Wind barrier for transition section of tunnel portal

Abstract

The utility model belongs to the technical field of traffic safety, and discloses a wind barrier for a tunnel portal transition section, which comprises a plurality of wind barrier units arranged at the tunnel portal transition section, each wind barrier unit comprises a stand column, a force transmission beam, a wind barrier blade, a blade base and a stand column base. The stand columns are fixed to the ground in the length direction of a road through stand column bases, every two adjacent stand columns are connected through a force transmission beam, the wind barrier blades are parallel to the stand columns, one ends of the wind barrier blades are connected with the force transmission beams, and the other ends of the wind barrier blades are connected with the ground through blade bases. The wind barrier unit is arranged on the side close to the excavation terrain. By adopting the vertically arranged wind barrier blades, the complexity of the structure can be effectively reduced, and the construction cost is reduced. And meanwhile, relative independence of all the parts is guaranteed while the mechanical properties of all the parts are organically combined, the construction and installation difficulty is lowered, later maintenance and replacement are facilitated, and construction and maintenance at the transition section of the tunnel portal are facilitated.

Description

Technical Field

[0001] The utility model belongs to the technical field of driving safety, and particularly relates to a wind barrier for a transition section at the tunnel entrance. Background Art

[0002] With the development of the economy, the quantity of tunnel construction increases. The geological conditions and environmental factors such as the wind field at the tunnel construction site are more severe and complex. Coupled with the more complex and heavy traffic tasks it undertakes, ensuring the driving safety inside and outside the tunnel, especially at the transition section of the tunnel entrance, has become an important research issue. Especially for high-speed railway tunnels, when the train is at the transition section of the tunnel entrance, there will be serious train safety problems when entering the tunnel exit with crosswind from the tunnel without crosswind.

[0003] In order to enhance the driving safety of vehicles under the action of lateral wind at the transition section of the tunnel entrance, wind barriers are usually set up to inhibit and reduce the equivalent wind speed at the transition section of the tunnel entrance. Starting from the source of lateral wind generation is the most effective method and technical measure to solve vehicle lateral wind at present.

[0004] The overall structure of the existing wind barriers at the tunnel exit is relatively complex, not suitable for the complex terrain conditions at the transition section of the tunnel entrance, and there are problems such as serious waste of materials and difficulties in construction and installation.

[0005] Therefore, it is necessary to design a wind barrier for the transition section of the tunnel entrance to solve the above technical problems. Content of the Utility Model

[0006] The purpose of the utility model is to provide a wind barrier suitable for the complex terrain conditions at the transition section of the tunnel entrance and easy to install. The specific technical solutions are as follows:

[0007] A wind barrier for a transition section of a tunnel entrance, one side of the transition section of the tunnel entrance is a filled terrain, and the other side is an excavated terrain. The wind barrier includes a plurality of wind barrier units arranged on the side of the transition section of the tunnel entrance close to the excavated terrain;

[0008] The wind barrier unit includes a column, a force transfer beam, a wind barrier blade, a blade base, and a column base;

[0009] The column is fixed on the ground along the length direction of the road through the column base, and adjacent columns are connected by a force transfer beam. The wind barrier blade is arranged parallel to the column. One end of the wind barrier blade is connected to the force transfer beam, and the other end is connected to the ground through the blade base.

[0010] Preferably, the widths of the wind barrier blades between different columns are different, so that the wind barrier forms an increasing ventilation rate in the direction away from the tunnel entrance; the wind barrier blades between different columns are arranged at the same interval.

[0011] Preferably, the wind barrier unit has at least four ventilation rates of 20%, 40%, 60% and 80%;

[0012] The width of the wind barrier blade with a ventilation rate of 20% is 3.5 - 4.5 m; the width of the wind barrier blade with a ventilation rate of 40% is 2.5 - 3.5 m; the width of the wind barrier blade with a ventilation rate of 60% is 1.5 - 2.5 m; the width of the wind barrier blade with a ventilation rate of 80% is 0.5 - 1.5 m.

[0013] Preferably, the column is an I-beam.

[0014] Preferably, the height of the column is 2.5 - 3.5 m and it is fixed to the column base by welding.

[0015] Preferably, the length of the force - transfer beam is 20 - 30 m and it is fixed to the column by welding.

[0016] Preferably, both ends of the wind barrier blade are connected to the force - transfer beam and the blade base respectively through a plurality of bolts.

[0017] Preferably, both the blade base and the column base are fixed to the ground by anchor bolts.

