CN210013231U

CN210013231U - Take piled raft foundation of cavity pile head of adjustable stake atress

Info

Publication number: CN210013231U
Application number: CN201920519229.4U
Authority: CN
Inventors: 杨鹏
Original assignee: Wuhan Hechuang Construction Engineering Design Co Ltd
Current assignee: Wuhan Hechuang Construction Engineering Design Co Ltd
Priority date: 2019-04-16
Filing date: 2019-04-16
Publication date: 2020-02-04
Anticipated expiration: 2029-04-16

Abstract

The utility model discloses a piled raft foundation with cavity pile heads capable of adjusting pile stress, which is characterized by comprising a cast-in-place pile and a raft plate, wherein the upper part of the cast-in-place pile is poured along a circle of the periphery of the cast-in-place pile to form an annular concrete retaining wall, and the upper end surface of the annular concrete retaining wall is partially spaced from the pile top of the cast-in-place pile; the steel cover plate is placed on the upper end surface of the annular concrete retaining wall, a cavity is formed between the steel cover plate and the top end of the cast-in-place pile, and a grouting material is poured into the cavity; meanwhile, the steel cover plate is used as a bottom die of the raft plate. The utility model discloses a piled raft foundation has solved on the whole that the proportion of undertaking the load between conventional foundation form stake and the soil body is undefined, and the more shortcoming of stake number for the soil body bears the load maximize of upper portion tower, and can be through the seal time of adjusting the cavity, and the proportion of adjustment stake soil load reaches the effect that reduces pile foundation quantity simultaneously.

Description

Take piled raft foundation of cavity pile head of adjustable stake atress

Technical Field

The utility model relates to a piled raft foundation field. More specifically, the utility model relates to a take piled raft foundation of cavity pile head of adjustable stake atress.

Background

When the foundation is designed, the soil quality condition is often higher, but the foundation reaction force exceeds the bearing capacity of the soil, such as the foundation of a super high-rise building. At this time, if the pile foundation is used, the soil body can be considered to bear a part of load, and the CFG pile composite foundation and the piled raft foundation can be adopted according to the conventional method.

The CFG composite foundation is an artificial foundation formed by reinforcing foundation soil by driving concrete piles into a natural foundation, and a soil body and the piles share the load under the load action, and belongs to the representative of rigid pile composite foundations. The effect that the stake just can exert the stake must satisfy certain interval can lead to the stake number than many like this, also can lead to partly extravagant, and what the actual norm provided is the theoretical value moreover, and the counter-force that stake and soil body bore is not very accurate.

The pile-raft foundation is a pile foundation which is formed by arranging piles in a full space or partially in a full space under a raft plate and is loaded by foundation piles and foundation soil under the raft plate. The proportion of the load borne by the soil body cannot be accurately known by the piled raft foundation, sometimes the piles are conservative, the proportion of the piled raft foundation is extremely large, or the action of the soil is not considered at all, and therefore more waste is caused.

It follows from this that the two basic forms described above have common disadvantages: firstly, the arrangement of piles is to meet a certain interval; secondly, the proportion of the load between the pile and the soil mass is not clear.

It is therefore imperative to develop a new piled raft foundation that overcomes the above disadvantages.

SUMMERY OF THE UTILITY MODEL

In order to achieve the above purposes, the utility model provides a piled raft foundation with a cavity pile head capable of adjusting the stress of piles, which comprises a cast-in-place pile and a raft plate, wherein the upper part of the cast-in-place pile is poured along the periphery of the cast-in-place pile to form an annular concrete retaining wall, and the upper end surface of the annular concrete retaining wall is partially spaced from the pile top of the cast-in-place pile; the steel cover plate is placed on the upper end surface of the annular concrete retaining wall, a cavity is formed between the steel cover plate and the top end of the cast-in-place pile, and a grouting material is poured into the cavity; meanwhile, the steel cover plate is used as a bottom die of the raft, and longitudinal bars of the cast-in-place piles are anchored into the raft after being bent.

Preferably, the pile-raft foundation with the cavity pile head capable of adjusting the stress of the pile is characterized in that the steel cover plate is upwards provided with a plurality of grouting pipelines which are communicated with the cavity so as to pour grouting materials into the cavity.

Preferably, the steel cover plate is upwards provided with a plurality of pipelines for detection.

Preferably, the pile-raft foundation with the cavity pile head capable of adjusting the stress of the pile wraps a layer of water-swelling sealing rod at the contact part of the annular concrete retaining wall and the cast-in-place pile.

