CN219450756U - Full-recovery vertical supporting steel column system for foundation pit engineering - Google Patents

Abstract

The utility model belongs to a fully recovered vertical support steel column system for foundation pit engineering, belonging to the field of geotechnical engineering. The technical proposal is as follows: the vertical supporting steel upright post is detachably connected with the horizontal support; in the height range of the base plate and the cushion layer, the isolation steel pipe is sleeved outside the vertical supporting steel upright post, the length of the isolation steel pipe is not smaller than the sum of the thicknesses of the base plate and the cushion layer, the annular outer water stop steel plate is welded on the outer surface of the isolation steel pipe within the thickness range of 1/2-1/3 of the base plate from the bottom surface of the base plate, the stiffening ring plate is arranged outside the isolation steel pipe, the stiffening ring plate is connected with the main rib of the base plate which is disconnected under the influence of the isolation steel pipe, and the disconnected main rib is welded with the stiffening ring plate. The full pile length and the full section of the vertical supporting steel upright post can be recycled, energy conservation and emission reduction can be realized to the maximum extent, and the environment is protected.

Description

Full-recovery vertical supporting steel column system for foundation pit engineering

Technical Field

The utility model relates to the field of geotechnical engineering, in particular to a fully recovered vertical supporting steel column system for foundation pit engineering.

Background

Along with the development of building industrialization technology, prefabrication of building structural members is rapidly developing and popularizing. In the deep foundation pit engineering, a horizontal support is erected inside, and a vertical support system is generally required to be arranged at a position with a larger span and is used for bearing the dead weight and other loads of a concrete support or a steel support rod piece. According to experience, for a support system with a large load, a vertical support system of a foundation pit usually adopts a form of inserting steel columns into pile foundations of the column piles, and for the condition of only one concrete support or a plurality of steel support rods, the vertical support system column can only adopt steel structure columns. The design of the section form and the dimension of the vertical supporting upright post steel structure is controlled by the upper load, and the design calculation is generally carried out according to the axle center/eccentric compression component.

The pile bottom of the vertical supporting upright post is usually required to be inserted into a stable soil layer below the foundation pit bottom plate to obtain enough vertical bearing capacity and anti-uplift capacity, but after the foundation pit bottom plate is constructed and the inner supporting structure is removed, only the steel upright post at the upper part of the bottom plate can be cut off and recycled, but the steel upright post below the bottom plate cannot be recycled, so that larger waste is caused to a certain extent, and particularly in foundation pit engineering with larger area scale and longer pile length under poor geological conditions, the waste amount of steel is more serious and the advocacy of energy conservation and environmental protection is not satisfied.

Disclosure of Invention

In order to solve the technical problems, the utility model provides a fully-recovered vertical support steel column system for foundation pit engineering, which can realize the recycling of the whole pile length and the whole section of the vertical support steel column, saves energy and reduces emission to the maximum extent, and is environment-friendly.

The technical scheme of the utility model is as follows: the fully recovered vertical support steel column system for foundation pit engineering is characterized in that a vertical support steel column is detachably connected with a horizontal support; in the height range of the base plate and the cushion layer, the isolation steel pipe is sleeved outside the vertical supporting steel upright post, the length of the isolation steel pipe is not smaller than the sum of the thicknesses of the base plate and the cushion layer, the annular outer water stop steel plate is welded on the outer surface of the isolation steel pipe within the thickness range of 1/2-1/3 of the base plate from the bottom surface of the base plate, the stiffening ring plate is arranged outside the isolation steel pipe, the stiffening ring plate is connected with the main rib of the base plate which is disconnected under the influence of the isolation steel pipe, and the disconnected main rib is welded with the stiffening ring plate.

Based on the technical characteristics: a detachable bracket connection is arranged at the intersection of the vertical supporting steel upright post and the horizontal support; the bracket comprises a steel bracket and a limiting frame; the steel corbels are arranged on the side walls of the vertical supporting steel upright posts and are used for supporting the horizontal supports; the limiting frame is enveloped with a horizontal support, and the bottom is fixed on the steel corbel.

