CN113684852B - Construction method of composite pile foundation and composite pile foundation - Google Patents

Abstract

The invention provides a construction method for a composite pile foundation, comprising the following steps: sinking a steel pipe column on the ground, and excavating the soil inside the steel pipe column; the side wall of the steel pipe column is provided with a construction hole for a steel pipe inclined pile; Drill down to form the cast-in-place pile hole of the bored pile; pass the steel cage under the steel pipe column, and the reinforcement cage extends upward from the bottom of the cast-in-place pile hole to the inner bottom section of the steel pipe column; Concrete is poured, and the poured concrete covers the steel cage and enters the cage section in the steel pipe column; in the steel pipe column, the steel pipe inclined column section is tilted downward through the jack, and multiple steel pipe inclined column sections that are inclined in turn are connected to form a steel pipe inclined pile; During the inclined jacking process, the jack is supported on the inner wall of the steel pipe column through the jack reaction seat; the inclined roof construction of each steel pipe inclined pile is completed one by one; concrete is poured into the steel pipe column. Finally, the composite pile foundation that provides vertical bearing capacity, horizontal bearing capacity and shear resistance function is realized.

Description

Construction method of composite pile foundation and composite pile foundation

technical field

The invention relates to a foundation in civil engineering, in particular to a construction method of a composite pile foundation and the composite pile foundation.

Background technique

Bored piles are commonly used as foundation forms and are indispensable in almost all civil engineering projects such as bridge engineering, construction engineering, and wharf engineering. They can provide good vertical bearing capacity, but their horizontal bearing capacity is very poor.

For foundations that generally need to provide large horizontal bearing capacity, such as bridge piers, anti-collision piers, arch bridge pier foundations, etc., almost all of them are pile group foundations of bored piles, and their remarkable feature is that they are generated by the original horizontal force. The bending moment is converted into the axial force of the pile foundation, and the shear force is borne by the pile foundation. However, the shear resistance level of the pile foundation is often low, and the efficiency of the pile foundation to bear the foundation bending moment effect is relatively low.

Contents of the invention

The purpose of the present invention is to overcome the deficiencies in the prior art and provide a construction method for combined pile foundations, which can provide favorable conditions for other construction procedures between components during the construction process, improve construction reliability, reduce The construction cost has achieved a good coordination effect; finally, a combined pile foundation that provides vertical bearing capacity, horizontal bearing capacity and shear resistance function is realized; the invention also provides a combined pile foundation formed by the above construction method. In order to achieve the above technical purpose, the technical solution adopted in the embodiment of the present invention is:

The embodiment of the present invention provides a kind of construction method of composite pile foundation, comprises the following steps:

Step S1, sinking the steel pipe column on the ground, and excavating the soil in the steel pipe column; the side wall of the steel pipe column is provided with a construction hole for a steel pipe inclined pile;

Step S2, drilling down through the steel pipe column to form the cast-in-place pile hole of the bored pile, and the mud retaining wall during the drilling process;

In step S3, the reinforcement cage is lowered through the steel pipe column, and the reinforcement cage extends upward from the bottom of the cast-in-place pile hole to the bottom section of the steel pipe column; then, concrete is poured into the cast-in-place pile hole and the bottom section of the steel pipe column, and the poured concrete covers the reinforcement cage and enters the steel pipe The cage section inside the column; after the first pour of concrete, the bored pile is formed;

Step S4, in the steel pipe column, use the jack to tilt the steel pipe inclined column section downwards, and the steel pipe inclined column sections that are inclined in turn are connected to form a steel pipe inclined pile; during the inclined jacking process, the jack is supported on the steel pipe through the jack reaction seat column inner wall;

Step S5, according to the design requirements, complete the inclined roof construction of each steel pipe inclined pile one by one, and then connect each steel pipe inclined pile to the steel pipe column;

Step S6, pouring concrete into the steel pipe column, and forming the steel pipe concrete column after pouring concrete for the second time.

