CN215105258U

CN215105258U - Small-diameter cast-in-place pile for resisting floating

Info

Publication number: CN215105258U
Application number: CN202120509310.1U
Authority: CN
Inventors: 熊继业; 刘武; 廖一兵; 王海霖; 吴健雄; 张道勇; 李佳敏; 彭维
Original assignee: China Machinery International Engineering Design and Research Institute Co Ltd
Current assignee: China Machinery International Engineering Design and Research Institute Co Ltd
Priority date: 2021-03-10
Filing date: 2021-03-10
Publication date: 2021-12-10
Anticipated expiration: 2031-03-10

Abstract

The utility model discloses a minor diameter bored concrete pile for anti superficial, a serial communication port, the pile body diameter of bored concrete pile (1) is less than or equal to 250mm, be provided with the steel reinforcement cage in bored concrete pile (1), the steel reinforcement cage includes anti-pulling reinforcement (4) of a plurality of vertical extensions, the top of bored concrete pile (1) is basement bottom plate (5), the top of anti-pulling reinforcement (4) is stretched out bored concrete pile (1) and is located basement bottom plate (5) and be in the level state of buckling. The utility model adopts the small-diameter cast-in-place pile to resist floating, can avoid using large-scale equipment such as a long spiral drilling rig, a rotary drilling rig and the like, can be constructed by using a traditional anchor rod drilling rig, is convenient to construct and saves the construction period; simultaneously, prestress tensioning is not needed to be carried out on the anti-pulling reinforcing steel bars, tensioning holes are not needed to be formed in the basement bottom plate, process crossing is reduced, and construction progress is improved.

Description

Small-diameter cast-in-place pile for resisting floating

Technical Field

The utility model relates to a minor diameter bored concrete pile for anti superficial belongs to building underground structure anti-floating structure technical field.

Background

Most basements have anti-floating problems. The solutions commonly adopted at present are anti-floating anchor rods, large-diameter anti-floating anchor piles or pre-stressed anchor rods. According to the regulation of the technical Standard for anti-floating of constructional engineering JGJ 476-2019: the anti-floating design grade is the first grade engineering, the design is carried out according to no crack, and the anchoring slurry body does not generate tensile stress under the standard combination of load effect; the anti-floating engineering with the design grade of B is designed according to crack control, and the tensile stress in the anchoring slurry body under the standard combination of load effect is not greater than the axial tensile strength of the anchoring slurry body. It is known that the conventional anchor rod with centered reinforcing steel bars has been limited to be used in the project with the anti-floating design grade of A due to poor anti-cracking performance. Therefore, the project with the anti-floating design grade of A can only select anti-floating anchor piles or prestressed anti-floating anchors.

The anti-floating anchor pile can bear water buoyancy and pressure of an upper structure. However, the diameter of the traditional pile is larger and is influenced by equipment or construction, the diameter of the long spiral pressure grouting pile is not less than 400mm, the diameter of the rotary excavating pile is not less than 600mm, and the diameter of the manual hole digging pile is not less than 800 mm; the construction machinery of the anti-floating anchor pile generally adopts a long spiral drilling machine and a rotary drilling machine, and has larger equipment and high cost.

The prestressed anchor rod has the advantages of complex construction process, long period, high cost and unsatisfactory waterproof effect.

SUMMERY OF THE UTILITY MODEL

In order to overcome the problem that exists among the prior art, the utility model provides a minor diameter bored concrete pile for anti superficial is favorable to simplifying construction equipment, reduces construction cost, avoids leaving the stretch-draw hole in the basement bottom plate simultaneously. The specific technical scheme is as follows.

The utility model provides a minor diameter bored concrete pile for anti floating, its characterized in that, bored concrete pile's pile body diameter is less than or equal to 250mm, be provided with the steel reinforcement cage in the bored concrete pile, the steel reinforcement cage includes the anti-pulling reinforcement of the vertical extension of a plurality of roots, the top of bored concrete pile is the basement bottom plate, the top of anti-pulling reinforcement is stretched out the bored concrete pile and is located the basement bottom plate and be in the horizontal bending state.

