CN113653067A - Foundation pit excavation advance support construction method - Google Patents
Foundation pit excavation advance support construction method Download PDFInfo
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- CN113653067A CN113653067A CN202111008533.0A CN202111008533A CN113653067A CN 113653067 A CN113653067 A CN 113653067A CN 202111008533 A CN202111008533 A CN 202111008533A CN 113653067 A CN113653067 A CN 113653067A
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D17/00—Excavations; Bordering of excavations; Making embankments
- E02D17/02—Foundation pits
- E02D17/04—Bordering surfacing or stiffening the sides of foundation pits
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Abstract
The invention belongs to the technical field of foundation pit supporting and discloses a construction method for foundation pit excavation advanced supporting, which comprises the steps of firstly excavating a plurality of pre-excavated deep grooves in a foundation pit excavation area, then placing a plurality of horizontal supporting structures into each designed excavation elevation in each pre-excavated deep groove according to the arrangement form of the horizontal supporting structures, connecting each horizontal supporting structure with ground connection walls on two sides of a foundation pit, wherein the connected horizontal supporting structures can bear engineering loads; and after all the horizontal supporting structures are installed, earth excavation of the foundation pit excavation area is carried out. The invention advocates that the advance support is carried out before the foundation pit is excavated, and the foundation pit is excavated after the supporting structure is installed, so that the situation that the supporting action lags behind the excavation of the foundation pit in the traditional foundation pit excavation construction is avoided, the displacement field developed under the excavation action of the foundation pit in the non-supporting state is eliminated, and the engineering displacement control standard of reducing the size from centimeter to millimeter in some major foundation pit engineering is further met.
Description
Technical Field
The invention belongs to the technical field of composite foundations, and particularly relates to a foundation pit excavation supporting construction method.
Background
In the excavation process of the foundation pit, the peripheral field of the foundation pit can be influenced by the excavation effect to generate a displacement field. Under the action of the displacement field, buildings and structures around the foundation pit deform and displace, so that the safety and the applicability of the foundation pit are reduced. At present, urban building distribution is more intensive, and meanwhile, foundation pit engineering is also developed towards a large-scale direction of 'deep, large and long', so that the method is a key problem of foundation pit engineering at the present stage, and how to better control a site displacement field in the foundation pit excavation process under the condition of increasing foundation pit excavation scale, and ensure the safety of buildings and structures in peripheral areas.
The traditional foundation pit supporting concept advocates layered excavation and layered supporting, and excavation is carried out firstly and then supporting is carried out. Specifically to the construction practice: firstly, excavating soil on the upper part of the designed excavation surface, then installing the enclosing purlin at the side part of the underground diaphragm wall exposed from the upper part of the excavation surface, and finally installing a horizontal supporting structure. The construction sequence is repeated until the designed excavation bottom surface is reached. In the practice of this foundation pit supporting concept, the foundation pit supporting action is always lagging behind the excavation process of the foundation pit. This will lead to the foundation ditch will be in the excavation of the unsupported state under the effect to develop certain displacement field before supporting. However, in some major projects, the control criteria for foundation pit engineering displacement have been reduced from "centimeter-scale" to "millimeter-scale". The traditional foundation pit supporting concept and the foundation pit supporting effect shown in engineering practice hardly meet the displacement control requirement of engineering.
Disclosure of Invention
The invention aims to solve the technical problem that the traditional foundation pit supporting concept and the foundation pit supporting effect shown in engineering practice are difficult to meet the stricter site displacement control standard, and provides a foundation pit excavation advance support construction method.
