CN112392051A - Foundation pit supporting and reinforcing structure and construction method - Google Patents

Abstract

The invention discloses a foundation pit supporting and reinforcing structure and a construction method, and particularly relates to the technical field of reinforcing structures and reinforcing methods of constructional engineering. The invention provides a foundation pit supporting and reinforcing structure and a construction method, wherein a connecting steel pipe, an upper steel pipe, a steel bracket and a lower steel pipe are designed, the connecting steel pipe is used as a stand column to support a supporting beam node, steel sheets are arranged on the upper end of the connecting steel pipe along the equilateral pitch in the vertical direction, the steel sheets are in a right-angled triangle shape, and the other right-angled edge is connected to a steel plate at the top end of the connecting steel sheet and is integrally formed with the steel plate; the integrity and the rigidity, the bearing capacity and the bending resistance of the whole supporting system are improved, the height of the supporting position can be adjusted by changing the height of the energy connecting column, the downwarping deformation is corrected, and the reinforcing cost is reduced; meanwhile, the method is scientific according to a certain sequence, the construction of the underground structure can not be influenced, the reinforcing effect is rapid and efficient, and the popularization and the use are convenient.

Description

Foundation pit supporting and reinforcing structure and construction method

Technical Field

The invention relates to the technical field of a reinforcing structure and a reinforcing method of constructional engineering, in particular to a foundation pit supporting and reinforcing structure and a construction method.

Background

With the continuous development of infrastructure construction, high-rise and high-quality buildings are increased gradually, and for the large buildings, the foundation pit of the large buildings is inevitably larger and deeper to ensure the construction quality. For large and deep foundation pits, the construction of the supporting structure of the foundation pit becomes more and more difficult, and simultaneously, new requirements are put forward on the supporting performance of the supporting structure.

The problems existing at present are as follows:

for general foundation pit supporting, a bored pile is generally adopted, a horizontal reinforced concrete support is arranged in a pit, when the foundation pit supporting is used for large building construction, such as a large-scale market, after the construction of inner supports is completed, the situation that the distance between the stand columns is too large and the span is subjected to bending deformation exists, so that the obvious downward bending deformation occurs to the supporting beam in the middle of the inner support, and how to solve the problem in a short time by a simple and low construction cost construction method under the condition of ensuring to meet the requirement of sufficient supporting strength.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides a foundation pit supporting and reinforcing structure and a construction method, and the problems are solved by designing a connecting steel pipe, an upper steel pipe, a steel bracket and a lower steel pipe.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

the utility model provides a foundation ditch support consolidates reinforcement structure, includes even the steel pipe, goes up steel pipe, steel bracket, lower steel pipe, its characterized in that: the steel connecting pipe is used as an upright post to support a supporting beam node, steel sheets are arranged on the upper end of the steel connecting pipe along the equilateral pitch in the vertical direction, the steel sheets are in a right-angled triangle shape, the other right-angled edge of the steel connecting pipe is connected to a steel plate at the top end of the steel connecting pipe and integrally formed with the steel plate, the supporting beam node is placed on the steel plate, and an adjustable end is connected to the lower portion of a reinforcing steel plate in the steel connecting pipe and is filled;

the top end of the connecting steel pipe is connected into the upper steel pipe, a bottom die is arranged at the position of the joint of the upper steel pipe and the lower steel pipe, the bottom die is used for fixing the connecting steel pipe into the steel pipe through the bottom die through the concrete joist, the connecting length of the connecting steel pipe can be adjusted by changing the concrete joist and the bottom die, and the supporting height can be further changed.

As another kind of preferred scheme, go up the welding of steel pipe lower extreme on the steel bracket, the steel bracket is H shaped steel bracket, steel bracket lower extreme left and right ends symmetric position department has welded a lower steel pipe respectively, the steel pipe upper end is connected with the steel sheet down and makes the batten plate, the steel sheet both sides outwards extend and exceed steel pipe circumference diameter, surpass the part and support through the bracket and connect under on the steel pipe, H shaped steel bracket pours behind the shaping of retarded soil and forms the stand stake with lower steel pipe.

As another preferred scheme, the upper pipe section of the lower steel pipe is positioned above the bottom of the foundation pit, and the lower pipe section is positioned below the bottom of the foundation pit.

As another preferred scheme, a reinforcing bolt is connected to the upper steel pipe at a position below the connecting steel pipe.

