Construction method of zero-foundation-trench underground engineering integrated construction

Abstract

The present application relates to the field of house building and municipal engineering construction, and more specifically, to a construction method for zero-furrow underground engineering integrated construction. The method comprises the following steps: S1, SMW method support construction: forming a foundation pit support structure by using SMW method pile construction, converting temporary support pile into an outer bearing carrier of the side wall of the permanent underground structure and a forming reference surface, the size of the foundation pit is consistent with the size of the structure outer contour, realizing zero-furrow intensive layout; S2, foundation pit earthwork excavation operation: after the support pile construction is completed, the foundation pit earthwork excavation is carried out, the inner surface of the support pile and the bottom surface of the foundation pit are exposed, and the operation space is provided for subsequent base surface treatment and waterproof construction. The construction method is a zero-furrow underground engineering integrated construction method which can realize the function conversion of the support structure, the integrated reconstruction of the base surface, and the collaborative integration of the support system. The present application is mainly applied to the field of zero-furrow underground engineering integrated construction.

Description

Technical Field

[0001] This invention relates to the field of building construction and municipal engineering construction, and more specifically, to a construction method for integrated construction of zero-furnishing underground engineering. Background Technology

[0002] With the continuous expansion of urban underground space development and utilization, the integrated construction of foundation pit engineering and underground main structures has become an important technological direction for industry development. Zero-excavation and backfilling technology can significantly reduce the amount of earthwork excavation and backfilling, and achieve the recycling of support components, aligning with the concept of green and low-carbon construction, and has received widespread attention and application exploration in the field of underground engineering. SMW (Soil Mooring and Water Stopping) method piles have both retaining and water-stopping functions, possessing significant technical and economic advantages in various deep foundation pit projects.

[0003] Traditional underground engineering construction requires reserving space for trenching operations between the support structure and the main structure, which leads to a series of engineering challenges. The large amount of earthwork excavation and backfilling in the trenching area significantly prolongs the construction period and increases the overall project cost; the compaction quality of the backfill soil in the trenching area is difficult to control evenly, which can easily lead to the risk of later ground settlement and structural lateral displacement; the waterproofing of the basement exterior walls is limited by the working conditions in the confined space, making it difficult to guarantee the construction quality and highlighting the risk of leakage.

[0004] Existing zero-fever trench technologies mostly focus on optimizing the stress of the support structure itself, with insufficient research on the integrated functional transformation of the inner base surface of the support. Most solutions do not coordinate the design of the waterproof reference surface and the single-sided formwork forming surface, resulting in low construction efficiency and difficulty in unifying the accuracy of the base surface due to the separation of processes; the supporting formwork system lacks synergy, the overall casting stability is poor, and it is difficult to meet the multiple requirements of structural stress, waterproof durability and construction efficiency. Summary of the Invention

[0005] To overcome the shortcomings of the existing technologies, this invention provides a construction method for integrated construction of zero-trench underground engineering. This method enables the functional transformation of the support structure, integrated reconstruction of the base surface, and collaborative integration of the formwork system, achieving integrated construction of zero-trench underground engineering. Through a systematic base surface treatment process, it simultaneously meets the stringent requirements of waterproofing layer application and concrete forming. It integrates a highly efficient and stable single-sided formwork and top slab support system, optimizes the waterproofing construction of key structural joints, and effectively improves the reliability of structural waterproofing and the quality of the finished product while reducing the amount of work, lowering costs, and shortening the construction period. This provides reliable support for the large-scale engineering application of zero-trench technology.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A construction method for integrated construction of zero-fertilizer underground engineering includes the following steps: S1, SMW method support construction: The SMW method pile construction is used to form the foundation pit support structure, and the temporary support piles are transformed into the outer load-bearing carrier and forming reference surface of the permanent underground structure sidewall. The foundation pit size is consistent with the outer contour size of the structure, realizing the zero-trap compact layout. S2. Excavation of foundation pit: After the construction of the support piles is completed, the foundation pit is excavated to expose the inner surface of the support piles and the working surface of the bottom of the foundation pit, providing working space for subsequent foundation surface treatment and waterproofing construction. S3. Support base surface reconstruction treatment: The inner surface of the support pile is successively cleaned, sprayed with concrete for leveling, and polystyrene board is laid to reconstruct a reference surface that meets the requirements of waterproof layer laying and single-sided formwork forming. S4. Waterproofing system node construction: Follow the principle of laying the large-area waterproofing layer from bottom to top and from details to large surfaces, and simultaneously complete the key node waterproofing treatment of external and embedded waterstops at structural joints. S5. Single-sided formwork and integral casting: Erect a single-sided formwork system with steel pipe top support for the side wall and a full-span support system for the top slab, and complete the underground structure concrete construction using the integral casting process of the side wall and the top slab.

