Structure for joint of road underpass and rear opening of existing underground structure

Abstract

The invention discloses a structure for a joint of a road underpass and a rear opening of an existing underground structure, which comprises the existing underground structure, and the rear opening is formed in the side wall of the existing underground structure; the protective ring beam is poured on the outer side of the side wall, the protective ring beam is arranged in a circle in the circumferential direction of the rear opening, and a rubber water stop strip is embedded in a construction joint between the side, facing the side wall, of the protective ring beam and the existing underground structure; the road underpass channel is coaxially arranged on the other side, away from the side wall, of the protective ring beam, and a deformation joint is formed between the road underpass channel and the other side of the protective ring beam; and the water stop belt is arranged in the deformation joint, and the two opposite sides of the water stop belt are buried in the road underpass channel and the protective ring beam correspondingly. The problem that the waterproof effect is poor when the rear opening is connected under the condition of asynchronous construction of the road underpass and the existing underground structure is solved.

Description

Construction of the connection between the highway underpass and the post-opening of the existing underground structure Technical Field

[0001] This invention relates to the field of building construction technology, specifically to a construction method for the connection between a highway underpass and an existing underground structure through a post-opening. Background Technology

[0002] With urban development, underground highway tunnels are becoming increasingly common. Underground highway tunnels offer significant advantages over elevated highways in terms of noise pollution and aesthetics. However, the requirements for waterproofing and appearance of underground highway tunnels are becoming increasingly stringent. For example, large-scale wet leaks are not permitted during final acceptance, and linear seepage is not allowed during operation. While modern underground tunnel projects have implemented measures such as external waterproof membranes, waterproof expansion joint structures, and drainage ditches along crash barriers to isolate and divert groundwater, providing good assurance for waterproofing, existing station underground structures constructed at different times, lacking pre-embedded construction joints and already covered with soil, require the excavation of new openings. Furthermore, the simultaneous casting of the station underground structure's top slab, side walls, and bottom slab makes direct connection of the highway tunnel impossible, leading to construction difficulties. If the construction joint between the existing underground structure of the station building and the urban underground highway passage is not properly treated and controlled, it will be difficult to remove the concrete at the construction joint later, and there will be a great risk of leakage. The waterproofing effect will be difficult to meet the design requirements, and it will also affect the construction period and increase the treatment cost.

[0003] The information disclosed in this background section is intended only to enhance the understanding of the overall background of the invention and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0004] To overcome the shortcomings of existing technologies, a new construction method is provided for the connection between a highway underpass and an existing underground structure through a post-opening, which solves the problem of poor waterproofing when the highway underpass and the existing underground structure are constructed asynchronously.

[0005] To achieve the above objectives, a construction method is provided for the connection between a highway underpass and an existing underground structure via a post-opening, comprising: an existing underground structure, wherein the sidewall of the existing underground structure has a post-opening; a protective ring beam, cast on the outer side of the sidewall, the protective ring beam being arranged in a ring along the circumferential direction of the post-opening, and a rubber waterstop strip being embedded in the construction joint between the side of the protective ring beam facing the sidewall and the existing underground structure; a highway underpass, coaxially arranged on the other side of the protective ring beam away from the sidewall, forming a deformation joint between the highway underpass and the other side of the protective ring beam; and a waterstop strip disposed in the deformation joint, with opposite sides of the waterstop strip embedded in the highway underpass and the protective ring beam, respectively.

[0006] Furthermore, a rebar is embedded in the side wall, with the other end of the rebar anchored in the protective ring beam. A water-stop rubber sleeve is fitted in the middle of the rebar, and the water-stop rubber sleeve abuts against one side of the protective ring beam.

[0007] Furthermore, the other end of the rebar is connected to the steel reinforcement structure of the protective ring beam.

[0008] Furthermore, the steel reinforcement structure of the protective ring beam includes an outer ring main reinforcement, an inner ring main reinforcement, and stirrups. The stirrups are clamped to the outer ring main reinforcement and the inner ring main reinforcement, and the other end of the anchor bar is connected to the outer ring main reinforcement or the inner ring main reinforcement.

[0009] Furthermore, the expansion joint is filled with a joint filler plate, and the joint filler plate is respectively provided on both sides of the waterstop.