The small-diameter cast-in-place pile is adopted for anti-floating, so that large-scale equipment such as a long spiral drilling rig and a rotary drilling rig can be avoided, construction can be carried out by using a traditional anchor rod drilling rig, construction is convenient, and the construction period is shortened; simultaneously, prestress tensioning is not needed to be carried out on the anti-pulling reinforcing steel bars, tensioning holes are not needed to be formed in the basement bottom plate, process crossing is reduced, and construction progress is improved.

Further, the steel reinforcement cage includes location steel pipe, spiral stirrup and the resistance to plucking reinforcing bar, the location steel pipe is provided with a plurality ofly along the direction of height interval, resistance to plucking reinforcing bar evenly distributed in the surface of location steel pipe and with location steel pipe fixed connection, spiral stirrup spiral winding in resistance to plucking reinforcing bar is peripheral. The positioning steel pipe can keep the external diameter and the coaxiality which are beneficial to keeping the whole reinforcement cage, and the spiral stirrups are beneficial to increasing the contact area of the reinforcement cage and the pile body of the cast-in-place pile and increasing the anchoring performance. Compared with the traditional anchor rod, the reinforcing cage in the form fully disperses the tensile stress, and is beneficial to enhancing the anti-cracking performance of the anchoring body.

Further, the length of the positioning steel tube along the height direction is 80-120 mm.

Furthermore, the anti-pulling steel bars are ordinary HRB400 steel bars.

Further, the pile body of the cast-in-place pile is cast by adopting a secondary grouting process, fine aggregate concrete with the strength grade not less than C30 or cement mortar with the strength grade not less than M30 is adopted for the first grouting, and cement mortar with the strength grade not less than M30 is adopted for the second grouting. By adopting the secondary grouting process, the pile body poured by the pile body is compact, has the functions of permeating, reinforcing and encrypting surrounding soil, and can improve the bearing capacity of the pile body.

The utility model discloses compare and have following beneficial effect in prior art:

1. the utility model discloses a minor diameter stake (stake footpath is less than or equal to 250mm), pore-forming simple process, the equipment requirement is low, can be under construction with traditional roofbolter, construction period is practiced thrift to convenient construction.

2. The small-diameter piles can be uniformly paved on the whole basement (the existing large-diameter anti-floating piles are generally arranged below the columns), the stress is dispersed, the anti-floating bottom plate (basement bottom plate) is uniformly stressed, the thickness of the bottom plate and the reinforcement are saved, and the cost is saved.

3. The single pile has low bearing capacity and is convenient to detect.

4. The vertical rigidity of the pile is small, and the structure is hardly influenced when the pile is stressed in the positive direction.

5. Construction is carried out before the basement bottom plate, so that the process intersection is reduced, and the construction progress is improved.

6. The pre-stressed tensioning channel is prevented from being reserved on the bottom plate, and the construction process of high-pressure grouting of the tensioning hole is reduced.

7. The basement bottom plate is poured as a whole, and leakage caused by stretching holes is avoided.

Drawings

Fig. 1 is a schematic view of a small-diameter cast-in-place pile according to the present invention;

fig. 2 is a schematic sectional view taken along line a-a in fig. 1.

In the figure: the cast-in-place pile comprises a cast-in-place pile 1, a positioning steel pipe 2, a spiral stirrup 3, an anti-pulling steel bar 4 and a basement bottom plate 5.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings.

Referring to fig. 1-2, a minor diameter bored concrete pile for anti-floating, bored concrete pile 1's pile body diameter is less than or equal to 250mm, be provided with the steel reinforcement cage in the bored concrete pile 1, the steel reinforcement cage includes location steel pipe 2, spiral stirrup 3 and resistance to plucking reinforcing bar 4, location steel pipe 2 is provided with a plurality ofly along the direction of height interval, resistance to plucking reinforcing bar 4 evenly distributed in the surface of location steel pipe 2 and with location steel pipe 2 fixed connection, 3 spiral windings of spiral stirrup are in the periphery of resistance to plucking reinforcing bar 4 and location steel pipe 2, the preferred three of number of resistance to plucking reinforcing bar 4, extend along vertical direction. The top of bored concrete pile 1 is basement bottom plate 5, and the top of resistance to plucking reinforcing bar 4 stretches out bored concrete pile 1 and is located basement bottom plate 5 and be in the horizontal bending state.

