Construction method for isolating and dismantling waste box culvert in water-rich soft soil deep foundation pit steel sheet pile cofferdam

Abstract

The invention relates to a construction method for isolating and dismantling a waste box culvert in a steel sheet pile cofferdam of a water-rich soft soil deep foundation pit. Comprising a double-row steel sheet pile cofferdam top integral top beam technical system, a dismantling area range outer hole implantation bag grouting plugging technical system, a long-arm excavator steel platform moving technical system, a cutting and dismantling segment clamp lifting-out technical system and a box culvert trepanning built-in steel pipe supporting frame technical system. The method has the beneficial effects that construction is convenient, operation is easy, the stress form is reasonable, and good technical and economic benefits are achieved; a movable steel platform structure is innovated, the whole platform can be freely moved and fixed, the construction efficiency of excavator operation is improved, and the construction quality is guaranteed; the cut and dismantled sections can be quickly clamped out, and manual carrying is not needed; by installing the supporting frame system in the box culvert opening, sudden collapse of a box culvert top plate during cutting and dismantling is avoided, and construction safety is guaranteed.

Description

Technical Field

[0001] The invention belongs to the technical field of soft soil deep foundation pits, and in particular relates to a construction method for isolating and dismantling abandoned box culverts by steel sheet pile cofferdams in a water-rich soft soil deep foundation pit. Background Art

[0002] As a mode of public transportation with large capacity, high speed and high punctuality, the subway plays an important role in alleviating the pressure of ground transportation and can significantly improve the overall operating efficiency of urban transportation.

[0003] Abandoned box culverts are subject to long-term erosion by the natural environment, such as rainwater infiltration and groundwater corrosion, and the box culvert structure may crack and break, and its strength and stability will be greatly reduced. If they continue to be preserved, they are very likely to collapse when encountering natural disasters such as heavy rains and earthquakes, posing a serious threat to surrounding pedestrians, buildings and roads. At the same time, with the development of cities, land resources are becoming increasingly scarce. Abandoned box culverts occupy valuable underground space. After demolition, space can be released to provide venues for projects such as the construction of underground comprehensive pipe corridors, underground parking lots, and subway line expansion in the city, promoting the modernization of the city. The removal of abandoned box culverts can enable limited urban maintenance resources to be more reasonably allocated, concentrated on key facilities and projects to ensure the normal operation of the city, and improve the overall operational efficiency of the city.

[0004] In view of the above-mentioned problem of dismantling abandoned box culverts in deep foundation pits with water-rich soft soil, it is urgent to propose a construction method that can improve construction efficiency while ensuring project quality and safety. Summary of the invention

[0005] The purpose of the present invention is to provide a construction method for isolating and removing abandoned box culverts in a deep foundation pit of water-rich soft soil with a steel sheet pile cofferdam, which is used to improve the construction efficiency of removing abandoned box culverts in a deep foundation of water-rich soft soil and ensure the quality and safety of the project.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil comprises the following steps:

[0008] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert, excavate a foundation pit between the double rows of steel sheet piles, and dismantle the abandoned box culvert;

[0009] S2. Drill holes on the outside of the foundation pit and inject grout through the grouting device to complete the plugging of the holes;

[0010] S3. Install the long-arm excavator steel platform mobile system;

[0011] S4. Installing a cutting and dismantling segment fixture hoisting system on the long-arm excavator steel platform mobile system to clean up the abandoned box culvert segments that have been cut and dismantled;

[0012] S5. Drill holes in the abandoned box culvert and install built-in steel pipe support frames.

[0013] As a preferred embodiment: in S1, the double-row steel sheet piles define the foundation pit by means of first steel sheet piles and second steel sheet piles arranged at intervals; core backfilling is performed between the first steel sheet piles and the second steel sheet piles, and a crown beam is installed on the top of the core backfill; steel pipe inner supports are provided between the double-row steel sheet piles, and the connection positions between the steel pipe inner supports and the double-row steel sheet piles are reinforced by means of connecting pieces and steel corbels.

