CN218843118U

CN218843118U - Silt basement structure is consolidated to deep basal pit

Info

Publication number: CN218843118U
Application number: CN202223212714.8U
Authority: CN
Inventors: 郭伟强; 杨旭; 马飞虎; 贾明金; 樊浩; 马良辰; 杨茂凯; 梁波; 王欢
Original assignee: China Railway No 2 Engineering Group Co Ltd; Shenzhen China Railway Second Bureau Engineering Co Ltd
Current assignee: China Railway No 2 Engineering Group Co Ltd; Shenzhen China Railway Second Bureau Engineering Co Ltd
Priority date: 2022-12-02
Filing date: 2022-12-02
Publication date: 2023-04-11
Anticipated expiration: 2032-12-02

Abstract

The utility model relates to a deep foundation pit reinforced silt foundation structure, which belongs to the technical field of silt foundation reinforcement, and comprises a pile structure arranged in a foundation pit and a pile structure arranged outside the foundation pit; the pile structure arranged outside the foundation pit comprises an occlusive pile (1), a waterproof curtain double-shaft cement mixing pile (2) and a pit outer double-shaft cement mixing pile (3) from inside to outside; the pile structure arranged in the foundation pit comprises a lattice column cast-in-place pile (4) arranged along the longitudinal center line of the foundation pit and reinforcing double-shaft cement mixing piles (5) arranged on two sides of the lattice column cast-in-place pile (4); the utility model discloses not only realized the effective reinforcement to the silt base, also guaranteed simultaneously that each item load and external force outside the foundation ditch in the construction do not cause the secondary to destroy to the silt base that has consolidated in the foundation ditch to the quality after the engineering completion has been protected.

Description

Silt basement structure is consolidated to deep basal pit

Technical Field

The utility model belongs to the technical field of the silt basement reinforcement, specific theory relates to a silt basement structure is consolidated to deep basal pit.

Background

With the continuous development of economy in China, more efficient and faster economic corridors are gradually established among cities. In the process of building these economic corridors, various projects with complex geological conditions are necessarily encountered, such as: the two cities are coastal cities, a tunnel penetrating through a water area between the two cities needs to be built, an open excavation section of the tunnel is arranged at the initial section of the tunnel, and the basement of the open excavation section of the tunnel is mucky soil. When mucky soil is used as a substrate, the first consideration is to reinforce the mucky soil to achieve the designed bearing capacity. The traditional method for reinforcing the sludge substrate generally adopts one or more of a pile foundation method, a soil replacement method, a grouting method, a cement stirring method and an open caisson foundation method in a staggered mode according to different working conditions in a foundation pit, so that the bearing capacity of the sludge substrate is improved. Whether one or more reinforcement methods are adopted inside the foundation pit, the base is difficult to resist deformation caused by the fact that the supporting structure moves around from the bottom of the supporting structure to the inside of the foundation pit. Once the basement warp, just mean that silt basement stable structure after the reinforcement suffers destruction, and the bearing capacity correspondingly can receive the influence of different degrees, brings huge potential safety hazard for the engineering, causes unestimable economic loss.

In view of the above, it is important to explore a method for reinforcing a sludge substrate by eliminating the supporting structure from the bottom of the supporting structure to the inside of the foundation pit, so as to eliminate potential safety hazards.

Disclosure of Invention

In order to overcome the problem that exists among the background art, the utility model provides a deep basal pit consolidates silt substructure has not only realized the effective reinforcement to the silt base, has also guaranteed simultaneously that each item load and external force outside the foundation ditch in the construction do not cause the secondary to destroy to the silt base that has consolidated in the foundation ditch to the quality after the engineering completion has been protected.

In order to achieve the above purpose, the utility model is realized by the following technical scheme:

the deep foundation pit reinforced sludge base structure comprises a pile structure arranged in the foundation pit and a pile structure arranged outside the foundation pit; the pile structure arranged outside the foundation pit comprises an occlusive pile, a waterproof curtain double-shaft cement stirring pile and a pit outer double-shaft cement stirring pile which are arranged outside the foundation pit from inside to outside; the pile structure arranged in the foundation pit comprises a lattice column cast-in-place pile arranged along the longitudinal center line of the foundation pit and reinforced double-shaft cement mixing piles arranged on two sides of the lattice column cast-in-place pile.

Preferably, the pile bottom elevation of the waterproof curtain biaxial cement mixing pile is 2-3m lower than the pile bottom elevation of the secant pile.

