CN111794261A

CN111794261A - Enlarged foundation and construction method and application thereof

Info

Publication number: CN111794261A
Application number: CN202010744833.4A
Authority: CN
Inventors: 王碧波; 余家富; 汪胜义; 肖德存; 邓高阳; 祁舒燕
Original assignee: China Railway Major Bridge Reconnaissance and Design Institute Co Ltd
Current assignee: China Railway Major Bridge Reconnaissance and Design Institute Co Ltd
Priority date: 2020-07-29
Filing date: 2020-07-29
Publication date: 2020-10-20

Abstract

The application relates to an enlarged foundation and a construction method and application thereof, wherein the enlarged foundation is located on a rock body and comprises a top plate and a side wall; the top plate is positioned below the building and used for supporting the building, and the top plate is positioned above the rock mass and is closely attached to the rock mass; the lateral wall is arranged along the periphery of the top plate, is positioned below the top plate and is embedded in a groove formed in the surface of the rock body for supporting the top plate. The building based on rock mass can be connected to the rock mass by means of the above-mentioned enlarged foundation. During construction, firstly, excavating a foundation pit of a top plate; excavating a foundation pit on the side wall; and then installing reinforcing steel bars, pouring the side walls and the top plate in sequence, carrying out rigid connection on the top plate and the side walls, namely completing construction of the enlarged foundation, and then carrying out construction of a building above the enlarged foundation. The foundation can be enlarged without excavating huge side slopes and foundation rock soil, the scale of foundation pit excavation engineering for enlarging the foundation is reduced, the foundation construction cost for enlarging is reduced, and the construction cost is saved by about 35 percent compared with the traditional foundation for enlarging.

Description

Enlarged foundation and construction method and application thereof

Technical Field

The application relates to the technical field of bridge engineering, in particular to an enlarged foundation and a construction method and application thereof.

Background

The enlarged foundation is a foundation form which directly transmits the load transmitted from the pier (platform) and the superstructure to a shallower supporting foundation, and is generally constructed by adopting an open cut foundation method, so that the enlarged foundation is also called as an open cut enlarged foundation or a shallow foundation.

Compared with pile foundations, open caisson foundations and the like, the enlarged foundations have the advantages of being good in advantages, convenient to construct, economical and reasonable. Conventional enlarged foundations are often used for smaller scale bridge structures, primarily because of the lower overhead loads that are transferred to the foundation. The existing large-span bridge is more and more common, and the conventional expanded foundation cannot exert the advantages of the conventional expanded bridge due to large deformation and high geological requirements.

In the related technology, a foundation pit is excavated by slope putting or supporting, then foundation concrete is poured to form an enlarged foundation, when the stress of the foundation is large, the scale of foundation engineering is huge, and particularly when the enlarged foundation is positioned at the edge of a hillside, the protection cost of the side slope of the foundation pit is high, so the construction cost is high. When the foundation is rock, especially when the strength of the rock mass of the foundation is greater than the self concrete strength of the enlarged foundation, the rock with higher strength is excavated and then replaced by the concrete with lower strength, thus causing the waste in engineering.

Disclosure of Invention

The application provides an enlarged foundation and a construction method and application thereof, and aims to solve the problems of large scale of foundation pit excavation engineering and high foundation pit slope protection cost in related technologies.

In a first aspect, there is provided an enlarged foundation for sitting on a rock mass, comprising: a top plate and a side wall; the top plate is positioned below the building and used for supporting the building, and the top plate is positioned above the rock mass and is closely attached to the rock mass; the lateral wall is along the vertical setting of roof border all around, is located the roof below to inlay in the recess that the rock mass surface set up, be used for supporting the roof.

In some embodiments, the enlarged foundation further comprises a partition wall located below the top plate and within the enclosed area formed by the side walls for supporting the top plate; the rock body is provided with grooves matched with the partition walls, and the partition walls are preferably arranged below the top plate in a criss-cross mode.

In some embodiments, a plurality of grouting pipes are arranged on the top plate.

In some embodiments, the top plate, the side walls and the partition wall are fixed on the rock body by grouting the rock body surrounded by the side walls and the partition wall through the grouting pipes so as to form the enlarged foundation.

In some embodiments, the size of the roof is larger than its interface with the building.

In some embodiments, the top plate is an integral plate.

In some embodiments, the building is a bridge, and the bridge is connected to the enlarged foundation by piers or abutments.

In a second aspect, a rock mass based building is provided, the building base being connected to the rock mass by means of the aforementioned enlarged foundation.

In a third aspect, a method for constructing an enlarged foundation is provided, comprising the following steps:

s1, excavating a foundation pit of the top plate;

s2, excavating a foundation pit on the side wall;

and S3, installing reinforcing steel bars, pouring the side wall and the top plate in sequence, and rigidly connecting the top plate and the side wall to complete construction of the enlarged foundation.