Preferably, the diameter of the steel pipe column is not less than 2.5m.

Preferably, in step S3, the distance for the reinforcement cage to enter into the steel pipe column is 1 m to 2 m.

Further, the top of the reinforcement cage extends out of the pile top reinforcement; in step S4, the pile top reinforcement that hinders the construction of the inclined roof of the steel pipe inclined column section is temporarily broken apart and then the inclined roof is constructed.

Further, the pile top reinforcement extends from the top of the reinforcement cage; in step S6, the concrete poured for the second time is connected with the pile top reinforcement.

Preferably, the second poured concrete fills the steel pipe inclined column section at the top of the steel pipe inclined pile.

A composite pile foundation is obtained through the above construction methods, including: steel pipe concrete columns, bored piles, and steel pipe inclined piles;

The bored piles are arranged vertically for being placed vertically into the foundation;

The concrete-filled steel pipe column is connected to the top of the bored pile and arranged vertically for vertical insertion into the foundation;

The steel pipe inclined pile is obliquely connected to the steel pipe concrete column, and is used to be inserted into the foundation obliquely downward.

Optionally, the steel pipe inclined pile is connected to one side or both sides of the steel pipe concrete column.

Further, the bored cast-in-place pile is formed by setting a reinforcement cage in the cast-in-place pile hole and pouring concrete; the steel pipe concrete column includes a steel pipe column; the steel cage extends upward from the bored cast-in-place pile to a section at the bottom of the steel pipe column ; the top of the reinforcement cage extends out of the pile top reinforcement; the steel pipe column is poured with concrete.

Furthermore, the steel pipe inclined pile is connected with the steel pipe column, and the steel pipe inclined column section at the top of the steel pipe inclined pile is poured with concrete together with the steel pipe column.

The beneficial effect brought by the technical solution provided by the embodiment of the present invention is: the application forms a combined pile foundation through the combination of steel pipe concrete columns, bored piles and steel pipe inclined piles. During the construction process, the components provide advantages for other construction processes. The condition improves the construction reliability, reduces the construction cost, and achieves a good coordination effect; finally realizes the composite pile foundation that provides vertical bearing capacity, horizontal bearing capacity, and shear resistance. Compared with the existing pile group foundation of bored piles, the present application can not only reduce the cost, but also provide a pile foundation with excellent vertical bearing capacity and horizontal bearing capacity.

Description of drawings

Fig. 1 is a schematic diagram of a sinking steel pipe column in an embodiment of the present invention.

Fig. 2 is a schematic diagram of the drilled cast-in-situ pile hole in the embodiment of the present invention.

Fig. 3 is a schematic diagram of the lower reinforcement cage and the first pouring of concrete in the embodiment of the present invention.

Fig. 4 is a schematic diagram of the construction of the inclined roof of steel pipe inclined piles in the embodiment of the present invention.

Fig. 5 is a schematic diagram of the construction and connection of the inclined roofs of steel pipe inclined piles one by one in the embodiment of the present invention.

Fig. 6 is a schematic diagram of forming a concrete-filled steel tube column after pouring concrete for the second time in an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Embodiments of the present invention provide a construction method for a combined pile foundation, comprising the following steps:

Step S1, as shown in Figure 1, sinks the steel pipe column 201 on the ground 1, and excavates the soil in the steel pipe column 201; the side wall of the steel pipe column 201 is provided with a construction hole for a steel pipe inclined pile; the steel pipe column 201 can be used as an excavation Soil maintenance structure, and as the construction casing of follow-up bored pile 3;

In order to facilitate the subsequent construction of the steel pipe inclined pile 4, the diameter of the steel pipe column 201 is not less than 2.5m, and its space is used as a space for constructing the inclined pile; the height of the steel pipe column 201 is 5m to 10m;