[0014] Preferably: in S2, the grouting device includes a flange, a delivery pipe, a bag, a grouting pressure device and a grouting pipe arranged above the opening; grouting is performed to the delivery pipe connected to the bottom of the flange through the grouting pressure device and the grouting pipe to complete the blocking of the hole; the delivery pipe is connected to the flange; the delivery pipe includes a first delivery pipe and a second delivery pipe; the bag includes a first bag and a second bag; a plurality of the first bags are alternately connected to the first delivery pipe and the second delivery pipe; the second bag is arranged at the bottom of the hole.

[0015] Preferably: the long-arm excavator steel platform moving system includes a steel platform moving system and a steel platform support system. In S3, the steel platform moving system includes a double-leg I-beam. After the steel platform moving system is moved to the outside of the foundation pit by moving the electric steel wheel, the jack set at the bottom of the double-leg I-beam is raised to fix the steel platform moving system; the steel platform support system includes steel pipe columns, steel cross bars, steel diagonal bars, steel plate cushions, I-beam load-bearing beams, Bailey beams, square timbers and an excavator operating platform.

[0016] As a preferred embodiment: in S4, the installation cutting and removal segment clamp lifting system includes a square tube column, the upper part of which is provided with a tail plate, a lifting port and a connecting buckle; the lower part of the square tube column is provided with a counterweight block and a rotating shaft, and drives the clamping plate to clamp out the cut abandoned box culvert removal segment.

[0017] As a preferred embodiment: in S5, a built-in steel pipe support frame is installed in the box culvert opening; the steel pipe support frame includes steel pipe columns, I-beam load-bearing beams, steel cross bars, scissor braces and sand boxes; the steel pipe support frame moves back and forth through a pulley base and a polyurethane pulley.

[0018] The beneficial effects of the present invention are:

[0019] 1) The integral crown beam system on the top of the double-row steel sheet pile cofferdam involved in the present invention forms a foundation pit positioning excavation position through two double-row steel sheet pile cofferdams, and supports the two double-row steel sheet piles by arranging steel pipe internal supports, connectors and steel corbels. It is convenient to construct, simple to operate, and has a reasonable force form, and has good technical and economic benefits.

[0020] 2) The long-arm excavator steel platform moving system involved in the present invention sets the entire platform to be freely movable and fixed, and can flexibly adjust the position of the platform, thereby improving the construction efficiency of the excavator operation and ensuring the construction quality.

[0021] 3) The cutting and removal segment clamp lifting system involved in the present invention can quickly clamp out the cut and removed segments by driving the clamping plate through the rotating shaft, without the need for manual handling, thus reducing labor costs.

[0022] 4) The box culvert opening involved in the present invention has a built-in steel pipe support frame system. By installing the support frame system inside the box culvert after the box culvert opening, the problem of sudden collapse of the box culvert top plate during cutting and removal is avoided, thereby ensuring construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the integral crown beam system structure at the top of the double-row steel sheet pile cofferdam;

[0024] Figure 2 It is a schematic diagram of the enlarged structure of the core filling and backfilling area;

[0025] Figure 3 It is a schematic diagram of the system structure of the hole insertion and grouting plugging of the bag outside the demolition area;

[0026] Figure 4 It is a schematic diagram of the mobile architecture of the steel platform of the long-arm excavator;

[0027] Figure 5 This is a front view of the clamp hoisting system for cutting and removing segments;

[0028] Figure 6 It is a side view of the clamp hoisting system for cutting and removing segments;

[0029] Figure 7 It is a schematic diagram of the box culvert opening and built-in steel pipe support frame system structure.

[0030] Explanation of reference numerals: 1 abandoned box culvert, 2 foundation pit, 3 steel pipe inner support, 4 first steel sheet pile, 5 second steel sheet pile, 6 connecting piece, 7 steel corbel, 8 crown beam, 9 core filling backfill, 10 grouting pressure device, 11 grouting pipe, 12 flange, 13 hole, 14 first conveying pipe, 15 second conveying pipe, 16 first bag, 17 second bag, 18 square wood, 19 Bailey beam, 20 I-beam load-bearing beam, 2 1 steel pipe column, 22 double-leg I-beam, 23 jack, 24 electric steel wheel, 25 excavator operating platform, 26 steel plate cushion, 27 steel cross bar, 28 steel diagonal bar, 29 square pipe column, 30 rotating shaft, 31 connecting buckle, 32 lifting port, 33 tail wing plate, 34 counterweight, 35 plywood, 36 box culvert top plate, 37 scissors brace, 38 box culvert bottom plate, 39 sand box, 40 pulley base, 41 polyurethane pulley. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with embodiments. The description of the following embodiments is only used to help understand the present invention. It should be noted that for ordinary persons in the art, without departing from the principle of the present invention, the present invention can also be modified in some ways, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0032] Embodiment 1

