Reinforced concrete support-steel pipe support combined system for deep foundation pit and construction method

Abstract

The invention relates to a deep foundation pit reinforced concrete support-steel pipe support combined system and a construction method, a steel pipe support and an underground diaphragm wall are temporarily mounted and fixed by prearranging components such as anchor bolt holes, support embedded parts and diagonal draw bars, on the basis of ensuring the mounting quality, the construction cost is reduced, the construction convenience is improved, and the construction efficiency is improved. The temporary components can be recycled, and the good environmental protection property is achieved; a steel latticed column and a cast-in-situ bored pile reinforcement cage are welded and anchored in a pile foundation, a channel steel coupling beam is welded and installed on a bracket to form a deep foundation pit stand column supporting system, the stability of foundation pit supporting is guaranteed, and then construction safety is guaranteed; the dragging type steel column is adopted for applying prestress to replace the latticed column needing to be cut off, and the influence on a permanent structure is small in the construction process.

Description

Technical Field

[0001] The invention belongs to the field of deep foundation pit support construction, and in particular relates to a deep foundation pit reinforced concrete support-steel pipe support combined system and a construction method. Background Art

[0002] In deep foundation pit construction, due to the complex geological conditions and sensitive surrounding environment, the design and construction of the foundation pit support system is particularly important. Reinforced concrete support and steel pipe support are two common support methods, each with significant characteristics and advantages. Reinforced concrete support has the characteristics of high strength, not easy to deform, and good stability, and is suitable for bearing large horizontal and vertical loads. Steel pipe support has the advantages of light weight, easy installation and dismantling, fast construction speed, and reusability, which is very effective in reducing the displacement of the support structure caused by the time effect.

[0003] However, in actual projects, a single support method is often difficult to meet the complex and changing needs of foundation pit support. Combining reinforced concrete support and steel pipe support to form a reinforced concrete support-steel pipe support combination system is an effective solution, but the conventional construction method is cumbersome and the stability and safety are difficult to control.

[0004] Therefore, it is of great significance to study the reinforced concrete support-steel pipe support combination system and construction method of deep foundation pit. Summary of the invention

[0005] The purpose of the present invention is to overcome the deficiencies in the prior art and to provide a deep foundation pit reinforced concrete support-steel pipe support combined system and a construction method.

[0006] The deep foundation pit reinforced concrete support-steel pipe support combined system includes an underground continuous wall, a deep foundation pit column support system, a structural beam, a drag-and-replacement steel column, and a steel pipe drag-and-replacement internal support removal system; the underground continuous wall side is installed with a steel pipe support through a support embedded part, and the steel pipe support side is diagonally pulled with the underground continuous wall through a diagonal tie rod;

[0007] The deep foundation pit column support system includes steel lattice columns and bored piles. The lower half of the steel lattice columns and bored piles are cast below the base plane.

[0008] The drag-and-replacement steel columns are supported on the structural beams and are used to replace the lattice columns that need to be removed; the steel pipe drag-and-replacement internal support removal system includes cast-in-place piles, cap beams and structural top plates.

[0009] Preferably, support embedded parts and reserved anchor holes are arranged in the underground continuous wall. When the steel pipe support is installed, the bottom is overlapped on the inclined support below the support embedded parts. A lifting lug is provided on the side of the steel pipe support. An L-shaped anchor plate is fixed to the wall surface of the underground continuous wall above the steel pipe support through anchor bolts and reserved anchor holes. The lifting lug and the L-shaped anchor plate are obliquely connected through diagonal tie rods and basket bolts.

[0010] Preferably, the steel lattice column is welded from angle steel and steel plate, and a corbel is provided on the side of the steel lattice column, on which a channel steel is welded; the bored cast-in-place pile is arranged below the base plane, and the lower half of the steel lattice column is welded and anchored in the pile foundation with the bored cast-in-place pile stirrups and the main reinforcement of the bored cast-in-place pile.