Based on the technical characteristics: the width of the annular outer water-stopping steel plate is more than or equal to 100mm, and the thickness of the annular outer water-stopping steel plate is more than or equal to 8mm.

Compared with the prior art that the upright post below the bottom plate can not be recycled, but only the steel upright post at the upper part of the bottom plate can be cut off and recycled, the utility model has the following remarkable advantages:

1. the whole pile length of the vertical supporting steel upright post can be recovered conveniently through the isolation steel pipe, a large amount of steel buried below the bottom plate is saved, energy is saved, consumption is reduced, and the whole vertical supporting steel upright post can be rented according to the renting price, so that the engineering cost is greatly reduced.

2. The process of sectionally cutting out the vertical supporting steel upright post is avoided, labor and cost are saved, the problems that the sectionally cut-out steel member is uneven in length, partially abandoned and reusable in a long side of welding and jointing with sufficient strength are solved, the whole section is recycled, the integrity of the steel member is ensured, the depreciation loss is reduced, welding and jointing are not needed, and recycling is facilitated.

3. The isolation steel pipe is provided with a water stop steel plate, and is connected with the steel bar foot strength of the base plate and is subjected to hole sealing and head collecting water stop design construction, so that the stress performance and the waterproof effect of the base plate are ensured.

4. The inner diameter of the isolation steel pipe is enveloped with the vertical supporting steel upright post, and a certain gap is reserved to facilitate loosening and pulling out during the whole recovery period.

Drawings

Fig. 1 is a schematic diagram of the connection of a vertical support steel column with a horizontal support and a foundation bedplate.

Fig. 2 is a schematic illustration of a vertical support steel column connected to a single horizontal support in accordance with an embodiment of the present utility model.

FIG. 3 is a detailed view of the connection of the isolation steel pipe and the stiffening ring plate according to an embodiment of the present utility model.

Fig. 4 is a detail view of an outer welded annular outer water stop steel plate of the isolation steel pipe.

Fig. 5 is a construction diagram of a closing-in measure of an isolated steel pipe according to an embodiment of the present utility model.

The reference numerals in the figures are shown as follows: isolating the steel pipe 1; a vertical support steel column 2; a horizontal support 3; an annular outer water stop steel plate 4; stiffening ring plates 5; a limit frame 6; steel corbels 7; a bottom plate 8; a cushion layer 9; stiffening ribs 10; steel column holes 11; gravel soil 12; a waterproof material 13; concrete 14; an inner water stop steel plate 15; micro-expansive concrete 16.

Detailed Description

The following describes the embodiments of the present utility model in further detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present utility model and are not intended to be limiting.

In the description of the present utility model, it should be noted that the terms "center", "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the apparatus or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model.

In the description of the present utility model, it should be noted that the terms "mounted," "connected," and "connected" are to be construed broadly, unless otherwise specifically defined and limited. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

In this embodiment, design construction of a foundation pit engineering is taken as an example. In general, the pile bottom of a vertical support steel column is required to be inserted into a stabilized soil layer below the foundation pit bottom plate to obtain sufficient vertical bearing capacity and anti-uplift capacity. After the foundation pit bottom plate is constructed and the inner supporting structure is dismantled, only the steel upright posts on the upper part of the bottom plate can be cut off and recycled, but the steel upright posts below the bottom plate cannot be recycled, so that larger waste is caused to a certain extent, and particularly in foundation pit engineering with larger area scale, the steel waste is more serious and the advocacy of energy conservation and environmental protection is not satisfied.