Preferably, the pile top elevation of the first row of the external double-shaft cement mixing piles is 3-4m lower than that of the waterproof curtain double-shaft cement mixing piles, and the pile top elevation of the second row of the external double-shaft cement mixing piles is 6-7m lower than that of the waterproof curtain double-shaft cement mixing piles.

Preferably, the occlusive piles are plain concrete piles and reinforced concrete piles which are arranged at intervals.

Preferably, the waterproof curtain double-shaft cement mixing pile is 1m away from the secant pile.

Preferably, the double-shaft cement mixing piles 3 are arranged in two rows at equal intervals.

The utility model has the advantages that:

the utility model discloses not only realized the effective reinforcement to the silt base, also guaranteed simultaneously that each item load and external force outside the foundation ditch in the construction do not cause the secondary to destroy to the silt base that has consolidated in the foundation ditch to the quality after the engineering completion has been protected.

Drawings

Fig. 1 is a schematic cross-sectional structure of the present invention;

fig. 2 is a schematic plan view of the present invention;

FIG. 3 is a construction flow of the present invention;

in the figure, 1, a secant pile 2, a waterproof curtain double-shaft cement stirring pile 3, an out-of-pit double-shaft cement stirring pile 4, a lattice column cast-in-place pile 5 and a reinforced double-shaft cement stirring pile are adopted.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the following will make a detailed description of a preferred embodiment of the present invention with reference to the accompanying drawings to facilitate understanding of the skilled person.

As shown in fig. 1-2, the deep foundation pit reinforced sludge foundation structure comprises a pile structure arranged in the foundation pit and a pile structure arranged outside the foundation pit. The pile structure arranged outside the foundation pit comprises an occlusive pile 1, a waterproof curtain double-shaft cement mixing pile 2 and a pit outer double-shaft cement mixing pile 3 from inside to outside. The pile structure arranged in the foundation pit comprises a lattice column cast-in-place pile 4 arranged along the longitudinal center line of the foundation pit and reinforcing double-shaft cement mixing piles 5 arranged on two sides of the lattice column cast-in-place pile 4.

The secant pile 1 is a plain concrete pile and a reinforced concrete pile which are arranged at intervals, the plain concrete pile is constructed firstly and then the reinforced concrete pile is constructed during construction, the plain concrete pile adopts super-retarding concrete, and the construction of the reinforced concrete pile is required to be completed before the initial setting of the plain concrete pile. When the reinforced concrete pile is constructed, the concrete at the intersection part of the adjacent plain concrete piles is cut off to realize occlusion, and a seamless continuous pile wall is formed.

The waterproof curtain double-shaft cement mixing pile 2 is 1m away from the secant pile 1. The elevation of the pile bottom of the waterproof curtain biaxial cement mixing pile 2 is 2-3m lower than that of the pile bottom of the secant pile 1, and the waterproof curtain biaxial cement mixing pile enters a waterproof layer for at least 2m. The waterproof curtain double-shaft cement stirring pile 2 is used for preventing underground water from permeating into the foundation pit and reinforcing silt outside the foundation pit.

Two rows of the double-shaft cement mixing piles 3 are arranged at equal intervals. The double-shaft cement mixing pile 3 and the waterproof curtain double-shaft cement mixing pile 2 jointly act to reinforce soil silted outside the foundation pit and prevent the secant pile from winding around the bottom of the secant pile.

The pile top elevation of the first row of the double-shaft cement mixing piles 3 is 3-4m lower than that of the waterproof curtain double-shaft cement mixing piles 2, and the pile top elevation of the second row of the double-shaft cement mixing piles is 6-7m lower than that of the waterproof curtain double-shaft cement mixing piles 2. Biax cement mixing stake 3 forms the stairstepping with waterproof curtain biax cement mixing stake 2, in material saving, more effectual effect of consolidating silt and bearing upper portion load and soil pressure that plays.

The utility model discloses a work progress demonstration:

as shown in fig. 3, the construction process of the present invention includes the following steps:

the method comprises the following steps: and (4) leveling the field, draining accumulated water in the field, and applying the ground as the full-casing secant pile 1. The secant pile is drilled by a casing drill. The construction mainly adopts the scheme of 'casing drilling machine + super concrete'. The arrangement mode of the piles is generally that a plain concrete pile (A pile) and a reinforced concrete pile (B pile) are arranged at intervals, the pile A is constructed firstly (first procedure) and then the pile B is constructed (second procedure) during construction, the pile A adopts super-retarding concrete, and the construction of the pile B is required to be completed before the concrete of the pile A is initially set. When the B pile is constructed, the concrete of the intersection part of the adjacent A piles is cut off to realize occlusion, and a seamless and continuous pile wall is formed.