[0011] Preferably, the tow-and-replaceable steel column includes a bottom end head plate, a corbel stiffening rib, a stiffening rib and a steel column; the bottom of the tow-and-replaceable steel column is fixed to a specified position on the structural upper surface of the structural beam by nuts, pads and anchor bolts; hydraulic jacks are respectively arranged between the corbel stiffening ribs on both sides of the tow-and-replaceable steel column body and the structural upper surface of the structural beam; the gap edge between the bottom end head plate and the structural upper surface is closed by a gap steel wedge, the bottom end head plate and the structural upper surface are anchored by anchor bolts, and a reserved grouting hole is opened on the bottom end head plate for injecting non-shrinkage filling slurry between the bottom end head plate and the structural upper surface.

[0012] Preferably, the steel pipe replacement internal support removal system includes a structural top plate, a crown beam, cast-in-place piles, steel pipe braces and steel pipe diagonal braces. End steel plates are arranged on opposite sides of the structural top plate, the crown beam and the cast-in-place piles. Steel pipe braces are arranged between the end steel plates of the structural top plate and the cast-in-place piles and between the structural top plate and the crown beam. Ash soil is backfilled between the cast-in-place piles and the foundation bottom plate. The ash soil and the steel pipe braces are used to jointly resist the soil pressure transmitted by the deep mixing piles and the cast-in-place piles. The end steel plate components are fixed to the crown beam and the cast-in-place piles by using embedded reinforcement. The end steel plates are provided with fixing holes for fixed installation, and the steel pipe braces are fully welded to the end steel plates.

[0013] Preferably, a construction safety rope is arranged between two steel lattice columns, cutting sections are divided on the concrete support between the two steel lattice columns, and steel wire ropes and steel wire rope clamps are used to suspend and connect the previous support and the concrete support currently planned to be demolished.

[0014] The construction method of the deep foundation pit reinforced concrete support-steel pipe support combined system includes the following construction steps:

[0015] S1. After the underground continuous wall is constructed, install the steel pipe support and make the diagonal connection;

[0016] S2. After the lower half of the steel lattice column is welded and fixed to the bored pile reinforcement cage, it is lowered and cast into one piece. The channel steel connecting beam is welded and installed on the side of the steel lattice column to form a deep foundation pit column support system;

[0017] S3. Use a hydraulic jack to apply prestress to the top of the drag-replacement steel column, pour non-shrinkage filling slurry into the gap below the drag-replacement steel column, and cut off the lattice column that needs to be removed;

[0018] S4. Set steel pipe supports between the cast-in-place piles, crown beams and the structural top plate, backfill the soil between the cast-in-place piles and the foundation bottom plate, and then dismantle the reinforced concrete supports on the sides of the crown beams.

[0019] Preferably, there is also step S5, which is specifically: dismantling the concrete support; before dismantling the concrete support, firstly arrange construction safety ropes on two steel lattice columns for workers to fasten their safety belts during construction, then draw a cutting line at the specified position of the concrete support to be dismantled, and manually chisel out the corner steel bars on the cut section, and then use the upper support above the concrete support to be dismantled to pass the steel wire rope through the exposed corner steel bars, and use the steel wire rope clamp to clamp and fix them, then cut the concrete support from the center to both sides, and release the steel wire rope on the corresponding cutting section, and finally remove the cut concrete support from the site.

[0020] The beneficial effects of the present invention are:

[0021] 1) The present invention proposes a deep foundation pit steel pipe support installation technology, which temporarily installs and fixes the steel pipe support to the underground continuous wall through preset anchor holes, support embedded parts, inclined rods and other components. On the basis of ensuring the installation quality, it reduces the construction cost and improves the construction convenience. The temporary components can be recycled and have good environmental protection.

[0022] 2) The present invention proposes a steel lattice column installation technology, in which the steel lattice column and the bored pile reinforcement cage are welded and anchored in the pile foundation, and a channel steel connecting beam is welded and installed on the corbel to form a deep foundation pit column support system, thereby ensuring the stability of the foundation pit support and thus ensuring construction safety.

[0023] 3) The present invention proposes a prestressed steel replacement technology for steel lattice columns, which uses a replacement steel column to apply prestress to replace the lattice column that needs to be removed. The construction process has little impact on the permanent structure, ensuring the safety and reliability of the structure. The replacement steel column can be recycled and reused, which has good economic and environmental protection properties.

