Simply supported beam supporting frame bridge type protective shed tunnel structure for high and steep slope tunnel portal

Abstract

The utility model belongs to the technical field of bridge and tunnel joint protection, and particularly relates to a simply supported beam supporting frame bridge type protective shed tunnel structure for a high and steep slope tunnel portal. Comprising two sets of built-in pile foundations located at a tunnel portal and two sets of reinforced concrete pile foundations away from the tunnel portal. A first bearing platform is arranged at the top of the built-in pile foundation, and a second bearing platform is arranged at the top of the reinforced concrete pile foundation; a first pier column is arranged at the top of the first bearing platform, and a second pier column is arranged at the top of the second bearing platform; a simply supported box girder is arranged between the pier tops of the first pier column and the second pier column; the shed tunnel structure comprises shed roof structures and stand columns, the stand columns are distributed at the tops of the simply-supported box girders at intervals in the length direction of the simply-supported box girders, and the shed roof structures stretch across the bridge and are connected with the stand columns on the two sides. The arrangement problem of the shed tunnel at the high and steep slope tunnel portal is solved, the prestressed cast-in-place concrete simply-supported box girder serves as a lower structure foundation of the shed tunnel, the number and height of lower structure stand columns are reduced, and the impact probability of dangerous rocks and falling rocks is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of bridge-tunnel junction protection, and specifically relates to a high-steep slope tunnel opening simply supported beam support frame bridge-type protection shed tunnel structure. Background Art

[0002] As a passive measure to prevent dangerous rockfall, tunnels have been widely used in rockfall protection of high-speed railways. The main types of existing tunnels include arch tunnels, frame tunnels, cantilever tunnels, etc. Among them, frame tunnels are relatively easy to construct and maintain, and have simple structural components. They are a common type of railway tunnel.

[0003] In dangerous mountainous areas, the tunnel entrance is directly connected to the bridge structure, and the height of the bridge pier is often as high as 20m or even higher. When using traditional shed tunnels, the foundation construction is difficult and the foundation volume is huge, the structural risk is doubled, and the requirements for construction machinery and equipment are greatly increased. The economy is poor, which aggravates the safety risk of construction personnel. In particular, when the length of the protective shed tunnel is long, the number of columns is increased, which greatly increases the probability of the columns being hit by dangerous rocks. The Chinese utility model patent (publication number CN202320876769.4) discloses a bridge separated shed tunnel, including a left pile foundation and a right pile foundation arranged on both sides of the existing railway, and the left pile foundation and the right pile foundation are respectively provided with a left pier and a right pier, and the left pier and the right pier are respectively provided with a cast-in-place concrete slab on the left pier and the right pier through the longitudinal beams at both ends, and the existing railway is located below the cast-in-place concrete slab. However, when the protection height of the shed tunnel is high, the excessive height of the pier will increase the deadweight of the structure, causing the shed tunnel to be unstable and unable to meet the bridge deck load. Therefore, a shed tunnel structure with low deadweight, strong stability and economical construction has important engineering significance for the safety of highway and railway traffic on steep slopes. Utility Model Content

[0004] The purpose of the utility model is to retain the advantages of the traditional frame-type shed hole such as simple structure and convenient construction, while improving the protection ability of the shed hole, reducing the height of the columns of the bridge protection shed hole, and protecting the safety of the shed hole structure.

[0005] The utility model provides the following technical solutions: a high-steep slope tunnel entrance simply supported beam support frame bridge type protective shed tunnel structure, comprising a shed tunnel structure and four groups of pile foundations arranged on both sides of the bridge, the pile foundations comprising two groups of embedded pile foundations located at the tunnel entrance and two groups of reinforced concrete pile foundations far from the tunnel entrance; a first cap is arranged on the top of the embedded pile foundation, and a second cap is arranged on the top of the reinforced concrete pile foundation; a first pier is arranged on the top of the first cap, and a second pier is arranged on the top of the second cap; a simply supported box beam is arranged between the pier tops of the first pier and the second pier on the same side of the bridge;

[0006] The shed tunnel structure includes a roof structure and columns. The columns are distributed at intervals along the length of the simply supported box girder on the top of the simply supported box girder, and the roof structure spans the bridge and is connected to the columns on both sides.

[0007] Furthermore, a supporting crossbeam is integrally cast on the bottom surface of the beam top plate at the position where the simply supported box beam is connected to the column, and the beam ends on both sides of the supporting crossbeam are connected to the box beam web of the simply supported box beam.

