Tie bar assembly type arched open cut tunnel structure and construction method

Abstract

The invention relates to the technical field of civil engineering and tunnel structure construction, in particular to a tie bar assembly type arched open cut tunnel structure and a construction method, through combination of prefabricated open cut tunnel structure blocks, rubber cushion layers and a steel bar tie bar system, the stability of the structure is greatly improved, and the influence of soil and stone pressure on an open cut tunnel is reduced; the construction mode of factory prefabrication and field assembly is adopted, the construction speed is high, the quality is high, and the problems of temperature stress and shrinkage cracking in a traditional cast-in-place structure are solved; the compression effect of the rubber cushion layer under stress further reduces the vertical soil and stone pressure; the method is suitable for the high-fill open cut tunnel structure, the construction period is remarkably shortened, the cost is reduced, and the safety and durability of the structure are guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of civil engineering and tunnel structure construction, and in particular to a reinforced assembled arched open-type tunnel structure and a construction method. Background Art

[0002] In arched open-cut structures, especially high-fill open-cut structures, the soil and rock pressure is high, and cracking problems are prone to occur during construction. In order to ensure the structural safety under fill load, the thickness of existing open-cut structures is usually increased to about 2.0 meters, and an arc-shaped inverted arch is used at the bottom to reduce the bending moment. However, excessive structural thickness will lead to a large temperature gradient between the inside and outside, which is easy to induce temperature stress and shrinkage cracking, seriously affecting the safety and durability of the open-cut. Existing technologies usually reduce hydration heat by methods such as block casting, laying water pipes, optimizing concrete raw materials, and opening holes, but these methods not only make the construction process complicated, but also increase the difficulty of quality control and engineering costs. In addition, in order to share the soil and rock pressure, the existing technology adds auxiliary facilities such as "arch cover + pile" structure. Although it can relieve the pressure, it is still mainly hard resistance, and it cannot effectively reduce the thickness and construction volume of the open-cut structure. Even if the soil and rock pressure is reduced to a certain extent by laying compression materials, the problems of large cast-in-place construction volume and long construction period have not been solved. Summary of the invention

[0003] In view of the many problems existing in the above-mentioned prior art, the present invention provides a reinforced assembled arched open hole structure and construction method. The present invention uses prefabricated open hole structural blocks and rubber cushion layers in combination with a steel bar reinforcement system to evenly distribute the soil and rock pressure to various parts of the structure, reduce local stress concentration, and prevent cracking. The elastic buffering effect of the rubber cushion layer further reduces the pressure on the open hole, achieving the stability and safety of the overall structure. Through this assembled structure, the construction time is significantly shortened and the quality is guaranteed.

[0004] A reinforced assembled arched open hole structure, comprising a prefabricated open hole structure block, a rubber cushion, a geotextile, a pre-buried connector and a steel bar.

[0005] The prefabricated open hole structure blocks are provided with a plurality of groups, and the prefabricated open hole structure blocks are connected by a groove structure, and the groove structure is designed to achieve a stable connection between the prefabricated open hole structure blocks and the adjacent structures;

[0006] The rubber cushion layer is placed in the middle of the trough structure to provide elastic buffering between the prefabricated open hole structural blocks and between the prefabricated open hole structural blocks and the bedrock or cast-in-place invert;

[0007] The geotextile is covered on the outside of the joints between the prefabricated open hole structural blocks to prevent backfill soil or gravel from entering the joints;

[0008] The embedded connector is pre-embedded in the outer side of the prefabricated open hole structural block and connected to the internal steel bars. The embedded connector is fixed to the steel bars through vertically aligned connection holes.

[0009] The steel bars are connected to the embedded connectors by bolts and buried in the backfill soil and rock. The steel bars act as tension bars by pulling the outer side of the assembled arched open hole structure.

[0010] Preferably, a groove is provided at the upper end of the prefabricated open hole structure block, and a protrusion is provided at the lower end, and the prefabricated open hole structure block is spliced ​​by embedding up and down.

[0011] Preferably, a rubber cushion layer is provided in the groove structure between the prefabricated open hole structural blocks, and the rubber cushion layer is used to be compressed under the action of soil and rock pressure to reduce the stress on the tensioned assembled arch open hole structure.

[0012] Preferably, the surface of the steel strip is treated with a zinc coating.

[0013] Preferably, the embedded connector is connected to the steel bars inside the prefabricated open hole structural block by welding.

[0014] Preferably, the geotextile is a high-strength water-permeable geotextile, which covers the outside of the joints between the prefabricated open hole structural blocks to prevent backfill gravel from entering the joints.