[0007] The SMW method pile construction of S1 specifically includes: S11. After the mixer is aligned and leveled along the guide frame, it cuts, mixes, and sinks the soil. No water is flushed during the pre-mixing and sinking process. S12. After the mixer sinks to the design depth, the grout pump is turned on and cement grout is continuously injected at an outlet pressure of 0.4 to 0.6 MPa. The mixer rotates and is lifted to the design pile top elevation while injecting grout. S13. 30 minutes after the completion of the mixing pile construction, the H-beam is inserted and fixed by its own weight.

[0008] The S3 base surface reconstruction first involves cleaning the base layer: using a high-pressure water gun to wash away the soil and debris on the surface of the support structure and the bottom of the foundation pit, and using an angle grinder to grind the laitance and protruding parts on the surface of the support piles to ensure that the base surface is flat, clean, and free of sharp protrusions.

[0009] After the base layer is cleaned, a leveling layer is constructed: sprayed concrete is used to level the support surface, and cement mortar is used to fill the internal and external corners where the support structure meets the bottom of the foundation pit to form rounded corners with a radius of ≥50mm.

[0010] After the leveling layer is completed, polystyrene boards are laid out: starting from the bottom of the side wall, the polystyrene boards are arranged with staggered joints in the horizontal direction and the staggered joint width is ≥1 / 3 of the board length. The distance between the board joint at the inside corner and the outside corner is ≥200mm. The adhesive mortar is applied and pasted using the dot-frame method. The pasting order is to first paste the inside and outside corners, and then paste towards the middle of the main surface. A laser line projector is used to control the verticality and horizontality.

[0011] The construction of the S4 waterproof layer follows the principle of laying from the bottom of the foundation pit upwards, starting with details and then moving to the larger areas, and mainly laying horizontally. When laying, remove the release film of the roll material, press it evenly onto the surface of the polystyrene board, and use a rubber scraper to press and expel air from the middle to both sides to ensure that there are no hollows or wrinkles.

[0012] Before the waterproofing construction of the key nodes of S4, the positioning should be marked by marking lines: mark the center line of the waterstop that is aligned with the center line of the joint on the concrete base layer on both sides of the joint, as well as the overlap line 150mm away from the center line, to ensure that the waterstop overlaps by 150mm on both sides; use a laser line projector for calibration, and the verticality deviation of the line should be ≤2mm / m.

[0013] The waterproofing of the nodes includes the construction of external and embedded waterstops: for external waterstops, start from the bottom of the side wall joint, align the center line of the waterstop with the center line of the joint and slowly lay it upwards, scraping and pressing out air from the center line to both sides; for embedded waterstops, first embed the embedded part into the structural joint and ensure that it is centered, and then pour concrete.

[0014] The single-sided formwork system of S5 adopts a support form of steel pipe plus top support, with a horizontal steel pipe spacing of 50cm between tops; the formwork panel is made of 15mm thick bamboo plywood, the main ribs of the formwork are made of double 48mm steel pipes, and the secondary ribs are made of 48mm steel pipes with a spacing of 10cm; the horizontal support and the main ribs are tightened together by the top support, the horizontal support is set along the entire length, and is fixed to the top plate disc buckle support frame with fasteners every 1.2 meters.

