Narrow deep foundation pit basement outer wall single-side formwork supporting system and construction method thereof

Abstract

The invention relates to a narrow deep foundation pit basement outer wall single-side formwork supporting system which comprises an outer wall formwork supporting device and a foundation pit supporting structure. The foundation pit supporting structure is arranged in the deep foundation pit; anti-floating ribs and embedded steel pipes are arranged in a basement bottom plate; one end of the horizontal supporting rod abuts against the outer wall formwork supporting device, and the other end of the horizontal supporting rod is connected with the three embedded steel pipes. Six rows of horizontal anti-sliding steel pipes are arranged on the outer side face of the outer wall formwork supporting device. The upper ends of the inclined supporting rods abut against the lower portions of the corresponding anti-sliding steel pipes respectively and are fixed to the outer wall formwork supporting device. The supporting stabilizing rods are obliquely fixed on the inclined supporting rods to form a single-row formwork supporting frame; the inner side faces of the two ends of the outer wall formwork supporting device are fixed through multiple sets of single-row formwork supporting frames. And a full-length connecting rod is arranged at the joint of the supporting stabilizing rod and the inclined supporting rod, so that a basement outer wall single-side formwork supporting system is formed. According to the method, data are extracted after BIM modeling simulation analysis is adopted, the basement outer wall single-side formwork supporting system is built, turnover use can be achieved, the construction efficiency is improved, and the construction cost is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of building construction, and in particular to a single-side formwork system for an outer wall of a narrow and deep foundation pit basement and a construction method thereof. Background Art

[0002] During the construction of the basement exterior wall, due to the narrow space between the foundation pit enclosure and the exterior wall to be constructed, there is insufficient construction space for the external formwork of the basement exterior wall. It is difficult to adopt traditional double-sided formwork construction. Therefore, single-sided formwork is generally adopted at present. The support system of single-sided formwork mostly adopts steel pipes as diagonal braces. The support strength of the current support system is insufficient. If the overall installation is adopted, due to the small space, large-scale lifting equipment needs to be customized, the construction cost is high, and the single-sided formwork cannot be fully reused after construction, resulting in material waste. In addition, during the current construction of the basement exterior wall, the basement exterior wall and the basement top plate are generally cast separately, which has a long construction period. Construction joints are easily generated after separate casting, resulting in the risk of exterior wall leakage. Summary of the Invention

[0003] In order to overcome the above-mentioned defects of the prior art, the purpose of the present invention is to provide a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement and a construction method thereof.

[0004] The present invention discloses a single-side formwork system for the outer wall of a narrow deep foundation pit basement, comprising a horizontal support rod, an oblique support rod, a support stabilizing rod, an outer wall formwork device and a foundation pit support structure; the foundation pit support structure is arranged in the deep foundation pit; a group of anti-floating reinforcement and three groups of pre-buried steel pipes are arranged at equal intervals in the basement floor from the wall to the outside; the outer wall formwork device is arranged outside the outer wall pouring area of the basement; one end of the horizontal support rod is against the outer wall formwork device, and the other end is connected to three pre-buried steel pipes on the same horizontal line through rotating fasteners; six rows of horizontal anti-slip steel pipes are arranged on the outer side of the outer wall formwork device from top to bottom; the upper surface of the six oblique support rods The ends are respectively placed under the corresponding anti-slip steel pipes and fixed to the external wall formwork device, and the lower ends of the diagonal braces are fixedly connected to the embedded steel pipes; the supporting stabilizing rods are obliquely fixed on the six diagonal braces, and the lower end of the middle supporting stabilizing rod is used as a support point at the intersection of the external wall formwork device and the basement floor, and the other two supporting stabilizing rods are equidistantly arranged on the upper and lower sides of the middle supporting stabilizing rod to form a single-row formwork frame; the inner sides of the left and right ends of the external wall formwork device are fixed by multiple groups of single-row formwork frames; a full-length connecting rod is provided at the connection between the supporting stabilizing rod and the diagonal brace, and is horizontally fixed to the multiple groups of single-row formwork frames through rotating fasteners to form a single-sided formwork system for the external wall of the basement.

[0005] Furthermore, the exterior wall formwork device includes a single-head screw, exterior wall wooden formwork, wooden beams, double steel pipe vertical supports and double steel pipe main ribs; the wall reinforcement is tied at the designed position of the basement exterior wall, and the single-head screw is fixed on the wall reinforcement; the exterior wall wooden formwork is installed on the single-head screw, and the wooden beam is fixed on the outside of the exterior wall wooden formwork; the double steel pipe main ribs are installed on the outer surface of the wooden beam; the double steel pipe vertical supports are arranged on the outside of the double steel pipe main ribs, and are tightened with the threaded end of the single-head screw through the double nuts located on the outside of the double steel pipe vertical supports, so that the bottom of the double steel pipe vertical supports contacts the inner side of the anti-floating reinforcement for welding and fixing.

