CN114622595B

CN114622595B - Three-stage old rubble retaining wall reinforcing method for adjoining deep foundation pit supporting structure

Info

Publication number: CN114622595B
Application number: CN202210339204.2A
Authority: CN
Inventors: 王文灵; 周志强; 陈图真; 连君; 张戈炜; 王超; 王希圹; 王刚; 方彦霖
Original assignee: GUANGZHOU XIEAN CONSTRUCTION ENGINEERING CO LTD
Current assignee: GUANGZHOU XIEAN CONSTRUCTION ENGINEERING CO LTD
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2023-06-13
Anticipated expiration: 2042-04-01
Also published as: CN114622595A

Abstract

The application discloses a method for reinforcing a three-stage old rubble retaining wall adjacent to a deep foundation pit supporting structure, which relates to the technical field of retaining wall reinforcement and comprises the following steps: s1, constructing a plurality of miniature steel pipe piles on a platform surface close to a second-stage retaining wall, adjusting a reinforcing tool after a steel pipe of the miniature steel pipe pile is inserted to a preset depth so as to increase the connection strength between the miniature steel pipe pile and earthwork, and grouting into the steel pipe; s2, connecting the miniature steel pipe piles into a whole by using a construction capping beam; s3, dismantling the first-stage retaining wall, and backfilling the original ground to the elevation required by pile driver operation; s4, carrying out support pile construction after hanging a net and spraying concrete on the outer side of the earthwork of the miniature steel pipe pile; s5, applying reinforced soil nails; s6, constructing a crown beam for connecting the support piles into a whole. The application has the effect of avoiding the influence of the reinforced secondary retaining wall on deep foundation pit support.

Description

Three-stage old rubble retaining wall reinforcing method for adjoining deep foundation pit supporting structure

Technical Field

The invention relates to the technical field of retaining wall reinforcement, in particular to a three-stage old rubble retaining wall reinforcement method adjoining a deep foundation pit supporting structure.

Background

With the development of urban construction, the condition of newly-built projects in the narrow sites of old urban areas continuously appears, and due to the shortage of urban land, the newly-built projects often have basements, and deep foundation pit projects constructed for basement construction become important in ensuring the safety of construction quality. In the prior art, in order to ensure the reinforcement strength, three-stage retaining walls are generally used for supporting the foundation pit.

In actual construction, the first-stage retaining wall 1 and the second-stage retaining wall 2 are arranged in a step shape, and the corresponding three planes are the ground, the platform surface and the slope top surface from bottom to top in sequence, when the three-stage rubble retaining wall is encountered and is adjacent to the deep foundation pit supporting pile and the supporting pile 7 is positioned below the platform surface (as shown in fig. 1), the first-stage retaining wall 1 inevitably needs to be dismantled. The second-stage retaining wall 2 is reinforced by adopting a traditional piling method, and the piling presser foot occupies the working surface of the supporting pile 7 at the corner, namely the construction of the supporting pile 7 is affected by reinforcing the second-stage retaining wall 2.

Therefore, it is necessary to provide a retaining wall reinforcing method that does not interfere with the construction of adjoining deep foundation pit supporting structures.

Disclosure of Invention

In order to avoid influencing adjacent deep foundation pit supporting structures when reinforcing the secondary retaining wall, the application provides a method for reinforcing the tertiary old rubble retaining wall adjacent to the deep foundation pit supporting structures.

The application provides a tertiary old rubble retaining wall reinforcement method of adjoining deep basal pit supporting construction adopts following technical scheme:

a method for reinforcing a three-stage old rubble retaining wall adjoining a deep foundation pit supporting structure comprises the following steps:

s1, constructing a plurality of miniature steel pipe piles on a platform surface close to a second-stage retaining wall, adjusting a reinforcing tool after a steel pipe of the miniature steel pipe pile is inserted to a preset depth so as to increase the connection strength between the miniature steel pipe pile and earthwork, and grouting into the steel pipe;

s2, connecting the miniature steel pipe piles into a whole by using a construction capping beam;

s3, dismantling the first-stage retaining wall, and backfilling the original ground to the elevation required by pile driver operation;

s4, carrying out support pile construction after hanging a net and spraying concrete on the outer side of the earthwork of the miniature steel pipe pile;

s5, applying reinforced soil nails;

s6, constructing a crown beam for connecting the support piles into a whole.

