Permanent and temporary combined assembly type underground structure plate wall connecting joint and construction method

Abstract

The invention discloses a permanent and temporary combined assembly type underground structure plate wall connecting node and a construction method, the connecting node comprises an assembly type underground diaphragm wall, a full-length steel plate is mounted on the side wall of the assembly type underground diaphragm wall, and a prefabricated structure plate is hoisted on the full-length steel plate; a gap between the prefabricated structural slab and the fabricated underground diaphragm wall is filled with ultra-high-performance concrete, and a steel bar structure is arranged in the ultra-high-performance concrete; the construction method comprises the following steps that the fabricated underground diaphragm wall is hoisted, and the steel bar connectors are reserved; anchoring steel bars are externally connected; mounting a profile steel bracket, and welding a full-length steel plate; prefabricated structural slabs are hoisted, and reserved U-shaped ribs and anchoring steel bars are arranged in a staggered mode; longitudinal main reinforcements are welded, and circumferential stirrups are bound; and casting ultrahigh-performance concrete in situ to finish node construction. The integrity of the structure is improved, and the safety and durability of the underground structure are fully guaranteed; the underground diaphragm wall is changed into a permanent structure, the construction period is shortened, and investment is saved.

Description

Technical Field

[0001] The invention belongs to the technical field of prefabricated underground structures, and particularly relates to a connection node and construction method for a permanent-temporary combined prefabricated underground structure slab wall. Background Technique

[0002] At present, the construction technology of prefabricated underground structures is becoming increasingly prosperous. It has many advantages such as saving construction period, improving production efficiency, being easy to control construction quality, and being less affected by climate factors. At the same time, it can greatly reduce the construction waste generated during the construction process. However, the current construction technology of prefabricated underground structures is still in the experimental research stage. Among them, most connection nodes still cannot achieve rigid connection similar to cast-in-place reinforced concrete structures. For example, Chinese Patent CN110042863A discloses a connection node and construction method for the underground wall and precast middle slab of a fully composite prefabricated subway station, and the slab wall node adopts a slot connection; Chinese Patent CN218027825U discloses a connection device for the side wall and diaphragm wall of a prefabricated subway station, and the diaphragm wall and the structural side wall are connected by anchor bolts; Chinese Patent CN116641725A discloses a joint of a precast assembled subway station lining structure, and the lining connection is realized in a mortise and tenon form.

[0003] In a few cases where rigid connection of the underground structure slab wall is achieved, an outer retaining structure still needs to be set up. For example, Chinese Patent CN113152690A discloses a connection node and construction method for the side wall and middle slab of a prefabricated structure. By reserving vertical connectors in the precast side wall, the slab wall connection is realized by using force-transferring steel plates, and post-cast concrete forms a connection node. This patent fails to combine the permanent structure side wall and the temporary retaining structure into one, and at the same time, the structural steel consumption is large, and the component installation is complicated. The use of a permanent-temporary combined underground structure can greatly reduce the waste engineering quantity of the temporary structure, save costs, and avoid repeated project construction and material waste.

[0004] Therefore, in order to better solve the problem of rigid connection of the prefabricated underground structure slab wall and make full use of the role of the diaphragm wall in the permanent use stage, the rigid connection node of the prefabricated diaphragm wall and slab of the present invention has great popularization value. Summary of the Invention

[0005] The present invention is proposed to solve the problems existing in the prior art, and its purpose is to provide a connection node and construction method for a permanent-temporary combined prefabricated underground structure slab wall.

[0006] The technical solution of the present invention is: a temporary and permanent combined prefabricated underground structural slab-wall connection node, including a prefabricated underground diaphragm wall, a full-length steel plate is installed on the side wall of the prefabricated underground diaphragm wall, a precast structural slab is suspended on the full-length steel plate, ultra-high performance concrete is filled in the gap between the precast structural slab and the prefabricated underground diaphragm wall, and a steel bar structure associated with the precast structural slab and the prefabricated underground diaphragm wall is arranged in the ultra-high performance concrete.

[0007] Furthermore, the steel bar structure includes a first steel bar assembly associated with the prefabricated underground diaphragm wall, a second steel bar assembly of the precast structural slab, and a third steel bar assembly connecting the first steel bar assembly and the second steel bar assembly.