[0006] Furthermore, the anti-slip steel pipe is fixedly connected to the double steel pipe vertical support through a rotating fastener; the lower end of the diagonal support rod is connected to the embedded steel pipe through a rotating fastener; the supporting stabilizing rod is tilted and fixed on the six diagonal support rods through a rotating fastener.

[0007] Furthermore, the upper and lower steel pipes of the double-steel-tube main rib are clamped on the single-head screw, and the outer screw portion of the single-head screw is provided with an adjusting piece that is threadedly connected to the single-head screw; the adjusting piece is provided with an arc-shaped groove corresponding to the outer circular surface of the upper and lower steel pipes of the double-steel-tube main rib, and the double-steel-tube main rib is fixed to the outer surface of the wooden beam through the arc-shaped groove of the adjusting piece, and then the double-steel-tube vertical support is hoisted and erected, and the two steel pipes of the double-steel-tube vertical support are put on the single-head screw and fit with the adjusting piece, and then the exterior wall wooden formwork, wooden beam, double-steel-tube main rib and double-steel-tube vertical support are fixed by tightening the double nuts; and the verticality of the double-steel-tube vertical support is ensured by adjusting the double nuts.

[0008] Furthermore, a top wooden formwork is provided below the top plate reinforcement for pouring the basement top plate; and the upper end of the exterior wall formwork device is supported below the top wooden formwork.

[0009] Furthermore, a steel formwork is provided in the shear wall concrete of the basement floor located between the foundation pit support structure and the outer wall wooden formwork; the steel formwork is fixed to the outer wall wooden formwork by connecting rods provided on the side; and a waterstop steel plate is provided in the steel formwork.

[0010] The present invention also provides a construction method for a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement, comprising the following steps: S1: splitting the load-bearing parameters and component dimensions of the basement outer wall single-sided formwork system according to basement design indicators, and performing BIM modeling using REVIT 3D software; performing simulation and finite element analysis based on the BIM model, modifying structures and dimensions that do not meet the requirements, and then performing simulation again until the structural strength and force distribution meet the standard requirements; S2: Extract the model data of BIM modeling, generate each parts drawing, and produce qualified parts; S3: Construct the foundation pit support structure in the deep foundation pit. Simultaneously, install one set of floating reinforcement and three sets of embedded steel pipes at equal intervals in the basement floor from the wall outward. The spacing between one set of floating reinforcement and three sets of embedded steel pipes is set according to the standard requirements after BIM modeling and simulation. Then, cast the basement floor; then cast the shear wall on the basement floor. S4: Installation of the exterior wall formwork: Tie the wall reinforcement at the designed location on the basement exterior wall and secure the single-threaded screws to the wall reinforcement. Then, use ordinary lifting equipment to lift the exterior wall timber formwork and install it on the single-threaded screws. Then, lift the wooden beams and secure them to the exterior wall timber formwork. Install the double steel tube main ribs on the outer surface of the wooden beams. Set the double steel tube vertical braces on the outside of the double steel tube main ribs and tighten the double nuts on the outside of the double steel tube vertical braces to the threaded end of the single-threaded screws, so that the bottom of the double steel tube vertical braces contacts the inside of the anti-floating reinforcement. Secure by welding. S5: Installation of single-row formwork: Place one end of the horizontal support rod against the exterior wall formwork device, and connect the other end to three pre-buried steel pipes on the same horizontal line through rotating fasteners; six rows of horizontal anti-slip steel pipes are arranged from top to bottom on the outer side of the exterior wall formwork device; the upper ends of the diagonal support rods are respectively placed under the corresponding anti-slip steel pipes and fixed to the exterior wall formwork device, and the lower ends of the diagonal support rods are fixedly connected to the pre-buried steel pipes; the supporting stabilizing rods are obliquely fixed on the six diagonal support rods, and the lower end of the middle supporting stabilizing rod is used as the support point at the intersection of the exterior wall formwork device and the basement floor, and the other two supporting stabilizing rods are equidistantly arranged on the upper and lower sides of the middle supporting stabilizing rod; the inner sides of the left and right ends of the exterior wall formwork device are fixed by multiple sets of single-row formwork frames; a full-length connecting rod is provided at the connection between the supporting stabilizing rod and the diagonal support rod, and is horizontally fixed to multiple sets of single-row formwork frames through rotating fasteners; the construction of the single-sided formwork system of the basement exterior wall is completed; S6: A steel formwork is set in the concrete of the shear wall; the steel formwork is fixed to the exterior wall wooden formwork via connecting rods set on the side; and a waterstop steel plate is then set in the steel formwork; S7: Set a top wooden formwork under the top plate reinforcement of the basement top plate; support and connect the bottom of the top wooden formwork with the upper end of the outer wall formwork device; then cast concrete for the basement outer wall and the basement top plate at one time.