Preferably, the pile-raft foundation with the cavity pile head capable of adjusting the stress of the pile comprises the steel cover plate, the steel cover plate is placed on the upper end face of the annular concrete retaining wall, and the steel cover plate avoids embedded steel bars in the annular concrete retaining wall.

Preferably, the said piled raft foundation with cavity pile head capable of regulating pile force is adhered waterproof adhesive tape between the steel cover plate and the ring concrete protecting wall.

Preferably, the pile-raft foundation with the cavity pile heads capable of adjusting the stress of the piles has the height of 300-400 mm.

The utility model discloses at least, include following beneficial effect: the utility model discloses a piled raft foundation has solved on the whole that the proportion of undertaking the load between conventional foundation form stake and the soil body is undefined, and the more shortcoming of stake number for the soil body bears the load maximize of upper portion tower, and can be through the seal time of adjusting the cavity, and the proportion of adjustment stake soil load reaches the effect that reduces pile foundation quantity simultaneously.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.

Drawings

Fig. 1 is a schematic structural view of a raft foundation with cavity pile heads capable of adjusting pile stress.

Detailed Description

The present invention is further described in detail below with reference to the drawings so that those skilled in the art can implement the invention with reference to the description.

As shown in fig. 1, the utility model provides a piled raft foundation with cavity pile heads capable of adjusting pile stress, which comprises a cast-in-place pile 1 and a raft 2, wherein, the upper part of the cast-in-place pile 1 is poured along the periphery circle to form an annular concrete retaining wall 3, and the upper end surface of the annular concrete retaining wall 3 is spaced from the pile top of the cast-in-place pile 1; the steel cover plate 6 is placed on the upper end surface of the annular concrete retaining wall 3, a cavity 4 is formed between the steel cover plate and the top end (namely the pile top) of the cast-in-place pile 1, and a grouting material is poured in the cavity; meanwhile, the steel cover plate 6 is used as a bottom die of the raft plate 2. The longitudinal bars of the cast-in-place piles 1 are bent and then anchored into a raft plate, so that the cast-in-place piles and the raft plate are bundled together;

in the above embodiment, the cast-in-place piles 1 are arranged below the raft 2, a 300mm to 400mm high cavity (i.e., the height of the cavity 4 between the upper end face of the annular concrete retaining wall 3 and the upper end face of the cast-in-place pile in fig. 1 is 300mm to 400mm) is arranged at the intersection position of each cast-in-place pile head (i.e., the top end of the cast-in-place pile 1 in fig. 1) and the raft 2, and in the process of tower construction, a soil body is stressed first, and after a certain load is reached, grouting is performed into the cavity to seal the cavity, so that the bearing capacity is transmitted like the cast-in-place piles, and at this time, the cast.

Taking a 46-storey residential building as an example, the counter force of the base is 650kPa, and the area of the raft is 1600m²The characteristic value fak of bearing capacity of foundation soil under raft is 270kPa, and is calculated according to the conventional basis as follows

A. And (3) arranging the CFG composite foundation by adopting 1 m-diameter cast-in-place piles with Ra of 5000kN according to 3.3m to obtain the CFG composite foundation with the bearing capacity of 662kPa and the total number of piles of 160.

B. Pile-raft foundation, 1m diameter cast-in-place pile is adopted, Ra is 5000kN, and the number of pile foundations is 179

By adopting the technical scheme, the cast-in-place piles with the diameter of 1m are adopted, Ra is 5000kN, 250kPa is borne according to the soil body, the actual number of the piles is 126, the length of a single pile is 30m, the manufacturing cost of a single pile is 3 ten thousand, and the single building is saved by 100 ten thousand compared with the CFG composite foundation scheme and is saved by 150 ten thousand compared with the piled raft foundation. Therefore, the technical calculation mode is simple and clear, namely the bearing capacity of the pile foundation is exerted after the soil plays a sufficient role, the number of the piles is less than that of other schemes, and the economic benefit is obvious.

In another embodiment, the piled raft foundation with cavity pile heads capable of adjusting pile stress further comprises:

the steel cover plate 6 is provided with a plurality of grouting pipelines 7 upwards, and the grouting pipelines 7 are communicated with the cavity 4 so as to pour grouting materials into the cavity 4.

In another embodiment, the steel cover plate 6 is provided with a plurality of pipelines 8 for detection upwards.