[0008] Furthermore, the first steel bar assembly includes a steel bar connector reserved at the side wall of the prefabricated underground diaphragm wall, and anchoring steel bars are arranged at the steel bar connector.

[0009] Furthermore, the second steel bar assembly includes reserved U-shaped steel bars reserved in the precast structural slab, and the reserved U-shaped steel bars protrude from the side wall of the precast structural slab and are parallel to the anchoring steel bars.

[0010] Furthermore, the third steel bar assembly includes longitudinal main steel bars, and the longitudinal main steel bars are fixedly welded to the reserved U-shaped steel bars.

[0011] Furthermore, the longitudinal main steel bars are parallel to the prefabricated underground diaphragm wall and the precast structural slab.

[0012] Furthermore, the third steel bar assembly further includes circumferential stirrups, and the circumferential stirrups connect adjacent reserved U-shaped steel bars.

[0013] Furthermore, a profiled steel corbel is installed on the side wall of the prefabricated underground diaphragm wall, and the full-length steel plate is fixed on the profiled steel corbel.

[0014] A construction method for a temporary and permanent combined prefabricated underground structural slab-wall connection node includes the following steps: S1. Hoist the prefabricated underground diaphragm wall and reserve the steel bar connectors; S2. Connect the anchoring steel bars externally at the reserved steel bar connectors; S3. Install the profiled steel corbels and weld the full-length steel plates; S4. Hoist the precast structural slab and stagger the reserved U-shaped steel bars and the anchoring steel bars; S5. Weld the longitudinal main steel bars and bind the circumferential stirrups; S6. Cast the ultra-high performance concrete in situ to complete the construction of the node.

[0015] Furthermore, in step S2, connecting the anchoring steel bars externally at the reserved steel bar connectors, the specific process is as follows: First, connect the anchor steel bars to the reserved steel bar connectors; Then, the anchor steel bars are arranged alternately by 135° hook anchoring and welding anchoring; Then, connect the welded anchor steel bars first; Finally, connect the 135° hook anchor steel bar.

[0016] The beneficial effects of the present invention are as follows: Compared with connection nodes using hinged forms or mortise and tenon forms, the connection nodes provided by the present invention are connected by pre-reserved anchor bars at the plate and wall joints and the main bars installed later to form a steel skeleton, and the plate and wall joints are connected together by pouring ultra-high performance concrete, which can form a rigid joint similar to cast-in-place reinforced concrete, ensuring the overall strength of the joint, while avoiding fatigue damage under long-term service conditions, and fully ensuring the overall safety and durability of the underground structure.

[0017] Compared with ordinary underground continuous walls that serve as temporary enclosure structures, the plate wall connection node provided by the present invention realizes the integration of the permanent structure side wall and the underground continuous wall. The use of a permanent and temporary combined underground structure can greatly reduce the amount of abandoned temporary structure projects, save costs, and avoid repeated construction and material waste.

[0018] The underground structural plates and walls in the connection nodes provided by the present invention are all prefabricated components. Such components are all prefabricated in the factory and transported to the site for construction and assembly, which can significantly improve the on-site construction efficiency, save construction time, and greatly reduce the construction waste generated during the construction process; at the same time, the quality of the structural construction is easy to control and is less affected by environmental and climatic factors.

[0019] The prefabricated structural slabs in the connection nodes provided by the present invention are pre-embedded with U-shaped bars at both ends in advance when the ground is cast. The assembled underground continuous wall is externally anchored with steel bars through reserved steel bar connectors. At the same time, the pre-embedded U-shaped bars and the assembled underground continuous wall anchor bars are arranged alternately without welding connection, which can greatly reduce the amount of steel bar binding and welding at the construction site and significantly improve the on-site construction efficiency.

[0020] In the connection node provided by the present invention, two steel corbels are arranged on one side of each prefabricated structural plate, and a full-length steel plate is welded on the steel corbel. The full-length steel plate serves as a bottom form for pouring ultra-high performance concrete. The arrangement of the steel corbels and the full-length steel plate can help determine the positioning elevation of the plate, reduce the erection of on-site formwork supports, ensure the accuracy of structural installation, and ensure the pouring quality of concrete; after the node is poured, the steel corbels can be permanently retained, which further increases the overall strength of the structure and makes full use of temporary components.