The anti-pulling steel bars 4 are HRB400 steel bars, the number and the diameter of the anti-pulling steel bars 4 can be calculated and determined according to specific conditions, the cast-in-place pile is a small-diameter mechanical drilling pile, and construction can be achieved by adopting a traditional anchor rod drilling machine.

The positioning steel pipes 2 are arranged at intervals of 2000mm in the height direction, the wall thickness of each positioning steel pipe 2 is 3-4 mm, the positioning steel pipes can be used as common pipe erecting devices, and the length in the height direction is 80-120 mm.

The manufacturing and mounting process of the cast-in-place pile reinforcement cage comprises the following steps: 1) removing oil stains and iron rust on the surface of the steel bar, and binding a steel bar cage according to design requirements; and binding the 2 grouting pipes with the reinforcing steel bars respectively. Sealing a slurry outlet hole and an end head of a high-pressure slurry injection pipe for secondary slurry injection; 2) the whole reinforcement cage is suitable to be hung; 3) the reinforcement cage should be suspended or supported to ensure the position and height of the concrete when grouting or pouring.

The cast-in-place pile hole forming and casting process comprises the following steps: 1) selecting proper mechanical pore-forming according to the geological condition, wherein the geological condition of a rock-soil layer can be judged according to the requirement during mechanical pore-forming and coring; 2) the hole site error is not more than 50 mm; 3) the perpendicularity deviation of the pile body is less than or equal to 1 percent; 4) casing protection wall drilling is preferably adopted for construction in unstable strata; 5) the bored concrete pile is drilled by adopting a dry drilling hole forming process, thereby avoiding the generation of mud skin caused by adopting a water drill and ensuring the construction quality of the bored concrete pile. The pile body is poured by adopting a secondary grouting process, wherein the primary grouting is performed by using fine aggregate concrete with the strength grade of more than or equal to C30 or cement mortar with the strength grade of more than or equal to M30, and the secondary grouting is performed by using cement mortar with the strength grade of more than or equal to M30. During the maintenance of the cast-in-place pile, random collision is avoided. And after the construction of all the cast-in-place piles is finished, carrying out the integral construction of the basement bottom plate.

The embodiments of the present invention have been described above with reference to the accompanying drawings, and features of the embodiments and examples of the present invention may be combined with each other without conflict. The present invention is not limited to the above-mentioned embodiments, which are only illustrative and not restrictive, and those skilled in the art can make many forms without departing from the spirit and the scope of the present invention, which is encompassed by the present invention.

Claims

1. The utility model provides a minor diameter bored concrete pile for anti floating, its characterized in that, the pile body diameter of bored concrete pile (1) is less than or equal to 250mm, be provided with the steel reinforcement cage in bored concrete pile (1), the steel reinforcement cage includes anti-pulling reinforcement (4) of a plurality of vertical extensions, the top of bored concrete pile (1) is basement bottom plate (5), the top of anti-pulling reinforcement (4) is stretched out bored concrete pile (1) and is located basement bottom plate (5) and be in the horizontal bending state.

2. The small-diameter cast-in-place pile for resisting floating according to claim 1, characterized in that the reinforcement cage comprises a positioning steel pipe (2), a plurality of spiral stirrups (3) and the anti-pulling reinforcement (4), the positioning steel pipe (2) is arranged at intervals along the height direction, the anti-pulling reinforcement (4) is uniformly distributed on the outer surface of the positioning steel pipe (2) and is fixedly connected with the positioning steel pipe (2), and the spiral stirrups (3) are spirally wound on the periphery of the anti-pulling reinforcement (4).

3. A small diameter bored concrete pile for anti-floating according to claim 2, wherein the length of said steel spud (2) in the height direction is 80-120 mm.

4. A small diameter bored concrete pile for anti-floating according to claim 2, wherein the anti-pulling steel bars (4) are HRB400 steel bars.

5. The small-diameter cast-in-place pile for resisting floating according to claim 1, characterized in that the pile body of the cast-in-place pile (1) is cast by a secondary grouting process, wherein the primary grouting is performed by using fine aggregate concrete with the strength grade of more than or equal to C30 or cement mortar with the strength grade of more than or equal to M30, and the secondary grouting is performed by using cement paste with the strength grade of more than or equal to M30.