As another preferable scheme, the lower steel pipe material is a phi 630 delta 12 steel pipe, and the length range of the upright post pile is as follows: 20.5-24 m; the retarded soil joist is 700 multiplied by 700 reinforced concrete joist, and the concrete adopts C40 superfluid early strength concrete; the vertical steel joist 4 is a duplex 700 multiplied by 300 multiplied by 13 multiplied by 24, and the connecting steel pipe 2 is a 609 steel pipe.

The invention also aims to provide a construction method of the foundation pit supporting and reinforcing structure, which is characterized by comprising the following steps:

00) preparing on-site materials and construction equipment;

01) paying off and positioning: (1) paying off is carried out according to the pile position plane arrangement drawing and the measurement reference points provided by the first square; (2) when the pile position is lofted, whether the pile position coincides with a constructed engineering pile or the edge-to-edge distance is less than 25cm is found out, and if the pile position does not coincide with the constructed engineering pile, the pile position continues to work; (3) pile position lofting is positioned one by using RTK, a steel nail or a steel bar head is used for marking and indicating a pile position number, protection is carried out, a corresponding device is processed by using a diagram to discharge a pile position line by taking the center of the pile position as a datum point, and the steel nails and the like are also used for marking in four directions so as to be convenient for accurate pile position positioning during construction; (4) when the pile position accuracy is influenced by soil disturbance or other factors, the pile must be restored; (5) pile position lofting allowable deviation is less than 10 mm.

02) The equipment is in place, and the point location is rechecked;

03) splicing steel pipes: (1) when the lower steel pipes are in butt welding, the superposition and the straightness of the axis and the sideline are ensured, in order to meet the requirements, a welding field is selected in a place where the foundation is smooth after the total package is paved in a pit, the field is tamped again, a vertical frame is processed by 48 steel pipes to be used as a welding platform for welding, and the platform is leveled by the line and is reinforced and stabilized; (2) laying corresponding construction electric facilities (cables and distribution boxes), wherein the distribution boxes are provided with corresponding leakage protectors and grounding wires, the lines are free of broken skins and are far away from conductors such as steel protective cylinders, the corresponding electric welding machines and oxyacetylene are arranged, and the electric distribution boxes are provided with protective covers and are placed at certain safety distances; (3) carrying out manual arc welding lengthening on a single section of 12m phi 630 steel pipe, wherein the type of the welding rod is E50 (the steel pipe is Q235B grade, and the welding rod is higher than the common type in consideration of the vibration influence of ICE), and the welding rod is used after being qualified and tested; (4) the end of the new steel pipe is in a V-shaped groove shape, the welding joint of the steel pipe is welded by adopting a two-side joint cutting opening, spot welding is adopted for fixing in four directions in the welding process, the steel protective cylinder is prevented from being heated and deformed by a method of welding, symmetrical reinforcement and the like, the welding steel pipe is correspondingly straightened, and the verticality is not more than one thousandth; (5) after the joint is in butt joint and full welding, 4 steel plates with the same thickness and a certain radian of 250 x 150mm in width are adopted to be in back welding (full welding) at the joint for strengthening connection; (6) in the vibration sinking process of the steel pipe with the thickness of 12mm, in order to avoid the falling of the clamping opening of the ICE clamp due to the relative thinness of the lower steel pipe, the upper end (power transmission end) of the lower steel pipe is wrapped by adopting an arc-shaped steel plate with the same thickness and width of 200mm in a wire-wound manner; (7) a hole with the size of 5cm is formed at the position 7cm away from the upper end port of the lower steel pipe, and is used for clamping and fixing the steel pipe for hoisting; (8) the welded lower steel pipe is checked, accepted and called after a welding joint is cooled;

4) the steel pipes are spliced and accepted, the steel pipes are hoisted when being qualified, and the steel pipes are spliced again when being unqualified;

5) observing hole positions and verticality, and sinking the steel pipe;