By adopting the technical scheme, after the first-stage retaining wall is dismantled, the miniature steel pipe piles replace the first-stage retaining wall to bear the load of the upper second-stage retaining wall, so that the second-stage retaining wall is reinforced, a construction surface is created for the deep foundation pit supporting structure, the safety of foundation pit construction is ensured, and the influence of the reinforced second-stage retaining wall on deep foundation pit supporting is avoided; in addition, through heightening and abutting the elevation of the deep foundation pit supporting piles, reinforcing steel nails are added, the foundation pit supporting structure is used as a redundant support of the retaining wall, the condition of integral landslide of the retaining wall is prevented, the stability and safety of the retaining wall are further improved, the soil disturbance of integral reinforcing operation on the existing retaining wall is reduced to the minimum, meanwhile, the safety construction in the reinforcing process is guaranteed, and a good reference effect is provided for the construction of the subsequent similar engineering.

Preferably, the reinforcing tool comprises a inserted link which is in sliding fit with the steel pipe of the miniature steel pipe pile along the radial direction of the miniature steel pipe pile, and the reinforcing tool further comprises a driving assembly which is used for driving the inserted link to penetrate through the steel pipe of the miniature steel pipe pile and be inserted into earthwork;

in step S1, the driving assembly drives the insert rod to be inserted into the earth, so as to increase the connection strength between the steel pipe of the miniature steel pipe pile and the earth.

Through adopting above-mentioned technical scheme, increased the joint strength between the steel pipe of miniature steel-pipe pile and its surrounding earthwork, and then improved the reinforcement effect to the second grade retaining wall.

Preferably, the driving assembly comprises a driving rod coaxially rotating in the inner cavity of the steel pipe of the miniature steel pipe pile, a cam coaxially fixedly arranged on the driving rod and a power piece for driving the driving rod to rotate.

Through adopting above-mentioned technical scheme, start power spare drive actuating lever and cam rotation, the inserted bar outwards stretches out under the effect of cam and inserts in the earthwork, realizes the drive to the inserted bar.

Preferably, the maximum outer diameter of the cam is smaller than the inner diameter of the steel pipe of the miniature steel pipe pile.

Through adopting above-mentioned technical scheme, make to leave the clearance between cam outer wall and the inner wall of steel pipe, be convenient for constructor insert drive assembly in the steel pipe again after miniature steel-pipe pile's steel pipe is inserted and is beaten.

Preferably, two inserting rods are symmetrically arranged on two sides of the miniature steel pipe pile in the arrangement direction, and a wedge-shaped surface is arranged on one side of each inserting rod, which faces away from the second-stage retaining wall;

step S11 is further arranged between the step S1 and the step S2, in the step S11, a secondary reinforcing groove is excavated on the outer side of the miniature steel pipe pile until the pile machine supporting the pile is operated to the required elevation, before slurry in the steel pipe is initially set, the secondary reinforcing member is inserted into earthwork on the outer side of the miniature steel pipe pile, so that two push rods in the secondary reinforcing member apply acting force to the two wedge-shaped surfaces, and the inserted rod is continuously pushed out outwards until the push rods are connected with the inserted rod.

Through adopting above-mentioned technical scheme, because the biggest external diameter of cam is less than the internal diameter of steel pipe for when cam drive inserted bar outwards moved, unable outside release the inserted bar to the max distance, through the cooperation of secondary reinforcement and wedge, make the inserted bar continue outwards to remove under the effect of push rod, increased the inserted bar and inserted the degree of depth in the earthwork, further improved the stability of being connected between steel pipe and the earthwork, and then improved the reinforcement effect to the retaining wall.

Preferably, the insert rod is provided with a slot for being matched with the push rod.