[0021] The connection node provided by the present invention adopts ultra-high performance concrete, and the anchorage length of the steel bars can be significantly reduced, so that the width of the joint between the slab wall can be reduced; at the same time, the spacing of the steel bar arrangement can be increased, reducing the amount of steel bars used, facilitating the hoisting and splicing of on-site precast components, and reducing the on-site operation difficulty.

[0022] The present invention realizes the rigid connection between two precast components, improves the integrity of the precast structure, ensures the safety and durability of the underground structure, saves the construction period and investment, and at the same time can significantly reduce the amount of on-site steel bars and the binding workload. It is convenient to install, the process is simple, the construction efficiency is significantly improved, and it has good practical significance and popularization value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of the connection node of the slab wall of the permanent-temporary combined precast underground structure in the present invention (excluding ultra-high performance concrete, main reinforcement and stirrups at the joint); Figure 2 is a schematic cross-sectional diagram of the connection node of the slab wall of the permanent-temporary combined precast underground structure in the present invention; Figure 3 is a plan view of the reinforcement of the connection node of the slab wall of the permanent-temporary combined precast underground structure in the present invention; Figure 4 is a cross-sectional view of the reinforcement of the connection node of the slab wall of the permanent-temporary combined precast underground structure in the present invention; Among them, 1. Permanent-temporary combined precast diaphragm wall, 2. Precast structural slab, 3. Steel bar coupler, 4. Reserved U-shaped steel bar, 5. Anchor reinforcement, 51. Fillet-welded anchor reinforcement, 52. 135° hook anchor reinforcement, 6. Longitudinal main reinforcement, 7. Circumferential stirrup, 8. Steel section bracket, 81. Bracket steel bar coupler, 9. Full-length steel plate, 10. Ultra-high performance concrete. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, the present invention will be described in detail with reference to the drawings and embodiments: As Figures 1 to 4 shown, a connection node of the slab wall of the permanent-temporary combined precast underground structure includes a permanent-temporary combined precast diaphragm wall 1, a full-length steel plate 9 is installed on the side wall of the permanent-temporary combined precast diaphragm wall 1, a precast structural slab 2 is suspended on the full-length steel plate 9, and ultra-high performance concrete 10 is filled in the gap between the precast structural slab 2 and the permanent-temporary combined precast diaphragm wall 1, and a steel bar structure associated with the precast structural slab 2 and the permanent-temporary combined precast diaphragm wall 1 is arranged in the ultra-high performance concrete 10.

[0025] The steel bar structure includes a first steel bar assembly associated with the permanent-temporary combined precast diaphragm wall 1, a second steel bar assembly of the precast structural slab 2, and a third steel bar assembly connecting the first steel bar assembly and the second steel bar assembly.

[0026] The first steel bar assembly includes a steel bar connector 3 reserved at the side wall of the prefabricated diaphragm wall 1, and an anchoring steel bar 5 is arranged at the steel bar connector 3.

[0027] The second steel bar assembly includes a reserved U-shaped steel bar 4 reserved in the precast structural slab 2. The reserved U-shaped steel bar 4 extends out of the side wall of the precast structural slab 2 and is parallel to the anchoring steel bar 5.

[0028] The third steel bar assembly includes longitudinal main steel bars 6, and the longitudinal main steel bars 6 are fixedly welded to the reserved U-shaped steel bars 4.

[0029] The longitudinal main steel bars 6 are parallel to the prefabricated diaphragm wall 1 and the precast structural slab 2.

[0030] The third steel bar assembly further includes circumferential stirrups 7, and the circumferential stirrups 7 connect adjacent reserved U-shaped steel bars 4.

[0031] A profiled steel corbel 8 is installed at the side wall of the prefabricated diaphragm wall 1, and the continuous steel plate 9 is fixed on the profiled steel corbel 8.

[0032] As Figure 2 shown, the side wall of the prefabricated diaphragm wall 1 forms an inward concave groove, and the corresponding position at the end of the precast structural slab 2 also forms a groove, ultra-high performance concrete 10.