6)1, concrete joist construction, construction flow: beam reinforcement cage manufacturing → paying-off positioning → grooving → laying bottom template cushion → placing reinforcement cage → erecting beam side template → adjusting reinforcement cage and side template → beam side backfilling soil mass and tamping → pouring concrete → maintenance; the specific process comprises the following steps: (1) 700 x 700 reinforced concrete joists are arranged at the top ends of the upright piles, the beam length is determined according to the pile spacing, the concrete is C40 superfluid early strength concrete, and the reinforcing steel bar protective layer is 50 mm; (2) manufacturing a beam reinforcement cage, arranging, connecting reinforcement main reinforcements by adopting 10D lap welding, and fully binding the main reinforcements and the stirrups by binding wires; (3) releasing a beam position line, then manually excavating the earthwork of the concrete joist (reducing disturbance), excavating a 'trapezoidal groove', wherein the upper opening is 1.1 m wide, the lower opening is 0.7 m wide and 0.7 m high, and the length is determined according to the length of each node joist beam; (4) leveling the bottom of the groove after excavation, paving a bottom die and a side die after leveling, and putting the well-made reinforcement cage in; the inner sides of upper and lower rows of steel bars of the steel bar cage are fixed by steel bars with the length of 0.7 meter and the length of the main steel bar at an interval of 1m to serve as an inner support of a side mould, earth is backfilled and tamped outside the side mould, and finally, the steel bars and the templates are adjusted and corrected to ensure that a protective layer, the flatness and the like meet requirements; (5) 850 × 850 δ 12 steel plates are arranged on the top of the steel pipe column pile to serve as batten plates, in order to meet the requirement that two column top steel plates are on the same horizontal plane, a horizontal ruler is used for leveling, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottom of the steel plates; (6) concrete pouring is carried out after the reinforced formwork is subjected to experience folding, and after all the concrete joist reinforced formworks are installed, pouring is carried out by using a top pump at one time; (7) when concrete is poured, the concrete needs to be vibrated and compacted, the top of the beam is leveled and is 1-2 cm higher than the bottom of the supporting beam, and the concrete is covered, watered and maintained after pouring, and the maintenance is carried out for not less than 7 days; 2. and (4) installing (1) double 700 x 300 x 13 x 24H-shaped steel joists on the top ends of the upright piles 2, wherein the beam length is determined according to the pile spacing. (2) Before the H-shaped steel bracket is installed, 850 × 850 δ 12 steel plates are arranged on the pile tops of the lower steel pipe columns to serve as batten plates, a leveling ruler is used for leveling in order to meet the condition that the two steel plates at the column tops are on the same horizontal plane, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottoms of the steel plates; (3) mechanically hoisting an H-shaped steel bracket to enable central axes of two ends of the H-shaped steel to coincide with central axes of the steel pipe upright piles, and then welding and connecting the H-shaped steel bracket by using 700-400 delta 12 steel plates;

7) installing upper steel pipe supports: (1) the upper steel pipe is based on the height of the corresponding beam node; (2) when the upper steel pipe support is installed, the central axis of the upper steel pipe support is coincided with the stress central point of the H-shaped steel bracket, and the upper steel pipe and the H-shaped steel bracket are restrained through spot welding; (3) the steel support is installed and prestressed according to the design requirement;

8) applying prestress: the connection of each node should be checked when the prestressing is applied.

The invention has the beneficial effects that:

according to the invention, through designing the upright posts and the upright post piles formed by connecting the steel pipes and the H-shaped rigid brackets, after the construction of the inner support is completed, when the condition that the spacing between the upright posts is too large and the span is subjected to bending deformation, so that the support beam is obviously subjected to downward bending deformation in the middle of the inner support occurs, the simple upright post piles and the upright posts can be additionally arranged at each part of the foundation pit, the upright posts and the upright post piles are used for strengthening the foundation pit, the integrity and the rigidity of the whole supporting system as well as the bearing capacity and the bending resistance are improved on the basis of fully utilizing the supporting structure, the height of the supporting position can be adjusted by changing the height of the connecting post, the downward bending deformation is further corrected; meanwhile, the method is scientific according to a certain sequence, the construction of the underground structure can not be influenced, the reinforcing effect is rapid and efficient, and the popularization and the use are convenient.

The foundation pit supporting, reinforcing and strengthening structure and the construction method designed by the invention have the advantages that any product implementing the invention does not necessarily need to achieve all the advantages.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a schematic structural view of a foundation pit supporting and reinforcing structure according to the present invention;

FIG. 2 is a schematic structural view of the column of the present invention;

FIG. 3 is a schematic structural view of the stud of the present invention;

FIG. 4 is a schematic structural view of a steel bracket according to the present invention;

FIG. 5 is a schematic structural view of the stiffening steel plates and steel sheets according to the present invention;

FIG. 6 is a diagram showing the application of the present invention in example 3;

FIG. 7 is a diagram showing the application of the present invention in example 4;

FIG. 8 is a flow chart of the construction of the present invention;

in the drawings, the components represented by the respective reference numerals are listed below:

1-supporting beam node, 2-connecting rigid pipe, 200-stiffening steel plate, 201-steel plate, 202-loose end plug iron, 203-bottom die, 204-retarded soil joist, 3-upper steel pipe, 301-reinforcing bolt, 4-steel bracket, 5-lower steel pipe, 501-steel plate and 502-bracket.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the 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 invention.

