Novel supporting system construction method for partition wall dismantling after foundation pit separate excavation

Abstract

The invention provides a novel supporting system construction method for partition wall dismantling after foundation pit separate excavation, and relates to the field of foundation pit excavation. The novel supporting system construction method for partition wall dismantling after separate excavation of the foundation pit comprises the steps of arranging reaction piers with reasonable intervals and heights, reserving rust-proof reaction pier steel bars on a first-stage structure, excavating earthwork step by step, breaking and removing isolation piles in a standard mode, and pouring a top beam support and a waist beam support according to a specific sequence. The problems that a traditional supporting system is poor in stability and prone to causing surrounding soil deformation are solved, tedious construction procedures are simplified, the construction period is shortened, meanwhile, the leakage risk of the post-cast strip is reduced by transporting concrete blocks and earthwork outwards in time, the construction safety and reliability are effectively improved, the engineering cost is reduced, and the construction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of foundation pit excavation, and in particular to a novel support system construction method for removing partition walls after separate excavation of foundation pits. Background Art

[0002] With the continuous advancement of urban construction, various types of construction projects are increasing. In construction, foundation pit engineering is an important basic work. When faced with large-scale or complex terrain foundation pits, separate excavation is often used to reduce construction difficulty and risk. After the foundation pit is excavated separately, the removal of partition walls is a key link in subsequent construction.

[0003] However, there are some problems with the existing support system construction method for the removal of partition walls after the foundation pit is excavated separately. For example, the stability of the support system in the traditional method is insufficient, which can easily cause the soil around the foundation pit to deform during the removal of the partition wall, threatening the safety of nearby buildings and underground pipelines. In addition, the construction process is cumbersome and the construction period is long, which leads to increased project costs. In addition, improper treatment of construction waste generated after the removal of the partition wall can easily cause environmental pollution, and during the subsequent construction of the post-casting strip, the unreasonable construction of the support system in the early stage may increase the risk of leakage. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a new support system construction method for dismantling partition walls after separate excavation of the foundation pit, which solves the problems of insufficient stability of the traditional support system, complicated construction procedures, long construction period, improper treatment of construction waste and high risk of leakage in the post-cast zone.

[0005] To achieve the above objectives, the present invention is implemented through the following technical solutions: A new support system construction method for removing partition walls after separate excavation of foundation pits, comprising the following steps:

[0006] S1. Pre-construction preparation

[0007] S1.1. Set isolation piles at the periphery of the first phase, and set reaction piers within the range of the isolation piles. The reaction piers are located on the first phase top plate, multiple first phase middle plates and the first phase bottom plate;

[0008] S1.2. Reaction pier reinforcements shall be reserved on the reaction piers of the first-stage top slab and multiple first-stage middle slabs, and the reaction pier reinforcements reserved on the first-stage bottom slab shall be determined according to the design conditions;

[0009] S2. Phase II support system construction in stages

[0010] S2.1. After the strength of the first-stage top plate, multiple first-stage middle plates and the first-stage bottom plate reaches the standard, excavate the second-stage earthwork to 10-15cm below the first-stage top plate, remove the exposed isolation piles, and cast the crown beam support on the basis of the reaction pier steel bars on the first-stage top plate;

[0011] S2.2, after the crown beam support strength meets the design requirements, excavate the earth step by step downwards, expose some broken isolation piles, and cast the first, second and third waist beam supports;

[0012] S3. Construction of the second phase main structure and removal of supports

[0013] The second phase foundation pit is excavated to the base. After the crown beam support and multiple second phase top plates are qualified, the construction of the second phase top plate and multiple second phase middle plates is carried out. After the strength of the second phase top plate and multiple second phase middle plates reaches the standard, the crown beam support, multiple waist beam supports and reaction piers are removed.

[0014] Preferably, the specific range of setting the reaction pier within the isolation pile range in S1.1 is:

[0015] The reaction pier spacing is 6-8m, and the reaction pier height is 2.5-3m.

[0016] Preferably, when reserving the reaction pier steel bars in step S1.2, the reserved reaction pier steel bars are subjected to rust-proof treatment.

[0017] Preferably, the construction steps of the crown beam support in S2.1 include:

[0018] Excavate the second phase surface soil to 10cm below the bottom elevation of the first waist beam support, break the isolation piles to 1m below the bottom elevation of the crown beam support, backfill the first phase top plate and isolation piles to 10cm below the bottom elevation of the crown beam support, pour a 10cm cushion layer and then tie the steel bars, first tie the reaction pier steel bars, then tie the crown beam support steel bars, and finally cast the whole into shape.