[0015] A construction method for implementing the above-mentioned reinforced assembled arched open hole structure comprises the following steps:

[0016] According to the height requirement of the bottom of the reinforced assembled arched open hole structure, the ground surface is processed; when the bottom of the reinforced assembled arched open hole structure is below the ground surface, the ground surface is excavated; when the bottom of the reinforced assembled arched open hole structure is above the ground surface, backfill to the required height;

[0017] When the bottom of the reinforced prefabricated arched open hole structure is bedrock, a bedrock trench is excavated to embed the prefabricated open hole structure blocks; when the bottom of the reinforced prefabricated arched open hole structure is not bedrock, the invert is cast on site;

[0018] The prefabricated open-cut structural blocks are installed sequentially from bottom to top, and rubber cushions are placed between each layer of prefabricated open-cut structural blocks. The rubber cushions are used to provide elastic buffers between the prefabricated open-cut structural blocks and between the prefabricated open-cut structural blocks and the foundation;

[0019] Covering the geotextile on the outside of the joints between the prefabricated open hole structural blocks to prevent backfill soil and rocks from entering the joints;

[0020] Backfill soil and rocks layer by layer from bottom to top and compact them. When the height of the backfill soil and rocks reaches the embedded connector, use bolts to connect the steel bars to the embedded connector. The steel bars are laid on the backfill soil and rocks to form a reinforcement structure. Then continue to backfill soil and rocks until the designed elevation is reached.

[0021] After the backfill soil and rocks reach the designed elevation and stabilize, remove the supporting structure used when installing the prefabricated open hole structural blocks;

[0022] After the reinforced assembled arched open hole structure is stable, cement slurry is injected into the joints between the prefabricated open hole structure blocks to fill the joints.

[0023] Preferably, the upper and lower ends of the prefabricated open hole structural block are respectively provided with a groove and a protrusion, and the groove and the protrusion are spliced ​​by embedding and fitting.

[0024] Preferably, the surface of the steel bar is treated with a zinc coating to enhance the corrosion resistance of the steel bar.

[0025] Preferably, the geotextile is a high-strength water-permeable material, which is used to effectively prevent crushed stone or other particles from entering the joints between the prefabricated open hole structural blocks during the backfilling process.

[0026] Compared with the prior art, the advantages and beneficial effects of the present invention are:

[0027] By adopting the reinforced assembled arched open hole structure, the construction speed is fast, the structural quality is high and the force is optimized;

[0028] The present invention arranges rubber cushions between the open hole structural blocks to compress the cushions under the soil and rock pressure, thereby reducing the vertical and horizontal pressures on the structure, greatly improving the stability of the open hole and reducing the risk of structural cracking.

[0029] In addition, the prefabricated structural blocks in the factory ensure the construction quality, and the prefabricated construction method makes the construction faster and easier, and the overall project cost can be effectively reduced; through the steel bar tensioning design, the present invention not only reduces the horizontal pressure on the side walls, but also greatly improves the overall stability of the structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a front view schematic diagram of the tie-bar assembled arched open hole structure of the present invention (the bottom is bedrock);

[0031] Figure 2 It is a front view schematic diagram of the tie-bar assembled arched open hole structure of the present invention (the bottom is not bedrock);

[0032] Figure 3 It is a front view schematic diagram of the seam between the open hole blocks of the present invention;

[0033] Figure 4 It is a front view schematic diagram of the pre-embedded connector of the tie rod and the open hole block of the present invention;

[0034] Among them, ①-steel bars, ②-opening blocks, ③-inter-opening block joints, ④-bedrock, ⑤-backfill soil and stone, ⑥-non-bedrock, ⑦-cast-in-place invert, ⑧-rubber pads, ⑨-geotextiles, ⑩-embedded connectors, -Connecting bolts. DETAILED DESCRIPTION

[0035] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are exemplary only and are not intended to limit the scope of the present disclosure. In the following detailed description, for ease of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present disclosure. However, it is obvious that one or more embodiments may also be implemented without these specific details. In addition, in the following description, descriptions of known structures and technologies are omitted to avoid unnecessary confusion of the concepts of the present disclosure.

[0036] The terms used herein are only for describing specific embodiments and are not intended to limit the present disclosure. The terms "comprise", "include", etc. used herein indicate the existence of the features, steps, operations and / or components, but do not exclude the existence or addition of one or more other features, steps, operations or components.

[0037] All terms (including technical and scientific terms) used herein have the meanings commonly understood by those skilled in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0038] See also Figures 1 to 4 As shown, a reinforced assembled arch open hole structure includes reinforcement (steel bars) ①, open hole blocks ②, cast-in-place inverted arches ⑦ (optional), rubber pads ⑧, geotextiles ⑨, embedded connectors ⑩ and connecting bolts ①1.