[0024] 4) The present invention proposes a steel pipe replacement internal support removal technology, which utilizes the completed vertical structure, dense backfill soil, and steel pipe supports to jointly resist the soil pressure after the removal of the reinforced concrete support. The entire process is reasonably connected, the construction efficiency is high, the stability is strong during the support removal and replacement process, and the used steel supports can be recycled, which has good economic and social benefits.

[0025] 5) The present invention proposes a reinforced concrete support dismantling technology, which uses steel wire ropes to lift the unremoved supports. Compared with conventional concrete support dismantling processes, it avoids the cumbersome temporary support erection, makes on-site safety easier to control, and the designed construction materials can be reused, saving resources and reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a technical diagram of the installation of steel pipe supports for deep foundation pits;

[0027] Figure 2 This is a technical diagram of steel lattice column installation;

[0028] Figure 3 This is a schematic diagram of the plane position of the drag-and-replace steel column;

[0029] Figure 4 This is a schematic diagram of the drag-and-replace steel column structure;

[0030] Figure 5 This is a top view of the drag-and-replace steel column;

[0031] Figure 6 This is a schematic diagram of the top installation of the drag-and-replace steel column;

[0032] Figure 7 This is a schematic diagram of the prestressing construction of the drag-replacement steel column;

[0033] Figure 8 This is a technical diagram of steel pipe dragging and replacing internal supports for removal;

[0034] Fig. 9 It is a schematic diagram of the end steel plate structure;

[0035] Fig.10 This is a schematic diagram of the construction of exposing the corner steel bars;

[0036] Fig.11 Schematic diagram of the reinforced concrete support removal technology.

[0037] Explanation of the reference numerals: 1-L-shaped anchor plate, 2-anchor hole, 3-anchor, 4-diagonal tie rod, 5-basket bolt, 6-lifting ear, 7-support embedded part, 8-steel pipe support, 9-diagonal support, 10-underground continuous wall, 11-base plane, 12-steel lattice column, 13-steel plate, 14-angle steel, 15-corbel, 16-channel steel, 17-bored pile, 18-cast-in-place pile main reinforcement, 19-cast-in-place pile stirrups, 20-structural beam, 21-lattice column to be removed, 22-replacement steel column, 23-corbel stiffening rib, 24-stiffening rib, 25-nut, 26-shim, 27-full weld connection, 28-bottom end cap plate, 29-anchor, 30-reserved injection Grout hole, 31-steel column, 32-upper surface of structure, 33-gap steel wedge, 34-hydraulic jack, 35-non-shrinkage filling slurry, 36-crown beam, 37-reinforced concrete support, 38-deep mixing pile, 39-cast pile, 40-original soil, 41-foundation bottom plate, 42-structure top plate, 43-steel pipe diagonal brace, 44-steel pipe brace, 45-end steel plate, 46-embedded reinforcement, 47-ash soil, 48-full welding connection, 49-fixing hole, 50-upper support, 51-concrete support, 52-wire rope clamp, 53-wire rope, 54-corner steel bar, 55-second cutting section, 56-first cutting section, 57-third cutting section, 58-safety rope. DETAILED DESCRIPTION

[0038] 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.

[0039] Embodiment 1

[0040] As an example, Figure 1 and Figure 2 As shown, this deep foundation pit reinforced concrete support-steel pipe support combined system includes an underground continuous wall 10 and a deep foundation pit column support system.

[0041] A steel pipe support 8 is installed on the side of the underground continuous wall 10 through a support embedded part 7, and the side of the steel pipe support 8 is inclined with the underground continuous wall 10 through an inclined tie rod 4.

[0042] Specifically, Figure 1As shown, firstly, the supporting embedded parts 7 and the reserved anchor bolt holes 2 are arranged in the underground continuous wall 10, then the underground continuous wall 10 is cleaned and the anchor bolt holes 2 are cleared, then the steel pipe support 8 is overlapped and installed with the supporting embedded parts 7 and supported on the oblique support 9 below, and finally the steel pipe support 8 and the underground continuous wall 10 are obliquely connected by using the oblique tie rod 4, basket bolt 5, lifting lug 6, L-shaped anchor pad 1, anchor bolt 3 and other components. The lifting lug 6 is welded and fixed to the side of the steel pipe support 8; the L-shaped anchor pad 1 is fixed to the wall surface of the underground continuous wall 10 through the anchor bolt 3 and the reserved anchor bolt hole 2.