In another embodiment, the pile-raft foundation with the cavity pile head capable of adjusting the stress of the pile is characterized in that a water-swelling water stop bar 9 is wrapped at the contact part of the annular concrete retaining wall 3 and the cast-in-place pile 1, so that the water-resisting sealing performance between the annular concrete retaining wall and the cast-in-place pile is better.

In another embodiment, the raft foundation with cavity pile heads capable of adjusting pile stress includes the steel cover plate 6, which is placed on the upper end surface of the annular concrete retaining wall 3 and avoids the embedded steel bars 5 in the annular concrete retaining wall 3.

In another embodiment, the said piled raft foundation with cavity pile head capable of regulating pile force is characterized by that between the above-mentioned steel cover plate 6 and the portion of ring-shaped concrete protecting wall 3 which are contacted with each other a water-proof adhesive tape is adhered, and the above-mentioned two portions are sealed.

The utility model discloses a piled raft foundation's work progress as follows:

1) after the cast-in-place pile is constructed to the elevation of the pile top, an annular concrete retaining wall 3 is formed by casting around the cast-in-place pile, a cavity with the height of 300mm-400mm is reserved between the cast-in-place pile 1 and the top end of the raft plate concrete retaining wall 3, a water swelling water stop strip is arranged between the concrete retaining wall 3 and the cast-in-place pile 1, and a raft plate is anchored into the concrete retaining wall by inclining 60 degrees (the raft plate is formed by binding steel bars);

2) placing the steel cover plate 6 on the cavity, wherein the steel cover plate 6 is required to avoid the steel bars of the concrete retaining wall, and a closed waterproof double-sided adhesive tape is arranged between the steel cover plate 6 and the lower annular concrete retaining wall 3;

3) 2

grouting pipelines

7 and 2 detection pipelines 8 are reserved and installed in the steel cover plate 6;

4) temporary plugging (avoiding blocking for construction site impurities) should be established to slip casting pipeline 7 and for detection 8 upper ends, should pay attention to when ligature raft plate reinforcing bar and prevent bumping loose steel pipe, should finish with the raft plate reinforcing bar spot welding after the reinforcement is fixed.

5) And pouring raft plate concrete, and then constructing an upper structure.

6) When the upper structure main body is constructed to a certain floor, the cavity is filled with non-shrinkage grouting material with the strength of M50, and the pile head is sealed.

7) Carrying out ultrasonic transmission detection on the pile head, and detecting the compactness of concrete; and detecting only the cast-in-place pile under the shear wall in the structure.

While the embodiments of the invention have been described above, it is not intended to be limited to the details shown, or described, but rather to cover all modifications, which would come within the scope of the appended claims, and all changes which come within the meaning and range of equivalency of the art are therefore intended to be embraced therein.

Claims

1. A piled raft foundation with a cavity pile head capable of adjusting the stress of piles is characterized by comprising a cast-in-place pile and a raft plate, wherein the upper part of the cast-in-place pile is poured along a circle of the periphery of the cast-in-place pile to form an annular concrete retaining wall, and the upper end surface of the annular concrete retaining wall is spaced from the pile top of the cast-in-place pile by a reserved part; the steel cover plate is placed on the upper end surface of the annular concrete retaining wall, a cavity is formed between the steel cover plate and the top end of the cast-in-place pile, and a grouting material is poured into the cavity; meanwhile, the steel cover plate is used as a bottom die of the raft plate.

2. A piled raft foundation having cavity heads with adjustable pile forces as claimed in claim 1, wherein said steel cover plate is upwardly fitted with grouting pipes, said grouting pipes communicating with said cavities for grouting said cavities.

3. The piled raft foundation with cavity pile heads capable of adjusting pile stress of claim 1, wherein said steel cover plate is equipped with a plurality of pipelines for detection upwards.

4. The pile-raft foundation with cavity pile heads capable of adjusting pile stress of claim 1, wherein a layer of water-swelling sealing rod is wrapped on the contact part of the annular concrete retaining wall and the cast-in-place pile.

5. The pile-raft foundation with cavity pile heads capable of adjusting pile stress of claim 1, wherein the steel cover plate is placed on the upper end surface of the annular concrete retaining wall and avoids embedded steel bars in the annular concrete retaining wall.

6. A piled raft foundation with hollow pile heads for regulating pile forces according to claim 1, characterised in that waterproof adhesive tape is adhered between the steel cover plate and the annular concrete retaining wall.

7. The piled raft foundation with cavity pile heads capable of adjusting pile stress of claim 1, wherein the height of the cavity is 300-400 mm.