According to the utility model, the vertical supporting steel upright post 2 is connected with the horizontal support 3 through the steel bracket, the isolating steel pipe 1 with water stopping and force transferring functions is additionally arranged in the range of the bottom plate 8 and the cushion layer 9, the whole section of the vertical supporting steel upright post 2 is conveniently fully recovered, and the upright post hole part below the bottom plate 8 and the inner hole in the range of the foundation bottom plate are backfilled in layers after recovery to recover the mouth, so that the stress performance and the waterproof effect of the foundation bottom plate are further ensured.

As shown in fig. 1 and 2, there is a detachable connection between the vertical bearing steel upright 2 and the horizontal support 3. A detachable bracket connection is arranged at the intersection of the vertical supporting steel upright post 2 and the horizontal support 3; the bracket comprises a steel bracket 7 and a limiting frame 6. The steel corbels 7 are arranged outside the side walls of the vertical supporting steel upright posts 2, the horizontal supports 3 are supported, the limiting frames 6 envelop the horizontal supports 3, and the bottoms of the limiting frames are fixed on the steel corbels 7.

In the height range of the bottom plate 8 and the cushion layer 9, the isolation steel pipe 1 is sleeved outside the vertical supporting steel upright post 2, the length of the isolation steel pipe 1 is not smaller than the sum of the thicknesses of the bottom plate 8 and the cushion layer 9, the annular outer water stop steel plate 4 is welded on the outer surface of the isolation steel pipe 1 within the thickness range of 1/2-1/3 of the bottom plate from the bottom surface of the bottom plate 8, the stiffening ring plate 5 is arranged outside the isolation steel pipe, the stiffening ring plate 5 is connected with the main rib of the bottom plate which is broken under the influence of the isolation steel pipe 1, and the broken main rib is welded with the stiffening ring plate 5.

The construction method for the fully recovered vertical support steel upright post comprises the following specific steps:

step one: before the foundation pit is excavated, a vertical supporting steel column 2 is driven in.

The section form and the dimension of the vertical support steel column structure can be determined by calculating the load of the horizontal support member, H-shaped steel, round steel pipes, square steel pipes and the like, and the section dimension and the thickness are determined according to the strength and stability checking result of the bidirectional bending member and the column pile body bearing capacity below the bottom plate.

(1) The horizontal support member load should take into account the eccentric effect.

(2) When the stability of the vertical supporting steel upright post 2 is checked, the length of the upright post in the range of the isolation steel pipe 1 is subtracted from the calculated length value of the upright post, namely the length of the upright post from the last supporting center line to the bottom elevation of the cushion layer 9 is taken from the lowest span.

(3) For more than two concrete horizontal supports, it is recommended to recheck the bearing capacity of the steel upright post pile body according to the geological condition of the pit bottom rock-soil body, if pile side grouting, pile bottom grouting and the like are required to be added, the friction reducing agent is required to be added in consideration of convenient recovery, but the friction reducing agent is required to recheck the reduction of the friction resistance of the steel upright post side.

(4) Before the foundation pit is excavated, a vertical supporting steel upright post 2 is arranged according to the positioning and elevation measurement paying-off of a construction drawing.

Step two: and excavating earthwork after the foundation pit enclosure meets the design requirement, and arranging a detachable bracket at the intersection of the vertical supporting steel upright post 2 and the horizontal support 3 to connect the vertical supporting steel upright post 2 and the horizontal support 3.

The bracket can be welded by adopting steel corbels 7 and limiting frames 6, and the strength and stability of the bracket are designed and checked according to the dead weight of the horizontal support and the load on the horizontal support.

(1) And excavating earthwork after the foundation pit enclosure meets the design requirement, excavating to the elevation of the bottom of the horizontal support, constructing the horizontal inner support, and grooving the connection bracket with the vertical supporting steel upright post 2 at the intersection.

(2) The steel corbels 7 and the vertical supporting steel upright posts 2 are preferably welded or connected by bolts, and the connection strength is checked according to load stress.

(3) When the vertical load of the vertical supporting steel upright post 2 is large, the cross section of the bracket structure is enlarged, and a plurality of reinforcing measures such as brackets are adopted.