[0010] Furthermore, the steel reinforcement structures within the highway underpass and the protective ring beam are respectively connected to clamps, which clamp one side of the waterstop.

[0011] This invention provides a construction method for the connection between a highway underpass and a post-opening of an existing underground structure, comprising the following steps: roughening the outer edge of the post-opening location on the sidewall of the existing underground structure; casting a protective ring beam on the outer side of the sidewall, such that the protective ring beam is arranged in a circle along the circumferential direction of the post-opening, and embedding a rubber waterstop strip in the construction joint between the side of the protective ring beam facing the sidewall and the existing underground structure; casting the highway underpass on the other side of the protective ring beam away from the sidewall, such that the highway underpass and the protective ring beam are coaxially arranged, and forming a deformation joint between the highway underpass and the other side of the protective ring beam; setting a waterstop strip in the deformation joint, with the opposite sides of the waterstop strip embedded in the highway underpass and the protective ring beam respectively.

[0012] The beneficial effects of this invention are that the expansion joint design at the connection between the underpass and the existing underground structure allows for relative displacement between the underpass and the existing structure, preventing damage to the waterproof layer due to uneven settlement. The waterstop has a certain degree of elasticity and toughness, maintaining its sealing performance even during structural deformation.

[0013] The protective ring beam constructed at the connection between the highway underpass and the post-opening of the existing underground structure in this invention serves as a transition structure, dispersing stress concentration at the connection and improving the joint's seismic and deformation resistance.

[0014] The connection between the underpass and the existing underground structure in this invention is constructed using non-destructive methods. The connection between the old and new structures is achieved through rebar installation, eliminating the need for large-scale removal of the original concrete or rebar welding, thus maximizing the protection of the existing structural integrity. The protective ring beam is cast outside the existing structure, providing ample construction space and facilitating formwork installation, rebar tying, and concrete pouring.

[0015] The connection structure between the highway underpass and the existing underground structure has significant advantages in terms of waterproof performance, structural safety, construction convenience, economy and sustainability. It is especially suitable for the "post-connection passage" engineering problem frequently encountered in urban underground space development, and has good engineering application prospects and technical promotion value. Attached Figure Description

[0016] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 is a structural schematic diagram of the connection between the highway underpass and the post-opening of the existing underground structure according to an embodiment of the present invention.

[0017] Figure 2 is a cross-sectional view of section AA in Figure 1.

[0018] Figure 3 is a schematic diagram of the upper part of the protective ring beam according to an embodiment of the present invention.

[0019] Figure 4 is a schematic diagram of the lower part of the protective ring beam according to an embodiment of the present invention.

[0020] Figure 5 is a schematic diagram of the side structure of the protective ring beam according to an embodiment of the present invention.

[0021] Figure 6 is a schematic diagram of the deformation joint in an embodiment of the present invention.

[0022] Figure 7 is a schematic diagram of the fixture according to an embodiment of the present invention.

[0023] Attached reference numerals: 1. Existing underground structure; 10. Opening; 11. Side wall; 2. Protective ring beam; 21. Rubber waterstop strip; 22. Rebar; 23. Waterstop rubber sleeve; 24. Outer ring main reinforcement; 25. Inner ring main reinforcement; 26. Stirrup; 3. Highway underpass; 30. Expansion joint; 31. Joint filler; 4. Waterstop strip; 41. Clamp. Detailed Implementation

[0024] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0025] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0026] Referring to Figures 1 to 7, the present invention provides a structure for the connection between a highway underpass and an existing underground structure, comprising: an existing underground structure 1, a protective ring beam 2, a highway underpass 3, and a waterstop 4.

[0027] In this embodiment, the existing underground structure 1 is a high-speed railway underground station building. The side wall 11 of the existing underground structure 1 has a rear opening 10. The highway underpass 3 is connected and penetrates the rear opening 10 of the side wall 11 of the existing underground structure 1.

[0028] The protective ring beam 2 is cast on the outer side of the side wall 11. The protective ring beam 2 is arranged in a ring along the circumferential direction of the rear opening 10. A rubber waterstop strip 21 is embedded in the construction joint between the side of the protective ring beam 2 facing the side wall 11 and the existing underground structure 1.

