A construction method of a "portico" structure across a common ground wall

Abstract

A construction method for an "arcade-style" structure spanning a shared diaphragm wall is disclosed. The method includes: construction of the diaphragm wall retaining structure for a subway station; removal of the second layer of internal support in the deep foundation pit; opening in the shared diaphragm wall to penetrate the inclined columns of the basement beams; construction of the basement beams and slabs; removal of the first layer of concrete internal support in the subway station; removal of the first layer of concrete internal support in the project; removal of the shared diaphragm wall above the basement beams and slabs; construction of the basement roof slab; removal of the shared diaphragm wall between the basement beams and slabs and the second basement beams and slabs; and construction of temporary openings in the floor slabs. This construction method saves land resources, shortens the construction period, improves construction efficiency, and reduces costs for the construction party.

Description

Technical Field

[0001] This invention relates to the field of "arcade-style" structure construction technology, and in particular to a construction method for an "arcade-style" structure that spans a shared ground wall. Background Technology

[0002] The transportation hub project (three underground levels) and the already capped subway main structure require that the diaphragm walls shared by the three underground levels not be demolished, but the diaphragm walls shared by the first and second underground levels must be demolished during construction. This is because the first and second underground levels both extend to the reserved positions of the subway main structure (which is a stepped structure). Therefore, the first and second underground levels are commonly known as "arcade-style" structures, which are connected to the subway main structure and become a connecting structure.

[0003] Since the diaphragm walls of the three underground levels are not demolished, the construction of the three underground levels of the transportation hub project follows the conventional sequential construction method.

[0004] The "arcade-style" structure appears in the first and second basement levels. If the "arcade-style" structure is constructed in two parts, the first and second basement levels within the project scope are constructed first, then the shared diaphragm walls are demolished, and then the first and second basement levels spanning the subway station are constructed. With this construction method, the first and second basement levels need to have steel reinforcement joints reserved, which will result in discontinuity in the entire structure and the formation of cold joints. How to construct a stable structure and how to ensure the structural safety of the subway station are the construction difficulties of transportation hub projects. Summary of the Invention

[0005] In view of this, in order to solve the technical problems existing in the prior art, the present invention provides a construction method for an arcade-style structure that spans a shared diaphragm wall. The shared diaphragm wall serves as a support wall for the subway station, a support wall for the deep foundation pit of this project, and another function is as a permanent structural wall for the three underground floors of this project (with the addition of an inner lining wall). This saves construction time and land, reduces construction costs, and improves economic and social benefits.

[0006] The present invention solves the above-mentioned technical problems through the following technical solutions:

[0007] A construction method for an "arcade-style" structure spanning a shared diaphragm wall includes a construction method for a transportation hub project and a subway station under construction with double foundation pits supported by a shared diaphragm wall. The construction method includes the following steps:

[0008] Step 1) Construction of the diaphragm wall retaining structure of the subway station: earthwork excavation, construction of the main structure of the fifth underground floor, construction of the diaphragm wall retaining structure of the transportation hub project, earthwork excavation, conventional construction of the basement floor slab and the beams and slabs of the second basement floor, the subway station and the transportation hub project have a 172-meter shared diaphragm wall.

[0009] Step 2) Remove the second internal support of the deep foundation pit: After the construction of the basement floor slab and the second basement level beam slab is completed, the second internal support of the deep foundation pit of the transportation hub project is removed.

[0010] Step 3) Opening a hole in the shared diaphragm wall to pass through the reinforcement of the beams and inclined columns on the first basement floor: Cut a hole in the shared diaphragm wall. The hole should not be too large to ensure the passage of the relevant beams and inclined columns on the first basement floor and a suitable construction surface. Next, pass through the beams and inclined columns on the first basement floor through the shared diaphragm wall.

[0011] Step 4) Construction of the beams and slabs on the first basement level: When constructing the floor slabs on both sides that intersect with the diaphragm wall, it is not necessary to make holes in the diaphragm wall, and the slab reinforcement does not need to be planted into the diaphragm wall. The slabs should be poured and shaped to the edge of the diaphragm wall in one go, so that the beams and slabs on the first basement level form a continuous horizontal support system.

