CN217629963U

CN217629963U - Internal support structure for reducing foundation pit deformation

Info

Publication number: CN217629963U
Application number: CN202221551152.7U
Authority: CN
Inventors: 李敏达; 龚存燕; 孙赑; 赵九洲; 蒋志坚; 罗俊; 黄旭东; 张娴慧
Original assignee: Shenzhen Water Planning And Design Institute Co ltd
Current assignee: Shenzhen Water Planning And Design Institute Co ltd
Priority date: 2022-06-20
Filing date: 2022-06-20
Publication date: 2022-10-21
Anticipated expiration: 2032-06-20

Abstract

An inner support structure for reducing foundation pit deformation comprises a foundation pit supporting pile, a top beam arranged at the top of the foundation pit supporting pile, a waist beam arranged between the upper part and the lower part of the supporting pile and a plurality of inner support rods, wherein the inner support rods are respectively and fixedly connected between the top beam and the waist beam; further comprising: the middle section of the inner supporting rod is provided with a negative displacement splicing section with a preset length, and the negative displacement splicing section can apply certain horizontal force to the direction of the inner supporting rod at two ends. The inner support rod is provided with a negative displacement splicing section which can apply a certain horizontal force to the direction of the inner support rod at two ends, so that a certain negative displacement can be generated, the temperature shrinkage and concrete shrinkage displacement of the inner support can be compensated, the positive displacement generated by active soil pressure after a part of foundation pit is excavated is offset, the deformation redundancy of the foundation pit is improved, and the purpose of safely and controllably arranging the foundation pit and the surrounding environment is achieved.

Description

Internal support structure for reducing foundation pit deformation

Technical Field

The application relates to the technical field of constructional engineering, in particular to an inner support structure for reducing foundation pit deformation.

Background

The foundation pit support is a common temporary retaining measure in civil construction engineering, and has the functions of protecting the construction of an underground main structure, the safety of the surrounding environment of the foundation pit and the like. An inner support structure is often adopted for controlling the deformation of the foundation pit, and the inner support mainly comprises a steel support or a concrete inner support.

Steel supports or concrete inner supports in foundation pit support can deform at a certain temperature, the concrete inner supports can also deform at a certain degree after pouring, and if the deformation allowance of the foundation pit is insufficient, the situation that the deformation of the foundation pit exceeds an early warning value and a limit value is often caused. In addition, after the foundation pit is excavated, the actual geological conditions are not as expected by design, and the condition that the deformation of the foundation pit exceeds the early warning value and the limit value is easy to occur. These conditions are not conducive to the safety of the foundation pit and the surrounding environment.

SUMMERY OF THE UTILITY MODEL

The application provides a simple structure just can effectively reduce inner support structure that foundation ditch warp.

According to an aspect of the present application, in one embodiment, an inner support structure for reducing deformation of a foundation pit is provided, which includes: the foundation pit supporting pile comprises a foundation pit supporting pile, a crown beam arranged at the top of the foundation pit supporting pile, a waist beam arranged between the upper part and the lower part of the supporting pile and a plurality of inner supporting rods, wherein the inner supporting rods are fixedly connected between the crown beam and the waist beam respectively;

further comprising: the middle section of the inner supporting rod is provided with a negative displacement splicing section with a preset length, and the negative displacement splicing section can apply a certain horizontal force to the directions of the inner supporting rods at the two ends.

Optionally, the negative displacement splicing section is an expansive concrete section, wherein the expansive concrete section is composed of concrete and a micro-expansive additive.

Optionally, the micro-expansion additive adopts a polymer fiber expansion agent.

Optionally, a reinforcing steel bar is axially arranged inside the expanded concrete section, and the length of the reinforcing steel bar extends into the inner supporting rods at two ends. A (c)

Optionally, the number of the reinforcing steel bars is at least two.

Optionally, the inner supporting rods at two ends are concrete supporting sections.

Optionally, the inner supporting rod further includes a set of axially arranged parallel main rib structures, and stirrups perpendicular to the main rib structures, where the stirrups are multiple and arranged at equal intervals.

Optionally, the negative displacement splicing section is connected with the inner support rods at two ends through a tongue-and-groove.