In order to solve the technical problems, the invention is realized by the following technical scheme:
according to one aspect of the invention, a construction method for a foundation pit excavation advance support is provided, which is characterized by comprising the following steps:
(1) excavating a plurality of pre-excavated deep grooves in a foundation pit excavation area, wherein the pre-excavated deep grooves can accommodate the horizontal supporting structures, and the depth of the pre-excavated deep grooves is equal to the designed excavation depth of the foundation pit;
(2) placing a plurality of horizontal supporting structures at each designed excavation elevation position in each pre-excavation deep groove according to the arrangement form of the horizontal supporting structures, and connecting each horizontal supporting structure with the ground connecting walls on two sides of the foundation pit, wherein the connected horizontal supporting structures can bear engineering load;
(3) and after the horizontal supporting structures are completely installed, earth excavation of the foundation pit excavation area is carried out.
Further, the pre-dug deep trench is vertically arranged and the top of the pre-dug deep trench is open.
Further, the horizontal support structure is a straight rod or a ring beam.
Further, the horizontal supporting structure is made of steel, concrete or wood.
Further, the horizontal supporting structure and the underground diaphragm wall are connected through riveting, bolting or flange connection.
Further, the bottom of the horizontal supporting structure is provided with soil drilling devices which are uniformly distributed, so that the step (1) and the step (2) are synchronously carried out.
According to another aspect of the invention, a construction method for a foundation pit excavation advance support is provided, which comprises the following steps:
(1) excavating a plurality of shield holes in a foundation pit excavation area, wherein the shield holes are arranged according to the shape and arrangement of a designed horizontal supporting structure, and the depth of each shield hole is positioned at each designed excavation elevation; the shield hole extends towards the interior of the diaphragm wall on two sides of the foundation pit to form an anchoring groove;
(2) pouring concrete grout into the shield holes and the anchoring grooves, and performing concrete curing to form a horizontal supporting structure; the horizontal supporting structure is connected with the ground connecting walls on the two sides of the foundation pit and can bear engineering load;
(3) and after the maintenance of all the horizontal supporting structures is finished, earth excavation of the foundation pit excavation area is carried out.
Furthermore, the shield hole is buried in the soil body of the site.
Further, the horizontal support structure is a straight rod or a ring beam.
The invention has the beneficial effects that:
the construction method for the forepoling of the foundation pit excavation renovates the traditional foundation pit excavation supporting concept of 'excavation before support', advocates to carry out forepoling before the foundation pit excavation, and carries out the foundation pit excavation after the supporting structure is installed.
Compared with the traditional foundation pit excavation supporting concept, the invention can change 'excavation before excavation and' advanced supporting 'after supporting' in the foundation pit excavation construction, thereby avoiding the situation that the supporting action lags behind the foundation pit excavation existing in the traditional foundation pit excavation construction, eliminating the displacement field developed under the excavation action of the foundation pit in the non-supporting state, and further meeting the engineering displacement control standard of reducing from centimeter level to millimeter level in some major foundation pit engineering.
Drawings
Fig. 1 is a schematic flow chart of a foundation pit excavation advance support construction method provided in embodiment 1 of the present invention;
fig. 2 is a schematic plan view of a pre-excavated deep trench in the foundation pit excavation advanced support construction method provided in embodiment 1 of the present invention;
fig. 3 is a vertical surface layout view of a horizontal support structure in the foundation pit excavation advance support construction method provided in embodiment 1 of the present invention;
fig. 4 is a ring beam plane layout diagram in the foundation pit excavation advance support construction method provided in embodiment 1 of the present invention;
FIG. 5 is a schematic construction view of the bottom of the horizontal support structure provided by the present invention with an earth drilling device installed;
fig. 6 is a schematic view of earth excavation construction in the foundation pit excavation advance support construction method provided in embodiment 1 of the present invention;
fig. 7 is a schematic flow chart of a foundation pit excavation advance support construction method provided in embodiment 2 of the present invention;
fig. 8 is a shield hole plane layout diagram in the foundation pit excavation advance support construction method provided in embodiment 2 of the present invention.
In the above figures: 1-a field soil body; 2-underground diaphragm wall; 3, pre-digging a deep groove; 4-a horizontal support structure; 5-field plane; 6-designing and excavating a bottom surface; 7-ring beam; 8-a soil drilling device; 9-excavating a foundation pit area; 10-shield holes; 11-concrete grout.