[0039] The tie bars (steel bars) ① are provided with a plurality of pieces spaced apart from each other, and the vertical spacing between two adjacent pieces is preferably set to be less than 40 cm. The steel bars are coated with zinc to increase their corrosion resistance. One end of the steel bars has a circular hole for aligning with the circular hole of the connecting piece and connecting with bolts. The steel bars may be specially treated to increase the friction between them and the backfill soil and rock.

[0040] The open hole block ② is provided with several groups, and the lower end of the open hole block ② is convex and embedded in the groove of the lower open hole block or the cast-in-place invert (such as Figure 1 ), or the lower end of the open hole block ② is flat and embedded in the bedrock groove (such as Figure 2 The top of the open hole block ② is a groove, so that the protrusion of the upper open hole block can be embedded. It is particularly noted that because the top open hole block is connected to the grooves of the open hole blocks on both sides, both ends of the top open hole block are protrusions.

[0041] The cast-in-place invert arch ⑦ is an optional component. When the bottom of the open hole is bedrock, it does not need to be set. When the bottom is not bedrock, it needs to be set. Its purpose is to increase the overall stability of the tensioned assembled open hole structure and reduce its settlement.

[0042] The rubber pads⑧ are provided in several groups and placed in the grooves. First, the rubber pads can prevent the protrusions from directly contacting the grooves; second, the compression of the rubber pads can increase the deformation of the steel bar assembly open hole structure, thereby reducing the soil and rock pressure on the structure; third, the "groove + rubber pad + protrusion" allows the open hole block to produce a small translation and rotation, and the internal stress of the "open hole + steel bar + fill" can be adaptively adjusted.

[0043] The geotextile ⑨ is provided with several groups and is pasted on the side of the fill near the joints between the open hole blocks. It is mainly used to prevent the backfill gravel material from entering the structure, thereby affecting the mutual movement between the open hole blocks and preventing local damage to the open hole blocks.

[0044] The embedded connector ⑩ is provided with several groups, which are cast in advance in the open hole block and connected to the steel bars in the open hole block (in the form of welding or steel bar binding). The connector is divided into two parts, the upper and lower parts, and the circular holes at the exposed ends of the upper and lower parts are vertically aligned.

[0045] The connecting bolts ①1 are provided in several groups for connecting the embedded connecting parts and the steel bars. Specifically, the connecting end of the steel bar is inserted into the middle of the upper and lower parts of the connecting part and the circular holes of the three are vertically aligned. Then, the bolts are inserted into the circular holes and tightened with an electric wrench to complete the connection.

[0046] The present invention also provides a construction method of a reinforced assembled arched open hole structure, comprising the following steps:

[0047] Step 1: Treat the foundation at the bottom of the open hole as needed. If the bottom of the open hole is below the ground surface, the surface needs to be excavated. If the bottom of the open hole is above the ground surface, the surface needs to be backfilled.

[0048] Step 2: When the bottom of the open hole is bedrock, a trench needs to be excavated at the corresponding position of the bottom of the open hole side wall so that the bottom open hole block can be embedded in the bedrock; when the bottom of the open hole is not bedrock (such as backfill soil and stone or miscellaneous fill after grouting treatment), the foundation needs to be processed to serve as the outer soil formwork of the cast-in-place invert, and then the invert and corresponding connecting parts are cast on site.

[0049] Step 3: Assemble the open hole blocks symmetrically from bottom to top. First, place rubber pads in the grooves, and then align the protrusions of the open hole blocks to be assembled with the grooves of the lower open hole blocks or cast-in-place inverts for assembly. During the assembly process, the open hole blocks need to be supported to ensure structural stability.

[0050] Step 4: Paste the geotextile on the outside of the joints between the open hole blocks or between the open hole blocks and the cast-in-place invert to prevent backfill soil and stone from entering the joints during backfilling and use.

[0051] Step 5: Backfill and compact the backfill soil and stone layer by layer from bottom to top and connect the embedded steel bars. When the height of the backfill soil and stone increases to the corresponding embedded connecting parts, connect one end of the steel bar to the connecting parts with bolts, and then lay the connected steel bar flat on the surface of the backfill soil and stone, continue to backfill and compact the next layer of backfill soil and stone, and gradually backfill to 1m from the top of the open hole.

[0052] Step 6: Remove the support of the open hole structure and continue to backfill and compact the soil and stone to the designed elevation.

[0053] Step 7: Optionally, after the reinforced prefabricated open hole structure is stable, cement mortar or the like is injected from the inside of the joint open hole to fill the joint to improve the overall strength and water resistance of the open hole structure.