As shown in fig. 1-8

The utility model provides a foundation ditch support consolidates reinforcement structure, includes even steel pipe 2, goes up steel pipe 3, steel bracket 4, lower steel pipe 5, its characterized in that: the steel connecting pipe 2 is used as an upright post to support a supporting beam node 1, steel sheets 201 are arranged on the upper end of the steel connecting pipe 2 along the equilateral pitch of the vertical direction, each steel sheet 201 is in a right-angled triangle shape, the other right-angled edge of each steel sheet 201 is connected to a steel plate 200 at the top end of the steel connecting pipe 2 and is integrally formed with the steel plate 200, the supporting beam node 1 is placed on the steel plate 200, and loose end plug-in irons 202 are connected below reinforcing steel plates in the steel connecting pipe 2;

the top end of the connecting steel pipe 2 is connected into the upper steel pipe 3, a bottom die 203 is arranged at the interface of the upper steel pipe and the lower steel pipe, the bottom die 203 is fixed in the steel pipe through the bottom die 203 by the concrete joist 204, the connecting steel pipe 2 can be adjusted in the connecting length by changing the concrete joist 204 and the bottom die 203, and the supporting height can be further changed.

As another preferred scheme, 3 lower extreme welding of going up the steel pipe are on steel bracket 4, steel bracket 4 is H shaped steel bracket, steel 5 has been welded respectively in the both ends symmetric position department about steel bracket 4 lower extreme, 5 upper ends of lower steel pipe are connected with steel sheet 501 and make the batten plate, steel sheet 401 both sides outwards extend and exceed steel pipe circumference diameter, surpass the part and support through bracket 502 and connect under on steel pipe 5, H shaped steel bracket pours behind the retarded soil one-tenth retarded soil joist and forms the stake with lower steel pipe 3.

As another preferable scheme, the lower steel pipe material is a phi 630 delta 12 steel pipe, and the length range of the upright post pile is as follows: 20.5-24 m; the retarded concrete joist 204 is a 700 x 700 reinforced concrete joist, and the concrete adopts C40 superfluid early strength concrete; the vertical steel joist 4 is a duplex 700 multiplied by 300 multiplied by 13 multiplied by 24, and the connecting steel pipe 2 is a 609 steel pipe.

As another preferred scheme, the upper pipe section of the lower steel pipe 5 is located above the bottom of the foundation pit, and the lower pipe section is located below the bottom of the foundation pit.

As another preferable scheme, a reinforcing bolt 301 is connected to the upper steel pipe 3 at a position below the connecting steel pipe 2.

The technical scheme of the invention is explained by combining the specific embodiment as follows:

example 1

The utility model provides a foundation ditch support consolidates reinforcement structure, includes even steel pipe 2, goes up steel pipe 3, steel bracket 4, lower steel pipe 5, its characterized in that: even steel pipe 2 supports a supporting beam node 1 as the stand, is equipped with steel sheet 201 all around along vertical direction equilateral pitch even on 2 upper ends of steel pipe, steel sheet 201 is the right angle triangle-shaped form, and another right angle limit is connected on the steel sheet 200 on connecting 2 tops of steel sheet to with steel sheet 200 integrated into one piece, a supporting beam node 1 is placed on steel sheet 200, in connecting steel pipe 2, it has loose end to strengthen the steel sheet below and has filled in iron 202, connect 2 tops of steel pipe and insert in last steel pipe 3, the two kneck is equipped with die block 203, die block 203 passes through concrete joist 204, will connect steel pipe 2 and fix in the steel pipe through die block 203, and the accessible changes concrete joist 204 and die block 203 and adjusts the access length of connecting the steel pipe, and then changes the support height, steel pipe material adopts phi 630 delta 12 steel pipe down, the stake length scope: 20.5-24 m; the retarded concrete joist 204 is a 700 x 700 reinforced concrete joist, and the concrete adopts C40 superfluid early strength concrete; the vertical steel joist 4 is a duplex 700 multiplied by 300 multiplied by 13 multiplied by 24, and the connecting steel pipe 2 is a 609 steel pipe.