[0015] The roof support system adopts a full-span disc buckle scaffolding form, and the side wall concrete and roof slab concrete are constructed simultaneously using an integral pouring process.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: This construction method achieves comprehensive performance improvement and benefit gains from multiple dimensions, including structural stress system, construction hierarchy, and construction methods, through the systematic construction of the support structure's functional transformation and integrated construction system.

[0017] From the perspective of the synergistic relationship between the foundation pit support and the main structure, the temporary SMW method support piles are transformed into the outer load-bearing carrier and forming reference surface of the permanent underground sidewall. This eliminates the trench space required for traditional construction, ensuring that the outline of the foundation pit excavation is consistent with the outer outline of the main structure. This significantly reduces the amount of earthwork excavation and backfilling, lowers the construction cost, and significantly improves the efficiency of intensive use of underground space, thus meeting the application needs of high-density development of underground space in urban core areas.

[0018] From the perspective of structural base surface and waterproof construction, through the multi-process integrated base surface reconstruction technology, an integrated structural layer with dual functions of waterproof base surface and formwork reference is formed on the inner side of the support structure. This not only ensures the flatness and fit of the base for waterproof layer laying and eliminates the quality blind spot in narrow space operations, but also provides a precise forming reference for single-sided formwork, improves the integrity and airtightness of the waterproof system, effectively reduces the risk of leakage in underground structures, and enhances the long-term durability of the structure.

[0019] From the perspective of formwork support and structural forming system, the single-sided formwork system and the top slab support system are connected by fasteners to form a stable load-bearing whole. Combined with the integral casting process of the side walls and the top slab, it enhances the continuity and integrity of the underground structure under stress, avoids the weak links of construction joints formed by staged casting, and improves the lateral stiffness of the formwork system. It ensures the forming accuracy of the wall and the stability of the structural dimensions, and has the dual advantages of construction efficiency and structural quality, and has good engineering promotion value. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the process of the present invention; Detailed Implementation

[0021] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0022] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0023] like Figure 1 As shown, a construction method for integrated construction of zero-fertilizer underground engineering includes the following steps: S1, SMW method support construction: The SMW method pile construction is used to form the foundation pit support structure, and the temporary support piles are transformed into the outer load-bearing carrier and forming reference surface of the permanent underground structure sidewall. The foundation pit size is consistent with the outer contour size of the structure, realizing the zero-trap compact layout. S2. Excavation of foundation pit: After the construction of the support piles is completed, the foundation pit is excavated to expose the inner surface of the support piles and the working surface of the bottom of the foundation pit, providing working space for subsequent foundation surface treatment and waterproofing construction. S3. Support base surface reconstruction treatment: The inner surface of the support pile is successively cleaned, sprayed with concrete for leveling, and polystyrene board is laid to reconstruct a reference surface that meets the requirements of waterproof layer laying and single-sided formwork forming. S4. Waterproofing system node construction: Follow the principle of laying the large-area waterproofing layer from bottom to top and from details to large surfaces, and simultaneously complete the key node waterproofing treatment of external and embedded waterstops at structural joints. S5. Single-sided formwork and integral casting: Erect a single-sided formwork system with steel pipe top support for the side wall and a full-span support system for the top slab, and complete the underground structure concrete construction using the integral casting process of the side wall and the top slab.

[0024] Preferably, the SMW method pile construction of S1 specifically includes: S11. After the mixer is aligned and leveled along the guide frame, it cuts, mixes, and sinks the soil. No water is flushed during the pre-mixing and sinking process. S12. After the mixer sinks to the design depth, the grout pump is turned on and cement grout is continuously injected at an outlet pressure of 0.4 to 0.6 MPa. The mixer rotates and is lifted to the design pile top elevation while injecting grout. S13. 30 minutes after the completion of the mixing pile construction, the H-beam is inserted and fixed by its own weight.