Step S2, as shown in Figure 2, drills down through the steel pipe column 201 to form the cast-in-place pile hole 301 of the bored pile 3, and the mud wall during the drilling process; the steel pipe column 201 can be used as the construction protection of the bored pile 3 cylinder;

Step S3, as shown in FIG. 3 , the reinforcement cage 302 is lowered through the steel pipe column 201, and the reinforcement cage 302 extends upward from the bottom of the cast-in-place pile hole 301 to a section at the bottom of the steel pipe column 201; Concrete is poured in one section, and the poured concrete covers the steel cage 302 and enters the cage section in the steel pipe column 201;

After pouring concrete for the first time, the bored pile 3 is formed;

As an optimization of this embodiment, the distance for the steel cage 302 to enter the steel pipe column 201 is 1m to 2m; so that when the concrete is poured for the first time, the steel pipe column 201 can form a structural connection with the bored pile 3, which is convenient for subsequent construction of the steel pipe When the inclined pile is used, the steel pipe column 201 and the bored pile 3 are used together as the reaction force device for the jacking construction; since there is a relatively large vertical reaction force (upward) during the process of jacking the inclined pile, it needs to be constructed Bored cast-in-place piles bear the burden, so a reliable connection between bored piles and steel pipe columns is required;

As an optimization of this embodiment, the top of the reinforcement cage 302 extends out of the pile top reinforcement 303; the pile top reinforcement 303 can strengthen the connection with the first poured concrete when the concrete is poured for the second time;

Step S4, as shown in FIG. 4 , in the steel pipe column 201, the steel pipe inclined column section 401 is inclined downward through the jack 5, and a plurality of steel pipe inclined column sections 401 that are inclined in turn are connected to form a steel pipe inclined pile 4; Among them, the jack 5 is supported on the inner wall of the steel pipe column 201 through the jack reaction force seat 6, and a large reaction force is obtained through the inner wall of the steel pipe column 201, and the reaction force is provided together by the connected steel pipe column 201 and the bored pile 3;

When there is a pile top reinforcement 303 on the top of the reinforcement cage 302, the pile top reinforcement 303 that hinders the construction of the steel pipe inclined column section 401 can be temporarily broken apart and then the construction of the slope can be carried out;

Step S5, as shown in Figure 5, according to the design requirements, complete the construction of the inclined roof of each steel pipe inclined pile 4 one by one, and then connect each steel pipe inclined pile 4 with the steel pipe column 201; for example, connect by welding;

According to the stress requirements of the combined pile foundation, each steel pipe inclined pile 4 can be distributed on one side or both sides of the steel pipe column 201;

Step S6, as shown in FIG. 6 , pour concrete into the steel pipe column 201, and form the steel pipe concrete column 2 after pouring concrete for the second time;

When the top of the reinforcement cage 302 has a pile top reinforcement 303, the concrete poured for the second time can be connected with the pile top reinforcement 303, so as to strengthen the connection firmness between the concrete poured twice before and after;

As an optimization of this embodiment, the concrete poured for the second time fills the steel pipe inclined column section 401 at the top of the steel pipe inclined pile 4; the connection strength between the steel pipe inclined pile 4 and the steel pipe concrete column 2 can be enhanced;

Through the above construction method, a composite pile foundation is obtained, including: steel pipe concrete column 2, bored cast-in-place pile 3, steel pipe inclined pile 4;

The bored cast-in-place pile 3 is arranged vertically, and is used for vertically inserting into the foundation, mainly providing vertical bearing capacity;

The concrete-filled steel pipe column 2 is connected to the top of the bored cast-in-situ pile 3, and is vertically arranged for being vertically inserted into the foundation, and mainly bears the shear bearing capacity of the foundation;

The steel pipe inclined pile 4 is obliquely connected to the steel pipe concrete column 2, and is used to be inserted into the foundation obliquely downward;