[0012] Step 5) Remove the first layer of concrete internal support in the subway station: After the entire basement floor slab has been poured and its strength has reached 100%, remove the first layer of concrete internal support in the subway station.

[0013] Step 6) Remove the first layer of concrete internal support: Remove the first layer of concrete internal support for the deep foundation pit of the transportation hub project;

[0014] Step 7) Demolish the common diaphragm wall above the beams and slabs of the first basement level: After removing the first layer of concrete internal support in the deep foundation pit, the common diaphragm wall above the beams and slabs of the first basement level is in a cantilevered retaining state. Demolish the diaphragm wall above the beams and slabs of the first basement level and use a 200-ton truck crane to lift and transport the concrete debris.

[0015] Step 8) Basement roof slab construction: After the basement roof slab is completed and the strength reaches 100%, it adds another horizontal continuous support system to the entire foundation pit, making the double foundation pit more stable.

[0016] Step 9) Demolish the shared diaphragm wall between the first basement floor beams and slabs and the second basement floor beams and slabs: Demolish the shared diaphragm wall between the second basement floor slab and the first basement floor slab, and transfer the residue to the ground.

[0017] Step 10) Construction of temporary openings in floor slabs: handle the temporary openings in the basement floor slabs left after the demolition of the shared diaphragm wall.

[0018] As a further improvement to the above technical solution, after the common ground diaphragm wall is removed in step 10), the slab opening is sealed with the same level of micro-expansion concrete to fill the opening through the slab on the first basement floor.

[0019] Compared with the prior art, the technical solution of the present invention has at least the following beneficial effects:

[0020] (1) The construction method of the present invention includes the construction of the diaphragm wall retaining structure of the subway station, the removal of the second inner support of the deep foundation pit, the opening of the common diaphragm wall to penetrate the inclined column reinforcement of the first basement floor beam, the construction of the first basement floor beam and slab, the removal of the first concrete inner support of the subway station, the removal of the first concrete inner support of the project, the removal of the common diaphragm wall above the first basement floor beam and slab, the construction of the basement roof slab, the removal of the common diaphragm wall between the first basement floor beam and slab and the second basement floor beam and slab, and the construction of temporary openings in the floor slab. The construction method of the present invention is mainly designed for the first and second basement floors to extend to the reserved position of the subway station, connecting with the subway station to form an "arcade-style" structure, and finally removing the common diaphragm wall between the first and second basement floors and the subway station to form a connected structure. The construction method of this invention is based on the shared diaphragm wall support structure of the deep foundation pit of the transportation hub project and the five-story underground subway station under construction. The shared diaphragm wall is not only the support structure of the two deep foundation pits, but also the side wall of the basement of the transportation hub project (with the addition of an inner lining wall), thus becoming a permanent load-bearing structure. This construction method saves land resources, shortens the construction period, improves construction efficiency, and saves the construction party's costs, resulting in significant economic and social benefits.

[0021] (2) This invention uses a method of cutting holes in the diaphragm wall to pass through the steel reinforcement of the beams on the first basement level. After the beams and slabs on the first basement level are poured, a continuous horizontal support system is formed, which ensures the structural stability of the double foundation pit. Then the first concrete support of this project and the subway station can be removed, thus solving the problem of cold joints during construction. If the "arcade-style" structure is constructed in two parts, cold joints will occur. The construction scheme of this invention can ensure the stability of the subway station structure and the normal operation of the transfer lines related to the subway station.

[0022] (3) After the first concrete internal support of the double foundation pit is removed, the diaphragm wall above the beams and slabs of the first basement floor is in a cantilevered retaining state. Therefore, it is logical to remove the diaphragm wall above the beams and slabs of the first basement floor.

[0023] (4) The main structure of the subway station is constructed first. The first support of the subway station is removed first to ensure the structural stability of the subway workshop. Then the first support of the transportation hub project is removed to ensure the structural safety of the deep foundation pit of the transportation hub project.

[0024] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, the following detailed description is provided in conjunction with preferred embodiments and accompanying drawings. Attached Figure Description

[0025] Figure 1 This is a schematic flowchart of the construction method for the arcade-style structure spanning a shared ground wall according to the present invention.

[0026] Figure 2This is a cross-sectional view of the transportation hub project and the subway station under construction according to the present invention.