[0011] Furthermore, in S3: the distances between the three embedded steel pipes and the outer wall of the basement are 1.6m, 2.5m and 3.4m respectively; the height of the embedded steel pipes is 550mm, and the embedded length is 300mm, serving as ground anchor support points; C16 steel bars are embedded 200mm from the shear wall flange as floating reinforcement for anti-floating tension joints, which are used for welding and fixing to the bottom of the double steel pipe vertical brace.

[0012] Furthermore, in S4: the exterior wall wooden formwork uses wooden plywood, and the exterior wall wooden formwork is marked and punched on site according to the pre-arranged single-head screw spacing. After being assembled into a whole piece by piece, the wooden beams, double steel pipe main ribs, adjustment parts and double steel pipe vertical supports are installed and locked with double nuts. The double nuts at the upper and lower ends are adjusted to adjust the verticality of the double steel pipe vertical supports.

[0013] Furthermore, in S5: the six diagonal braces have six contact intersections with the double steel pipe vertical braces, and the six contact intersections are 900mm, 1350mm, 1800mm, 2300mm, 2800mm and 3350mm from the ground from bottom to top; the lower ends of the first diagonal brace and the second diagonal brace from left to right are fixedly connected to the embedded steel pipe on the left, the lower ends of the third diagonal brace and the fourth diagonal brace are fixedly connected to the embedded steel pipe in the middle, and the lower ends of the fifth diagonal brace and the sixth diagonal brace are fixedly connected to the embedded steel pipe on the right, and the lower ends of the first diagonal brace, the second diagonal brace, the third diagonal brace, the fourth diagonal brace, the fifth diagonal brace and the sixth diagonal brace are in contact with the surface of the basement floor to ensure the supporting effect.

[0014] To sum up: the present invention extracts data through BIM modeling, conducts feasibility and cost analysis, and selects the best solution. The basement exterior wall single-sided formwork system of the present invention adopts modular components, and the exterior wall formwork device of the steel pipe support system plus wooden formwork and double steel pipe vertical braces and double steel pipe main ribs has high overall support strength and good stability. It also has the following advantages: First, the basement exterior wall and basement top plate structure can be cast in one time with concrete, which saves construction time, avoids the retention of horizontal construction joints, and reduces the risk of leakage; secondly, there is no need to use specific large-scale equipment for lifting, which solves the problem of setting up lifting equipment in deep foundation pits with narrow sites and avoids the safety risks of lifting large facilities; then, compared with the characteristic that steel formwork needs to be customized, the ordinary steel pipe support system wooden formwork can be assembled according to the structural characteristics, with flexible turnover, which reduces construction costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic diagram of the facade structure of the formwork system of the present invention.

[0016] Figure 2 For the present invention Figure 1 Enlarged structural diagram at H in the middle.

[0017] Figure 3 This is a schematic diagram of the distribution of embedded steel pipes in the present invention.

