A construction method for the bottom slab at the middle partition wall in a deep foundation pit

Abstract

The present invention relates to a construction method for the bottom slab at the middle partition wall of a deep foundation pit, which includes the following steps: demolish the middle partition wall to above the bottom slab plane; chisel out the steel bars corresponding to the bottom slab positions on both sides of the middle partition wall; connect the steel bars of the middle partition wall and the bottom slab through couplers; make up the structures on both sides of the middle partition wall. The construction method for the bottom slab at the middle partition wall of the deep foundation pit provided by the present invention, on the premise of meeting safety requirements, compared with the traditional construction method, can avoid the risk of confined water gushing caused by the post-construction area left at the bottom slab and the middle partition wall, reduce the retention and maintenance time of the confined water wells, reduce the force transfer devices arranged between the bottom slab and the middle partition wall, and reduce the manpower and material resources spent on pumping, maintenance, finished product protection, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of foundation pit construction in underground space, and particularly to a construction method for the bottom slab at the middle partition wall of a deep foundation pit. Background Art

[0002] For large-scale urban underground space development, in order to meet the development nodes of different single entities of the development project and at the same time reduce the adverse impact of soft soil foundation pit excavation on the surrounding environment, there must be foundation pit group construction of dividing a large pit into small ones and excavating in sections. Controlling the appropriate one-time excavation area is an important factor considered in the retaining structure design. Therefore, during the retaining structure design, it is necessary to set a common retaining wall (middle partition wall) between pits. After the underground structures of adjacent two foundation pits are constructed, the middle partition wall retaining structure is demolished layer by layer and section by section from top to bottom until the middle partition wall at the bottom slab is chiseled out and the middle partition wall is demolished below the bottom slab plane, and then the structures are connected to form an overall stable structure (as Figure 3 shown). For the bottom slabs on both sides of the traditional middle partition wall, the bottom slabs are connected after the middle partition wall is demolished.

[0003] However, in the traditional method, the post-construction area left at the bottom slab and the middle partition wall will bring the risk of confined water gushing. The retaining time of the confined water well is long, the construction time of the force transfer device arranged between the bottom slab and the middle partition wall is long, and the construction cost is high. At the same time, a lot of manpower and material resources are required for pumping, maintenance, finished product protection, etc. Summary of the Invention

[0004] In order to solve the problems of long construction period, high construction cost and high risk of confined water gushing in the existing construction method for the bottom slab at the middle partition wall, the technical solution adopted by the present invention is: a construction method for the bottom slab at the middle partition wall of a deep foundation pit, including the following steps:

[0005] Chisel out the steel bars at the positions corresponding to the bottom slabs on both sides of the middle partition wall;

[0006] Connect the steel bars of the middle partition wall and the bottom slab through a coupler;

[0007] Place a water stop facility and pour the bottom slab concrete;

[0008] Demolish the support system of the deep foundation pit and backfill the basement structure;

[0009] Demolish the middle partition wall to above the bottom slab plane;

[0010] Make up for the structures on both sides of the middle partition wall.

[0011] Further improved, reinforcing bars extending towards both sides of the middle partition wall are arranged at the positions corresponding to the bottom slab of the middle partition wall.

[0012] Further improved, the length of the reinforcing bars extending from each side of the middle partition wall needs to meet the anchorage requirements.

[0013] Further improvement is that at least one water stop strip is arranged at the corresponding positions of the bottom plates on both sides of the middle partition wall.

[0014] Further improvement is that there are two upper and lower water stop strips on each side of the middle partition wall.

[0015] Further improvement is that the water stop strip is located at one-third to two-thirds of the thickness direction of the bottom plate.

[0016] Further improvement is that a water stop plate is arranged between the two water stop strips.

[0017] Further improvement is that the water stop plate includes a connecting plate and a transverse plate. The connecting plate is fixedly connected to the steel bars of the middle partition wall, and the transverse plate is connected to the connecting plate.