Example 2

The construction method comprises the following steps:

00) preparing on-site materials and construction equipment;

01) paying off and positioning: (1) paying off work is carried out according to the pile position plane arrangement drawing and the measuring datum points; (2) when the pile position is lofted, whether the pile position coincides with a constructed engineering pile or the edge-to-edge distance is less than 25cm is found out, and if the pile position does not coincide with the constructed engineering pile, the pile position continues to work; (3) pile position lofting is positioned one by using RTK, a steel nail or a steel bar head is used for marking and indicating a pile position number, protection is carried out, a pile position line is released by taking the center of the pile position as a datum point, and steel nails and the like are used for marking in four directions, so that the pile position is accurately positioned during construction; (4) when the pile position accuracy is influenced by soil disturbance or other factors, the pile must be restored; (5) pile position lofting allowable deviation is less than 10 mm.

02) The equipment is in place, and the point location is rechecked;

03) splicing steel pipes: (1) when the lower steel pipes 5 are in butt welding, the coincidence and the straightness of the axis and the sideline are ensured, in order to meet the requirements, a welding field is selected in a place where the foundation is smooth after the foundation is paved in a pit by a main bag, the field is tamped again, a vertical frame is processed by 48 steel pipes to be used as a welding platform for welding, and the platform is leveled by the line and is reinforced stably; (2) laying corresponding construction electric facilities (cables and distribution boxes), wherein the distribution boxes are provided with corresponding leakage protectors and grounding wires, have no broken skins on lines, are far away from conductors such as steel protective cylinders and the like, are provided with corresponding electric welding machines and oxyacetylene, are provided with protective covers, and are placed at a certain safety distance; (3) carrying out manual arc welding lengthening on a single section of steel pipe with the diameter of 12m and the diameter of 630 m, wherein the type of a welding rod is E50; (4) the end of the new steel pipe is in a V-shaped groove shape, the welding joint of the steel pipe is welded by adopting a two-side joint cutting opening, spot welding is adopted for fixing in four directions in the welding process, the steel protective cylinder is prevented from being heated and deformed by a method of welding, symmetrical reinforcement and the like, the welding steel pipe is correspondingly straightened, and the verticality is not more than one thousandth; (5) after the joint is in butt joint and full welding, 4 steel plates with the same thickness and a certain radian of 250 x 150mm in width are adopted to be in back welding (full welding) at the joint for strengthening connection; (6) in the vibration sinking process of the steel pipe with the thickness of 12mm, in order to avoid the falling of the clamping opening of the ICE clamp due to the relative thinness of the lower steel pipe, the upper end (power transmission end) of the lower steel pipe is wrapped by adopting an arc-shaped steel plate with the same thickness and width of 200mm in a wire-wound manner; (7) a hole with the size of 5cm is arranged at the position 7cm away from the upper end port of the lower steel pipe 5, and is used for clamping and fixing the steel pipe for hoisting; (8) the welded lower steel pipe 5 is tested, accepted and called after the welding joint is cooled;

4) splicing and accepting the lower steel pipe 5, hoisting the steel pipe if the steel pipe is qualified, and splicing again if the steel pipe is not qualified;

5) observing the hole site and the verticality, and sinking the lower steel pipe 5;

6)1, concrete joist construction, construction flow: beam reinforcement cage manufacturing → paying-off positioning → grooving → laying bottom template cushion → placing reinforcement cage → erecting beam side template → adjusting reinforcement cage and side template → beam side backfilling soil mass and tamping → pouring concrete → maintenance; the specific process comprises the following steps: (1) 700 x 700 reinforced concrete joists are arranged at the top ends of the upright piles, the beam length is determined according to the pile spacing, the concrete is C40 superfluid early strength concrete, and the reinforcing steel bar protective layer is 50 mm; (2) manufacturing a beam reinforcement cage, arranging, connecting reinforcement main reinforcements by adopting 10D lap welding, and fully binding the main reinforcements and the stirrups by binding wires; (3) releasing a beam position line, then manually excavating the earthwork of the concrete joist (reducing disturbance), excavating a 'trapezoidal groove', wherein the upper opening is 1.1 m wide, the lower opening is 0.7 m wide and 0.7 m high, and the length is determined according to the length of each node joist beam; (4) leveling the bottom of the groove after excavation, paving a bottom die and a side die after leveling, and putting the well-made reinforcement cage in; the inner sides of upper and lower rows of steel bars of the steel bar cage are fixed by steel bars with the length of 0.7 meter and the length of the main steel bar at an interval of 1m to serve as an inner support of a side mould, earth is backfilled and tamped outside the side mould, and finally, the steel bars and the templates are adjusted and corrected to ensure that a protective layer, the flatness and the like meet requirements; (5) 850 × 850 δ 12 steel plates are arranged on the top of the steel pipe column pile to serve as batten plates, in order to meet the requirement that two column top steel plates are on the same horizontal plane, a horizontal ruler is used for leveling, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottom of the steel plates; (6) concrete pouring is carried out after the reinforced formwork is subjected to experience folding, and after all the concrete joist reinforced formworks are installed, pouring is carried out by using a top pump at one time; (7) when concrete is poured, the concrete needs to be vibrated and compacted, the top of the beam is leveled and is 1-2 cm higher than the bottom of the supporting beam, and the concrete is covered, watered and maintained after pouring, and the maintenance is carried out for not less than 7 days; 2. and (4) installing (1) double 700 x 300 x 13 x 24H-shaped steel joists on the top ends of the upright piles 2, wherein the beam length is determined according to the pile spacing. (2) Before the H-shaped steel bracket is installed, 850 × 850 δ 12 steel plates are arranged on the pile tops of the lower steel pipe columns to serve as batten plates, a leveling ruler is used for leveling in order to meet the condition that the two steel plates at the column tops are on the same horizontal plane, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottoms of the steel plates; (3) manually hoisting an H-shaped steel bracket by matching with a machine, enabling central axes of two ends of the H-shaped steel to coincide with central axes of the steel pipe upright piles, and then welding and connecting the H-shaped steel bracket by using 700 x 400 delta 12 steel plates;