[0033] As an embodiment, a construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil is proposed, comprising the following steps:

[0034] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert 1, excavate a foundation pit 2 between the double rows of steel sheet piles, and dismantle the abandoned box culvert 1; Figure 1 and Figure 2 As shown, firstly, the first steel sheet pile 4 and the second steel sheet pile 5 are inserted into the soil, and the core backfill 9 is performed between them. At the same time, the integral crown beam 8 is welded and fixed on the top of the backfill soil, so that the two double-row steel sheet piles are tightly connected together; then, the steel pipe inner support 3, the connecting piece 6 and the steel corbel 7 are applied between the first steel sheet piles 4 on the left and right sides to improve the stability of the overall structure; finally, the foundation pit 2 is excavated and the abandoned box culvert 1 is demolished. In this embodiment, an integral crown beam system at the top of the double-row steel sheet pile cofferdam is adopted, and the excavation position of the foundation pit 2 is located by forming two double-row steel sheet pile cofferdams, and the two double-row steel sheet piles are supported by setting the steel pipe inner support 3, the connecting piece 6 and the steel corbel 7. The construction is convenient, the operation is simple, the force form is reasonable, and it has good technical and economic benefits.

[0035] S2, drilling a hole 13 outside the foundation pit 2, injecting grout through a grouting device to complete the plugging of the hole 13.

[0036] S3. Install the long arm excavator steel platform moving system.

[0037] S4. Install a cutting and dismantling segment clamp hoisting system on the long-arm excavator steel platform mobile system to clean up the abandoned box culvert 1 segment that has been cut and dismantled.

[0038] S5. Drill a hole on the abandoned box culvert 1 and install a built-in steel pipe support frame.

[0039] Embodiment 2

[0040] As another embodiment, this embodiment proposes, based on the first embodiment, a more specific construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil, comprising the following steps:

[0041] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert 1, excavate a foundation pit 2 between the double rows of steel sheet piles, and dismantle the abandoned box culvert 1.

[0042] S2, the hole 13 outside the foundation pit 2 is bored, and grouting is performed by the grouting device to complete the plugging of the hole 13; Figure 3 As shown, the grouting device includes a flange 12, a delivery pipe, a bag, a grouting pressure device 10 and a grouting pipe 11 arranged above the opening; grouting is performed to the delivery pipe connected to the bottom of the flange 12 by the grouting pressure device 10 and the grouting pipe 11, so as to ensure that the slurry smoothly enters the hole from the outside; the delivery pipe is connected to the flange 12; the delivery pipe includes a first delivery pipe 14 and a second delivery pipe 15; the bag includes a first bag 16 and a second bag 17; four first bags 16 are staggeredly connected to the first delivery pipe 14 and the second delivery pipe 15; the second bag 17 is arranged at the bottom of the hole 13, and opening the grouting pressure device 10 can allow the slurry to enter the bag to complete the plugging of the hole 13.

[0043] S3. Install the long arm excavator steel platform moving system.

[0044] S4. Install the cutting and dismantling segment clamp hoisting system on the long-arm excavator steel platform mobile system, and clean up the abandoned box culvert 1 segment that was cut and dismantled.

[0045] S5. Drill holes on the box culvert and install built-in steel pipe support frames.

[0046] It should be noted that the parts in this embodiment that are the same or similar to those in the first embodiment can be referenced to each other and will not be described in detail in this application.