[0025] Preferably, the base surface reconstruction of S3 first involves cleaning the base layer: using a high-pressure water gun to wash away the soil and debris on the surface of the support structure and the bottom of the foundation pit, and using an angle grinder to grind the laitance and protruding parts on the surface of the support piles to ensure that the base surface is flat, clean, and free of sharp protrusions.

[0026] Preferably, after the base layer is cleaned, a leveling layer is constructed: sprayed concrete is used to level the support surface, and cement mortar is used to fill the internal and external corners where the support structure meets the bottom of the foundation pit to form rounded corners with a radius of ≥50mm.

[0027] Preferably, after the leveling layer is completed, polystyrene boards are laid: starting from the bottom of the side wall, the polystyrene boards are laid out with staggered joints in the horizontal direction and the staggered joint width is ≥1 / 3 of the board length. The distance between the board joint at the inside corner and the outside corner is ≥200mm. The bonding mortar is applied and pasted using the dot-frame method. The pasting order is to first paste the inside and outside corners and then paste towards the middle of the main surface. A laser line projector is used to control the verticality and horizontality.

[0028] Preferably, the construction of the S4 waterproof layer follows the principle of laying from the bottom of the foundation pit upwards, starting with details and then moving to the larger areas, and mainly laying horizontally. When laying, remove the release film of the roll material, press it evenly onto the surface of the polystyrene board, and use a rubber scraper to press and expel air from the middle to both sides to ensure that there are no hollows or wrinkles.

[0029] Preferably, before the waterproofing construction of the key nodes of S4, the positioning should be marked with a line: mark the center line of the waterstop that is aligned with the center line of the joint on the concrete base layer on both sides of the joint, as well as the overlap line 150mm away from the center line, to ensure that the waterstop overlaps by 150mm on both sides; use a laser line projector for calibration, and the verticality deviation of the line is ≤2mm / m.

[0030] Preferably, the joint waterproofing includes the construction of externally applied waterstops and embedded waterstops: for externally applied waterstops, start from the bottom of the side wall joint, align the center line of the waterstop with the center line of the joint and slowly lay it upwards, scraping and pressing out air from the center line to both sides; for embedded waterstops, first embed the embedded part into the structural joint and ensure that it is centered, and then pour concrete.

[0031] Preferably, the single-sided formwork system of S5 adopts a support form of steel pipe plus top support, with a horizontal steel pipe spacing of 50cm between tops; the formwork panel is made of 15mm thick bamboo plywood, the main ribs of the formwork are made of double-splitting 48mm steel pipes, and the secondary ribs are made of 48mm steel pipes with a spacing of 10cm; the horizontal support is tightened with the main ribs by the top support, the horizontal support is set along the entire length, and is fixed to the top plate disc buckle support frame with fasteners every 1.2 meters.

[0032] Preferably, the roof support system adopts a full-span disc-lock scaffolding system, and the side wall concrete and roof concrete are constructed simultaneously using an integral pouring process.

[0033] The above description only illustrates the preferred embodiments of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention, and all such changes should be included within the protection scope of the present invention.

Claims

1. A construction method for integrated construction of zero-fertilizer trench underground engineering, characterized in that: Includes the following steps: S1, SMW method support construction: The SMW method pile construction is used to form the foundation pit support structure, and the temporary support piles are transformed into the outer load-bearing carrier and forming reference surface of the permanent underground structure sidewall. The foundation pit size is consistent with the outer contour size of the structure, realizing the zero-trap compact layout. S2. Excavation of foundation pit: After the construction of the support piles is completed, the foundation pit is excavated to expose the inner surface of the support piles and the working surface of the bottom of the foundation pit, providing working space for subsequent foundation surface treatment and waterproofing construction. S3. Support base surface reconstruction treatment: The inner surface of the support pile is successively cleaned, sprayed with concrete for leveling, and polystyrene board is laid to reconstruct a reference surface that meets the requirements of waterproof layer laying and single-sided formwork forming. S4. Waterproofing system node construction: Follow the principle of laying the large-area waterproofing layer from bottom to top and from details to large surfaces, and simultaneously complete the key node waterproofing treatment of external and embedded waterstops at structural joints. S5. Single-sided formwork and integral casting: Erect a single-sided formwork system with steel pipe top support for the side wall and a full-span support system for the top slab, and complete the underground structure concrete construction using the integral casting process of the side wall and the top slab.

2. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: The SMW method pile construction of S1 specifically includes: S11. After the mixer is aligned and leveled along the guide frame, it cuts, mixes, and sinks the soil. No water is flushed during the pre-mixing and sinking process. S12. After the mixer sinks to the design depth, the grout pump is turned on and cement grout is continuously injected at an outlet pressure of 0.4 to 0.6 MPa. The mixer rotates and is lifted to the design pile top elevation while injecting grout. S13. 30 minutes after the completion of the mixing pile construction, the H-beam is inserted and fixed by its own weight.

3. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: The S3 base surface reconstruction first involves cleaning the base layer: using a high-pressure water gun to wash away the soil and debris on the surface of the support structure and the bottom of the foundation pit, and using an angle grinder to grind the laitance and protruding parts on the surface of the support piles to ensure that the base surface is flat, clean, and free of sharp protrusions.

4. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 3, characterized in that: After the base layer is cleaned, a leveling layer is constructed: sprayed concrete is used to level the support surface, and cement mortar is used to fill the internal and external corners where the support structure meets the bottom of the foundation pit to form rounded corners with a radius of ≥50mm.

5. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 4, characterized in that: After the leveling layer is completed, polystyrene boards are laid out: starting from the bottom of the side wall, the polystyrene boards are arranged with staggered joints in the horizontal direction and the staggered joint width is ≥1 / 3 of the board length. The distance between the board joint at the inside corner and the outside corner is ≥200mm. The adhesive mortar is applied and pasted using the dot-frame method. The pasting order is to first paste the inside and outside corners, and then paste towards the middle of the main surface. A laser line projector is used to control the verticality and horizontality.

6. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: The construction of the S4 waterproof layer follows the principle of laying from the bottom of the foundation pit upwards, starting with details and then moving to the larger areas, and mainly laying horizontally. When laying, remove the release film of the roll material, press it evenly onto the surface of the polystyrene board, and use a rubber scraper to press and expel air from the middle to both sides to ensure that there are no hollows or wrinkles.

7. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: Before the waterproofing construction of the key nodes of S4, the positioning should be marked by marking lines: mark the center line of the waterstop that is aligned with the center line of the joint on the concrete base layer on both sides of the joint, as well as the overlap line 150mm away from the center line, to ensure that the waterstop overlaps by 150mm on both sides; use a laser line projector for calibration, and the verticality deviation of the line should be ≤2mm / m.

8. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 7, characterized in that: The waterproofing of the nodes includes the construction of external and embedded waterstops: for external waterstops, start from the bottom of the side wall joint, align the center line of the waterstop with the center line of the joint and slowly lay it upwards, scraping and pressing out air from the center line to both sides; for embedded waterstops, first embed the embedded part into the structural joint and ensure that it is centered, and then pour concrete.

9. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: The single-sided formwork system of S5 adopts a support form of steel pipe plus top support, with a horizontal steel pipe spacing of 50cm between tops; the formwork panel is made of 15mm thick bamboo plywood, the main ribs of the formwork are made of double 48mm steel pipes, and the secondary ribs are made of 48mm steel pipes with a spacing of 10cm; the horizontal support and the main ribs are tightened together by the top support, the horizontal support is set along the entire length, and is fixed to the top plate disc buckle support frame with fasteners every 1.2 meters.

10. The construction method for integrated construction of zero-fertilizer trench underground engineering according to claim 1, characterized in that: The roof support system adopts a full-span disc buckle scaffolding form, and the side wall concrete and roof slab concrete are constructed simultaneously using an integral pouring process.

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