[0018] Among them: basement floor 1; embedded steel pipe 2; anti-floating reinforcement 3; horizontal support rod 4; diagonal support rod 5; full-length connecting rod 6; support stabilizing rod 7; anti-slip steel pipe 8; basement top plate 9; double steel pipe vertical support 10; double steel pipe main rib 11; wooden beam 12; exterior wall wooden formwork 13; foundation pit support structure 14; basement exterior wall 15; single-head screw 16; adjustment part 17; waterstop steel plate 18; steel formwork 19; connecting rod 20; top wooden formwork 21. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0020] like Figures 1 to 3 As shown, a single-sided formwork system for the outer wall of a narrow deep foundation pit basement includes a horizontal support rod 4, an oblique support rod 5, a supporting stabilizing rod 7, an outer wall formwork device and a foundation pit supporting structure 14; the foundation pit supporting structure 14 is arranged in a deep foundation pit; a group of floating reinforcements 3 and three groups of embedded steel pipes 2 are arranged at equal intervals in the basement floor 1 from the wall to the outside; the outer wall formwork device is arranged on the outside of the pouring area of the basement outer wall 15; one end of the horizontal support rod 4 is against the outer wall formwork device, and the other end is connected to the three embedded steel pipes 2 on the same horizontal line through a rotating fastener; the outer side surface of the outer wall formwork device is provided with six rows of horizontal anti-slip steel pipes 8 from top to bottom; the upper surface of the six oblique support rods 5 The ends are respectively placed under the corresponding anti-slip steel pipes 8 and fixed to the exterior wall formwork device, and the lower ends of the diagonal braces 5 are fixedly connected to the embedded steel pipe 2; the supporting stabilizing rods 7 are obliquely fixed on the six diagonal braces 5, and the lower end of the middle supporting stabilizing rod 7 uses the intersection of the exterior wall formwork device and the basement floor 1 as the support point, and the other two supporting stabilizing rods 7 are equidistantly arranged on the upper and lower sides of the middle supporting stabilizing rod 7 to form a single-row formwork frame; the inner side surfaces of the left and right ends of the exterior wall formwork device are fixed by multiple groups of single-row formwork frames; a full-length connecting rod 6 is provided at the connection between the supporting stabilizing rod 7 and the diagonal braces 5, and is horizontally fixed to the multiple groups of single-row formwork frames by rotating fasteners to form a single-sided formwork system for the exterior wall of the basement. The present invention adopts modular components with high overall supporting strength and good stability. Ordinary lifting equipment can be used to complete the lifting of parts in a small space without the need to use specific large-scale equipment for lifting. This solves the problem of setting up lifting equipment in deep foundation pits with narrow sites, avoids the safety risks of lifting large facilities, and improves construction efficiency. Moreover, ordinary steel pipe support systems and wooden formwork can be assembled according to structural characteristics, with flexible turnover, thereby reducing construction costs.

[0021] As a preferred embodiment, Figure 1 and Figure 2As shown, the exterior wall formwork device includes a single-head screw 16, an exterior wall wooden formwork 13, a wooden beam 12, a double steel tube vertical support 10 and a double steel tube main rib 11; the wall reinforcement is tied at the designed position of the basement exterior wall 15, and the single-head screw 16 is fixed on the wall reinforcement. The spacing of the single-head screw 16 is 450mm, and it is welded according to the exterior wall position line. The exposed size of the single-head screw 16 is suitable for the reinforcement of the double steel tube main rib 11; the exterior wall wooden formwork 13 is installed on the single-head screw 16, and the wooden beam 12 is fixed on the outside of the exterior wall wooden formwork 13; the double steel tube main rib 11 is installed on the outer surface of the wooden beam 12; the double steel tube vertical support 10 is arranged on the outside of the double steel tube main rib 11, and is tightened with the threaded end of the single-head screw 16 through the double nut located on the outside of the double steel tube vertical support 10, so that the bottom of the double steel tube vertical support 10 is in contact with the inner side of the anti-floating reinforcement 3, and is welded and fixed. The exterior wall formwork device has the characteristics of modularity, is easy to assemble, and is light in weight and small in size, making it easy to lift with ordinary lifting equipment. The present invention adopts a single-head screw 16 instead of the tension screw commonly used in construction for reinforcement, which can avoid the damage of the tension screw to the foundation pit support structure 14 and the waterproof layer between the basement exterior wall, and is more convenient for the integrated casting of the basement exterior wall 15 and the basement top plate 9, avoiding the generation of construction joints and the risk of exterior wall leakage.

[0022] As a preferred embodiment, the anti-slip steel pipe 8 is fixedly connected to the double steel pipe vertical support 10 through a rotating fastener; the lower end of the diagonal support rod 5 is connected to the embedded steel pipe 2 through a rotating fastener; the supporting stabilizing rod 7 is tilted and fixed on the six diagonal support rods 5 through a rotating fastener. The fastener connection method is convenient for disassembly and assembly, can be repeatedly reused, and reduces material costs.