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

[0019] The construction method of the bottom plate at the middle partition wall of the deep foundation pit provided by the present invention can avoid the risk of confined water gushing due to the post-construction area left at the bottom plate and the middle partition wall compared with the traditional construction method on the premise of meeting safety requirements, reduce the retention and maintenance time of the confined water wells, reduce the force transfer devices arranged between the bottom plate and the middle partition, and reduce the manpower and material resources spent on pumping, maintenance, finished product protection, etc. Description of the Drawings

[0020] The present invention will be further described below with reference to the drawings and embodiments.

[0021] Figure 1 It is a schematic diagram of the construction method of the bottom plate at the middle partition wall of the deep foundation pit of the present invention;

[0022] Figure 2 It is a schematic diagram of the construction method of the bottom plate at the middle partition wall of the deep foundation pit of the present invention;

[0023] Figure 3 It is the traditional bottom plate construction method. Specific Embodiments

[0024] Now the present invention will be further described in detail with reference to the drawings. These drawings are all simplified schematic diagrams, only illustrating the basic structure of the present invention in a schematic way, so they only show the components related to the present invention.

[0025] In the description of the invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the invention.

[0026] In addition, the terms "first" and "second" are used only for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the invention, "a plurality of" means two or more unless otherwise specifically defined.

[0027] In the invention, unless otherwise clearly specified and limited, the terms such as "installed", "connected", "joined", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

[0028] As Figure 1 and Figure 2 shown, the present invention provides a construction method for the bottom slab at the middle partition wall in a deep foundation pit, including the following steps:

[0029] Chisel out the steel bars at the positions corresponding to the bottom slab 2 on both sides of the middle partition wall 1;

[0030] Connect the steel bars of the middle partition wall 1 and the bottom slab 2 through the coupler 3;

[0031] Place the water-stop facilities and pour the bottom slab concrete;

[0032] Demolish the support system of the deep foundation pit and backfill the basement structure;

[0033] Demolish the middle partition wall 1 above the plane of the bottom slab 2;

[0034] Make up the structures on both sides of the middle partition wall 1.

[0035] The construction method of the bottom slab at the middle partition wall of the deep foundation pit provided by the present invention can avoid the risk of confined water gushing due to the post-construction area left at the bottom slab and the middle partition wall, reduce the retention and maintenance time of the confined water wells, reduce the force transmission devices arranged between the bottom slab and the middle partition wall, and reduce the manpower and material resources spent on pumping, maintenance, and finished product protection compared with the traditional construction method on the premise of ensuring safety.

[0036] In order to further improve the connection strength between the middle partition wall and the bottom slab, a further improvement of this technical solution is that reinforcing bars 4 extending towards both sides of the middle partition wall are provided at the corresponding positions of the bottom slab 2 of the middle partition wall 1. The reinforcing bars 4 can be embedded in the middle partition wall. For the convenience of transportation, the reinforcing bars 4 can be bent along the wall surface of the middle partition wall during embedding and then poured. When it is necessary to connect with the bottom slab, only the reinforcing bars 4 need to be chiseled out and then restored to the direction consistent with the extension direction of the bottom slab.

[0037] Although there are reinforcing bars 4, in order to meet the requirement that the reinforcing bars can strengthen the connection strength between the two, a further improvement of this technical solution is that the length of the reinforcing bars 4 extending from each side of the middle partition wall 1 needs to meet the anchorage requirement.

[0038] In order to prevent water at the bottom of the bottom slab from seeping upward through the connection gap between the two, a further improvement of this technical solution is that at least one water stop strip 5 is provided at the corresponding positions of the bottom slab 2 on both sides of the middle partition wall 1. The water stop strip 5 adopts a water-swelling water stop strip. When water seeps upward, the water stop strip swells when it meets water, improving the sealing degree at the connection gap between the middle partition wall and the bottom slab and preventing water from seeping upward.

[0039] In order to improve the sealing degree at the connection between the middle partition wall and the bottom slab, a further improvement of this technical solution is that two water stop strips 5 are provided on each side of the middle partition wall 1, one above the other.