[0043] The deep foundation pit column support system includes steel lattice columns 12 and bored piles 17 . The lower half of the steel lattice columns 12 and the bored piles 17 are cast below the base plane 11 .

[0044] Specifically, Figure 2 As shown, the steel lattice column 12 is made by welding the angle steel 14 and the steel plate 13, and the bored pile 17 is constructed on site. Then, the lower part of the steel lattice column 12 is welded and anchored to the bored pile 17 reinforcement cage, and the steel lattice column 12 and the bored pile 17 reinforcement cage are placed at the designated position, and then concrete is poured into the pile hole. Finally, the corbel 15 is installed on the steel lattice column 12 and the channel steel 16 connecting beam is welded on the corbel to form a deep foundation pit column support system.

[0045] Embodiment 2

[0046] As another embodiment, this embodiment 2 proposes, based on the embodiment 1, a more specific deep foundation pit reinforced concrete support-steel pipe support combination system, such as Figures 3 to 9 As shown, it also includes a structural beam 20, a towable steel column 22 and a steel pipe towable internal support removal system.

[0047] The drag-and-replacement steel column 22 is supported on the structural beam 20 and is used to replace the lattice column 21 that needs to be removed to bear the force;

[0048] Specifically, Figures 3 to 7 As shown, a tow-type steel column 22 supported on a structural beam 20 is arranged on both sides of the lattice column 21 to be removed. First, the top of the tow-type steel column 22 is fixed on the bottom surface 59 of the structure. Then, the tow-type steel column 22 and the hydraulic jack 34 are installed at the designated construction position and prestressed. Then, a gap steel wedge 33 is filled in the gap between the bottom end head plate 28 and the upper surface 32 of the structure. At the same time, a non-shrinkage filling slurry 35 is poured into the gap position around the gap steel wedge 33 through the reserved grouting holes 30. The non-shrinkage filling slurry 35 is C60 non-shrinkage filling slurry. Finally, after the filling slurry reaches the strength requirement, the hydraulic jack 34 is removed, and the lattice column 21 to be removed is cut off.

[0049] The steel pipe drag-replacement internal support removal system includes cast-in-place piles, cap beams and structural top plates.

[0050] like Figure 8 , Fig. 9 As shown, end steel plates 45 are respectively arranged at designated positions of the structure top plate 42, the crown beam 36 and the cast-in-place piles 39, and then the steel pipe braces 44 and the steel pipe diagonal braces 43 are installed. Both ends of the steel pipe braces are fully welded and connected 48 to the end steel plates 45. Then, a portion of original soil 40 is reserved between the cast-in-place piles 39 and the foundation bottom plate 41, and then 2:8 gray soil 47 is used for dense backfilling. Finally, the reinforced concrete support 37 is dismantled. After the construction is completed, the steel pipe braces are dismantled and recovered in sections.

[0051] 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.

[0052] Embodiment 3

[0053] As another embodiment, this embodiment 3 proposes, based on the embodiments 1 and 2, a construction method of the deep foundation pit reinforced concrete support-steel pipe support combination system, comprising the following construction steps:

[0054] S1, such as Figure 1 As shown, during the construction of the underground continuous wall 10, the supporting embedded parts 7 and the reserved anchor holes 2 are arranged at the designed position. After the strength of the underground continuous wall 10 reaches the requirement, the wall surface and the reserved anchor holes 2 are cleaned, and then the bottom of the steel pipe support 8 is installed on the supporting embedded parts 7 and supported on the inclined support 9 below. At the same time, the steel pipe support 8 and the underground continuous wall 10 are obliquely connected by using the inclined rod 4, basket bolt 5, lug 6 and L-shaped anchor plate 1, and the L-shaped anchor plate 1 is fixed to the reserved anchor hole 2 of the underground continuous wall 10 by the anchor bolt 3.

[0055] S2, such as Figure 2 As shown, firstly, the steel lattice column 12 is welded by using the angle steel 14 and the steel plate 13, and then the bored pile 17 is constructed below the base plane 11 as required, and the lower half of the steel lattice column 12 is welded and fixed with the bored pile stirrups 19 and the bored pile main reinforcement 18 and lowered to the specified position in the pile hole, and then the bored pile 17 concrete construction is carried out, and the steel lattice column 12 is anchored in the bored pile 17, and finally the corbel 15 is welded on the steel lattice column 12 and the channel steel 16 connecting beam is welded and installed on the corbel to form a deep foundation pit column support system.