[0023] As a preferred embodiment, Figure 2 As shown, the upper and lower steel pipes of the double steel pipe main rib 11 are clamped on the single-head screw 16, and the outer screw portion of the single-head screw 16 is provided with an adjusting piece 17 that is threadedly connected to the single-head screw 16; the adjusting piece 17 is provided with an arc-shaped groove corresponding to the outer circular surface of the upper and lower steel pipes of the double steel pipe main rib 11, and the double steel pipe main rib 11 is fixed to the outer surface of the wooden beam 12 through the arc-shaped groove of the adjusting piece 17, and then the double steel pipe vertical support 10 is hoisted and erected, and the two steel pipes of the double steel pipe vertical support 10 are sleeved on the single-head screw 16 and fit with the adjusting piece 17, and then the exterior wall wooden formwork 13, the wooden beam 12, the double steel pipe main rib 11 and the double steel pipe vertical support 10 are fixed by tightening the double nuts; and the verticality of the double steel pipe vertical support 10 is ensured by adjusting the double nuts. A top wooden formwork 21 is provided under the top plate steel bars used for pouring the basement top plate 9; the upper end of the exterior wall formwork device is supported under the top wooden formwork 21, thereby ensuring the pouring quality of the basement exterior wall 15 and the basement top plate 9, ensuring the structural strength, and improving the service life of the building.

[0024] As a preferred embodiment, a steel formwork 19 is provided in the shear wall concrete of the basement floor 1 located between the foundation pit support structure 14 and the exterior wall wooden formwork 13; the steel formwork 19 is fixed to the exterior wall wooden formwork 13 by a connecting rod 20 arranged on the side; a water-stop steel plate 18 is provided in the steel formwork 19. This structure can avoid the problem of formwork explosion caused by tamping and vibration during concrete pouring, and extend the water seepage path of the basement exterior wall 15. The self-waterproofing effect of the structure is significantly improved, which greatly avoids the quality and safety risks of exterior wall seepage in the later stage.

[0025] The present invention also provides a construction method for a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement, comprising the following steps: S1: splitting the load-bearing parameters and component dimensions of the single-sided formwork system for the outer wall of the basement according to basement design indicators, and performing BIM modeling using REVIT three-dimensional software; performing simulation and finite element analysis based on the BIM model, modifying structures and dimensions that do not meet the requirements, and then performing simulation again until the structural strength and stress distribution meet the standard requirements; selecting a location with the maximum basement pouring height and the most unfavorable construction as a BIM model based on the construction conditions of the single-sided formwork for the outer wall of the basement, establishing a stress analysis model, performing stress finite element analysis, and then performing simulation; S2: Extract the model data of BIM modeling, generate each parts drawing, and produce qualified parts; S3: Construct the foundation pit support structure 14 in the deep foundation pit; simultaneously, install a set of floating reinforcement bars 3 and three sets of embedded steel pipes 2 at equal intervals in the basement floor 1 from the wall outward, with the spacing between the set of floating reinforcement bars 3 and the three sets of embedded steel pipes 2 set according to the dimensions that meet the standard requirements after BIM modeling simulation, and then cast the basement floor 1; then cast the shear wall on the basement floor 1; S4: Installation of the exterior wall formwork device: tie the wall reinforcement at the designed position of the basement exterior wall 15, and fix the single-head screw 16 on the wall reinforcement; then use ordinary lifting equipment to lift the exterior wall wooden formwork 13 and install it on the single-head screw 16, and then lift the wooden beam 12 and fix it to the exterior wall wooden formwork 13, which solves the lifting convenience in a narrow space and reduces the construction difficulty and lifting cost of specific large-scale lifting equipment; install the double steel pipe main rib 11 to the outer surface of the wooden beam 12; set the double steel pipe vertical support 10 on the outside of the double steel pipe main rib 11, and tighten the double nut located on the outside of the double steel pipe vertical support 10 with the threaded end of the single-head screw 16, so that the bottom of the double steel pipe vertical support 10 is in contact with the inner side of the anti-floating reinforcement 3, and weld and fix it as the main force point of the bottom side pressure; S5: Installation of single-row formwork frame: Place one end of the horizontal support rod 4 against the external wall formwork device, and connect the other end to three pre-buried steel pipes 2 on the same horizontal line through rotating fasteners; six rows of horizontal anti-slip steel pipes 8 are arranged from top to bottom on the outer side of the external wall formwork device; the upper ends of the diagonal support rods 5 are respectively placed under the corresponding anti-slip steel pipes 8 and fixed to the external wall formwork device, and the lower ends of the diagonal support rods 5 are fixedly connected to the pre-buried steel pipes 2; the support stabilizing rods 7 are fixed obliquely on the six diagonal support rods 5, and the lower end of the middle support stabilizing rod 7 is connected to the external wall formwork device and the basement floor The intersection of the plates 1 is the support point, and the other two supporting and stabilizing rods 7 are equidistantly arranged on the upper and lower sides of the middle supporting and stabilizing rod 7. The three supporting and stabilizing rods 7 are connected to the diagonal bracing rods 5 in an inverted triangle through rotating fasteners, thereby improving the supporting strength and stability of the basement exterior wall single-sided formwork system; the inner sides of the left and right ends of the exterior wall formwork device are fixed by multiple groups of single-row formwork frames; a full-length connecting rod 6 is provided at the connection between the supporting and stabilizing rods 7 and the diagonal bracing rods 5, and is horizontally fixed to the multiple groups of single-row formwork frames through rotating fasteners; thus completing the construction of the basement exterior wall single-sided formwork system; S6: A steel formwork 19 is set in the concrete of the shear wall; the steel formwork 19 is fixed to the exterior wall wooden formwork 13 via a connecting rod 20 set on the side; then a waterstop steel plate 18 is set in the steel formwork 19; S7: Set the top wooden formwork 21 under the top plate steel bars of the basement top plate 9; support and connect the bottom of the top wooden formwork 21 with the upper end of the outer wall formwork device; then cast concrete for the basement outer wall 15 and the basement top plate 9 at one time.