Through adopting above-mentioned technical scheme, when the one end of push rod inserts in the slot, stops promoting the secondary reinforcement, realizes being connected between secondary reinforcement and the inserted bar.

Preferably, the secondary reinforcement is provided with preset steel bars, the preset steel bars extend out of the earthwork, and in step S4, the concrete connects the preset steel bars into a whole.

Through adopting above-mentioned technical scheme, hang behind the earthwork department in miniature steel-pipe pile outside and net spouts the concrete, connect into whole a plurality of secondary reinforcement and miniature steel-pipe pile, increased the wholeness and the reinforcement intensity to the reinforced structure of second grade retaining wall.

Preferably, the insert rod is clamped and matched with the steel pipe of the miniature steel pipe pile.

Through adopting above-mentioned technical scheme, realized the connection between the steel pipe of inserted bar and miniature steel-pipe pile.

Preferably, in step S1, a brick enclosing wall is built on top of the second-stage retaining wall.

By adopting the technical scheme, the building on the slope is protected, and the safety of the building on the slope in the construction process is ensured.

In summary, the present application includes at least one of the following beneficial technical effects:

1. after the first-stage retaining wall is dismantled, the miniature steel pipe piles replace the first-stage retaining wall to bear the load of the upper second-stage retaining wall, so that the second-stage retaining wall is reinforced, a construction surface is created for the deep foundation pit supporting structure, the safety of foundation pit construction is ensured, and the influence of the reinforced second-stage retaining wall on deep foundation pit supporting is avoided;

2. the elevation of the foundation pit supporting piles is heightened and adjoining, reinforced soil nails are added, the foundation pit supporting structure is used as a redundant support of the retaining wall, the condition of integral landslide of the retaining wall is prevented, and the stability and safety of the retaining wall are further improved;

3. through the cooperation of secondary reinforcement and wedge for the inserted bar continues outwards to remove under the effect of push rod, has increased the inserted bar and has inserted the degree of depth in the earthwork, further has improved the stability of being connected between steel pipe and the earthwork, and then has improved the reinforcement effect to the retaining wall.

Drawings

Fig. 1 is a schematic view of a pile reinforcement method in the background art, and a ground, a platform surface, and a slope top surface.

Fig. 2 is a schematic diagram of mini steel pipe pile reinforcement in an embodiment.

Fig. 3 is a schematic partial structure of a reinforcing tool in an embodiment.

Fig. 4 is a schematic cross-sectional view showing the connection structure between the insert rod and the steel pipe and the dimensional relationship between the cam and the steel pipe in the embodiment.

Fig. 5 is a schematic partial structural view of a connection relationship between a secondary reinforcing tool and an insert rod in the embodiment.

Fig. 6 is a schematic plan view of a connection relationship between the secondary reinforcing tool and the insert rod in the embodiment.

Fig. 7 is a schematic cross-sectional view of a pile construction in an embodiment.

Reference numerals illustrate:

1. a first-stage retaining wall;

2. a second-stage retaining wall;

3. miniature steel pipe piles; 31. a steel pipe; 311. a slip groove; 312. a clamping groove;

4. a rod; 41. the clamping bulge; 42. a wedge surface; 43. a slot;

5. a drive assembly; 51. a driving rod; 52. a cam; 53. a motor; 54. a bracket;

6. a secondary reinforcement; 61. a cross bar; 62. a push rod; 63. presetting reinforcing steel bars;

7. supporting piles;

8. a reinforced soil nail;

9. brick enclosing walls;

10. and (5) a secondary reinforcement groove.

Detailed Description

The present application is described in further detail below in conjunction with figures 2-7.

The embodiment of the application discloses a three-stage old rubble retaining wall reinforcing method for a contiguous deep foundation pit supporting structure, which is used for reinforcing a second-stage retaining wall 2 for a contiguous deep foundation pit supporting structure.

Referring to fig. 2, a brick enclosing wall 9 is provided on the slope top surface at the edge of the second-stage retaining wall 2 to enclose the building on the slope surface, thereby ensuring the safety of the building on the slope surface in the construction process.