[0019] Preferably, the construction steps of the waist beam support in S2.1 include:

[0020] Excavate the second layer of earth to 10cm below the bottom elevation of the first waist beam support, break the isolation piles to 1m below the bottom elevation of the first waist beam support, backfill the earth in the isolation pile area to 10cm below the bottom elevation of the waist beam support, pour a 10cm cushion layer and then tie the steel bars, first tie the reaction pier steel bars, then tie the first waist beam support steel bars, and finally cast the whole into shape.

[0021] Preferably, the construction steps of gradually excavating earthwork downwards in step S2.2 include:

[0022] During earth excavation, the bottom elevation of the earth and stone shall not be lower than the elevation of the isolation piles by 1.5m. The earth should be excavated to 10cm below the bottom height of each waist beam support to ensure the safety of the blasting of the isolation piles and the manual cutting of steel bars.

[0023] Preferably, during the removal of the isolation piles in the exposed portion, the concrete blocks are transported out together with the earthwork to reduce the risk of leakage during the construction of the post-cast zone.

[0024] The present invention provides the following beneficial effects: the present invention arranges reaction piers with reasonable spacing and height, reserves rust-proof reaction pier steel bars on the first-phase structure, adopts methods such as step-by-step excavation of earthwork, standardized removal of isolation piles, and casting crown beam supports and waist beam supports in a specific order, thereby avoiding the problems of poor stability of traditional support systems and easy deformation of surrounding soil, simplifying cumbersome construction procedures, shortening the construction period, and reducing the risk of leakage of post-casting strips by timely transporting concrete blocks and earthwork, effectively improving construction safety and reliability, reducing engineering costs, and improving construction efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A top view construction drawing of a new type of support system construction method for removing partition walls after separate excavation of foundation pits proposed by the present invention;

[0026] Figure 2 This is a side view construction drawing of a new type of support system construction method for removing partition walls after separate excavation of foundation pits proposed by the present invention.

[0027] Among them, 1. Isolation piles; 2. Phase I top plate; 3. Phase I middle plate; 4. Phase I bottom plate; 5. Reaction pier; 6. Reaction pier reinforcement; 7. Crown beam support; 8. Waist beam support; 9. Phase II top plate; 10. Phase II middle plate. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1:

[0030] like Figure 1-2 As shown, an embodiment of the present invention provides a new support system construction method for removing partition walls after separate excavation of foundation pits, comprising the following steps:

[0031] S1. Pre-construction preparation

[0032] S1.1. Isolation piles 1 are set at the periphery of the first phase, and reaction piers 5 are set within the range of the isolation piles 1. The reaction piers 5 are located on the first phase top plate 2, multiple first phase middle plates 3 and the first phase bottom plate 4. By setting the isolation piles 1, the first phase and second phase construction areas are clearly divided to prevent construction interference; the reaction piers 5 are set on the first phase top plate 2, multiple first phase middle plates 3 and the first phase bottom plate 4 to provide a stable reaction foundation for the subsequent support system and enhance the connection stability between the support system and the existing structure;

[0033] S1.2. Reserve reaction pier steel bars 6 on the reaction piers 5 of the first-stage top plate 2 and multiple first-stage middle plates 3. Reserve reaction pier steel bars 6 on the first-stage bottom plate 4 according to the design situation. Reserve reaction pier steel bars 6 to facilitate subsequent connection with the crown beam support 7 and the waist beam support 8 to form a complete support system. The flexibility of the reaction pier steel bars 6 reserved on the first-stage bottom plate 4 can meet different design requirements and ensure the rationality of the support system design.

[0034] S2. Phase II support system construction in stages

[0035] S2.1. After the strength of the first-phase top plate 2, multiple first-phase middle plates 3 and the first-phase bottom plate 4 reaches the standard, excavate the second-phase earthwork to 10 cm below the first-phase top plate 2, break the exposed part of the isolation pile 1, and cast the crown beam support 7 on the basis of the reaction pier steel bars 6 on the first-phase top plate 2. Carry out the second-phase earthwork excavation on the basis of the first-phase structural strength reaching the standard to ensure the construction safety; excavate to 10 cm below the first-phase top plate and break the exposed part of the isolation pile 1 to create conditions for the construction of the crown beam support 7, and cast the crown beam support 7 based on the reaction pier steel bars 6 to enhance the integrity and stability of the support system;

[0036] S2.2, after the strength of the crown beam support 7 meets the design requirements, the earthwork is excavated downward step by step, and the exposed isolation piles 1 are broken, and the first, second and third waist beam supports 8 are cast. After the strength of the crown beam support 7 meets the standard, subsequent excavation and waist beam support 8 casting are carried out to ensure the safety of each step of construction and the stability of the support system. The step-by-step downward construction conforms to the principles of mechanics, can effectively control the deformation of the soil around the foundation pit, and ensure construction safety;