(4) In order to reduce the displacement of the vertical supporting steel upright post 2 and increase the stability outside a plane, a limiting frame 6 is arranged above the bracket, and the size of the limiting frame 6 is enveloped with the cross section size of the horizontal support 3.

(5) When the horizontal support 3 is a double-spliced member or a combined section, the vertical support steel upright 2 can be provided with double-sided brackets, and the stability and bearing capacity of the vertical support steel upright should be further checked.

Step three: and before the foundation pit is excavated to the pit bottom and the cushion layer 9 and the bottom plate 8 are constructed, the vertical supporting steel upright post 2 is wrapped with the isolation steel pipe 1, and the annular outer water stop steel plate 4 and the stiffening ring plate 5 are welded.

The length of the isolation steel pipe 1 is not smaller than the sum of the thickness of the bottom plate and the thickness of the cushion layer, an annular outer water-stopping steel plate 4 is welded on the outer surface of the isolation steel pipe 1 within the range of 1/2-1/3 of the thickness of the bottom plate from the bottom surface of the bottom plate, and the isolation steel pipe is connected with the main rib of the bottom plate by a stiffening ring plate 5. The method comprises the following steps:

(1) As shown in fig. 3, the isolation steel pipe 1 can be formed by splitting a round steel pipe into 2 to 4 blocks, for convenient construction, the isolation steel pipe 1 is suggested to be split into 2 blocks, sleeved on the outer side of the vertical supporting steel upright post 2, and spliced into the round isolation steel pipe 1 by plug welding, and is erected at the bottom of a cushion layer.

(2) The inner diameter of the isolation steel pipe 1 is sized to envelop the vertical support steel upright post 2, and a certain gap is reserved to facilitate loosening and pulling out during the whole root recovery period.

(3) As shown in fig. 3, when constructing the bottom plate lower skin steel bar, 2 to 4 stiffening ring plates 5 are welded at the same elevation of the outer wall of the isolation steel pipe 1 and used for connecting the main bars which are disconnected under the influence of the isolation steel pipe 1, the disconnected main bars and the stiffening ring plates 5 are preferably welded in double sides, the length of a welding line is more than or equal to 5d, and the unaffected bottom plate main bars at the two sides of the isolation steel pipe 1 are normally pulled through for construction; the stiffening ring plate 5 is preferably 10mm or more in thickness, and the stiffening ribs 10 are provided to ensure stability of the stiffening ring plate 5.

(4) As shown in FIG. 4, the annular outer water-stop steel plate 4 is welded on the outer surface of the isolation steel pipe 1 within the range of 1/2 to 1/3 of the thickness of the bottom plate from the bottom surface of the bottom plate, and the width of the annular outer water-stop steel plate 4 is more than or equal to 100mm, and the thickness of the annular outer water-stop steel plate 4 is more than or equal to 8mm.

(5) When the steel is constructed to the upper skin steel of the bottom plate, a stiffening annular plate 5 is welded at the same elevation of the outer wall of the isolation steel pipe 1, the disconnected main steel bar is welded with the annular plate in double sides, and the rest main steel bars which are not disconnected are pulled through.

Step four: and after the bottom plate is constructed and the horizontal support is dismantled, the whole length of the vertical support steel upright post is extracted and recovered.

The method comprises the following steps: and after the bottom plate is constructed and meets the design strength requirement, removing the lowest horizontal support, constructing the basement structure, removing the horizontal support layer by layer upwards, constructing the basement structure, and recovering the whole length of the steel upright post full pile after all the horizontal supports are removed.

Step five: as shown in fig. 5, the vertical support steel column 2 and the isolation steel pipe 1 are closed. The method comprises the following steps:

(1) And backfilling and compacting the steel upright holes 11 ranging from the bottom of the vertical supporting steel upright 2 to below the cushion layer 9 by using well-graded gravels 12 or melon seed pieces.