7) installing upper steel pipe supports: (1) the upper steel pipe is based on the height of the corresponding beam node; (2) when the upper steel pipe support is installed, the central axis of the upper steel pipe support is coincided with the stress central point of the H-shaped steel bracket, and the upper steel pipe and the H-shaped steel bracket are restrained through spot welding; (3) the steel support is installed and prestressed according to the design requirement;

8) applying prestress: the connection of each node should be checked when the prestressing is applied.

Example 3

Based on the embodiment 1-2, the foundation pit supporting reinforcing structure is applied to reinforcing and reinforcing in the process that the supporting beam is obviously deformed downwards in the middle of the construction ground inner support.

The total area of the foundation pit of the project to be built is about 26861.1 square meters, the perimeter is 651m, and the excavation depth is 4.2 m-9.9 m. The foundation pit supporting adopts a single row of supporting piles (phi 600, phi 800 and phi 1000mm) +1 reinforced concrete inner support (ring support 1150 x 800mm and support 700 x 700mm) enclosing structure, and in the earth excavation process after the inner support construction is finished, the obvious downward deflection deformation (the column spacing is overlarge and the midspan deflection deformation) occurs to the supporting beam in the middle of the inner support.

During specific implementation, lower upright posts and upright posts are additionally arranged at the support alignment part, the southwest corner support part, the southeast corner support part and the northeast corner support part in the middle of the foundation pit. The lower steel pipe 5 is used as a vertical column pile, the pile length is 20.5-24 m, a duplex 700 multiplied by 300 multiplied by 13 multiplied by 24H-shaped steel joist is arranged at the upper part of the vertical column pile, an upper steel pipe 3 support is arranged on the H-shaped steel joist and used as a vertical column, prestress is applied to the steel pipe support, and the magnitude of the prestress is undetermined.

Example 4

Based on embodiment 3, the piling sequence of the foundation pit supporting, reinforcing and strengthening structure is shown by letter sequence labels A-G in fig. 6, and the upright posts are added one by one from the middle position middle and right support part → the northeast corner support part → the southeast corner support part → the south corner support part → the middle position left support part.

In the description herein, references to the description of "one embodiment," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The preferred embodiments of the invention disclosed above are intended to be illustrative only. The preferred embodiments are not intended to be exhaustive or to limit the invention to the precise embodiments disclosed. Obviously, many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and the practical application, to thereby enable others skilled in the art to best utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims (7)

1. The utility model provides a foundation ditch support reinforcement structure which characterized in that: the steel plate supporting device comprises a connecting steel pipe, an upper steel pipe, a steel bracket and a lower steel pipe, wherein the connecting steel pipe is used as an upright post to support a supporting beam node, steel plates are arranged at the upper end of the connecting steel pipe along the vertical direction at the equilateral pitch, the steel plates are in a right-angled triangle shape, the other right-angled edge is connected to a steel plate at the top end of the connecting steel plate and is integrally formed with the steel plate, the supporting beam node is placed on the steel plate, and loose end inserting iron is connected to the lower portion of a reinforcing;

the top end of the connecting steel pipe is connected into the upper steel pipe, a bottom die is arranged at the position of the joint of the upper steel pipe and the lower steel pipe, the bottom die is used for fixing the connecting steel pipe into the steel pipe through the bottom die through the concrete joist, the connecting length of the connecting steel pipe can be adjusted by changing the concrete joist and the bottom die, and the supporting height can be further changed.