[0026] As a preferred embodiment, in S3: the distances between the three embedded steel pipes 2 and the basement outer wall 15 are 1.6m, 2.5m and 3.4m respectively; the height of the embedded steel pipe 2 is 550mm, and the embedded length is 300mm, which serves as the anchor support point; C16 steel bars are embedded at 200mm from the shear wall flange as floating reinforcement 3 of the anti-floating tension node, which is used to be welded and fixed to the bottom of the double steel pipe vertical support 10; the point distribution of the embedded steel pipe 2 is as follows Figure 3 As shown, according to the different sizes of the basement exterior wall construction, the points of the embedded steel pipes 2 can be marked on the basement floor 1 for selective installation.

[0027] As a preferred embodiment, in S4: the exterior wall wooden formwork 13 uses wooden plywood, and the exterior wall wooden formwork 13 is marked and punched on site according to the pre-arranged single-head screw 16 spacing. After being assembled into a whole piece by piece, the wooden beams 12, double steel pipe main ribs 11, adjustment parts 17 and double steel pipe vertical supports 10 are installed and locked with double nuts. The double nuts at the upper and lower ends are adjusted to adjust the verticality of the double steel pipe vertical supports 10.

[0028] As a preferred embodiment, in S5: the six diagonal braces 5 have six contact intersections with the double steel pipe vertical braces 10, and the six contact intersections are 900mm, 1350mm, 1800mm, 2300mm, 2800mm and 3350mm from the ground from bottom to top; the lower ends of the first diagonal brace and the second diagonal brace from left to right are fixedly connected to the embedded steel pipe 2 on the left, the lower ends of the third diagonal brace and the fourth diagonal brace are fixedly connected to the embedded steel pipe 2 in the middle, and the lower ends of the fifth diagonal brace and the sixth diagonal brace are fixedly connected to the embedded steel pipe 2 on the right, and the lower ends of the first diagonal brace, the second diagonal brace, the third diagonal brace, the fourth diagonal brace, the fifth diagonal brace and the sixth diagonal brace are in contact with the surface of the basement floor 1 to ensure the supporting effect. The present invention extracts data through BIM modeling, conducts feasibility and cost analysis, and selects the best solution. The basement exterior wall single-sided formwork system of the present invention adopts modular components, and the exterior wall formwork device of the steel pipe support system plus wooden formwork and double steel pipe vertical supports 10 and double steel pipe main ribs 11 has high overall support strength and good stability. It also has the following advantages: First, the basement exterior wall 15 and the basement top plate 9 structure can be cast in one time with concrete, which saves construction time, avoids the retention of horizontal construction joints, and reduces the risk of leakage; secondly, there is no need to use specific large-scale equipment for lifting, which solves the problem of setting up lifting equipment in deep foundation pits with narrow sites and avoids the safety risks of lifting large facilities; then, compared with the characteristic that steel formwork needs to be customized, the ordinary steel pipe support system wooden formwork can be assembled according to the structural characteristics, with flexible turnover and lower construction cost.

[0029] Although the above describes and illustrates the specific embodiments of the present invention in detail, it should be pointed out that: we can make various equivalent changes and modifications to the above embodiments based on the concept of the present invention, and the functional effects produced therefrom still do not exceed the spirit covered by the specification, and should all be within the scope of protection of the present invention.