Detailed Description
In order to further understand the contents, features and effects of the present invention, the following embodiments are illustrated and described in detail with reference to the accompanying drawings:
the construction method for the foundation pit excavation advance support provided by the invention embodies the foundation pit support concept of 'firstly supporting and then excavating' in the foundation pit excavation, and mainly solves the problem that the traditional foundation pit support concept of 'firstly excavating and then supporting' and the foundation pit support effect shown in engineering practice are difficult to meet the stricter site displacement control standard.
Example 1
As shown in fig. 1, the embodiment provides a method for constructing a forepoling in excavation of a foundation pit, which includes the following steps:
firstly, before excavation of a foundation pit, a plurality of pre-excavated deep ditches 3 are excavated in a foundation pit excavation area 9 according to the shape and the arrangement form of the horizontal support structures 4, as shown in fig. 2.
The pre-dug deep groove 3 is vertically arranged and is open at the top, and the form and the distribution of the pre-dug deep groove are determined according to the shape and the arrangement form of the horizontal supporting structure 4. The pre-trenched trench 3 is typically of the same length as the horizontal support structure 4, is typically of the same width or slightly greater than the horizontal support structure 4, and is typically of the same depth as the excavation depth of the pit design.
Wherein, the material of the horizontal supporting structure 4 is not limited, such as: steel, concrete, wood, etc.
And step two, placing a plurality of horizontal supporting structures 4 at each designed excavation elevation position in each pre-excavated deep trench 3 according to the arrangement form of the horizontal supporting structures 4, and carrying out effective mechanical connection on each horizontal supporting structure 4 and the underground diaphragm walls 2 at two sides of the foundation pit, so that the horizontal supporting structures 4 are firmly fixed and can bear engineering load. As shown in fig. 3. At this time, since the excavation of the foundation pit is not performed, the site soil body 1 is still located between the site plane 5 and the designed excavation bottom surface 6.
The arrangement form of the horizontal supporting structures 4 is set according to the conventional technology, and different changes can be made according to the shapes of the horizontal supporting structures, the horizontal supporting structures can be arranged in parallel arrays for straight rod-shaped horizontal supporting structures 4, and also can be horizontal inclined strut structures matched with the ring beams 7, and the like, as shown in fig. 4.
The mechanical connection between the horizontal support structure 4 and the diaphragm wall 2 on both sides of the foundation pit is not limited, and may be, for example, riveting, bolting, flange connection, etc.
The engineering load that the horizontal supporting structure 4 can bear is the passive soil pressure of the soil outside the pit generated in the excavation process of the foundation pit under the conventional construction state.
In addition, the horizontal support structure 4 can also be designed in an automatic downhole manner, in order to achieve a higher degree of automation of the construction. As shown in fig. 5, the soil drilling devices 8 which are uniformly distributed are installed at the bottom of the horizontal supporting structure 4, the soil drilling devices 8 are started, the soil bodies at the bottom of the horizontal supporting structure 4 can be dug by the soil drilling devices 8, meanwhile, the horizontal supporting structure 4 is also sunk continuously, the ditching in the step one and the horizontal supporting structure 4 in the step two are synchronously carried out, then, each horizontal supporting structure 4 is mechanically connected with the underground connecting walls 2 at two sides of the foundation pit effectively, and the automation degree of construction is improved.
And step three, after the horizontal supporting structures 4 are completely installed, performing earth excavation of the foundation pit excavation area 8, as shown in fig. 6.
And the earth excavation step of the foundation pit excavation area 8 is carried out according to the design and a conventional construction mode.
Example 2
As shown in fig. 7, the embodiment provides a method for constructing a forepoling in excavation of a foundation pit, which includes the following steps:
firstly, before the excavation of the foundation pit, according to the design of the horizontal supporting structure 4, a small-sized shield machine is adopted to excavate a plurality of shield holes 10 in a foundation pit excavation area 9, as shown in fig. 8.