[0047] Embodiment 3

[0048] As another embodiment, this embodiment proposes, on the basis of the second embodiment, a more specific construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil, comprising the following steps:

[0049] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert 1, excavate a foundation pit 2 between the double rows of steel sheet piles, and dismantle the abandoned box culvert 1.

[0050] S2, drilling a hole 13 outside the foundation pit 2, injecting grout through a grouting device to complete the plugging of the hole 13.

[0051] S3. Install the long-arm excavator steel platform mobile system; Figure 4 As shown, the long-arm excavator steel platform mobile system includes a steel platform mobile system and a steel platform support system. The steel platform mobile system includes a double-limb I-beam 22. After the steel platform mobile system is moved to the outside of the foundation pit 2 by moving the electric steel wheel 24, the jack 23 set at the bottom of the double-limb I-beam 22 is raised to fix the steel platform mobile system; the steel platform support system includes a steel pipe column 21, a steel cross bar 27, a steel diagonal bar 28, a steel plate cushion layer 26, an I-beam load-bearing beam 20, a Bailey beam 19, a square wood 18 and an excavator operating platform 25, which can play a supporting role during the excavator construction. In this embodiment, by setting the overall platform to be freely movable and fixed, the position of the platform can be flexibly adjusted, the construction efficiency of the excavator operation is improved, and the construction quality is guaranteed.

[0052] S4. Install the cutting and dismantling segment clamp hoisting system on the long-arm excavator steel platform mobile system, and clean up the abandoned box culvert 1 segment that was cut and dismantled.

[0053] S5. Drill a hole in the exhaust culvert 1 and install a built-in steel pipe support frame.

[0054] It should be noted that the parts in this embodiment that are the same or similar to those in the second embodiment can be referenced to each other and will not be described in detail in this application.

[0055] Embodiment 4

[0056] As another embodiment, this embodiment proposes, on the basis of the third embodiment, a more specific construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil, comprising the following steps:

[0057] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert 1, excavate a foundation pit 2 between the double rows of steel sheet piles, and dismantle the abandoned box culvert 1.

[0058] S2, drilling a hole 13 outside the foundation pit 2, injecting grout through a grouting device to complete the plugging of the hole 13.

[0059] S3. Install the long arm excavator steel platform moving system.

[0060] S4. Install the cutting and dismantling segment clamp hoisting system on the long-arm excavator steel platform mobile system to clean up the abandoned box culvert 1 segment that has been cut and dismantled; Figure 5 and Figure 6As shown, first, a tail wing plate 33 is welded on the main square pipe column 29, and a hoisting port 32 is provided in the tail wing plate 33 for easy hoisting by a crane. A connecting buckle 31 is provided on the upper part of the tail wing plate 33, which can be connected to a mechanical device; then, a counterweight block 34 is installed on the lower part of the main square pipe column 29 for counterweighting, and a clamping plate 35 is provided at the same time, and the clamping plate 35 is driven by the rotating shaft 30 for construction. In this embodiment, the clamping plate 35 is driven by the rotating shaft 30, so that the cut and removed segments can be quickly clamped out without manual handling, thereby reducing labor costs.

[0061] S5. Drill a hole on the abandoned box culvert 1 and install a built-in steel pipe support frame.

[0062] It should be noted that the parts in this embodiment that are the same or similar to those in Embodiment 3 can be referenced to each other and will not be described in detail in this application.

[0063] Embodiment 5

[0064] As another embodiment, this embodiment proposes, on the basis of the fourth embodiment, a more specific construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil, comprising the following steps:

[0065] S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert 1, excavate a foundation pit 2 between the double rows of steel sheet piles, and dismantle the abandoned box culvert 1.

[0066] S2, drilling a hole 13 outside the foundation pit 2, injecting grout through a grouting device to complete the plugging of the hole 13.

[0067] S3. Install the long arm excavator steel platform moving system.

[0068] S4. Install the cutting and dismantling segment clamp hoisting system on the long-arm excavator steel platform mobile system, and clean up the abandoned box culvert 1 segment that was cut and dismantled.