Claims

1. A single-sided formwork system for the outer wall of a narrow and deep foundation pit basement, characterized in that: It includes horizontal support rods, oblique support rods, support stabilizing rods, external wall formwork devices and foundation pit support structures; the foundation pit support structure is arranged in a deep foundation pit; a group of floating reinforcements and three groups of embedded steel pipes are arranged at equal intervals in the basement floor from the wall to the outside; the external wall formwork device is arranged on the outside of the basement external wall casting area; one end of the horizontal support rod is against the external wall formwork device, and the other end is connected to the three embedded steel pipes on the same horizontal line through rotating fasteners; six rows of horizontal anti-slip steel pipes are arranged on the outer side of the external wall formwork device from top to bottom; the upper ends of the six oblique support rods are respectively against the corresponding anti-slip steel pipes The lower end of the diagonal support rod is fixed to the embedded steel pipe; the supporting stabilizing rod is tilted and fixed on the six diagonal support rods, and the lower end of the middle supporting stabilizing rod uses the intersection of the external wall formwork device and the basement floor as the support point, and the other two supporting stabilizing rods are equidistantly arranged on the upper and lower sides of the middle supporting stabilizing rod to form a single-row formwork frame; the inner side surfaces of the left and right ends of the external wall formwork device are fixed by multiple groups of single-row formwork frames; a full-length connecting rod is provided at the connection between the supporting stabilizing rod and the diagonal support rod, and is horizontally fixed to the multiple groups of single-row formwork frames by rotating fasteners to form a single-sided formwork system for the external wall of the basement.

2. A single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 1, characterized in that: The exterior wall formwork device includes a single-head screw, an exterior wall wooden formwork, a wooden beam, a double steel pipe vertical support and a double steel pipe main rib; the wall reinforcement is tied at the designed position of the basement exterior wall, and the single-head screw is fixed on the wall reinforcement; the exterior wall wooden formwork is installed on the single-head screw, and the wooden beam is fixed on the outside of the exterior wall wooden formwork; the double steel pipe main rib is installed on the outer surface of the wooden beam; the double steel pipe vertical support is arranged on the outside of the double steel pipe main rib, and is tightened with the threaded end of the single-head screw through the double nut located on the outside of the double steel pipe vertical support, so that the bottom of the double steel pipe vertical support contacts the inner side of the anti-floating reinforcement and is welded and fixed.

3. The single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 2 is characterized in that: The anti-slip steel pipe is fixedly connected to the double steel pipe vertical support through a rotating fastener; the lower end of the diagonal support rod is connected to the embedded steel pipe through a rotating fastener; the supporting stabilizing rod is tilted and fixed on the six diagonal support rods through a rotating fastener.

4. The single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 2, characterized in that: The upper and lower steel pipes of the double-steel-tube main rib are clamped on the single-head screw, and the outer screw portion of the single-head screw is provided with an adjusting piece that is threadedly connected to the single-head screw; the adjusting piece is provided with an arc-shaped groove corresponding to the outer circular surface of the upper and lower steel pipes of the double-steel-tube main rib, and the double-steel-tube main rib is fixed to the outer surface of the wooden beam through the arc-shaped groove of the adjusting piece, and then the double-steel-tube vertical support is hoisted and erected, and the two steel pipes of the double-steel-tube vertical support are put on the single-head screw and fit with the adjusting piece, and then the exterior wall wooden formwork, wooden beam, double-steel-tube main rib and double-steel-tube vertical support are fixed by tightening the double nuts; and the verticality of the double-steel-tube vertical support is ensured by adjusting the double nuts.

5. The single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 1 is characterized in that: A top wooden formwork is arranged below the top plate steel bars for pouring the basement top plate; and the upper end of the outer wall formwork device is supported below the top wooden formwork.

6. The single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 2, characterized in that: A steel formwork is provided in the shear wall concrete of the basement floor located between the foundation pit support structure and the exterior wall wooden formwork; the steel formwork is fixed to the exterior wall wooden formwork through a connecting rod provided on the side; and a waterstop steel plate is provided in the steel formwork.