[0056] S3, such as Figures 3 to 7As shown, according to the design and site requirements, the steel column 31, the bottom end plate 28, the bracket stiffening rib 23, and the stiffening rib 24 are pre-welded to complete the processing of the tow-type steel column 22. First, the anchor hole is drilled at the specified position of the bottom surface 59 of the structure, and the anchor 29 is used to fix the top of the tow-type steel column 22 to the structure. Then, the hydraulic jack 34 is installed at the specified position between the bracket stiffening rib 23 and the upper surface 32 of the structure and prestressed. Then, the gap between the bottom end plate 28 and the upper surface 32 of the structure is filled with a gap steel wedge 33 and the two are welded and fixed. Then, the bottom end plate 28 is anchored at the specified position of the upper surface 32 of the structure using the anchor 29, and the C60 non-shrinkage filling slurry 35 is injected through the reserved grouting hole 30. Finally, after the filling slurry reaches the strength requirement, the hydraulic jack 34 is removed, and the lattice column 21 that needs to be removed is cut off.

[0057] It should be noted that the parts in this embodiment that are the same or similar to those in Embodiments 1 and 2 can be referenced to each other and will not be described in detail in this application.

[0058] Embodiment 4

[0059] As another embodiment, this embodiment 4 proposes, on the basis of the embodiment 3, a more specific construction method of a deep foundation pit reinforced concrete support-steel pipe support combination system:

[0060] S4, such as Figure 8 and Fig. 9 As shown, when the structure top plate 42 is constructed, an end steel plate 45 is preset, and reinforcement 46 is embedded at the designated positions of the cast-in-place piles 39 and the crown beam 36 to install the end steel plate 45, and then the steel pipe brace 44 and the steel pipe diagonal brace 43 are installed, and the two ends of the steel pipe brace are fully welded and connected 48 to the end steel plate 45, and then a part of the original soil 40 is reserved between the cast-in-place piles 39 and the foundation bottom plate 41, and then the ash soil 47 is used for dense backfilling, and the ash soil 47 is 2:8 ash soil, and then the reinforced concrete support 37 is dismantled, and the completed vertical structure, the backfilled dense ash soil 47, the steel pipe brace 44 and the steel pipe diagonal brace 43 are used to jointly resist the soil pressure after the removal of the reinforced concrete support 37, and finally, after the construction is completed, the steel pipe support is dismantled and recovered in sections.

[0061] S5, such as Fig.10 and Fig.11As shown, before the concrete support is removed, first, a construction safety rope 58 is arranged on the two steel lattice columns 12 for workers to buckle their safety belts during construction, and then a cutting line is drawn at a specified position of the concrete support 51, and at the same time, the corner steel bars 54 on the cutting section are manually chiseled out, and then a steel wire rope 53 is used to pass through the exposed corner steel bars 54 using the upper support 50, and is clamped and fixed using a steel wire rope clamp 52, and then a rope saw is used to cut the concrete support 51 in the order of the first cutting section 56 → the second cutting section 55 → the third cutting section 57, and after cutting, a forklift is used to support the cutting section, and the steel wire rope 53 on the corresponding cutting section is released, and finally the cut concrete support 51 is transported out of the site.

[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] 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 deep foundation pit reinforced concrete support-steel pipe support combined system, characterized by: It includes underground continuous wall, deep foundation pit column support system, structural beam, drag-replacement steel column and steel pipe drag-replacement internal support removal system; the side of the underground continuous wall is installed with steel pipe support through support embedded parts, and the side of the steel pipe support is inclined with the underground continuous wall through inclined rods; The deep foundation pit column support system includes steel lattice columns and bored piles. The lower half of the steel lattice columns and bored piles are cast below the base plane. The drag-and-replacement steel columns are supported on the structural beams and are used to replace the lattice columns that need to be removed; the steel pipe drag-and-replacement internal support removal system includes cast-in-place piles, cap beams and structural top plates.