The inner support structure for reducing foundation pit deformation according to the embodiment comprises a foundation pit supporting pile, a crown beam arranged at the top of the foundation pit supporting pile, a waist beam arranged between the upper part and the lower part of the supporting pile and a plurality of inner support rods, wherein the inner support rods are respectively and fixedly connected between the crown beam and the waist beam; further comprising: the middle section of the inner supporting rod is provided with a negative displacement splicing section with a preset length, and the negative displacement splicing section can apply certain horizontal force to the direction of the inner supporting rod at two ends. The inner support rod is provided with a negative displacement splicing section which can apply a certain horizontal force to the direction of the inner support rod at two ends, so that a certain negative displacement can be generated, the temperature shrinkage and concrete shrinkage displacement of the inner support can be compensated, the positive displacement generated by active soil pressure after a part of foundation pit is excavated is offset, the deformation redundancy of the foundation pit is improved, and the purpose of safely and controllably arranging the foundation pit and the surrounding environment is achieved.

Drawings

Fig. 1 is an overall schematic view of an inner support structure for reducing deformation of a foundation pit according to this embodiment;

fig. 2 is a schematic structural diagram of an inner support rod in the inner support structure provided in this embodiment.

In the figure: 1-supporting a pile; 2-a crown beam; 3-waist rail; 4-inner support; 5-negative displacement splicing section and micro-expansion concrete section; 6-tongue and groove; 7-main reinforcement; 8-stirrup; 9-reinforcing steel bars.

Detailed Description

The present application will be described in further detail below with reference to the accompanying drawings by way of specific embodiments. Wherein like elements in different embodiments are numbered with like associated elements. In the following description, numerous specific details are set forth in order to provide a better understanding of the present application. However, those skilled in the art will readily recognize that some of the features may be omitted or replaced with other elements, materials, methods in different instances. In some instances, certain operations related to the present application have not been shown or described in detail in order to avoid obscuring the core of the present application from excessive description, and it is not necessary for those skilled in the art to describe these operations in detail, so that they may be fully understood from the description in the specification and the general knowledge in the art.

Furthermore, the features, operations, or characteristics described in the specification may be combined in any suitable manner to form various embodiments, and the operation steps involved in the embodiments may be interchanged or modified in order as will be apparent to those skilled in the art. Accordingly, the description and drawings are merely for clarity of description of certain embodiments and are not intended to necessarily refer to a required composition and/or order.

The numbering of the components as such, e.g., "first", "second", etc., is used herein only to distinguish the objects as described, and does not have any sequential or technical meaning. The term "connected" and "coupled" when used in this application, unless otherwise indicated, includes both direct and indirect connections (couplings).

As is known in the art, the inner support structure in current abandoned pit timbering is often deformed.

The inner support structure provided in this embodiment includes a foundation pit support pile, a crown beam disposed at the top of the foundation pit support pile, a waist beam disposed between the upper and lower sides of the support pile, and a plurality of inner support rods fixedly connected between the crown beam and the waist beam; further comprising: the middle section of the inner supporting rod is provided with a negative displacement splicing section with a preset length, and the negative displacement splicing section can apply certain horizontal force to the direction of the inner supporting rod at two ends. Because the inner supporting rod adopts a negative displacement splicing section which can apply a certain horizontal force to the direction of the inner supporting rod at two ends, a certain negative displacement can be generated, the temperature cold shrinkage and concrete dry shrinkage displacement of the inner support can be compensated, the positive displacement generated by the active soil pressure after a part of foundation pits are excavated is offset, the deformation redundancy of the foundation pits is improved, and the purpose of safely and controllably arranging the foundation pits and the surrounding environment is achieved.

Referring to fig. 1 and fig. 2 in combination, in the present embodiment, an inner supporting structure for reducing deformation of a foundation pit is provided, which includes: the foundation ditch props up 1, the guan roof beam 2 that this foundation ditch props up 1 top setting, the waist rail 3 and many internal support rods 4 between 1 about of props up 1, many these internal support rods 4 fixed connection respectively between this guan roof beam 2 and this waist rail 3, the negative displacement splice section 5 of presetting length that the interlude of this internal support rod 4 was equipped with, this negative displacement splice section 5 can exert certain horizontal force in the direction of this internal support rod 4 at both ends.

The foundation pit support pile 1 in this embodiment is a pile that mainly bears lateral thrust in the foundation pit. The pile can be used for foundation pit support, side slope support and landslide control, bears horizontal soil pressure or landslide thrust, generally needs higher reinforcement than a foundation pile bearing vertical force, and is often used together with an anchor rod (cable) (pile anchor structure).

The crown beam 2 in the embodiment is used for connecting all pile foundations at the top of the foundation pit supporting pile 1 together so as to prevent collapse of the top edge of the foundation pit (vertical shaft). The wale 3 is a member provided between the upper and lower sides of the support pile 1 for connecting the inner support rods 4.

The inside of this inner support rod 4 has the parallel a set of owner muscle 7 structure of axial setting to and this 7 structure stirrup 8 of owner muscle of perpendicular to, this stirrup 8's quantity is a plurality of, and equidistant range. Wherein, a set of main muscle 7 structure is two reinforcing bars that set up from top to bottom.