The shield hole 10 is buried in the ground soil 1 and is not visible from the ground plane 5.
Wherein, the shape and the size of the shield holes 10 are the same as the shape and the arrangement form of the designed horizontal supporting structure 4. The cross section of the shield hole 10 is consistent with the cross section of the designed horizontal supporting structure 4 in shape, the space direction of the shield hole 10 is consistent with the arrangement mode of the designed horizontal supporting structure 4, and the depth of the shield hole 10 is the elevation of each design excavation.
In order to form effective mechanical connection between the horizontal supporting structure 4 and the underground diaphragm wall 2 after the maintenance is finished in the future, the shield hole 10 needs to drill a certain distance into the underground diaphragm wall 2 in the excavation process, and an anchoring groove is formed on each wall body of the underground diaphragm walls 2 on the two sides of the foundation pit.
And step two, vertically drilling a well hole downwards through the field plane 5 to be communicated with the shield hole 10 formed in the step 1, then pouring concrete slurry 11 into the shield hole 10 and the anchoring groove of the underground diaphragm wall 2 through the well hole, curing the concrete, and forming the horizontal supporting structure 4 of the concrete after curing.
The horizontal support structure 4 that the maintenance was accomplished reaches design mechanical strength to inlay the base at 4 tip of horizontal support structure in the reservation anchor recess of hole both sides diaphragm wall 2, utilize the shear strength and the resistance to plucking intensity of concrete, horizontal support structure 4 forms effectual mechanics with diaphragm wall 2 and is connected, makes horizontal support structure 4 fixed firm and can bear the engineering load.
At this time, since the excavation of the foundation pit is not performed, the site soil body 1 is still located between the site plane 5 and the designed excavation bottom surface 6.
The arrangement form of the horizontal supporting structures 4 can be changed differently according to the shapes of the horizontal supporting structures, the horizontal supporting structures can be arranged in parallel arrays of straight rod-shaped horizontal supporting structures 4, and can also be horizontal inclined strut structures matched with ring beams 7, and the like, as shown in fig. 4.
The horizontal supporting structure 4 can bear engineering load, which means passive soil pressure of soil outside the pit generated in the excavation process of the foundation pit in the conventional construction state.
And step three, after the concrete slurry 11 of the horizontal supporting structure 4 completely reaches the maintenance age, carrying out earthwork excavation of the foundation pit excavation area 9.
And the earth excavation step of the foundation pit excavation area 7 is carried out according to the design and a conventional construction mode.
Although the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above-described embodiments, which are merely illustrative and not restrictive, and those skilled in the art can make various changes and modifications within the spirit and scope of the present invention without departing from the spirit and scope of the appended claims.
Claims (9)
1. A foundation pit excavation advance support construction method is characterized by comprising the following steps:
(1) excavating a plurality of pre-excavated deep grooves in a foundation pit excavation area, wherein the pre-excavated deep grooves can accommodate the horizontal supporting structures, and the depth of the pre-excavated deep grooves is equal to the designed excavation depth of the foundation pit;
(2) placing a plurality of horizontal supporting structures at each designed excavation elevation position in each pre-excavation deep groove according to the arrangement form of the horizontal supporting structures, and connecting each horizontal supporting structure with the ground connecting walls on two sides of the foundation pit, wherein the connected horizontal supporting structures can bear engineering load;
(3) and after the horizontal supporting structures are completely installed, earth excavation of the foundation pit excavation area is carried out.
2. The method of claim 1, wherein the pre-excavated deep trench is vertically arranged and has an open top.
3. The method of claim 1, wherein the horizontal support structure is a straight rod or a ring beam.
4. The method of claim 1, wherein the horizontal support structure is made of steel, concrete or wood.
5. The method of claim 1, wherein the horizontal supporting structure is riveted, bolted or flanged to the underground diaphragm wall.