[0037] S3. Construction of the second phase main structure and removal of supports

[0038] After the second phase foundation pit is excavated to the base and the groove is inspected and qualified, the second phase top plate 9 and multiple second phase middle plates 10 are constructed. After the strength of the second phase top plate 9 and multiple second phase middle plates 10 reaches the standard, the crown beam support 7, multiple waist beam supports 8 and reaction pier 5 are removed. After the second phase foundation pit is excavated to the base and the groove is inspected and qualified, the main structure is constructed to ensure the stability of the foundation; after the strength of the second phase top plate 9 and multiple second phase middle plates 10 reaches the standard, the support is removed to ensure that the main structure can withstand its own and subsequent loads. The removal time is reasonable to avoid adverse effects on structural safety and construction progress.

[0039] In S1.1, the specific range of setting the reaction pier 5 within the range of the isolation pile 1 is:

[0040] The spacing between the reaction piers 5 is 6-8m, and the height of the reaction piers 5 is 2.5-3m. Reasonable spacing and height of the reaction piers 5 can evenly distribute the reaction force of the reaction piers 5, ensure the balanced force of the support system, improve the stability and reliability of the support system, and adapt to different geological conditions and foundation pit scales.

[0041] When reserving the reaction pier steel bars 6 in step S1.2, the reserved reaction pier steel bars 6 are subjected to anti-rust treatment, and anti-rust measures are taken for the reaction pier steel bars 6 to prevent the steel bars from rusting and corroding, thereby ensuring the strength and connection performance of the steel bars, ensuring the long-term stability and safety of the support system, and extending the service life of the support system.

[0042] The construction steps of the crown beam support 7 in S2.1 include:

[0043] Excavate the second phase surface soil to 10cm below the bottom elevation of the first waist beam support 8, break the isolation pile 1 to 1m below the bottom elevation of the crown beam support 7, backfill the first phase top plate 2 and isolation pile 1 to 10cm below the bottom elevation of the crown beam support 7, pour a 10cm cushion layer and then tie the steel bars, first tie the reaction pier steel bars 6, then tie the crown beam support 7 steel bars, and finally cast the whole into shape. Detailed construction steps ensure accurate and stable construction of the crown beam support 7. First excavate and break the isolation pile 1, then backfill and pour the cushion layer, which provides a good foundation for steel bar tying and overall casting. Tie the steel bars in a specific order to ensure that the crown beam support 7 and the reaction pier 5 work effectively together to enhance the connection strength of the support system.

[0044] The construction steps of the waist beam support 8 in S2.1 include:

[0045] Excavate the second layer of earth to 10 cm below the bottom elevation of the first waist beam support 8, break the isolation pile 1 to 1 m below the bottom elevation of the first waist beam support 8, backfill the earth in the isolation pile 1 area to 10 cm below the bottom elevation of the waist beam support 8, pour a 10 cm cushion layer and then tie the steel bars, first tie the reaction pier steel bars 6, then tie the first waist beam support 8 steel bars, and finally cast the whole into shape. The construction steps of waist beam support 8 are similar to those of crown beam support 7 to ensure the construction specifications and stability of the support system. From earth excavation, breaking of isolation pile 1 to backfilling, cushion pouring, steel bar tying and overall pouring, each step is closely coordinated to ensure that the waist beam support 8 and the reaction pier 5 and the surrounding soil interact effectively, and improve the support effect of the support system on the foundation pit.

[0046] The construction steps of gradually excavating the earthwork downward in step S2.2 include:

[0047] During earth excavation, the bottom elevation of the earth and stone shall not be lower than the elevation of isolation pile 1 by 1.5m. The earth shall be excavated to a height of 10cm above the bottom of each waist beam support 8 to ensure the safety of the blasting of the isolation piles and manual cutting of steel bars. The earth excavation elevation requirements shall be clarified to ensure the safety of the isolation pile 1 breaking and steel bar cutting operations, avoid affecting the stability of the isolation pile 1 due to excessive earth excavation, prevent safety accidents, and ensure a safe and orderly construction process.

[0048] During the removal of the exposed isolation piles 1, the concrete blocks are transported out together with the earth to reduce the risk of leakage during the construction of the post-cast strip. The concrete blocks after the exposed isolation piles 1 are removed are transported out together with the earth to clean up the construction site in time to avoid the accumulation of construction waste. The risk of leakage caused by factors such as garbage residue during the construction of the post-cast strip is reduced, the construction quality of the post-cast strip is improved, and the waterproof performance of the building structure is guaranteed.