(2) The part of the bottom surface of the cushion layer 9, which is lower than the range of 1-2m, is poured and compacted by a waterproof material 13; it is suggested that micro-expansive concrete or cement slurry with early strength agent can be used for pouring.

(3) Draining residual water (if any) in the isolation pipe before the cavity of the isolation steel pipe is blocked in the range of the bottom plate, pouring concrete 14 with the same label as the bottom plate, pouring the concrete 14 below the top surface of the bottom plate by about 80mm, and welding 1 inner water-stop steel plate 15 in the isolation steel pipe 1 after the concrete 14 is finally solidified, wherein the thickness of the inner water-stop steel plate 15 is preferably more than or equal to 8mm; the weld should meet the water tightness requirement.

(4) And finally, pouring the residual cavity at the top of the isolation steel pipe 1 by using micro-expansion concrete 16, wherein the strength grade of the micro-expansion concrete can be the same as that of the bottom plate, and closing up is completed.

In the utility model, the design checking calculation of the related load design, the connection bending shear torsion resistance and the like of the vertical supporting structure can be determined according to the existing national concrete structure design specification, foundation pit supporting technical standards, steel structure design standards and the like.

Compared with the existing design that the upright post below the bottom of the bottom plate cannot be recovered, but only the steel upright post at the upper part of the bottom plate can be cut off for recovery, the utility model can more conveniently realize the full-pile length and whole-section recovery of the vertical supporting steel upright post, avoids the step of sectionally cutting off the steel upright post, saves labor and cost, and simultaneously solves the problems that the sectionally cut-off steel member is uneven in length and short, partially abandoned and needs sufficient strength for welding and lengthening and can be reused; meanwhile, the stress performance and the waterproof effect of the foundation slab are further ensured through a series of internal and external water stop and steel bar connection, hole sealing and closing measures.

Through rechecking and checking, the fully-recovered vertical supporting steel upright post in the utility model can recover and reuse the non-recoverable part of the steel upright post to the maximum extent, improves the utilization rate of steel by 50-70%, and is low-carbon and environment-friendly.

The above description is only illustrative of the preferred embodiments of the present utility model and is not intended to limit the scope of the present utility model, and any alterations and modifications made by those skilled in the art based on the above disclosure shall fall within the scope of the appended claims.

Claims (3)

1. The utility model provides a full recovery vertical supporting steel stand system of foundation ditch engineering which characterized in that: the vertical supporting steel upright post (2) is detachably connected with the horizontal support (3); in the height range of the base plate (8) and the cushion layer (9), the isolation steel pipe (1) is sleeved outside the vertical supporting steel upright post (2), the length of the isolation steel pipe (1) is not smaller than the sum of the thicknesses of the base plate (8) and the cushion layer (9), an annular outer water stop steel plate (4) is welded on the outer surface of the isolation steel pipe (1) within the thickness range of 1/2-1/3 of the bottom surface of the base plate (8), a stiffening ring plate (5) is arranged outside the isolation steel pipe (1), the stiffening ring plate (5) is connected with a main rib of the base plate (8) which is disconnected under the influence of the isolation steel pipe (1), and the disconnected main rib is welded with the stiffening ring plate (5).

2. The fully recovered vertical support steel column system for foundation pit engineering of claim 1, wherein: a detachable bracket connection is arranged at the intersection of the vertical supporting steel upright post (2) and the horizontal support (3); the bracket comprises a steel bracket (7) and a limiting frame (6); the steel corbels (7) are arranged on the side walls of the vertical supporting steel upright posts (2) and used for supporting the horizontal supports (3); the limiting frame (6) is enveloped on the horizontal support (3), and the bottom of the limiting frame is fixed on the steel corbel (7).

3. The fully recovered vertical support steel column system for foundation pit engineering of claim 1, wherein: the width of the annular outer water-stopping steel plate (4) is more than or equal to 100mm, and the thickness of the annular outer water-stopping steel plate (4) is more than or equal to 8mm.