[0029] Before pouring the protective ring beam, reinforcing bars 22 are inserted into the side wall 11. During the pouring of the protective ring beam, the other end of the reinforcing bar 22 is anchored in the protective ring beam 2. A water-stop rubber sleeve 23 is fitted in the middle of the reinforcing bar 22. The water-stop rubber sleeve 23 abuts against one side of the protective ring beam 2.

[0030] In this embodiment, the other end of the rebar 22 is connected to the steel reinforcement structure of the protective ring beam 2.

[0031] Referring to Figures 3 to 5, the steel reinforcement structure of the protective ring beam 2 includes outer ring main reinforcement 24, inner ring main reinforcement 25, and stirrups 26. Stirrups 26 are attached to the outer ring main reinforcement 24 and the inner ring main reinforcement 25. The other end of the anchor bar 22 is connected to either the outer ring main reinforcement 24 or the inner ring main reinforcement 25.

[0032] Referring to Figure 3, two rows of reinforcing bars are installed on the side wall. The other ends of the two reinforcing bars extend into the protective ring beam and connect to the outer ring main reinforcement of the protective ring beam. In this embodiment, the stirrups of the protective ring beam are disconnected stirrups. These will be used later for installing the waterstop 4.

[0033] Referring to Figure 4, the side wall is also equipped with two layers of rebar. The two layers of rebar are respectively connected to the outer ring main reinforcement and the inner ring main reinforcement of the protective ring beam.

[0034] Referring to Figure 5, structural columns are provided on opposite sides of the rear opening in the side wall. One end of the rebar is inserted into the structural column, and the other end is connected to the outer and inner main reinforcing bars of the protective ring beam.

[0035] The underpass 3 is coaxially positioned on the other side of the protective ring beam 2, away from the side wall 11. An expansion joint 30 is formed between the underpass 3 and the other side of the protective ring beam.

[0036] Waterstop 4 is installed in expansion joint 30. The opposite sides of waterstop 4 are respectively embedded in highway underpass 3 and protective ring beam 2.

[0037] In this embodiment, the steel reinforcement structures within the highway underpass 3 and the protective ring beam 2 are respectively connected to clamps 41. The clamps 41 are held in place on one side of the waterstop 4.

[0038] Referring to Figure 6, the steel reinforcement structure of the highway underpass 3 is connected with clamps 41. The steel reinforcement structure within the protective ring beam 2 is also connected with clamps 41. The clamps on both sides of the expansion joint are respectively clamped to the opposite sides of the waterstop.

[0039] In a preferred embodiment, the expansion joint 30 is filled with a joint filler plate 31. Joint filler plates 31 are respectively provided on opposite sides of the waterstop 4.

[0040] The construction of the connection between the highway underpass and the post-opening of the existing underground structure significantly improves waterproof reliability and durability.

[0041] The present invention employs a multi-layered waterproofing system at the connection point between the underpass and the existing underground structure, which works synergistically. This includes embedding a rubber waterstop strip in the construction joint between the protective ring beam and the existing structure to form the first waterproof barrier; setting a waterstop (such as a centrally embedded steel-edged waterstop) in the expansion joint between the protective ring beam and the underpass to form the second waterproof barrier; covering the middle of the rebar with a waterstop rubber sleeve to further enhance the sealing of the rebar crossing area; and using a joint filler board and clamping system in conjunction to ensure accurate positioning, tightness, and no leakage of the waterstop.

[0042] The expansion joint design at the connection point between the underpass and the existing underground structure in this invention allows for relative displacement between the underpass and the existing structure, preventing damage to the waterproofing layer due to uneven settlement. The waterstop has a certain degree of elasticity and toughness, maintaining its sealing performance even during structural deformation.

[0043] The present invention utilizes a reinforced concrete anchor and a protective ring beam at the connection point between the underpass and the existing underground structure to provide load-bearing capacity. The anchored concrete anchor extends into the sidewall of the existing structure and connects with the reinforced concrete structure of the protective ring beam, forming a force transmission path and enhancing the overall integrity of the new and old structures. The protective ring beam, as a transitional structure, disperses stress concentration at the connection point, improving the joint's seismic and deformation resistance.