In the inner support rod 4 in this embodiment, the inner support rods 4 at both ends are concrete support sections, and the middle is an expanded concrete section, wherein the expanded concrete section is composed of concrete and a micro-expansion additive. Because this expansive concrete section can be to producing the inflation after pouring the completion, also can exert certain pressure to the concrete support section at both ends promptly, this expansive concrete section can exert certain horizontal force to foundation ditch fender pile 1, produces certain negative displacement, can compensate the temperature shrinkage and the concrete shrinkage displacement of interior support to offset the positive displacement that some foundation ditch excavation back initiative soil pressure produced, improve foundation ditch deformation richness, increase foundation ditch and all around environment security.

It is understood that the length of the micro-expansion concrete section 5 is a preset length, wherein the preset length can be calculated and determined according to the material expansion rate and the negative displacement to be pre-added, the negative displacement to be pre-added can be calculated and determined by considering the temperature difference between the air temperature during casting and the air temperature during winter low temperature, the length of the inner support rod 4 and the linear expansion coefficient, and the concrete shrinkage deformation can be calculated and determined according to the concrete shrinkage rate and the inner support length.

It can be noted that the micro-expansion additive in this embodiment is a polymer fiber expansion agent.

In some embodiments, in order to eliminate the shrinkage deformation of the concrete inner supporting rod 4 after casting, the micro-expansion concrete section 5 can be formed by casting after the concrete age of the inner supporting rods 4 at two ends reaches a certain number of days.

In some embodiments, a reinforcing steel bar 9 is axially arranged inside the expanded concrete section, and the length of the reinforcing steel bar 9 extends into the inner support rods 4 at both ends. Thereby reducing the stress of the micro-expansion concrete section 5 and improving the strength of the integral inner supporting rod 4.

This reinforcing bar 9's quantity can be many, and reinforcing bar 9 quantity in this embodiment is 2, and the longitudinal symmetry sets up, the increase of strength.

In some embodiments, the negative displacement splice section and the inner support rods 4 at both ends are connected by the tongue and groove 6, so that the good concrete connection between the expanded concrete section and the concrete support section can be ensured.

In other embodiments, the negative displacement splice may also be another rod with a horizontal force applied in the direction of the inner support rod 4 at both ends.

In the embodiment, the inner support structure for reducing the deformation of the foundation pit is characterized in that a plurality of inner support rods 4 are arranged in the foundation pit at certain intervals, and the inner support rods 4 are internally provided with one section of micro-expansion concrete structure to replace the original inner support structure, so that after the micro-expansion concrete is poured, a certain horizontal force can be applied to the support pile 1 to generate a certain negative displacement, the temperature shrinkage and the concrete shrinkage displacement of the inner support can be compensated, the positive displacement generated by the active soil pressure after a part of the foundation pit is excavated can be offset, the deformation redundancy of the foundation pit is improved, and the safety of the foundation pit and the surrounding environment is improved.

It is right to have used specific individual example above the utility model discloses expound, only be used for helping to understand the utility model discloses, not be used for the restriction the utility model discloses. To the technical field of the utility model technical personnel, the foundation the utility model discloses an idea can also be made a plurality of simple deductions, warp or replacement.

Claims

1. An internal support structure for reducing deformation of a foundation pit, comprising: the foundation pit supporting pile comprises a foundation pit supporting pile, a crown beam arranged at the top of the foundation pit supporting pile, a waist beam arranged between the upper part and the lower part of the supporting pile and a plurality of inner supporting rods, wherein the inner supporting rods are fixedly connected between the crown beam and the waist beam respectively;

2. The internal support structure of claim 1 wherein the negative displacement splice section is an expanded concrete section, wherein the expanded concrete section is comprised of concrete and a micro-expansion additive.

3. The internal support structure of claim 2 wherein the micro-expansion additive comprises a polymer fiber expansion agent.

4. An internal support structure as claimed in claim 2, wherein reinforcing bars are provided axially within the expanded concrete section, the reinforcing bars extending in length into the internal support struts at both ends.

5. The internal support structure of claim 4, wherein the number of reinforcing bars is at least two.

6. The internal support structure of claim 2 wherein the internal support struts at each end are concrete support sections.

7. The inner support structure of claim 1, wherein the inner support rod further comprises an axially disposed set of parallel main rib structures and a plurality of stirrups arranged at equal intervals perpendicular to the main rib structures.

8. The internal support structure of claim 1 wherein said negative displacement splice section and said internal support struts at both ends are tongue and groove connected.