2. The deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 1 is characterized in that: Support embedded parts and reserved anchor holes are arranged in the underground continuous wall. When the steel pipe support is installed, the bottom is overlapped on the inclined support below the support embedded parts. A lifting lug is provided on the side of the steel pipe support. An L-shaped anchor plate is fixed to the wall surface of the underground continuous wall above the steel pipe support through anchor bolts and reserved anchor holes. The lifting lug and the L-shaped anchor plate are obliquely connected through oblique tie rods and basket bolts.

3. The deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 1 is characterized in that: The steel lattice column is welded by angle steel and steel plate, and a corbel is provided on the side of the steel lattice column, and a channel steel is welded on the corbel; the bored cast-in-place pile is arranged below the base plane, and the lower half of the steel lattice column is welded and anchored in the pile foundation with the bored cast-in-place pile stirrups and the main reinforcement of the bored cast-in-place pile.

4. The deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 1 is characterized in that: The tow-and-replacement steel column comprises a bottom end head plate, a corbel stiffening rib, a stiffening rib and a steel column. The bottom of the tow-and-replacement steel column is fixed to a specified position on the structural upper surface of the structural beam by nuts, pads and anchor bolts. Hydraulic jacks are respectively arranged between the corbel stiffening ribs on both sides of the tow-and-replacement steel column body and the structural upper surface of the structural beam. The gap edge between the bottom end head plate and the structural upper surface is closed by a gap steel wedge. The bottom end head plate and the structural upper surface are anchored by anchor bolts. A reserved grouting hole is opened on the bottom end head plate for injecting non-shrinkage filling slurry between the bottom end head plate and the structural upper surface.

5. The deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 1 is characterized in that: The steel pipe dragging and replacement internal support removal system includes a structural top plate, a crown beam, cast-in-place piles, steel pipe braces and steel pipe diagonal braces. End steel plates are arranged on opposite sides of the structural top plate, the crown beam and the cast-in-place piles. Steel pipe braces are arranged between the end steel plates of the structural top plate and the cast-in-place piles, and between the structural top plate and the crown beam. Ash soil is backfilled between the cast-in-place piles and the foundation bottom plate. The ash soil and the steel pipe braces are used to jointly resist the soil pressure transmitted by the deep mixing piles and the cast-in-place piles. The end steel plate components are fixed on the crown beam and the cast-in-place piles by using embedded reinforcement. The end steel plates are provided with fixing holes for fixed installation, and the steel pipe braces are fully welded to the end steel plates.

6. The deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 1 is characterized in that: A construction safety rope is arranged between two steel lattice columns, cutting sections are divided on the concrete support between the two steel lattice columns, and steel wire ropes and wire rope clamps are used to connect the previous support and the concrete support currently planned to be demolished.

7. The construction method of the deep foundation pit reinforced concrete support-steel pipe support combined system as claimed in claim 1, characterized in that: The construction steps include: S1. After the underground continuous wall is constructed, install the steel pipe support and make the diagonal connection; S2. After the lower half of the steel lattice column is welded and fixed to the bored pile reinforcement cage, it is lowered and cast into one piece. The channel steel connecting beam is welded and installed on the side of the steel lattice column to form a deep foundation pit column support system; S3. Use a hydraulic jack to apply prestress to the top of the drag-replacement steel column, pour non-shrinkage filling slurry into the gap below the drag-replacement steel column, and cut off the lattice column that needs to be removed; S4. Set steel pipe supports between the cast-in-place piles, crown beams and the structural top plate, backfill the soil between the cast-in-place piles and the foundation bottom plate, and then dismantle the reinforced concrete supports on the sides of the crown beams.

8. The construction method of the deep foundation pit reinforced concrete support-steel pipe support combined system according to claim 7, characterized in that: There is also step S5, which is specifically: dismantling the concrete support; before dismantling the concrete support, first arrange construction safety ropes on the two steel lattice columns for workers to fasten their safety belts during construction, then draw a cutting line at the designated position of the concrete support to be dismantled, and manually chisel out the corner steel bars on the cut section, and then use the upper support above the concrete support to be dismantled to pass the steel wire rope through the exposed corner steel bars, and use the steel wire rope clamp to clamp and fix them, then cut the concrete support from the center to both sides, and release the steel wire rope on the corresponding cutting section, and finally remove the cut concrete support from the site.

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