[0033] More specifically, the groove depth of the groove in the prefabricated diaphragm wall 1 and the precast structural slab 2 is not greater than the outermost steel bar protection layer thickness of the prefabricated diaphragm wall 1 and the precast structural slab 2.

[0034] Specifically, the end of the precast structural slab 2 is treated with a rough surface, and the corresponding side wall position of the prefabricated diaphragm wall 1 is also treated with a rough surface.

[0035] Specifically, a corbel steel bar connector 81 is reserved in the prefabricated diaphragm wall 1, and the profiled steel corbel 8 is fixed at the side wall of the prefabricated diaphragm wall 1 through the corbel steel bar connector 81.

[0036] More specifically, at least two profiled steel corbels 8 are arranged on one side of each precast structural slab 2.

[0037] As Figure 3 shown, the steel bar connectors 3 are evenly distributed in each precast structural slab 2, and the steel bar connectors 3 are densely arranged at the junction of adjacent precast structural slabs 2.

[0038] Specifically, the protruding lengths of the reserved U-shaped steel bars 4 and the anchoring steel bars 5 are not greater than the distance between the prefabricated diaphragm wall 1 and the precast structural slab 2.

[0039] Specifically, the reserved U-shaped bars 4 and the anchoring bars 5 are arranged at intervals between the precast underground diaphragm wall 1 and the precast structural slab 2.

[0040] As Figure 4 shown, the steel bar couplers 3 are arranged in three layers vertically, the longitudinal main bars 6 are arranged in four layers vertically, and the reserved U-shaped bars 4 are double U-shaped steel bars inside and outside.

[0041] Specifically, there are eight longitudinal main bars 6. Three longitudinal main bars 6 are laid flat on the topmost layer, and one longitudinal main bar 6 is arranged close to the topmost layer. This longitudinal main bar 6 is arranged diagonally with the longitudinal main bar 6 close to the precast structural slab 2 on the topmost layer. Three longitudinal main bars 6 are laid flat on the bottommost layer, and one longitudinal main bar 6 is arranged close to the bottommost layer. This longitudinal main bar 6 is arranged diagonally with the longitudinal main bar 6 close to the precast structural slab 2 on the bottommost layer.

[0042] Specifically, the anchoring bars 5 include welded anchoring bars 51 and 135° hook anchoring bars 52.

[0043] Specifically, the topmost steel bar coupler 3 is connected to the 135° hook anchoring bar 52, and the hook part of the 135° hook anchoring bar 52 passes through the longitudinal main bar 6 close to the precast structural slab 2 on the topmost layer and the longitudinal main bar 6 close to the topmost layer.

[0044] Similarly, the bottommost steel bar coupler 3 is connected to the 135° hook anchoring bar 52 and is symmetric with the 135° hook anchoring bar 52 on the topmost layer.

[0045] Specifically, the steel bar coupler 3 is also connected to the welded anchoring bar 51, and the welded anchoring bar 51 is welded and fixed.

[0046] A construction method for the connection node of the permanent-temporary combined precast underground structural slab wall includes the following steps: S1. Hoist the precast underground diaphragm wall 1 and reserve the steel bar couplers 3; S2. Connect the anchoring bars 5 externally at the reserved steel bar couplers 3; S3. Install the steel section corbels 8 and weld the full-length steel plates 9; S4. Hoist the precast structural slab 2 and arrange the reserved U-shaped bars 4 and the anchoring bars 5 staggeredly; S5. Weld the longitudinal main bars 6 and tie the circumferential stirrups 7; S6. Cast the ultra-high performance concrete 10 to complete the construction of the node.

[0047] Specifically, in step S1, hoist the precast underground diaphragm wall 1 and reserve the steel bar couplers 3. The specific process is as follows: Lift and lower the prefabricated assembled diaphragm wall 1 to the position required by the design, and reserve steel bar couplers 3 at the connection position between the assembled diaphragm wall 1 and the precast structural slab 2.