[0027] Figure 3 This is a construction diagram of the second internal support for the deep foundation pit according to the present invention.

[0028] Figure 4 This is a construction diagram of the shared ground diaphragm wall opening and beam reinforcement of the present invention.

[0029] Figure 5 This is a construction diagram of the beam and slab construction of the first basement level of the present invention.

[0030] Figure 6 This is a construction diagram illustrating the dismantling of the first concrete support of a subway station according to the present invention.

[0031] Figure 7 This is a construction diagram of the first concrete internal support for the deep foundation pit of a transportation hub project according to the present invention.

[0032] Figure 8 This is a construction diagram illustrating the demolition of the shared diaphragm wall above the first basement floor beams and slabs according to the present invention.

[0033] Figure 9 This is a construction schematic diagram of the basement roof slab of the present invention.

[0034] Figure 10 This is a construction diagram illustrating the removal of the shared diaphragm wall between the second basement floor slab and the first basement floor slab according to the present invention.

[0035] Figure 11 This is a schematic diagram of the construction of the floor slab at the common ground floor diaphragm wall of the present invention. Figure 1 .

[0036] Figure 12 This is a schematic diagram of the construction of the floor slab at the common ground floor diaphragm wall of the present invention. Figure 2 .

[0037] In the diagram: 1. Second internal support for deep foundation pit; 2. First concrete support for subway station; 3. First concrete internal support for project; 4. Common diaphragm wall above the beams and slabs of the first basement level; 5. Common diaphragm wall between the beams and slabs of the first basement level and the beams and slabs of the second basement level; 6. Basement roof slab; 7. Common diaphragm wall; 8. First basement floor slab. Detailed Implementation

[0038] The present invention will now be described in detail with reference to the accompanying drawings, which form part of this specification. The principles of the invention are illustrated by means of embodiments, and other aspects, features, and advantages of the invention will become apparent from this detailed description. In the accompanying drawings, the same or similar parts in different figures are indicated by the same reference numerals.

[0039] The specific implementation project of this invention is the Zhongshan 8th Road Transportation Hub Project. The project is located inside the No. 64 Zhongshan 8th Road Bus Terminal in Guangzhou. The main building has 3 underground floors and 6 floors above ground. The floor height of the third basement level is 5.2m, the floor height of the second basement level is 5.0m, the floor height of the first basement level is 5.2m, and the roof height is 30m. The total building area is approximately 67,369㎡ (the building area above ground is 36,311㎡, and the building area underground is 31,058㎡). The third basement level of this project shares a 172-meter-long underground continuous wall (hereinafter referred to as the diaphragm wall) with the Zhongshan 8th Road Metro Station of Line 11. The Zhongshan 8th Road Metro Station of Line 11 (under construction, the main structure has been capped and entered the decoration stage) is adjacent to the Zhongshan 8th Road Station of Line 5, which is currently in operation.

[0040] like Figure 1-2 As shown, this invention provides a construction method for an "arcade-style" structure spanning a shared diaphragm wall 7, including a construction method for a transportation hub project and a subway station under construction with double foundation pits supported by a shared diaphragm wall 7. The shared underground continuous wall is a diaphragm wall, and the construction method includes the following construction steps:

[0041] Step 1) Construction of diaphragm wall retaining structure for subway station: earthwork excavation, construction of the main structure of the fifth underground floor, construction of diaphragm wall retaining structure for transportation hub project, earthwork excavation, conventional construction of basement floor slab and second basement floor beams and slabs, the subway station and transportation hub project have a 172-meter shared diaphragm wall 7.

[0042] Step 2) Remove the second inner support 1 of the deep foundation pit: After the construction of the basement floor slab and the beams and slabs of the second basement level is completed, the second inner support 1 of the deep foundation pit of the transportation hub project is removed;

[0043] Step 3) Opening a hole in the common diaphragm wall 7 to pass through the reinforcement of the beams and inclined columns of the basement: Cut a hole in the common diaphragm wall 7. The hole should not be too large to ensure the passage of the relevant beams and inclined columns of the basement and a suitable construction surface. Next, pass through the beams and inclined columns of the basement in the common diaphragm wall 7.