[0054] Step 8: Optionally, after the reinforced prefabricated open hole structure is stable, a layer of lining can be cast on the inside of the open hole to improve the overall bearing capacity of the open hole structure.

[0055] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems or computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware.

[0056] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A reinforced assembled arched open hole structure, comprising a prefabricated open hole structure block, a rubber cushion, a geotextile, a pre-buried connector and a steel bar, characterized in that: The prefabricated open hole structure blocks are provided with a plurality of groups, and the prefabricated open hole structure blocks are connected by a groove structure, and the groove structure is designed to achieve a stable connection between the prefabricated open hole structure blocks and the adjacent structures; The rubber cushion layer is placed in the middle of the trough structure to provide elastic buffering between the prefabricated open hole structural blocks and between the prefabricated open hole structural blocks and the bedrock or cast-in-place invert; The geotextile is covered on the outside of the joints between the prefabricated open hole structural blocks to prevent backfill soil or gravel from entering the joints; The embedded connector is pre-embedded in the outer side of the prefabricated open hole structural block and connected to the internal steel bars. The embedded connector is fixed to the steel bars through vertically aligned connection holes. The steel bars are connected to the embedded connectors by bolts and buried in the backfill soil and rock. The steel bars act as tension bars by pulling the outer side of the assembled arched open hole structure.

2. The tie-bar assembled arched open hole structure according to claim 1 is characterized in that: The upper end of the prefabricated open hole structure block is provided with a groove, and the lower end is provided with a protrusion. The prefabricated open hole structure block is spliced ​​by embedding up and down.

3. The tie-bar assembled arched open hole structure according to claim 2 is characterized in that: A rubber cushion is provided in the groove structure between the prefabricated open hole structural blocks. The rubber cushion is used to be compressed under the action of soil and rock pressure to reduce the stress on the tensioned assembled arch open hole structure.

4. The tie-bar assembled arched open hole structure according to claim 1 is characterized in that: The surface of the steel bars is treated with zinc coating.

5. The tie-bar assembled arched open hole structure according to claim 1 is characterized in that: The embedded connectors are connected to the steel bars inside the prefabricated open hole structural blocks by welding.

6. The tie-bar assembled arched open hole structure according to claim 1 is characterized in that: The geotextile is a high-strength, water-permeable geotextile, which covers the outside of the joints between the prefabricated open hole structural blocks to prevent backfill gravel from entering the joints.

7. A construction method for implementing the tie-bar assembled arched open-type structure described in any of claims 1 to 6, characterized in that: The following steps are involved: According to the height requirement of the bottom of the reinforced assembled arched open hole structure, the ground surface is processed; when the bottom of the reinforced assembled arched open hole structure is below the ground surface, the ground surface is excavated; when the bottom of the reinforced assembled arched open hole structure is above the ground surface, backfill to the required height; When the bottom of the reinforced prefabricated arched open hole structure is bedrock, a bedrock trench is excavated to embed the prefabricated open hole structure blocks; when the bottom of the reinforced prefabricated arched open hole structure is not bedrock, the invert is cast on site; The prefabricated open-cut structural blocks are installed sequentially from bottom to top, and rubber cushions are placed between each layer of prefabricated open-cut structural blocks. The rubber cushions are used to provide elastic buffers between the prefabricated open-cut structural blocks and between the prefabricated open-cut structural blocks and the foundation; Covering the geotextile on the outside of the joints between the prefabricated open hole structural blocks to prevent backfill soil and rocks from entering the joints; Backfill soil and rocks layer by layer from bottom to top and compact them. When the height of the backfill soil and rocks reaches the embedded connector, use bolts to connect the steel bars to the embedded connector. The steel bars are laid on the backfill soil and rocks to form a reinforcement structure. Then continue to backfill soil and rocks until the designed elevation is reached. After the backfill soil and rocks reach the designed elevation and stabilize, remove the supporting structure used when installing the prefabricated open hole structural blocks; After the reinforced assembled arched open hole structure is stabilized, cement slurry can be optionally injected into the joints between the prefabricated open hole structure blocks to fill the joints.

8. The construction method of the tensioned assembled arched open hole structure according to claim 7 is characterized in that: The upper and lower ends of the prefabricated open hole structural block are respectively provided with a groove and a protrusion, and the groove and the protrusion are spliced ​​by embedding and matching.

9. The construction method of the reinforced assembled arched open hole structure according to claim 7 is characterized in that: The surface of the steel bar is treated with zinc coating to enhance the corrosion resistance of the steel bar.

10. The construction method of the reinforced assembled arched open hole structure according to claim 7, characterized in that: Geotextile is a high-strength, water-permeable material used to effectively prevent gravel or other particles from entering the joints between prefabricated open hole structural blocks during the backfill process.

Images