[0008] Furthermore, the roof structure includes longitudinal beams, transverse beams, a roof plate of the shed hole and a buffer structure; the longitudinal beams are connected between the tops of the columns on the same side of the bridge, the transverse beams are connected between the longitudinal beams on both sides of the bridge, the roof plate of the shed hole is located above the transverse beams, and the buffer structure is located above the roof plate of the shed hole.

[0009] Furthermore, the buffer structure includes geotextile, composite EPS buffer structure, steel plate and slag layer from bottom to top; the geotextile is fully spread on the roof of the shed hole, the geotextile extends outward from the roof of the shed hole on all sides, the composite EPS buffer structure is laid on the geotextile, the extension range of the geotextile includes the composite EPS buffer structure, the steel plate covers the composite EPS buffer structure, and the slag layer covers the steel plate.

[0010] Furthermore, the thickness of the composite EPS cushioning structure is 60 cm.

[0011] Furthermore, the cross section of the supporting beam is rectangular.

[0012] Furthermore, a pad stone is arranged on the top of the first pier column, and the simply supported box girder falls on the pad stone.

[0013] Furthermore, the simply supported box beams, longitudinal beams, transverse beams and roof slabs are cast-in-place concrete structures.

[0014] Compared with the prior art, the advantages of the present invention are:

[0015] The utility model provides a simply supported beam supporting frame bridge type protective shed tunnel structure for a high and steep slope tunnel entrance, which solves the problem of setting up the shed tunnel at the high and steep slope tunnel entrance. Prestressed cast-in-place concrete simply supported box beams are used as the lower structure foundation of the shed tunnel, which reduces the number and height of the lower structure columns and reduces the probability of impact from dangerous rock falls. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the simply supported beam supporting frame bridge type protective shed tunnel structure;

[0017] Figure 2 for Figure 1 Left side view;

[0018] Figure 3 This is a schematic diagram of the roof structure;

[0019] Figure 4This is a cross-sectional view of a simply supported box girder.

[0020] In the figure: 1- embedded pile foundation; 2- reinforced concrete pile foundation; 3- first cap; 4- second cap; 5- first pier; 6- second pier; 7- simply supported box girder; 7.1- supporting crossbeam; 8- column; 9- longitudinal beam; 10- cross beam; 11- roof of shed; 12- composite EPS buffer structure; 13- steel plate; 14- slag layer; 15- cushion stone. DETAILED DESCRIPTION

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] like Figure 1 , Figure 2 As shown: a simply supported beam supporting frame bridge type protective shed tunnel structure for a high and steep slope tunnel entrance, including a shed tunnel structure and four groups of pile foundations arranged on both sides of the bridge, the pile foundations including two groups of embedded pile foundations 1 located at the tunnel entrance and two groups of reinforced concrete pile foundations 2 far away from the tunnel entrance; a first pedestal 3 is arranged on the top of the embedded pile foundation 1, and a second pedestal 4 is arranged on the top of the reinforced concrete pile foundation 2; a first pier 5 is arranged on the top of the first pedestal 3, and a second pier 6 is arranged on the top of the second pedestal 4; a simply supported box beam 7 is arranged between the pier tops of the first pier 5 and the second pier 6 on the same side of the bridge; the first pier 5 and the second pier 6 are square columns with a cross-sectional area of ​​2*4.4cm and a height of 15 to 12.5m.

[0023] The slope at the tunnel entrance is high and the terrain is steep, making it difficult to position construction equipment and lacking construction space. Therefore, in order to reduce the scope of slope excavation, embedded pile foundations 1 are constructed on both sides of the bridge at the tunnel entrance, and reinforced concrete pile foundations 2 are constructed on both sides of the bridge away from the tunnel entrance.

[0024] The shed tunnel structure includes a shed roof structure and columns 8. The columns 8 are distributed at intervals along the length of the simply supported box girder 7 on the top of the simply supported box girder 7. The shed roof structure spans the bridge and is connected to the columns 8 on both sides.

[0025] like Figure 4 As shown: in order to enhance the stability of the column 8, a supporting cross beam 7.1 is integrally cast on the bottom surface of the beam top plate at the connection position between the simply supported box beam 7 and the column 8, and the two side beam ends of the supporting cross beam 7.1 are connected to the box beam web of the simply supported box beam 7; the cross section of the supporting cross beam 7.1 is rectangular.