[0044] The protective ring beam constructed at the connection point between the highway underpass and the existing underground structure's post-opening is a steel reinforcement skeleton composed of outer ring main bars, inner ring main bars, and stirrups. This structure has a clear stress distribution, facilitating quality control. The clamping system ensures that the waterstop does not shift or break during concrete pouring, guaranteeing the accuracy of the waterproofing construction.

[0045] The connection between the underpass and the existing underground structure in this invention is constructed using non-destructive methods. The connection between the old and new structures is achieved through rebar installation, eliminating the need for large-scale removal of the original concrete or rebar welding, thus maximizing the protection of the existing structural integrity. The protective ring beam is cast outside the existing structure, providing ample construction space and facilitating formwork installation, rebar tying, and concrete pouring.

[0046] The connection structure between the highway underpass and the existing underground structure has significant advantages in terms of waterproof performance, structural safety, construction convenience, economy and sustainability. It is especially suitable for the "post-connection passage" engineering problem frequently encountered in urban underground space development, and has good engineering application prospects and technical promotion value.

[0047] The present invention provides a construction method for the connection between a highway underpass and an existing underground structure with a post-opening, comprising the following steps: S1, roughening the outer edge of the post-opening 10 on the side wall 11 of the existing underground structure 1.

[0048] S2. Cast a protective ring beam 2 on the outside of the side wall 11, so that the protective ring beam 2 is set in a circle along the circumferential direction of the rear opening 10, and embed a rubber waterstop strip 21 in the construction joint between the side of the protective ring beam 2 facing the side wall 11 and the existing underground structure 1.

[0049] S3. On the other side of the protective ring beam 2 away from the side wall 11, the highway underpass 3 is poured, so that the highway underpass 3 and the protective ring beam 2 are set coaxially. An expansion joint 30 is formed between the highway underpass 3 and the other side of the protective ring beam. A waterstop 4 is set in the expansion joint 30. The opposite sides of the waterstop 4 are respectively buried in the highway underpass 3 and the protective ring beam 2.

[0050] In this embodiment, the underground passage crossing the highway connects to the underground passage of the high-speed railway station. Since the high-speed railway station was constructed first, and the subsequent underground passage connection was not planned in advance, it is necessary to construct the opening and connection later. The underground passage's waterproofing design level is Class I, and the construction contract stipulates a zero-leakage waterproofing requirement. To ensure that no quality problems such as water leakage occur at the underground passage connection after construction, conventional methods cannot guarantee construction quality, and extensive subsequent chiseling and repairs pose a significant risk of leakage.

[0051] To meet the above requirements, this method involves first casting a protective ring beam between the sidewalls of the highway underpass and the existing underground structure. The protective ring beam is connected to the highway underpass via an expansion joint. The expansion joint consists of an external rubber waterstop, joint sealing material, a centrally embedded steel-edged waterstop rubber strip, reinforcing bars, nuts, double-ended bolts, and flat steel for fixing. The protective ring beam consists of reinforcing bars, reinforcing bar connectors, and concrete. Rubber waterstop strips and reinforcing bar waterstop rubber sleeves are installed in the construction joint between the protective ring beam and the existing underground structure.

[0052] During construction, the following steps are carried out in sequence: surveying and setting out, roughening the joints of openings, drilling holes and installing reinforcing bars at openings, construction expansion joints, pre-embedding construction joint waterstops, rubber stoppers, formwork installation, and concrete pouring.

[0053] When using rebar anchoring, the original concrete of the anchoring component must be free of local defects. If local defects exist, reinforcement or strengthening treatment should be carried out before rebar anchoring. The adhesive used for rebar anchoring must be a modified epoxy or modified vinyl ester (including modified urethane) adhesive, using Grade A adhesive, and its quality and performance should meet relevant regulations. The anchoring location should avoid the existing rebar in the component and must not damage the existing rebar. The location of the existing rebar in the component should be determined using instruments or the protective layer should be removed to expose the existing rebar before drilling. The clear distance between the newly anchored rebar and the original rebar at the lap joint should meet the corresponding requirements.

[0054] After measurement and layout, the same type of steel bars are used to install the steel bars and connect them firmly to the steel bars of the opening structure floor slab, side walls and bottom slab through steel bar connectors. The steel bar binding and welding are carried out in accordance with the specifications.