Optionally, the steel pipe inclined pile 4 is connected to one or both sides of the steel pipe concrete column 2. For a one-way horizontal force foundation, such as an arch bridge foundation, it is only set on one side; for a two-way horizontal force foundation, such as an extra-large bridge pier foundation, you can use bilateral settings;

As an optimization of this embodiment, the bored cast-in-place pile 3 is formed by setting a reinforcement cage 302 in the cast-in-place pile hole 301 and pouring concrete; the steel pipe concrete column 2 includes a steel pipe column 201; the steel cage 302 is poured from the borehole The pile 3 extends upwards to a section at the bottom of the steel pipe column 201; the top of the steel cage 302 extends out of the pile top steel bar 303; the steel pipe column 201 is poured with concrete;

As an optimization of this embodiment, the steel pipe inclined pile 4 is connected to the steel pipe column 201, and the steel pipe inclined column section 401 at the top of the steel pipe inclined pile 4 is poured with concrete together with the steel pipe column 201;

In the above composite pile foundation, the bored cast-in-situ pile 3 mainly provides vertical bearing capacity, the steel pipe inclined pile 4 can provide horizontal bearing capacity and vertical bearing capacity, and the steel pipe concrete column 2 can provide horizontal thrust and also provide vertical bearing capacity; Finally, the composite pile foundation that provides vertical bearing capacity, horizontal bearing capacity and shear resistance function is realized.

Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention without limitation, although the present invention has been described in detail with reference to examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be carried out Modifications or equivalent replacements without departing from the spirit and scope of the technical solution of the present invention shall be covered by the claims of the present invention.

Claims (3)

1. A construction method of combined pile foundation, is characterized in that, comprises the following steps: Step S1, sinking the steel pipe column (201) on the ground (1), and excavating the soil inside the steel pipe column (201); the side wall of the steel pipe column (201) is provided with a construction hole for steel pipe inclined piles; Step S2, drilling down through the steel pipe column (201) to form the cast-in-place pile hole (301) of the bored cast-in-place pile (3), and the mud retaining wall during the drilling process; Step S3, lower the reinforcement cage (302) through the steel pipe column (201), and the reinforcement cage (302) extends upward from the bottom of the cast-in-place pile hole (301) to a section at the inner bottom of the steel pipe column (201); Concrete is poured into the bottom section of the inner and steel pipe column (201), and the poured concrete covers the reinforcement cage (302) and enters the cage section in the steel pipe column (201); after the first pouring of concrete, a bored cast-in-place pile (3) is formed; Step S4, in the steel pipe column (201), the steel pipe inclined column section (401) is tilted downward through the jack (5), and a plurality of steel pipe inclined column sections (401) are connected to form a steel pipe inclined column section (4); During the inclined jacking process, the jack (5) is supported on the inner wall of the steel pipe column (201) through the jack reaction seat (6); Step S5, according to the design requirements, complete the inclined roof construction of each steel pipe inclined pile (4) one by one, and then connect each steel pipe inclined pile (4) with the steel pipe column (201); Step S6, pouring concrete into the steel pipe column (201), and forming the steel pipe concrete column (2) after pouring concrete for the second time; The pile top reinforcement (303) is extended from the top of the reinforcement cage (302); in step S4, the pile top reinforcement (303) that hinders the construction of the inclined roof of the steel pipe inclined column section (401) is temporarily broken apart and then the inclined roof construction is performed; The pile top reinforcement (303) is extended from the top of the reinforcement cage (302); the concrete poured for the second time in step S6 is connected with the pile top reinforcement (303); The concrete poured for the second time fills the steel pipe inclined column section (401) at the top of the steel pipe inclined pile (4). 2. the construction method of composite pile foundation as claimed in claim 1, is characterized in that, The diameter of the steel pipe column (201) is not less than 2.5m. 3. the construction method of composite pile foundation as claimed in claim 1, is characterized in that, In step S3, the distance for the reinforcement cage (302) to enter into the steel pipe column (201) is 1m-2m.

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