And when the secant pile is constructed, adopting a soil-taking drilling machine to take the pile position rock soil every 3 to 5 meat piles, sending the pile position rock soil to a corresponding laboratory for mechanical property test, and verifying the geological condition of the same section.

Step two: after the secant pile is constructed, submitting corresponding parameters of the rock and soil to a design institute according to the rock and soil properties and the mechanical properties of each section mastered in the step one, and checking and adjusting the plane arrangement and the pile length of the originally designed reinforcing pile according to the rock and soil properties and the mechanical properties of each section by the design institute.

Step three: and after the secant pile is constructed, constructing a row of waterproof curtain double-shaft cement mixing piles 2 on the secant pile along the outer side of the foundation pit. The distance between the waterproof curtain double-shaft cement mixing pile and the secant pile is 1m during construction. Besides being used for preventing underground water from permeating into the foundation pit, the reinforcing device is also used for reinforcing silt soil outside the foundation pit.

The elevation of the bottom of the waterproof curtain biaxial cement mixing pile is 2-3m lower than that of the bottom of the secant pile, and the waterproof curtain biaxial cement mixing pile enters the impervious layer for at least 2m.

Step four: in the waterproof curtain biax cement mixing stake outside, through measuring the unwrapping wire, the outer biax cement mixing stake 3 of two rows of pits of equidistant arrangement, two rows of stake and waterproof curtain biax cement mixing stake combined action realize the reinforcement of silt earth outside the foundation ditch and prevent that the secant stake from moving around the secant pile bottom.

The elevation of the top of a first row of piles of the double-shaft cement stirring piles outside the pit is lower than 3 to 4m of waterproof curtain double-shaft cement stirring piles, the elevation of the top of a second row of piles is lower than 6 to 7m of waterproof curtain double-shaft cement stirring piles, the two rows of piles and the waterproof curtain double-shaft cement stirring piles form a step shape, materials are saved, and meanwhile the functions of reinforcing sludge and bearing upper loads and soil pressure are effectively achieved.

Step five: and constructing a row of lattice column cast-in-place piles 4 on the center line of the foundation pit along the longitudinal direction of the foundation pit inside the foundation pit.

Step six: and (5) constructing a reinforced double-shaft cement mixing pile 5 in the foundation pit according to the design file in the foundation pit according to the width of the foundation pit. When the reinforced double-shaft cement mixing pile is constructed, construction quality must be controlled strictly according to a special construction scheme.

Step seven: and after the foundation pit is excavated to the designed elevation, detecting the bearing capacity of the sludge substrate.

Finally, the above preferred embodiments are only intended to illustrate the technical solution of the present invention and not to limit it, and although the present invention has been described in detail by the above preferred embodiments, it should be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the present invention as defined by the appended claims.

Claims

1. A deep foundation pit reinforced sludge base structure is characterized by comprising a pile structure arranged in a foundation pit and a pile structure arranged outside the foundation pit; the pile structure arranged outside the foundation pit comprises an occlusive pile (1), a waterproof curtain double-shaft cement mixing pile (2) and a pit outer double-shaft cement mixing pile (3) from inside to outside; the pile structure arranged in the foundation pit comprises a lattice column cast-in-place pile (4) arranged along the longitudinal center line of the foundation pit and reinforcing double-shaft cement mixing piles (5) arranged on two sides of the lattice column cast-in-place pile (4).

2. The deep foundation pit reinforced sludge foundation structure as claimed in claim 1, wherein the elevation of the pile bottom of the waterproof curtain biaxial cement mixing pile (2) is 2-3m lower than that of the secant pile (1).

3. The deep foundation pit reinforced sludge base structure of claim 1 or 2, wherein the biaxial cement mixing piles (3) are arranged in two rows at equal intervals.

4. The deep foundation pit reinforced sludge foundation structure as claimed in claim 3, wherein the elevation of the pile top of the first row of the external biaxial cement mixing piles (3) is 3-4m lower than that of the waterproof curtain biaxial cement mixing piles (2), and the elevation of the pile top of the second row of the external biaxial cement mixing piles is 6-7m lower than that of the waterproof curtain biaxial cement mixing piles (2).

5. The deep foundation pit reinforced sludge foundation structure as claimed in claim 1, wherein the occlusive piles (1) are plain concrete piles and reinforced concrete piles which are arranged at intervals.

6. The deep foundation pit reinforced sludge foundation structure of claim 1, wherein the waterproof curtain biaxial cement mixing pile (2) is spaced from the interlocking pile (1) by 1m.