[0040] A further improvement is that the water stop strip 5 is located at one-third to two-thirds of the thickness direction of the bottom slab 2 to improve the sealing strength and the water stopping ability.

[0041] Since the connection gap between the middle partition wall and the bottom slab is vertically upward and the barrier to water seeping upward is small, in order to improve the water seepage prevention ability, a further improvement of this technical solution is that a horizontally extending water stop plate 6 is provided between the two water stop strips 5, so that the connection gap between the middle partition wall and the bottom slab is not vertical but has a horizontal bend, making the water seepage path blocked. Combined with the water stop strip, the water stopping ability at the connection gap is further improved, preventing water from seeping upward through the connection gap.

[0042] The structure and construction method of the water stop plate 6 are as follows: The water stop plate 6 includes a connecting plate 61 and a transverse plate 62. The middle partition wall at the installation position of the water stop plate is chiseled open to expose the reinforcement bars under the wall surface. The connecting plate 61 is welded and fixedly connected to the reinforcement bars of the middle partition wall 1, and the transverse plate 62 is welded to the connecting plate 61. Among them, the connecting plate mainly plays the role of a connection platform, providing a plane for the installation of the transverse plate, increasing the fixing area of the transverse plate, and improving the stability of its fixation. In this embodiment, the connecting plate is made of angle steel, and the transverse plate is made of a full-length steel plate, which is convenient for material collection and has a low cost.

[0043] This technical solution has the following advantages compared with the traditional method:

[0044] The intersection of the bottom plate and the middle partition wall is sealed in advance, reducing the risk of confined water gushing;

[0045] The dewatering wells reserved for removing the middle partition wall and filling the gaps can be sealed in advance, reducing the maintenance cost;

[0046] The force transmission device between the bottom plate and the middle partition wall is cancelled, reducing the construction cost;

[0047] The cost of finished product protection of the bottom plate reinforcement bars during the later removal of the middle partition wall is reduced.

[0048] Inspired by the ideal embodiments of the present invention described above, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of this invention. The technical scope of this invention is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. A construction method for the bottom slab at the middle partition wall of a deep foundation pit, characterized in that, It includes the following steps: Chisel out the steel bars at the corresponding positions of the bottom plates on both sides of the middle partition wall; Connect the steel bars of the middle partition wall and the bottom plate through couplers; Place the water-stop facilities and pour the bottom plate concrete; Demolish the deep foundation pit support system and backfill the basement structure; Demolish the middle partition wall up to above the bottom plate plane; Make up the structures on both sides of the middle partition wall.

2. The construction method of the bottom slab at the middle partition wall in the deep foundation pit according to claim 1, characterized in that, Reinforcing bars extending towards both sides of the middle partition wall are provided at the corresponding positions of the bottom plate of the middle partition wall.

3. The construction method of the bottom slab at the middle partition wall in the deep foundation pit according to claim 2, characterized in that, The length of the reinforcing bars extending out from each side of the middle partition wall needs to meet the anchorage requirements.

4. The construction method of the bottom slab at the middle partition wall in the deep foundation pit according to claim 1, wherein, At least one water-stop strip is provided at the corresponding positions of the bottom plates on both sides of the middle partition wall.

5. The construction method of the bottom slab at the middle partition wall of the deep foundation pit according to claim 4, wherein, Two upper and lower water-stop strips are provided on each side of the middle partition wall.

6. The construction method of the bottom slab at the middle partition wall in the deep foundation pit according to claim 5, characterized in that, The water-stop strip is located at one-third to two-thirds of the bottom plate thickness direction.

7. The construction method of the bottom slab at the middle partition wall of the deep foundation pit according to claim 5, characterized in that, A water-stop plate is provided between the two water-stop strips.

8. The construction method of the bottom slab at the middle partition wall in the deep foundation pit according to claim 7, characterized in that, The water-stop plate includes a connecting plate and a transverse plate. The connecting plate is fixedly connected to the steel bars of the middle partition wall, and the transverse plate is connected to the connecting plate.

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