[0044] Step 4) Construction of the beams and slabs on the first basement level: When constructing the floor slabs on both sides that intersect with the diaphragm wall, it is not necessary to make holes in the diaphragm wall, and the slab reinforcement does not need to be planted into the diaphragm wall. The slabs should be poured and shaped to the edge of the diaphragm wall in one go, so that the beams and slabs on the first basement level form a continuous horizontal support system.

[0045] Step 5) Remove the first concrete internal support 2 of the subway station: After the entire basement floor slab has been poured and the strength has reached 100%, remove the first concrete internal support 2 of the subway station.

[0046] Step 6) Remove the first layer of concrete internal support 3: Remove the first layer of concrete internal support 3 of the deep foundation pit of the transportation hub project;

[0047] Step 7) Demolish the common diaphragm wall 4 above the beams and slabs of the first basement level: After demolishing the first concrete internal support 3 of the deep foundation pit, the common diaphragm wall 4 above the beams and slabs of the first basement level is in a cantilevered retaining state. After demolishing the diaphragm wall 4 above the beams and slabs of the first basement level, use a 200-ton truck crane to lift and transport the concrete debris.

[0048] Step 8) Construction of basement roof slab 6: After the construction of basement roof slab 6 is completed and the strength reaches 100%, it adds another horizontal continuous support system to the entire deep foundation pit, making the double foundation pit more stable.

[0049] Step 9) Remove the common diaphragm wall 5 between the beams and slabs of the first basement level and the beams and slabs of the second basement level: After removing the common diaphragm wall 5 between the beams and slabs of the first basement level and the beams and slabs of the second basement level, the residue is transferred to the ground level for a second time.

[0050] Step 10) Construction of temporary openings in floor slabs: handle the temporary openings in the basement floor slab 8 left after the demolition of the shared diaphragm wall 7.

[0051] The construction method of this invention first involves cutting a hole in the shared foundation diaphragm wall 7 to pass through the reinforcing steel bars of the basement beams. After the basement beams and slabs are poured, a continuous horizontal support system is formed. Then, the first layer of concrete internal support for the double foundation pit is removed, followed by the removal of the shared foundation diaphragm wall 4 above the basement slab. Next, the basement roof slab 6 is constructed. Finally, the shared foundation diaphragm wall 5 between the basement beams and slabs and the basement beams and slabs is removed. Existing shared foundation diaphragm wall construction methods use a one-time removal approach, which can easily lead to structural instability. To ensure structural stability, the construction method of this invention involves first completing the entire basement, including the basement roof slab 6, so that the entire deep foundation pit forms a continuous horizontal support system before removing the second section of the shared foundation diaphragm wall 7. This provides more reliable protection for the double foundation pit of the subway station and also solves the problem of cold joints during construction.

[0052] like Figure 3-10 As shown in the figure, Embodiment 1 of the present invention provides a schematic diagram of the specific construction operations involved in the construction process of the shared ground diaphragm wall, and the specific details are as follows:

[0053] Figure 3 The diagram shown is a construction schematic of the second internal support 1 for dismantling the deep foundation pit of the transportation hub project according to the present invention.

[0054] Figure 4 The diagram shown is a construction schematic of the common diaphragm wall 7 opening through the inclined column reinforcement of the basement beam in this invention.

[0055] Figure 5 The diagram shows a construction schematic of the continuous horizontal support system formed by the beams and slabs on the first basement floor according to the present invention.

[0056] Figure 6 The diagram shown is a construction schematic of dismantling the first concrete internal support 2 of a subway station according to the present invention.

[0057] Figure 7 The diagram shown is a construction schematic of the first concrete internal support 3 for the demolition of the deep foundation pit of the transportation hub project according to the present invention.

[0058] Figure 8 The diagram shown is a construction schematic of the demolition of the shared diaphragm wall 4 above the beams and slabs on the first basement floor according to the present invention.

[0059] Figure 9 The diagram shows the construction of a continuous horizontal support system for the entire deep foundation pit after the basement roof slab 6 of the present invention has been completed.

[0060] Figure 10 The diagram shown is a construction schematic of the removal of the shared diaphragm wall 5 between the second basement floor slab and the first basement floor slab according to the present invention.