[0026] like Figure 3As shown: the roof structure includes longitudinal beams 9, transverse beams 10, a shed hole roof 11 and a buffer structure; the longitudinal beams 9 are connected between the tops of the columns 8 on the same side of the bridge, the transverse beams 10 are connected between the longitudinal beams 9 on both sides of the bridge, the shed hole roof 11 is located above the transverse beams 10, and the buffer structure is located above the shed hole roof 11.

[0027] A pad stone 15 is provided on the top of the first pier 5 , and the simply supported box girder 7 falls on the pad stone 15 .

[0028] The simply supported box beam 7, longitudinal beam 9, transverse beam 10 and shed top plate 11 are cast-in-place concrete structures; the construction of the simply supported box beam includes:

[0029] Step 1: Install the support. Roughen the top surface of the pad stone 15, clean the reserved holes, install the anchor bolts and the support, support the side molds around the support, and fill the reserved holes and the gaps between the support bottom plate and the top surface of the pad stone with epoxy mortar;

[0030] Step 2: Bailey beam installation and formwork construction, including construction of steel pipe column foundation, hoisting of Bailey beam and support of formwork;

[0031] Construct the steel pipe column foundation, which is constructed based on the cap, the steel pipe column foundation is connected with the embedded parts on the first pier 5 and the second pier 6, and a sand box is set on the top of the steel pipe column foundation;

[0032] Bailey beams are installed between the sand boxes on the same side of the bridge. Bailey beams consist of several Bailey plates. When Bailey plates are installed, they are first spliced ​​longitudinally and then hoisted and spliced ​​in spans. The installation sequence is to hoist the middle first and then hoist the Bailey plates on both sides symmetrically. Bailey plates are combined into a piece in pairs, and every two Bailey plates are connected as a whole by a support frame. At the same time, angle steel is used to connect the Bailey plates into sections of every 3 meters.

[0033] Support formwork, lay steel sections perpendicular to the Bailey beam on the Bailey beam, lay square timbers parallel to the Bailey beam on the upper part of the steel sections, lay the bottom formwork of the simply supported box beam on the top surface of the square timbers, and then install the inner formwork, side formwork, top formwork and end formwork of the simply supported box beam, and reserve a notch on the top formwork at the position where the column 8 is connected;

[0034] Step 3: Install the beam body steel bars and prestressed pipes. The beam body steel bars of the simply supported box beam 7 are tied as a whole. First, the steel bars in the bottom plate and web of the simply supported box beam 7 are tied, and then the steel bars in the top plate of the simply supported box beam 7 are tied. The prestressed pipe is a galvanized metal corrugated pipe, and the steel strand is inserted into the prestressed pipe.

[0035] Step 4: Construction of reserved steel bars for columns. The reserved steel bars for columns are inserted into the range of supporting beams from the reserved gaps of the top template;

[0036] Step 5: Concrete pouring;

[0037] Step 6: Tensioning and grouting. After loosening the inner formwork and removing the end formwork, automatic tensioning and grouting are used. After the pre-tensioning is completed, the inner formwork is removed and the side formwork is removed. The final tensioning is carried out after the strength and elastic modulus of the beam concrete reach the design value. After the final tensioning is completed, the grouting of the channel is completed within 48 hours, and the anchor sealing treatment is carried out;

[0038] Step 7: Demoulding and maintenance.

[0039] The buffer structure includes geotextile, composite EPS buffer structure 12, steel plate 13 and slag layer 14 from bottom to top; the geotextile is fully spread on the roof 11 of the shed, and the overlap between the geotextiles is ensured to be at least 5 cm. The geotextile extends outward from the roof 11 of the shed on all sides, extending 3m outward. The composite EPS buffer structure 12 is laid on the geotextile, and the thickness of the composite EPS buffer structure 12 is 60cm. The extension range of the geotextile includes the composite EPS buffer structure 12, the steel plate 13 covers the composite EPS buffer structure 12, and the slag layer 14 covers the steel plate 13.

