforcement at the overfilled end of the steel cage 2. The steel isolation sleeve 3 uses an EPE foam tube with a length greater than the anchoring section of the steel cage 2 by 5 cm, an inner diameter greater than the steel bar diameter by 5-10 mm, and a wall thickness of 5-10 mm. The steel bar is tied and fixed to the steel cage 2 with a tie 4 at 5 cm-8 cm from the top and bottom of the steel bar. Then, an isolation membrane 5 is pre-installed on the steel cage 2 at the overfilled part to form an inner weak ring and an outer weak ring. Weak link, then install and position the steel cage 2, according to the calculated pile top elevation (the pile top elevation is the isolation membrane 5 installation plane), weld the suspension bar, and then pour concrete. After pouring concrete, re-measure the steel cage 2 elevation. If the elevation deviation is greater than 20mm, it is necessary to use a crane to lift or an excavator to put a steel pipe to lower the steel cage 2 for adjustment. After the pile head reaches the designed strength, the pile head can be broken, and the excavator bucket can be used to act on the pile top to break or knock off the pile head. A steel wedge can also be used to knock in along the isolation membrane 5 to break the pile head (such as Figure 4 As shown), the flexural strength at the isolation membrane 5 is calculated based on the axial force and moment balance analysis:

[0027] Fp*L>Ff·(r / 2)=ftk·π·r 2 (r / 2)

[0028] Where: Fp is the excavation force (acting force) of the excavator, L is the distance from the action point to the weak ring, Ff is the tensile axial force of the pile head, r is the effective section radius at the weak ring, and ftk is the tensile strength. Take the C35 concrete pile and the effective section radius of the weak ring of the isolation membrane 5 as 390mm:

[0029] Fp>ftk·π·r2·r / 800=2.2*3.14*195 2 *195 / 800=64027 (N) i.e. Fp>64kN, where the tensile strength of C35 is 2.20N / mm 2 Therefore, as long as the excavator exerts a force greater than 64kN on the pile top, the pile head can be broken.

[0030] An isolation membrane 5 is designed at the top of the pile to separate the over-filled concrete at the top of the pile. By pre-embedding and sparse concrete materials in the early stage to separate the concrete, the over-filled part of the pile top is separated in advance to form a weak section. It utilizes the characteristics of the solidified concrete, which is homogeneous and can be directed along the weak point to brittle fracture, and the principle that the moment of the fixed point of the uniform rod end fixed at one end is the largest, and the principle that the uniform rod fixed at one end is subjected to shear force and stress concentration occurs at the defect of the rod. The essence is to pre-shape the isolation concrete, and then use a steel wedge or an excavator to simply and quickly cut (break) the pile head to form a neat section, eliminating the process of trimming the pile head, and achieving the effect of reducing costs and increasing efficiency.

[0031] The upper invalid pile head is separated by the isolation membrane 5 to form an annular defect, so as to achieve the purpose of quickly breaking the invalid pile head. The pile head can be broken by applying a sufficiently large force (or impact force) perpendicular to the pile body at the pile end by the excavator bucket. When breaking a large pile diameter, the gap of the pre-buried isolation membrane 5 of the present invention can be used to directly nail the steel wedge into the cracked pile head.

[0032] The above-mentioned implementation modes are only preferred implementation modes of the present invention, and cannot be used to limit the protection scope of the present invention. Any non-substantial changes and substitutions made by technicians in this field on the basis of the present invention shall fall within the scope of protection required by the present invention.

Claims

1. A concrete pile head structure that does not require any repair, comprising a steel cage (2), characterized in that: A plurality of the steel cages (2) are provided, and the plurality of the steel cages (2) are distributed in a ring shape. An isolation sleeve (3) is sleeved on the outer surface of each steel cage (2). An isolation membrane (5) is sleeved on the plurality of isolation sleeves (3). The inner opening of the isolation membrane (5) is designed to form a pouring hole (52). Concrete is poured on the plurality of steel cages (2) and the isolation membrane (5) to form a concrete pile head (1), and the upper and lower parts of the concrete pile head (1) are separated into a pile head part and an over-pouring part by the isolation membrane (5).

2. A repair-free concrete pile head structure as claimed in claim 1, characterized in that: An elastic rubber ring (7) is arranged inside the inner ring of the injection hole (52), a wire ring (6) is arranged inside the outer edge of the isolation membrane (5), and the isolation membrane (5) is designed to be tightened by the elastic rubber ring (7) and the wire ring (6).

3. The non-repairing concrete pile head structure according to claim 1, characterized in that: The isolation membrane (5) comprises two layers of geomembranes, the outer edge of the isolation membrane (5) is designed with hot-melt sealing, and a geotextile is sandwiched between the two layers of the geomembranes, and the geotextile adopts a specification of 300-500g, wherein the geomembrane adopts a double-sided impermeable geomembrane.

4. The non-repairing concrete pile head structure according to claim 1, characterized in that: The isolation membrane (5) is provided with a plurality of steel bar through-holes (51) distributed in a ring shape, and the size of the steel bar through-holes (51) matches the size of the isolation sleeve (3).

5. The repair-free concrete pile head structure according to claim 1, characterized in that: The isolation membrane (5) is divided into an outer weak ring and an inner weak ring by a plurality of steel cages (2), and the isolation membrane (5) is located between the pile head part and the over-pouring part.

6. The non-repairing concrete pile head structure according to claim 1, characterized in that: The isolation sleeve (3) is an EPE foam tube, and the upper and lower ends of the isolation sleeve (3) are fixed to the steel cage (2) by means of cable ties (4); There is a 5-8 cm gap between the upper tie (4) and the top end of the steel cage (2), and there is a 5-8 cm gap between the lower tie (4) and the bottom end of the isolation sleeve (3).

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