[0061] like Figure 11-12 As shown, after the beam reinforcement passes through the basement in step 4), the floor slab reinforcement extends to the wall of the common ground diaphragm wall 7 and is poured together with the floor in the same area in one go. There is no need to implant the common ground diaphragm wall. After the common ground diaphragm wall 7 is removed, the slab opening is sealed with the same grade of micro-expansion concrete, thereby realizing the filling of the opening through the slab on the basement.

[0062] Compared with the prior art, the technical solution disclosed in the above embodiments has the following beneficial effects:

[0063] In the above embodiments, the construction method of the present invention involves first completing the entire basement, including the basement roof slab 6, so that the entire deep foundation pit forms a continuous horizontal support system. Then, the second section of the shared diaphragm wall 7 is removed. This provides more robust protection for the double foundation pits of the transportation hub project and the subway station, and also solves the problem of cold joints during construction. The construction method of the present invention can be used for the double foundation pit support of deep foundation pits in transportation hub projects and foundation pits of subway transfer stations under construction. The shared diaphragm wall applied during construction serves as both the support structure for the two foundation pits and the side wall of the basement of the transportation hub project, i.e., a permanent load-bearing structure. Using this construction method can shorten the construction period, improve construction efficiency, save construction costs, and greatly improve economic benefits.

[0064] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A construction method for an "arcade-style" structure spanning a shared ground diaphragm wall, characterized in that: The construction method for a transportation hub project and a subway station under construction with double foundation pits supported by a shared diaphragm wall includes the following construction steps: Step 1) Construction of the diaphragm wall retaining structure of the subway station: earthwork excavation, construction of the main structure of the fifth underground floor, construction of the diaphragm wall retaining structure of the transportation hub project, earthwork excavation, conventional construction of the basement floor slab and the beams and slabs of the second basement floor, the subway station and the transportation hub project have a 172-meter shared diaphragm wall. Step 2) Remove the second internal support of the deep foundation pit: After the construction of the basement floor slab and the second basement level beam slab is completed, the second internal support of the deep foundation pit of the transportation hub project is removed. Step 3) Opening a hole in the shared diaphragm wall to pass through the reinforcement of the beams and inclined columns on the first basement floor: Cut a hole in the shared diaphragm wall. The hole should not be too large to ensure the passage of the relevant beams and inclined columns on the first basement floor and a suitable construction surface. Next, pass through the beams and inclined columns on the first basement floor through the shared diaphragm wall. Step 4) Construction of the beams and slabs on the first basement level: When constructing the floor slabs on both sides that intersect with the diaphragm wall, it is not necessary to make holes in the diaphragm wall, and the slab reinforcement does not need to be planted into the diaphragm wall. The slabs should be poured and shaped to the edge of the diaphragm wall in one go, so that the beams and slabs on the first basement level form a continuous horizontal support system. Step 5) Remove the first layer of concrete internal support in the subway station: After the entire basement floor slab has been poured and its strength has reached 100%, remove the first layer of concrete internal support in the subway station. Step 6) Remove the first layer of concrete internal support: Remove the first layer of concrete internal support for the deep foundation pit of the transportation hub project; Step 7) Demolish the common diaphragm wall above the beams and slabs of the first basement level: After removing the first layer of concrete internal support in the deep foundation pit, the common diaphragm wall above the beams and slabs of the first basement level is in a cantilevered retaining state. Demolish the diaphragm wall above the beams and slabs of the first basement level and use a 200-ton truck crane to lift and transport the concrete debris. Step 8) Basement roof slab construction: After the basement roof slab is completed and its strength reaches 100%, it adds another layer of horizontal continuous support system to the entire foundation pit. Step 9) Remove the shared diaphragm wall between the beams and slabs of the first basement level and the beams and slabs of the second basement level: Remove the shared diaphragm wall between the beams and slabs of the second basement level and the beams and slabs of the first basement level, and transfer the residue to the ground level for a second time; Step 10) Construction of temporary openings in floor slabs: handle the temporary openings in the beams and slabs of the basement level left after the demolition of the shared diaphragm wall.

2. The construction method for the "arcade-style" structure spanning a shared diaphragm wall according to claim 1, characterized in that: The temporary openings in the basement beams and slabs left after the demolition of the shared diaphragm wall described in step 10) include: sealing the beam and slab openings with the same grade of micro-expansion concrete to fill the gaps in the basement beams and slabs.

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