6. The method for constructing the forepoling of foundation pit excavation according to claim 1, wherein the bottom of the horizontal supporting structure is provided with uniformly distributed earth drilling devices so as to synchronously carry out the step (1) and the step (2).
7. A foundation pit excavation advance support construction method is characterized by comprising the following steps:
(1) excavating a plurality of shield holes in a foundation pit excavation area, wherein the shield holes are arranged according to the shape and arrangement of a designed horizontal supporting structure, and the depth of each shield hole is positioned at each designed excavation elevation; the shield hole extends towards the interior of the diaphragm wall on two sides of the foundation pit to form an anchoring groove;
(2) pouring concrete grout into the shield holes and the anchoring grooves, and performing concrete curing to form a horizontal supporting structure; the horizontal supporting structure is connected with the ground connecting walls on the two sides of the foundation pit and can bear engineering load;
(3) and after the maintenance of all the horizontal supporting structures is finished, earth excavation of the foundation pit excavation area is carried out.
8. The method of claim 7, wherein the shield hole is buried in the soil of the site.
9. The method of claim 7, wherein the horizontal support structure is a straight rod or a ring beam.
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| CN202111008533.0A CN113653067B (en) | 2021-08-31 | 2021-08-31 | Foundation pit excavation advance support construction method |
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| CN202111008533.0A CN113653067B (en) | 2021-08-31 | 2021-08-31 | Foundation pit excavation advance support construction method |
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| CN113653067A true CN113653067A (en) | 2021-11-16 |
| CN113653067B CN113653067B (en) | 2023-03-31 |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103255771A (en) * | 2013-05-24 | 2013-08-21 | 山西太行建设开发有限公司 | Method for excavating super-deep foundation pit engineering piles in graded mode and graded composite supporting of supporting piles |
| CN103422863A (en) * | 2013-07-24 | 2013-12-04 | 中铁四局集团第四工程有限公司 | Method for ultra-deep foundation pit construction in complex environments |
| CN104452773A (en) * | 2014-11-18 | 2015-03-25 | 上海建工七建集团有限公司 | Construction method for foundation pit support with strengthening structure |
| CN108316283A (en) * | 2018-01-25 | 2018-07-24 | 天津大学 | The devices and methods therefor of influence of foundation excavation is controlled using hole rising pouring slurry ground-connecting-wall |
| CN110821503A (en) * | 2019-11-27 | 2020-02-21 | 中铁九局集团第四工程有限公司 | Construction method for main body of ultra-deep shield section air shaft after tunnel advance |
| CN111560957A (en) * | 2020-05-06 | 2020-08-21 | 中铁隆工程集团有限公司 | Shield receiving well foundation pit excavation and supporting non-dewatering construction method |
-
2021
- 2021-08-31 CN CN202111008533.0A patent/CN113653067B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103255771A (en) * | 2013-05-24 | 2013-08-21 | 山西太行建设开发有限公司 | Method for excavating super-deep foundation pit engineering piles in graded mode and graded composite supporting of supporting piles |
| CN103422863A (en) * | 2013-07-24 | 2013-12-04 | 中铁四局集团第四工程有限公司 | Method for ultra-deep foundation pit construction in complex environments |
| CN104452773A (en) * | 2014-11-18 | 2015-03-25 | 上海建工七建集团有限公司 | Construction method for foundation pit support with strengthening structure |
| CN108316283A (en) * | 2018-01-25 | 2018-07-24 | 天津大学 | The devices and methods therefor of influence of foundation excavation is controlled using hole rising pouring slurry ground-connecting-wall |
| CN110821503A (en) * | 2019-11-27 | 2020-02-21 | 中铁九局集团第四工程有限公司 | Construction method for main body of ultra-deep shield section air shaft after tunnel advance |
| CN111560957A (en) * | 2020-05-06 | 2020-08-21 | 中铁隆工程集团有限公司 | Shield receiving well foundation pit excavation and supporting non-dewatering construction method |
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