One side of the second-stage retaining wall 2 is provided with miniature steel pipe piles 3, and a plurality of miniature steel pipe piles 3 are uniformly distributed at intervals along the extending direction of the second-stage retaining wall 2.

Referring to fig. 2 and 3, a steel pipe 31 of the mini steel pipe pile 3 is provided with a reinforcing tool for increasing the stability of the connection with the surrounding earth. The reinforcing fixture comprises an inserted rod 4 in sliding fit with a steel pipe 31, a driving assembly 5 for driving the inserted rod 4 to be inserted outwards into the earth, and a secondary reinforcing member 6 for further driving the inserted rod 4 to extend outwards.

Two inserting rods 4 are symmetrically arranged on two radial sides of the steel pipe 31, and a plurality of groups of inserting rods 4 are uniformly distributed along the axial direction of the steel pipe 31.

Referring to fig. 3 and 4, the insert rod 4 is slidably fitted to the steel pipe 31 in a radial direction of the steel pipe 31, a sliding groove 311 for sliding the insert rod 4 is formed in the steel pipe 31, and the insert rod 4 is guided by the insert rod 4 and the sliding groove 311 in a key connection manner. A clamping groove 312 is formed in one side wall of the sliding groove 311, a clamping protrusion 41 matched with the clamping groove 312 is arranged on the outer wall of the inserted link 4, and when the inserted link 4 does not extend out of the outer wall of the steel pipe 31, the clamping protrusion 41 is embedded in the clamping groove 312 to limit the movement of the inserted link 4 relative to the steel pipe 31.

The driving assembly 5 includes a driving rod 51 coaxially disposed with the steel pipe 31, a cam 52 coaxially fixed to the outside of the driving rod 51, and a motor 53 for driving the driving rod 51 to rotate, the maximum outer diameter of the cam 52 being smaller than the inner diameter of the steel pipe 31. In order to facilitate the installation and positioning of the driving rod 51 by constructors, the top end of the steel tube 31 is tightly connected with a bracket 54 by using bolts, a motor 53 is fixed on the bracket 54, an output shaft of the motor 53 is coaxially fixed with the top end of the driving rod 51, and the driving rod 51 is rotatably connected with the bracket 54.

Referring to fig. 2, 5 and 6, the secondary reinforcement 6 is provided in a U-shape, and includes a cross bar 61 and push rods 62 integrally formed at both ends of the cross bar 61, the push rods 62 are perpendicular to the cross bar 61, and a diagonal brace for increasing the connection strength between the push rods 62 and the cross bar 61 is provided between the push rods 62 and the cross bar 61. The surface of the insert rod 4 facing the outside of the earth is provided as a wedge surface 42, and one end of the push rod 62 facing away from the cross rod 61 is used for being matched with the wedge surface 42, so that a force is applied to the insert rod 4 to enable the insert rod 4 to move away from the steel pipe 31.

The wedge-shaped surface 42 of the inserted link 4 is provided with a slot 43, and one end of the push rod 62, which is away from the cross rod 61, is inserted into the slot 43 to realize the connection between the push rod 62 and the inserted link 4.

The middle position of the outer wall of the cross bar 61 is also fixed with a preset steel bar 63 perpendicular to the cross bar.

In order to connect the plurality of secondary reinforcements 6 corresponding to the same miniature steel pipe pile 3, the plurality of secondary reinforcements 6 are fixed by the same connection plate.

s1, constructing a miniature steel pipe pile 3: constructing miniature steel pipe piles 3 on a platform surface close to the second-stage retaining wall 2, wherein the bottom insertion depth of the miniature steel pipe piles 3 is positioned below the lowest point of the first-stage retaining wall 1, and a plurality of miniature steel pipe piles 3 are uniformly distributed along the extending direction of the second-stage retaining wall 2 at intervals;

after the steel pipe 31 of the miniature steel pipe pile 3 is inserted to a preset depth, the driving rod 51 and the cam 52 are driven by the starting motor 53, and the inserted rod 4 is outwards moved and inserted into the earthwork around the steel pipe 31 under the action of the cam 52, so that the connection strength between the steel pipe 31 and the surrounding earthwork is increased;

the bracket 54 is detached from the steel pipe 31, taken along with the driving lever 51, the cam 52 and the motor 53, and injected into the steel pipe 31 to a predetermined injection amount.