7. The construction method of a single-side formwork system for the outer wall of a narrow and deep foundation pit basement according to any one of claims 1 to 6, characterized in that: Here are the steps: S1: Based on the basement design indicators, the load-bearing parameters and component dimensions of the basement exterior wall single-sided formwork system were broken down and BIM modeling was performed using REVIT 3D software. Based on the BIM model, simulation and finite element analysis were performed to modify any structures and dimensions that did not meet the requirements. Simulation was then repeated until the structural strength and force distribution met the standard requirements. S2: Extract the model data of BIM modeling, generate each parts drawing, and produce qualified parts; S3: Construct the foundation pit support structure in the deep foundation pit. Simultaneously, install one set of floating reinforcement and three sets of embedded steel pipes at equal intervals in the basement floor from the wall outward. The spacing between one set of floating reinforcement and three sets of embedded steel pipes is set according to the standard requirements after BIM modeling and simulation. Then, cast the basement floor; then cast the shear wall on the basement floor. S4: Installation of the exterior wall formwork: Tie the wall reinforcement at the designed location on the basement exterior wall and secure the single-head screws to the wall reinforcement. Then, use ordinary lifting equipment to lift the exterior wall timber formwork and install it on the single-head screws. Finally, lift the wooden beams and secure them to the exterior wall timber formwork. Install the double steel tube main ribs to the outer surface of the wooden beam; The double steel pipe vertical support is set on the outside of the double steel pipe main rib, and the double nuts located on the outside of the double steel pipe vertical support are tightened with the threaded end of the single-head screw, so that the bottom of the double steel pipe vertical support contacts the inside of the anti-floating reinforcement, and then welded and fixed; S5: Installation of single-row formwork: Place one end of the horizontal support rod against the exterior wall formwork device, and connect the other end to three pre-buried steel pipes on the same horizontal line through rotating fasteners; six rows of horizontal anti-slip steel pipes are arranged from top to bottom on the outer side of the exterior wall formwork device; the upper ends of the diagonal support rods are respectively placed under the corresponding anti-slip steel pipes and fixed to the exterior wall formwork device, and the lower ends of the diagonal support rods are fixedly connected to the pre-buried steel pipes; the supporting stabilizing rods are obliquely fixed on the six diagonal support rods, and the lower end of the middle supporting stabilizing rod is used as the support point at the intersection of the exterior wall formwork device and the basement floor, and the other two supporting stabilizing rods are equidistantly arranged on the upper and lower sides of the middle supporting stabilizing rod; the inner sides of the left and right ends of the exterior wall formwork device are fixed by multiple sets of single-row formwork frames; a full-length connecting rod is provided at the connection between the supporting stabilizing rod and the diagonal support rod, and is horizontally fixed to multiple sets of single-row formwork frames through rotating fasteners; the construction of the single-sided formwork system of the basement exterior wall is completed; S6: A steel formwork is set in the concrete of the shear wall; the steel formwork is fixed to the exterior wall wooden formwork via connecting rods set on the side; and a waterstop steel plate is then set in the steel formwork; S7: Set a top wooden formwork under the top plate reinforcement of the basement top plate; support and connect the bottom of the top wooden formwork with the upper end of the outer wall formwork device; then cast concrete for the basement outer wall and the basement top plate at one time.

8. The construction method of a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 7, characterized in that: In S3: the distances between the three embedded steel pipes and the basement exterior wall are 1.6m, 2.5m, and 3.4m, respectively; the embedded steel pipes are 550mm high and 300mm long, serving as ground anchor support points; C16 steel bars are embedded 200mm from the shear wall flange as floating reinforcement for anti-floating joints, which are welded and fixed to the bottom of the double steel pipe vertical braces.

9. The construction method of a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 7, characterized in that: In S4: The exterior wall wooden formwork uses plywood. The exterior wall wooden formwork is marked and punched on site according to the pre-arranged single-head screw spacing. After being assembled into a whole piece by piece, the wooden beams, double steel pipe main ribs, adjustment parts and double steel pipe vertical supports are installed and locked with double nuts. The double nuts at the upper and lower ends are adjusted to adjust the verticality of the double steel pipe vertical supports.

10. The construction method of a single-sided formwork system for the outer wall of a narrow and deep foundation pit basement according to claim 7, characterized in that: In S5: the six diagonal braces have six contact intersections with the double steel pipe vertical braces, and the six contact intersections are 900mm, 1350mm, 1800mm, 2300mm, 2800mm and 3350mm from the ground from bottom to top; the lower ends of the first diagonal brace and the second diagonal brace from left to right are fixedly connected to the embedded steel pipe on the left, the lower ends of the third diagonal brace and the fourth diagonal brace are fixedly connected to the embedded steel pipe in the middle, and the lower ends of the fifth diagonal brace and the sixth diagonal brace are fixedly connected to the embedded steel pipe on the right, and the lower ends of the first diagonal brace, the second diagonal brace, the third diagonal brace, the fourth diagonal brace, the fifth diagonal brace and the sixth diagonal brace are in contact with the surface of the basement floor to ensure the supporting effect.

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