[0048] Step S2: Connect the external anchoring steel bars 5 at the reserved steel bar couplers 3. The specific process is as follows: First, connect the external anchoring steel bars 5 at the reserved steel bar couplers 3; Then, the anchoring steel bars 5 are arranged alternately in two ways: 135° hook anchoring and fillet welding anchoring; Next, connect the fillet welding anchoring steel bars 51 first; Finally, connect the 135° hook anchoring steel bars 52.

[0049] Specifically, for step S3, install the profiled steel corbels 8 and weld the continuous steel plates 9. The specific process is as follows: First, install the positioning profiled steel corbels 8 of the precast structural slab 2 on the assembled diaphragm wall 1; Then, connect the profiled steel corbels 8 to the corbel steel bar couplers 81 pre-embedded in the assembled diaphragm wall 1; Next, set two profiled steel corbels 8 on one side of each precast structural slab 2; Finally, weld the continuous steel plates 9 on the profiled steel corbels 8.

[0050] Specifically, for step S4, lift and install the precast structural slab 2, and stagger the reserved U-shaped steel bars 4 and the anchoring steel bars 5. The specific process is as follows: First, pre-embed the U-shaped steel bars 4 at both ends in advance when the precast structural slab 2 is cast in the precast yard; Then, lift and install the precast structural slab 2 onto the continuous steel plate 9, and at the same time, stagger the pre-embedded U-shaped steel bars 4 and the anchoring steel bars 5 of the assembled diaphragm wall 1.

[0051] Specifically, for step S5, weld the longitudinal main steel bars 6 and tie the circumferential stirrups 7. The specific process is as follows: First, place the longitudinal main steel bars 6 at the joint between the assembled diaphragm wall 1 and the precast structural slab 2; Then, spot-weld the longitudinal main steel bars 6 to the pre-embedded U-shaped steel bars 4; Finally, tie the circumferential stirrups 7 around the longitudinal main steel bars 6.

[0052] Specifically, for step S6, cast the ultra-high performance concrete 10 to complete the joint construction. The specific process is as follows: First, cast the ultra-high performance concrete 10 at the joint between the assembled diaphragm wall 1 and the precast structural slab 2; Then, the continuous steel plate 9 on the profiled steel corbel 8 serves as the bottom formwork for the casting of the ultra-high performance concrete 10; Finally, when the ultra-high performance concrete 10 is cured to reach the strength required by the design, a safe and reliable connection can be formed between the precast diaphragm wall 1 and the precast structural slab 2.

[0053] Specifically, in step S2, the steel bar spacing of the anchoring steel bars 5 and the embedded U-shaped steel bars 4 should be the same, so as to ensure that the precast structural slab can be smoothly hoisted and lowered in step S4.

[0054] Specifically, in step S6, after the ultra-high performance concrete 10 reaches the design strength, the steel section bracket 8 can be selected to be removed or permanently retained according to functional requirements.

[0055] Specifically, in the present invention, the concrete material grade of the precast diaphragm wall 1 and the precast structural slab 2 is preferably selected as C50 as the optimal embodiment; the ultra-high performance concrete 10 is preferably selected as UC130 as the optimal embodiment, and the corresponding preferred axial compressive strength design value is 62.5 MPa.

[0056] Specifically, the groove depth in the precast diaphragm wall 1 and the precast structural slab 2 is not greater than the outermost steel bar protection layer thickness of the precast diaphragm wall 1 and the precast structural slab 2, and the depth is not less than 6 mm. The end joint surfaces are all coated with release agent and rough surface treatment is carried out.

[0057] Specifically, in step S2, the model of the anchoring steel bars 5 is preferably HRB400 steel bars; according to the provisions of DBJ / T15-244-2022 "Technical Specification for Precast Ultra-High Performance Concrete Municipal Bridge Structures", ribbed steel bars with a diameter d greater than 25 mm are preferably selected, and the minimum anchorage length of the hooked end tension steel bars is 15.7d, which is significantly smaller than the 35d anchorage length of ordinary reinforced concrete.

[0058] Specifically, in step S2, the steel bar spacing of the anchoring steel bars 5 and the embedded U-shaped steel bars 4 should be the same, and the preferred steel bar spacing is 200 mm, so as to ensure that the precast structural slab can be smoothly hoisted and lowered in step S4.