Compared with the prior art, the technical scheme provided by the application has the following beneficial effects:

the foundation can be enlarged without excavating huge side slopes and foundation rock soil, the scale of foundation pit excavation engineering for enlarging the foundation is reduced, the foundation construction cost for enlarging is reduced, and the construction cost is saved by about 35 percent compared with the traditional foundation for enlarging.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is an elevation view of an enlarged base provided by an embodiment of the present application

FIG. 2 is a top view of an enlarged base provided by an embodiment of the present application;

FIG. 3 is a bottom view of an enlarged base provided in accordance with an embodiment of the present application;

in fig. 1 to 3: 1-a building; 2-a top plate; 3-side wall; 4-partition wall; 5-grouting a pipeline; 6-the original rock mass within the enclosed region formed by the side walls; 7-rock mass.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present application, it should be noted that the terms "upper", "lower", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience in describing the present application and simplifying the description, but do not indicate or imply that the referred device must have a specific orientation, be constructed in a specific orientation, and operate, and thus, should not be construed as limiting the present application. Unless expressly stated or limited otherwise, the terms "mounted," "connected," and "connected" are intended to be inclusive and mean, for example, that they may be fixedly connected, detachably connected, or integrally connected; may be directly connected or indirectly connected through an intermediate. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

As shown in fig. 1 to 3, the present application provides an enlarged base which is seated on a rock mass 7, and includes: a top plate 2 and side walls 3; the top plate 2 is arranged at the bottom of the building 1 and used for supporting the building 1, and the top plate 2 is positioned above the rock mass 7 and clings to the rock mass 7; lateral wall 3 is located roof 2 below along roof 2 vertical setting of border all around to inlay in the recess that 7 surfaces of rock mass set up, lateral wall 3 forms frame type structure for support roof 2.

Further, when only the side wall 3 is arranged below the top plate 2 and cannot meet the requirement of expanding the stress of the foundation, a plurality of criss-cross partition walls 4 can be arranged to ensure that the original rock mass 6 in the surrounding area formed by the side wall 3 can form a composite foundation for bearing the load of the building 1 together with the side wall 3 and the top plate 2. Specifically, the partition wall 4 is located below the ceiling 2 and within the enclosed area formed by the side walls 3; the rock mass 7 is provided with a groove which is inosculated with the partition wall 4.

Furthermore, a plurality of grouting pipes 5 are arranged on the top plate 2, and specifically, the grouting pipes 5 are used for grouting the rock mass 7 surrounded by the side walls 3 and the partition walls 4, so that the top plate 2, the side walls 3 and the partition walls 4 are fixedly connected to the rock mass 7, and the four forms an enlarged foundation together.

Specifically, the size of the roof 2 is larger than the size of the contact surface with the building 1 to increase the contact area with the rock mass 7.

Specifically, the top plate 2 is an integral plate, the thickness and rigidity of the top plate 2 are required to ensure that the building 1 is firmly connected with a finally formed enlarged foundation, and the thickness and depth of the side wall 2 are determined according to stress.

Preferably, the building 1 is a bridge. Specifically, the bridge is connected to the enlarged foundation through a pier or an arch.

The construction method provided by the application comprises the following steps:

and S1, excavating a foundation pit of the top plate 2.

And S2, excavating a foundation pit on the side wall 3. And (5) synchronously excavating foundation pits of the partition wall 4 when necessary.

And S3, installing reinforcing steel bars, pouring concrete on the side wall 3 and the top plate 2 in sequence, and rigidly connecting the top plate 2 and the side wall 3 to complete construction of the enlarged foundation. The partition walls 4 are poured as necessary. And a grouting pipeline 5 is reserved when the top plate 2 is poured if necessary. And grouting and reinforcing the original rock mass 6 in the surrounding area formed by the side wall 3 by using a grouting pipeline 5 if necessary so as to ensure that the side wall 3, the top plate 2 and the original rock mass 6 in the surrounding area formed by the side wall 3 are tightly combined.

And S4, pouring or installing the building 1, and completing construction of the rock mass-based enlarged foundation.

The above description is merely exemplary of the present application and is presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An enlarged footing, for sitting on a rock mass (7), comprising:

the roof (2) is positioned below the building (1) and used for supporting the building (1), and the roof (2) is positioned above the rock mass (7) and is closely attached to the rock mass (7); and

and the side wall (3) is arranged along the periphery of the top plate (2), is positioned below the top plate (2), is embedded in a groove formed in the surface of the rock body (7), and is used for supporting the top plate (2).

2. The enlarged foundation of claim 1, wherein: the enlarged foundation further comprises a partition wall (4), wherein the partition wall (4) is supported below the top plate (2) and is positioned in an enclosed area formed by the side walls (3); the rock body (7) is provided with a groove matched with the partition wall (4).

3. The enlarged foundation of claim 2, wherein: the partition walls (4) are arranged in a criss-cross mode.

4. The enlarged foundation of claim 2, wherein: and the top plate (2) is provided with a plurality of grouting pipelines (5).

5. The enlarged foundation of claim 4, wherein: and grouting is carried out in the rock mass (7) surrounded by the side wall (3) and the partition wall (4) through the grouting pipeline (5), so that the top plate (2), the side wall (3) and the partition wall (4) are all fixedly connected on the rock mass (7) to form an enlarged foundation together.

6. The enlarged foundation of claim 1, wherein: the size of the top plate (2) is larger than the size of the contact surface of the top plate and the building (1).

7. The enlarged foundation of claim 1, wherein: the top plate (2) is an integrated plate.

8. The enlarged foundation of claim 1, wherein: the building (1) is a bridge, and the bridge is connected to an expansion foundation through a pier or an arch center.

9. A building based on rock mass which characterized in that: the bottom of the building (1) is connected with the rock mass (7) through the enlarged foundation of any one of claims 1-8.

10. The method of constructing an enlarged foundation according to any one of claims 1 to 8, comprising the steps of:

s1, excavating a foundation pit of the top plate (2);

s2, excavating a foundation pit on the side wall (3);

and S3, installing reinforcing steel bars, pouring the side wall (3) and the top plate (2) in sequence, and rigidly connecting the top plate (2) and the side wall (3) to complete construction of the enlarged foundation.