2. A foundation pit supporting, reinforcing and reinforcing structure according to claim 1, wherein: go up steel pipe lower extreme welding on the steel bracket, the steel bracket is H shaped steel bracket, steel bracket lower extreme left and right ends symmetric position department has welded a lower steel pipe respectively, the steel pipe upper end is connected with the steel sheet down and makes the batten plate, the steel sheet both sides outwards extend and exceed steel pipe circumference diameter, surpass the part and support through the bracket and connect under on the steel pipe, H shaped steel bracket pour behind the set retarding soil shaping with steel pipe formation stand pile down.

3. A foundation pit supporting, reinforcing and reinforcing structure according to claim 2, wherein: the lower steel pipe is arranged above the bottom of the foundation pit, and the upper pipe section is arranged below the bottom of the foundation pit.

4. A foundation pit supporting, reinforcing and reinforcing structure according to claim 3, wherein: and a reinforcing bolt is connected to the lower position of the upper steel pipe and the lower position of the connecting steel pipe.

5. A foundation pit supporting, reinforcing and reinforcing structure according to claim 1, wherein: the lower steel pipe material adopts phi 630 delta 12 steel pipes, and the length range of the upright post pile is as follows: 20.5-24 m; the retarded soil joist is 700 multiplied by 700 reinforced concrete joist, and the concrete adopts C40 superfluid early strength concrete; the vertical steel joist 4 is a duplex 700 multiplied by 300 multiplied by 13 multiplied by 24, and the connecting steel pipe 2 is a 609 steel pipe.

6. A construction method for a foundation pit supporting and reinforcing structure is characterized by comprising the following steps:

00) preparing on-site materials and construction equipment;

01) paying off and positioning: (1) paying off is carried out according to the pile position plane arrangement drawing and the measurement reference points provided by the first square; (2) when the pile position is lofted, whether the pile position coincides with a constructed engineering pile or the edge-to-edge distance is less than 25cm is found out, and if the pile position does not coincide with the constructed engineering pile, the pile position continues to work; (3) pile position lofting is positioned one by using RTK, a steel nail or a steel bar head is used for marking and indicating a pile position number, protection is carried out, a corresponding device is processed by using a diagram to discharge a pile position line by taking the center of the pile position as a datum point, and the steel nails and the like are also used for marking in four directions so as to be convenient for accurate pile position positioning during construction; (4) when the pile position accuracy is influenced by soil disturbance or other factors, the pile must be restored; (5) pile position lofting allowable deviation is less than 10 mm.

02) The equipment is in place, and the point location is rechecked;

03) splicing steel pipes: (1) when the lower steel pipes are in butt welding, the superposition and the straightness of the axis and the sideline are ensured, in order to meet the requirements, a welding field is selected in a place where the foundation is smooth after the total package is paved in a pit, the field is tamped again, a vertical frame is processed by 48 steel pipes to be used as a welding platform for welding, and the platform is leveled by the line and is reinforced and stabilized; (2) laying corresponding construction electric facilities (cables and distribution boxes), wherein the distribution boxes are provided with corresponding leakage protectors and grounding wires, the lines are free of broken skins and are far away from conductors such as steel protective cylinders, the corresponding electric welding machines and oxyacetylene are arranged, and the electric distribution boxes are provided with protective covers and are placed at certain safety distances; (3) carrying out manual arc welding lengthening on a single section of 12m phi 630 steel pipe, wherein the type of the welding rod is E50 (the steel pipe is Q235B grade, and the welding rod is higher than the common type in consideration of the vibration influence of ICE), and the welding rod is used after being qualified and tested; (4) the end of the new steel pipe is in a V-shaped groove shape, the welding joint of the steel pipe is welded by adopting a two-side joint cutting opening, spot welding is adopted for fixing in four directions in the welding process, the steel protective cylinder is prevented from being heated and deformed by a method of welding, symmetrical reinforcement and the like, the welding steel pipe is correspondingly straightened, and the verticality is not more than one thousandth; (5) after the joint is in butt joint and full welding, 4 steel plates with the same thickness and a certain radian of 250 x 150mm in width are adopted to be in back welding (full welding) at the joint for strengthening connection; (6) in the vibration sinking process of the steel pipe with the thickness of 12mm, in order to avoid the falling of the clamping opening of the ICE clamp due to the relative thinness of the lower steel pipe, the upper end (power transmission end) of the lower steel pipe is wrapped by adopting an arc-shaped steel plate with the same thickness and width of 200mm in a wire-wound manner; (7) a hole with the size of 5cm is formed at the position 7cm away from the upper end port of the lower steel pipe, and is used for clamping and fixing the steel pipe for hoisting; (8) the welded lower steel pipe is checked, accepted and called after a welding joint is cooled;