[0059] The present invention provides a connection node for a permanent and temporary combined precast underground structural slab wall, which is applicable to an underground frame structure with a precast diaphragm wall as the retaining structure, and is applicable to different slab layers such as the bottom slab, middle slab and top slab of the underground structure according to engineering needs.

[0060] The above embodiments have explained the present invention in detail, but the content described is only a relatively preferred embodiment of the present invention, and shall not be used to limit the scope of implementation of the present invention. Any adjustments, combinations, substitutions and improvements made within the scope of the application of the present invention shall be included in the protection scope of the present invention.

Claims

1. A permanent and temporary combined assembled underground structural panel wall connection node, comprising an assembled underground continuous wall (1), characterized in that: A full-length steel plate (9) is installed on the side wall of the assembled underground continuous wall (1), a prefabricated structural plate (2) is suspended on the full-length steel plate (9), a gap between the prefabricated structural plate (2) and the assembled underground continuous wall (1) is filled with ultra-high performance concrete (10), and a steel bar structure associated with the prefabricated structural plate (2) and the assembled underground continuous wall (1) is arranged in the ultra-high performance concrete (10).

2. A permanent and temporary combined assembled underground structural panel wall connection node according to claim 1, characterized in that: The steel bar structure comprises a first steel bar component associated with the assembled underground continuous wall (1), a second steel bar component associated with the prefabricated structural panel (2), and a third steel bar component connecting the first steel bar component and the second steel bar component.

3. A permanent and temporary combined assembled underground structural panel wall connection node according to claim 2, characterized in that: The first steel bar assembly comprises a steel bar connector (3) reserved at the side wall of the assembled underground continuous wall (1), and anchor steel bars (5) are arranged at the steel bar connector (3).

4. A permanent and temporary combined assembled underground structural panel wall connection node according to claim 3, characterized in that: The second steel bar assembly comprises a reserved U-shaped bar (4) reserved for the prefabricated structural plate (2), wherein the reserved U-shaped bar (4) protrudes out of the side wall of the prefabricated structural plate (2) and is parallel to the anchoring steel bar (5).

5. A permanent and temporary combined assembled underground structural panel wall connection node according to claim 4, characterized in that: The third steel bar assembly comprises a longitudinal main bar (6), and the longitudinal main bar (6) is fixed to the reserved U-shaped bar (4) by welding.

6. A permanent and temporary combined assembled underground structural panel wall connection node according to claim 5, characterized in that: The longitudinal main reinforcement (6) is parallel to the assembled underground continuous wall (1) and the prefabricated structural panel (2).

7. The permanent and temporary combined assembled underground structural panel wall connection node according to claim 5 is characterized by: The third steel bar assembly further comprises annular stirrups (7), wherein the annular stirrups (7) connect adjacent reserved U-shaped bars (4).

8. The permanent and temporary combined assembled underground structure panel wall connection node according to claim 1 is characterized by: A steel bracket (8) is installed on the side wall of the assembled underground continuous wall (1), and the full-length steel plate (9) is fixed on the steel bracket (8).

9. A construction method for a permanent and temporary combined assembled underground structure panel wall connection node, characterized in that: The following steps are involved: S1. Lifting the assembled underground continuous wall (1), and reserving the steel bar connector (3); S2. An external anchoring steel bar (5) is connected to the reserved steel bar connector (3); S3. Install the steel bracket (8) and weld the full-length steel plate (9); S4. Hoisting the prefabricated structural plate (2), staggered arrangement of reserved U-shaped bars (4) and anchor bars (5); S5. Weld the longitudinal main reinforcement (6) and tie the annular stirrups (7); S6. Cast-in-place ultra-high performance concrete (10) to complete the node construction.

10. The construction method of a permanent and temporary combined assembled underground structure panel wall connection node according to claim 9, characterized in that: Step S2 is to connect the anchoring steel bar (5) to the reserved steel bar connector (3). The specific process is as follows: First, an external anchoring steel bar (5) is connected to the reserved steel bar connector (3); Then, the anchor steel bars (5) are arranged alternately by 135° hook anchoring and welding anchoring; Then, first connect the welded anchor steel bars (51); Finally, connect the 135° hook anchor reinforcement (52).

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