[0049] In the construction process of the partition wall removal after the foundation pit is separated, the construction method of the support system is crucial. There are differences in many aspects between traditional support construction and the construction of additional reaction piers. The following is a detailed comparison of the two construction methods.

[0050] Table 1 is a comparison between traditional support construction and additional reaction pier construction

[0051]

[0052]

[0053] Table 1

[0054] It can be clearly seen from Table 1 that the construction of adding reaction piers shows obvious advantages in terms of labor, efficiency, operational convenience and cost control. Compared with traditional support construction, it is more reasonable and efficient, and can better meet the construction needs of partition wall demolition after separate excavation of foundation pit.

[0055] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A new support system construction method for removing partition walls after separate excavation of foundation pits, characterized in that: The following steps are involved: S1. Pre-construction preparation S1.

1. Isolation piles (1) are arranged at the periphery of the first phase, reaction piers (5) are arranged within the range of the isolation piles (1), and the reaction piers (5) are located on the first phase top plate (2), a plurality of first phase middle plates (3) and the first phase bottom plate (4); S1.

2. Reaction pier steel bars (6) are reserved on the reaction piers (5) of the first-stage top plate (2) and multiple first-stage middle plates (3), and the reaction pier steel bars (6) are reserved on the first-stage bottom plate (4) according to the design conditions; S2. Phase II support system construction in stages S2.

1. After the strength of the first-stage top plate (2), multiple first-stage middle plates (3) and the first-stage bottom plate (4) reaches the standard, excavate the second-stage earthwork to 10 to 15 cm below the first-stage top plate (2), remove the exposed isolation piles (1), and cast the crown beam support (7) on the basis of the reaction pier steel bars (6) on the first-stage top plate (2); S2.

2. After the strength of the crown beam support (7) meets the design requirements, the earthwork is excavated downward step by step, and part of the broken isolation piles (1) are exposed, and the first, second and third waist beam supports (8) are cast; S3. Construction of the second phase main structure and removal of supports The second phase foundation pit is excavated to the base, and after the crown beam support (7) and a plurality of second phase top plates (9) are inspected and qualified, the second phase top plate (9) and a plurality of second phase middle plates (10) are constructed. After the strength of the second phase top plate (9) and a plurality of second phase middle plates (10) meet the standard, the crown beam support (7), a plurality of waist beam supports (8) and the reaction pier (5) are removed.

2. A new type of support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1, characterized in that: The specific range of setting the reaction pier (5) within the range of the isolation pile (1) in S1.1 is: The spacing between the reaction piers (5) is 6-8m, and the height of the reaction piers (5) is 2.5-3m.

3. The new support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1 is characterized by: When the reaction pier steel bars (6) are reserved in step S1.2, the reserved reaction pier steel bars (6) are subjected to rust prevention treatment.

4. The novel support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1 is characterized in that: The construction steps of the crown beam support (7) in S2.1 include: Excavate the second-stage surface soil to 10 cm below the bottom elevation of the first waist beam support (8), break the isolation pile (1) to 1 m below the bottom elevation of the crown beam support (7), backfill the first-stage top plate (2) and isolation pile (1) to 10 cm below the bottom elevation of the crown beam support (7), pour a 10 cm cushion layer and tie the steel bars, first tie the reaction pier steel bars (6), then tie the crown beam support (7) steel bars, and finally cast the entire structure into shape.

5. The new support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1 is characterized in that: The construction steps of the waist beam support (8) in S2.1 include: Excavate the second layer of earthwork to 10 cm below the bottom elevation of the first waist beam support (8), break the isolation pile (1) to 1 m below the bottom elevation of the first waist beam support (8), backfill the earthwork in the isolation pile (1) area to 10 cm below the bottom elevation of the waist beam support (8), pour a 10 cm cushion layer and then tie the steel bars, first tie the reaction pier steel bars (6), then tie the first waist beam support (8) steel bars, and finally cast the entire structure into shape.

6. The new support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1 is characterized in that: The construction steps of gradually excavating the earthwork downward in step S2.2 include: During earth excavation, the bottom elevation of the earthwork shall not be lower than 1.5m of the isolation pile (1) elevation. The earthwork shall be excavated to 10cm below the bottom elevation of each waist beam support (8) to ensure the safety of the isolation pile blasting machine and manual cutting of steel bars.

7. The new support system construction method for removing partition walls after separate excavation of foundation pit according to claim 1 is characterized in that: During the removal of the isolation piles (1) at the exposed part, the concrete blocks are transported out together with the earthwork, thereby reducing the risk of leakage during the construction of the post-casting zone.

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