S2, excavating a secondary reinforcing groove 10: and (3) excavating a secondary reinforcement groove 10 at one side of the miniature steel pipe pile 3, which is opposite to the second-stage retaining wall 2, to the elevation required by the pile machine operation of the supporting pile 7, inserting the secondary reinforcement 6 into the earthwork outside the miniature steel pipe pile 3 until the push rod 62 is abutted on the wedge-shaped surface 42 of the inserted rod 4 until the push rod 62 is inserted into the slot 43, and continuing to push the secondary reinforcement 6 to move towards the miniature steel pipe pile 3 until the push rod 62 is inserted into the slot 43, and stopping the insertion of the secondary reinforcement 6.

S3, constructing a top beam: after the miniature steel pipe piles 3 are formed into piles, a capping beam is constructed, and the top ends of the miniature steel pipe piles 3 are connected into a whole.

S4, removing the retaining wall: and dismantling the first-stage retaining wall 1, and backfilling the original ground to the elevation required by the operation of the pile machine to form a pile machine construction platform surface.

S5, reinforcing earthwork outside the miniature steel pipe pile 3: the outside of the earthwork of the miniature steel pipe pile 3 is hung with a net and sprayed with concrete, a plurality of preset steel bars 63 are connected into a whole, redundant parts of the preset steel bars 63 are cut off, a plurality of secondary reinforcing members 6 are connected with the miniature steel pipe pile 3 into a whole, and the integrity and the reinforcing strength of the reinforcing structure of the second-stage retaining wall 2 are improved.

S6, construction of a support pile 7: and carrying out supporting pile 7 construction on the pile foundation construction platform surface through a pile machine.

S7, applying reinforced soil nails 8: and the reinforced soil nails 8 are obliquely inserted and driven between the adjacent support piles 7, and the inclination angle of the reinforced soil nails 8 is 20 degrees obliquely downwards in the horizontal plane.

S7, constructing a crown beam: and constructing a crown beam at the top end of each support pile 7, and fixing the crown beam and one end of the reinforced soil nail 8 after connecting each support pile 7 into a whole.

As shown in fig. 2, the layout area of the insert rod 4 in the height direction is located between the height of the construction platform of the rotary drilling rig and the corresponding height between the slope top platforms.

According to the three-stage old rubble retaining wall reinforcing method adjacent to the deep foundation pit supporting structure, after the first-stage retaining wall 1 is dismantled, the miniature steel pipe piles 3 replace the first-stage retaining wall 1 to bear the load of the upper second-stage retaining wall 2, so that the second-stage retaining wall 2 is reinforced, a construction surface is created for the deep foundation pit supporting structure, the safety of foundation pit construction is ensured, and the influence of the reinforced second-stage retaining wall 2 on deep foundation pit supporting is avoided; in addition, by heightening the elevation of the adjacent deep foundation pit supporting piles 7 and adding the reinforced soil nails 8, the foundation pit supporting structure is used as a redundant support of the retaining wall, so that the condition of integral landslide of the retaining wall is prevented, and the stability and safety of the retaining wall are further improved; before the slurry in the steel tube 31 of the miniature steel tube pile 3 is initially set, the inserted rod 4 is driven to be inserted outwards continuously through the secondary reinforcing member 6, and a plurality of secondary reinforcing members 6 are connected into a whole through the preset reinforcing steel bars 63 through the hanging net concrete spraying, so that the supporting strength of the miniature steel tube pile 3 is ensured.

The foregoing are all preferred embodiments of the present application, and are not intended to limit the scope of the present application in any way, therefore: all equivalent changes in structure, shape and principle of this application should be covered in the protection scope of this application.