4) the steel pipes are spliced and accepted, the steel pipes are hoisted when being qualified, and the steel pipes are spliced again when being unqualified;

5) observing hole positions and verticality, and sinking the steel pipe;

6)1, concrete joist construction, construction flow: beam reinforcement cage manufacturing → paying-off positioning → grooving → laying bottom template cushion → placing reinforcement cage → erecting beam side template → adjusting reinforcement cage and side template → beam side backfilling soil mass and tamping → pouring concrete → maintenance; the specific process comprises the following steps: (1) 700 x 700 reinforced concrete joists are arranged at the top ends of the upright piles, the beam length is determined according to the pile spacing, the concrete is C40 superfluid early strength concrete, and the reinforcing steel bar protective layer is 50 mm; (2) manufacturing a beam reinforcement cage, arranging, connecting reinforcement main reinforcements by adopting 10D lap welding, and fully binding the main reinforcements and the stirrups by binding wires; (3) releasing a beam position line, then manually excavating the earthwork of the concrete joist (reducing disturbance), excavating a 'trapezoidal groove', wherein the upper opening is 1.1 m wide, the lower opening is 0.7 m wide and 0.7 m high, and the length is determined according to the length of each node joist beam; (4) leveling the bottom of the groove after excavation, paving a bottom die and a side die after leveling, and putting the well-made reinforcement cage in; the inner sides of upper and lower rows of steel bars of the steel bar cage are fixed by steel bars with the length of 0.7 meter and the length of the main steel bar at an interval of 1m to serve as an inner support of a side mould, earth is backfilled and tamped outside the side mould, and finally, the steel bars and the templates are adjusted and corrected to ensure that a protective layer, the flatness and the like meet requirements; (5) 850 × 850 δ 12 steel plates are arranged on the top of the steel pipe column pile to serve as batten plates, in order to meet the requirement that two column top steel plates are on the same horizontal plane, a horizontal ruler is used for leveling, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottom of the steel plates; (6) concrete pouring is carried out after the reinforced formwork is subjected to experience folding, and after all the concrete joist reinforced formworks are installed, pouring is carried out by using a top pump at one time; (7) when concrete is poured, the concrete needs to be vibrated and compacted, the top of the beam is leveled and is 1-2 cm higher than the bottom of the supporting beam, and the concrete is covered, watered and maintained after pouring, and the maintenance is carried out for not less than 7 days; 2. and (4) installing (1) double 700 x 300 x 13 x 24H-shaped steel joists on the top ends of the upright piles 2, wherein the beam length is determined according to the pile spacing. (2) Before the H-shaped steel bracket is installed, 850 × 850 δ 12 steel plates are arranged on the pile tops of the lower steel pipe columns to serve as batten plates, a leveling ruler is used for leveling in order to meet the condition that the two steel plates at the column tops are on the same horizontal plane, and 4 pieces of 100 × 250 × 100 δ 12T-shaped steel sheets are used for welding and constraining at the bottoms of the steel plates; (3) mechanically hoisting an H-shaped steel bracket to enable central axes of two ends of the H-shaped steel to coincide with central axes of the steel pipe upright piles, and then welding and connecting the H-shaped steel bracket by using 700-400 delta 12 steel plates;

7) installing upper steel pipe supports: (1) the upper steel pipe is based on the height of the corresponding beam node; (2) when the upper steel pipe support is installed, the central axis of the upper steel pipe support is coincided with the stress central point of the H-shaped steel bracket, and the upper steel pipe and the H-shaped steel bracket are restrained through spot welding; (3) the steel support is installed and prestressed according to the design requirement;

8) applying prestress: the connection of each node should be checked when the prestressing is applied.

7. A foundation pit supporting and reinforcing structure and construction method as claimed in any one of claims 1-6, wherein the structure is used for reinforcing foundation pit supporting in examples 1-4.

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