[0069] S5. Drill holes in the waste box culvert 1 to install a built-in steel pipe support frame. By installing the support frame system inside the waste box culvert 1 after drilling holes, the problem of sudden collapse of the box culvert top plate 36 during cutting and removal is avoided, ensuring construction safety. Figure 7 As shown, the built-in steel pipe support frame includes a pulley base 40 and a polyurethane pulley 41 pre-installed at the bottom of the steel pipe column 21, and a steel cross bar 27 and a scissor brace 37 are welded between adjacent steel pipe columns 21 to improve the strength of the overall structure; then the installed steel pipe frame is placed in the box culvert opening composed of a box culvert top plate 36 and a box culvert bottom plate 38; finally, a sand box 39 and an I-beam load-bearing beam 20 are installed on the upper part of the steel pipe column 21, and the height of the I-beam load-bearing beam 20 can be controlled by the sand box 39, so that the I-beam load-bearing beam 20 is tightly fitted with the box culvert top plate 36.

[0070] It should be noted that the parts in this embodiment that are the same or similar to those in the fourth embodiment can be referenced to each other and will not be described in detail in this application.

[0071] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

Claims

1. A construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil, characterized in that: The following steps are involved: S1. Insert double rows of steel sheet piles into the soil on both sides of the abandoned box culvert, excavate a foundation pit between the double rows of steel sheet piles, and dismantle the abandoned box culvert; S2. Drill holes on the outside of the foundation pit and inject grout through the grouting device to complete the plugging of the holes; S3. Install the long-arm excavator steel platform mobile system; S4. Installing a cutting and dismantling segment fixture hoisting system on the long-arm excavator steel platform mobile system to clean up the abandoned box culvert segments that have been cut and dismantled; S5. Drill holes in the abandoned box culvert and install built-in steel pipe support frames.

2. The construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil according to claim 1 is characterized by: In S1, the double-row steel sheet piles define the foundation pit by means of the first steel sheet piles and the second steel sheet piles arranged at intervals; core backfilling is performed between the first steel sheet piles and the second steel sheet piles, and a crown beam is installed on the top of the core backfilling; steel pipe inner supports are arranged between the double-row steel sheet piles, and the connection positions between the steel pipe inner supports and the double-row steel sheet piles are reinforced by means of connecting pieces and steel corbels.

3. The construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil according to claim 1 is characterized by: In S2, the grouting device includes a flange, a delivery pipe, a bag, a grouting pressure device and a grouting pipe arranged above the opening; grouting is performed to the delivery pipe connected to the bottom of the flange through the grouting pressure device and the grouting pipe to complete the plugging of the hole; the delivery pipe is connected to the flange; the delivery pipe includes a first delivery pipe and a second delivery pipe; the bag includes a first bag and a second bag; a plurality of the first bags are staggeredly connected to the first delivery pipe and the second delivery pipe; the second bag is arranged at the bottom of the hole.

4. The construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil according to claim 1 is characterized by: The long-arm excavator steel platform moving system includes a steel platform moving system and a steel platform support system. In S3, the steel platform moving system includes a double-leg I-beam. After the steel platform moving system is moved to the outside of the foundation pit by moving the electric steel wheel, the jack set at the bottom of the double-leg I-beam is raised to fix the steel platform moving system; the steel platform support system includes steel pipe columns, steel cross bars, steel diagonal bars, steel plate cushions, I-beam load-bearing beams, Bailey beams, square timbers and an excavator operating platform.

5. The construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil according to claim 1 is characterized by: In S4, the installation cutting and removal segment clamp lifting system includes a square pipe column, the upper part of which is provided with a tail plate, a lifting port and a connecting buckle; the lower part of the square pipe column is provided with a counterweight block and a rotating shaft, and drives the clamping plate to clamp out the cut abandoned box culvert removal segment.

6. The construction method for isolating and removing abandoned box culverts by steel sheet pile cofferdam in a deep foundation pit of water-rich soft soil according to claim 1 is characterized in that: In S5, a built-in steel pipe support frame is installed in the opening of the box culvert; the steel pipe support frame includes steel pipe columns, I-beam load-bearing beams, steel cross bars, scissor braces and sand boxes; the steel pipe support frame moves back and forth through a pulley base and a polyurethane pulley.

Images