Claims

1. The method for reinforcing the three-stage old rubble retaining wall adjoining the deep foundation pit supporting structure is characterized by comprising the following steps of:

s1, constructing a plurality of miniature steel pipe piles (3) on a platform surface close to a second-stage retaining wall (2), adjusting a reinforcing tool after a steel pipe (31) of the miniature steel pipe piles (3) is inserted to a preset depth so as to increase the connection strength between the miniature steel pipe piles (3) and earthwork, and grouting into the steel pipe (31);

s2, connecting the miniature steel pipe piles (3) into a whole by using a construction capping beam;

s3, dismantling the first-stage retaining wall (1), and backfilling the original ground to the elevation required by pile driver operation;

s4, hanging a net on the outside of the earthwork of the miniature steel pipe pile (3) for spraying concrete, and then constructing a support pile (7);

s5, applying reinforced soil nails (8);

s6, constructing a crown beam for connecting the support piles (7) into a whole;

the reinforcing tool comprises a inserted link (4) which is in sliding fit with a steel pipe (31) of the miniature steel pipe pile (3) along the radial direction of the miniature steel pipe pile (3), and further comprises a driving assembly (5) which is used for driving the inserted link (4) to penetrate through the steel pipe (31) of the miniature steel pipe pile (3) and be inserted into earthwork;

in the step S1, the insert rod (4) is driven by the driving assembly (5) to be inserted into the earthwork outwards, so that the connection strength between the steel pipe (31) of the miniature steel pipe pile (3) and the earthwork is increased;

two inserting rods (4) are symmetrically arranged on two sides of the miniature steel pipe piles (3) in the arrangement direction, and a wedge-shaped surface (42) is arranged on one side, facing away from the second-stage retaining wall (2), of each inserting rod (4);

step S11 is further arranged between the step S1 and the step S2, in the step S11, a secondary reinforcing groove (10) is excavated outside the miniature steel pipe pile (3) until the pile machine supporting the pile (7) operates at the required elevation, before slurry in the steel pipe (31) is initially set, the secondary reinforcing member (6) is inserted into earthwork outside the miniature steel pipe pile (3), so that two push rods (62) in the secondary reinforcing member (6) apply acting force to the two wedge-shaped surfaces (42), and the inserted rod (4) is pushed out outwards continuously until the push rods (62) are connected with the inserted rod (4).

2. The method for reinforcing a three-stage old rubble retaining wall adjoining a deep foundation pit supporting structure according to claim 1, wherein: the driving assembly (5) comprises a driving rod (51) coaxially rotating in the inner cavity of the steel pipe (31) of the miniature steel pipe pile (3), a cam (52) coaxially fixedly arranged on the driving rod (51) and a power piece for driving the driving rod (51) to rotate.

3. The method for reinforcing a three-stage old rubble retaining wall adjoining a deep foundation pit supporting structure according to claim 2, wherein: the maximum outer diameter of the cam (52) is smaller than the inner diameter of the steel pipe (31) of the miniature steel pipe pile (3).

4. A method of reinforcing a tertiary old rubble retaining wall adjoining a deep foundation pit supporting structure as set forth in claim 3, wherein: the inserting rod (4) is provided with a slot (43) matched with the push rod (62).

5. A method of reinforcing a tertiary old rubble retaining wall adjoining a deep foundation pit supporting structure as set forth in claim 3, wherein: the secondary reinforcement (6) is provided with preset steel bars (63), the preset steel bars (63) extend out of the outside of the earthwork, and in the step S4, the concrete connects a plurality of preset steel bars (63) into a whole.

6. The method for reinforcing a three-stage old rubble retaining wall adjoining a deep foundation pit supporting structure according to claim 2, wherein: the inserted link (4) is clamped and matched with a steel pipe (31) of the miniature steel pipe pile (3).

7. The method for reinforcing a three-stage old rubble retaining wall adjoining a deep foundation pit supporting structure according to claim 1, wherein: in step S1, a brick enclosing wall (9) is built at the top end of the second-stage retaining wall (2).