[0040] Construction Examples

[0041] The entrance mileage of a tunnel in Guangxi Zhuang Autonomous Region is DK255+239.97. The entrance slope and right side of the tunnel are tall mountains. The upward slope is slightly gentle, and the right slope is relatively steep. There are dangerous rocks and rocks on the slope. The pier of the tunnel entrance is 11m high, the main beam is 3.5m high, the shed column is 8.5m high, and the top plate of the shed is 23m above the ground. On the one hand, if a conventional shed is used, the shed column is 23m high. If the concrete column is too high, it will increase the deadweight of the structure, resulting in instability of the shed. In addition, the excessive height of the column will easily lead to cracks and cracks, which will bring hidden dangers to the safety of the shed and cannot bear the load of rockfall impact.

[0042] On the other hand, since the slope here is relatively steep and there are dangerous rocks and falling stones, in order to protect the bridge at the entrance, a shed tunnel protection length of 23m is set. According to the calculation of 7-8 meters per conventional shed tunnel, 3 shed tunnels are needed, with a total of 8 columns, 4 on each side, which significantly increases the probability of the columns being hit by dangerous rocks and falling stones.

[0043] In addition, due to the high slope height and steep terrain, it is difficult to put the construction equipment in place and there is a lack of construction space. Therefore, it is necessary to find a bridge protection shed tunnel suitable for the high and steep slope bridge-tunnel transition section tunnel entrance with high protection height and long protection distance.

[0044] The high-steep-slope tunnel entrance simply-supported-beam-supported-frame-bridge-type protective shed-tunnel structure provided in this embodiment is used in the shed-tunnel construction of the above-mentioned tunnel engineering.

[0045] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high steep slope tunnel entrance simply supported beam support frame bridge type protective shed tunnel structure, characterized in that: The invention comprises a tunnel shed structure and four groups of pile foundations arranged on both sides of the bridge, wherein the pile foundations comprise two groups of embedded pile foundations (1) located at the tunnel entrance and two groups of reinforced concrete pile foundations (2) far from the tunnel entrance; a first cap (3) is arranged on the top of the embedded pile foundation (1), and a second cap (4) is arranged on the top of the reinforced concrete pile foundation (2); a first pier (5) is arranged on the top of the first cap (3), and a second pier (6) is arranged on the top of the second cap (4); a simply supported box beam (7) is arranged between the tops of the first pier (5) and the second pier (6) on the same side of the bridge; The shed tunnel structure comprises a shed roof structure and columns (8), wherein the columns (8) are spaced apart along the length direction of the simply supported box girder (7) and are arranged on the top of the simply supported box girder (7), and the shed roof structure spans the bridge and is connected to the columns (8) on both sides.

2. According to claim 1, a high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure is characterized by: A supporting crossbeam (7.1) is integrally cast on the bottom surface of the beam top plate at the connection position between the simply supported box beam (7) and the column (8), and the beam ends on both sides of the supporting crossbeam (7.1) are connected to the box beam web of the simply supported box beam (7).

3. A high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure according to claim 1 or 2, characterized in that: The roof structure comprises longitudinal beams (9), transverse beams (10), a roof plate (11) and a buffer structure; the longitudinal beams (9) are connected between the tops of the columns (8) on the same side of the bridge, the transverse beams (10) are connected between the longitudinal beams (9) on both sides of the bridge, the roof plate (11) of the roof is located above the transverse beams (10), and the buffer structure is located above the roof plate (11) of the roof.

4. According to claim 3, a high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure is characterized by: The buffer structure comprises, from bottom to top, a geotextile, a composite EPS buffer structure (12), a steel plate (13), and a slag layer (14); the geotextile is fully spread on the roof plate (11) of the shed hole, the four sides of the geotextile extend outward from the roof plate (11) of the shed hole, the composite EPS buffer structure (12) is laid on the geotextile, the extension range of the geotextile includes the composite EPS buffer structure (12), the steel plate (13) covers the composite EPS buffer structure (12), and the slag layer (14) covers the steel plate (13).

5. According to claim 4, a high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure is characterized by: The composite EPS buffer structure (12) has a thickness of 60 cm.

6. The high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure according to claim 2, characterized in that: The cross section of the supporting beam (7.1) is rectangular.

7. The high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure according to claim 1, characterized in that: A cushion stone (15) is arranged on the top of the first pier column (5), and the simply supported box girder (7) falls on the cushion stone (15).

8. The high steep slope tunnel portal simply supported beam support frame bridge type protection shed tunnel structure according to claim 3, characterized in that: The simply supported box beam (7), longitudinal beam (9), transverse beam (10), and roof plate (11) of the shed are cast-in-place concrete structures.

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