[0055] The waterproofing material for construction expansion joints and construction joints must be firmly fixed and adhered, bolts tightened, and the joints filled completely, in accordance with the specifications and standards.

[0056] At all junctions between old and new concrete, roughen the surface of the old concrete to expose the fresh concrete completely, with a roughening depth of 10-20mm. Clean the roughened surface with clean water and a wire brush to remove dust. Before pouring new concrete, cure the roughened surface with water for at least 12 hours, and apply a cement slurry with a water-cement ratio of 0.5, using 32.5 MPa ordinary Portland cement, half an hour before pouring. Before installing the formwork, tighten it only after the expansion joint structure and construction joint structure are firmly installed.

[0057] Concrete is poured in layers. First, the bottom layer of concrete that overlaps with the floor slab is poured. After the bottom concrete has initially set, the upper layer of concrete is poured in layers.

[0058] The connection between the underpass and the existing underground structure in this invention does not require steel reinforcement welding through the wall, thus avoiding delays and increased costs associated with later repairs.

[0059] The waterproof connection structure constructed at the junction of the underpass and the existing underground structure of the present invention has good integrity, which greatly improves the waterproof effect of the underpass.

[0060] The construction of the connection between the highway underpass and the existing underground structure is convenient and avoids the possibility of workers arbitrarily using reinforcement methods that do not meet the specifications during construction, such as reinforcing with iron wire or extensive chiseling, which could damage the main structure of the station building's basement and thus avoid the risk of leakage.

[0061] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A construction method for the connection between a highway underpass and an existing underground structure's post-opening entrance, characterized in that, include: The existing underground structure has a rear-opening opening in its sidewall; A protective ring beam is cast on the outer side of the side wall, and a ring is set around the circumference of the rear opening. A rubber waterstop strip is embedded in the construction joint between the side of the protective ring beam facing the side wall and the existing underground structure. A highway underpass is coaxially set on the other side of the protective ring beam away from the side wall, and an expansion joint is formed between the highway underpass and the other side of the protective ring beam. A waterstop strip is set in the expansion joint, and the opposite sides of the waterstop strip are respectively embedded in the highway underpass and the protective ring beam.

2. The construction of the connection between the highway underpass and the existing underground structure as described in claim 1, characterized in that, The side wall is implanted with a rebar, the other end of which is anchored in the protective ring beam. A water-stop rubber sleeve is provided in the middle of the rebar, and the water-stop rubber sleeve abuts against one side of the protective ring beam.

3. The construction of the connection between the highway underpass and the existing underground structure's post-opening section as described in claim 2, characterized in that... The other end of the rebar is connected to the steel reinforcement structure of the protective ring beam.

4. The construction of the connection between the highway underpass and the existing underground structure as described in claim 3, characterized in that, The steel reinforcement structure of the protective ring beam includes an outer ring main reinforcement, an inner ring main reinforcement, and stirrups. The stirrups are clamped to the outer ring main reinforcement and the inner ring main reinforcement, and the other end of the anchor bar is connected to the outer ring main reinforcement or the inner ring main reinforcement.

5. The construction method for the connection between the highway underpass and the existing underground structure as described in claim 1, characterized in that, The expansion joint is filled with a joint filler board, and the joint filler board is respectively provided on both sides of the waterstop.

6. The construction method for the connection between the highway underpass and the existing underground structure as described in claim 5, characterized in that, The underpass and the steel reinforcement structure within the protective ring beam are respectively connected to clamps, which clamp one side of the waterstop.

7. A construction method for the connection between a highway underpass and an existing underground structure as described in any one of claims 1 to 6, characterized in that, Includes the following steps: The outer edge of the rear opening on the side wall of the existing underground structure is roughened; a protective ring beam is cast on the outer side of the side wall, so that the protective ring beam is arranged in a circle along the circumference of the rear opening, and a rubber waterstop strip is embedded in the construction joint between the side of the protective ring beam facing the side wall and the existing underground structure; a highway underpass is cast on the other side of the protective ring beam away from the side wall, so that the highway underpass is coaxial with the protective ring beam, and an expansion joint is formed between the highway underpass and the other side of the protective ring beam, and a waterstop strip is installed in the expansion joint, with the opposite sides of the waterstop strip embedded in the highway underpass and the protective ring beam respectively.

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