[0018] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0019] A wind barrier for the transition section of a tunnel entrance of the present utility model includes a plurality of wind barrier units arranged in the transition section of the tunnel entrance; the wind barrier unit includes a column, a force - transfer beam, a wind barrier blade, a blade base and a column base; the column is fixed to the ground along the road length direction through the column base, and adjacent columns are connected by a force - transfer beam, the wind barrier blade is arranged parallel to the column, one end of the wind barrier blade is connected to the force - transfer beam, and the other end is connected to the ground through the blade base; one side of the transition section of the tunnel entrance is a filled - in terrain and the other side is an excavated terrain, and the wind barrier unit is arranged on the side close to the excavated terrain. The present utility model can effectively reduce the complexity of the structure, lower the construction difficulty and reduce the construction cost by arranging the wind barrier blades vertically. At the same time, while achieving an organic combination of mechanical properties for each component, the relative independence of each component is also ensured, reducing the construction and installation difficulty, making it more convenient for maintenance and replacement, and facilitating construction and repair at the transition section of the tunnel entrance.

[0020] Through the following detailed description of the exemplary embodiments of the present utility model with reference to the accompanying drawings, other features and advantages of the present utility model will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1It is a schematic diagram of the overall structure of a wind barrier for the transition section of a tunnel entrance;

[0022] Figure 2 It is a schematic layout diagram of the wind barrier in the terrain of the transition section of the tunnel entrance;

[0023] Figure 3 It is a schematic assembly diagram of the column and the column base in the embodiment;

[0024] Figure 4 It is a schematic assembly diagram of the wind barrier blade and the blade base in the embodiment;

[0025] In the figure: 1. Column; 2. Force transfer beam; 3. Wind barrier blade with a ventilation rate of 20%; 4. Ventilation rate of the wind barrier blade with a ventilation rate of 40%; 5. Wind barrier blade with a ventilation rate of 60%; 6. Wind barrier blade with a ventilation rate of 80%; 7. Blade base; 8. Column base; 9. Tunnel entrance. Detailed implementation mode

[0026] The following will describe the embodiments of the present invention in detail with reference to the accompanying drawings, but the present invention can be implemented in many different ways defined and covered by the claims.

[0027] Embodiment:

[0028] Refer to Figure 1 and Figure 2 , a wind barrier for the transition section of a tunnel entrance, comprising a plurality of wind barrier units arranged in the transition section of the tunnel entrance; the wind barrier unit includes a column 1, a force transfer beam 2, a wind barrier blade, a blade base 7 and a column base 8; the column 1 is fixed on the ground along the road length direction through the column base 8, and adjacent two columns 1 are connected by a force transfer beam 2, the wind barrier blade is arranged parallel to the column 1, one end of the wind barrier blade is connected to the force transfer beam 2, and the other end is connected to the ground through the blade base 7; one side of the transition section of the tunnel entrance 9 is a filled terrain, and the other side is an excavated terrain, and the wind barrier unit is arranged on the side close to the excavated terrain.

[0029] In this embodiment, as Figure 2 shown, considering the characteristics of the semi-filled and semi-excavated terrain of the actual engineering tunnel entrance comprehensively, effectively utilizing the favorable wind-resistant terrain on one side of the transition section of the tunnel entrance, so that it is only necessary to set up a wind barrier on one side, and cooperate with the filled terrain on the other side to ensure the effective utilization of each structure and the driving vision, etc., effectively saving materials, facilitating installation and maintenance in the transition section of the tunnel entrance, and at the same time ensuring the windproof effect.

[0030] In this embodiment, a wind barrier with a length four times that of the vehicle head is adopted, and the ventilation rates are 20%, 40%, 60%, and 80% in sequence along the direction away from the transition section of the tunnel entrance. It is formed by setting a wind barrier blade of one specification between every two columns. Four groups of wind barriers with different widths are set in this embodiment. The wind barrier blades between different columns 1 are arranged at the same spacing. Refer to Figure 1 , 3 is the wind barrier blade with a ventilation rate of 20%; 4 is the ventilation rate of the wind barrier blade with a ventilation rate of 40%; 5 is the wind barrier blade with a ventilation rate of 60%; 6 is the wind barrier blade with a ventilation rate of 80%;

[0031] In this embodiment, the width of the wind barrier blade with a ventilation rate of 20% is 4m; the width of the wind barrier blade with a ventilation rate of 40% is 3m; the width of the wind barrier blade with a ventilation rate of 60% is 2m; the width of the wind barrier blade with a ventilation rate of 80% is 1m.

[0032] Refer to Figure 3 , the column 1 is an I-beam. The height of the column 1 is 3.2m, and it is fixed to the column base 8 by welding.

[0033] The length of the force transfer beam 2 is 25m, and it is fixed to the column 1 by welding.

[0034] Refer to Figure 4 , both ends of the wind barrier blade are connected to the force transfer beam 2 and the blade base 7 through a plurality of bolts respectively.

[0035] Both the blade base 7 and the column base 8 are fixed to the ground by anchor bolts.

[0036] Through the above settings and after test calculations, it can be obtained that setting the ventilation rates of each section of the wind barrier in a linear proportion can significantly reduce important aerodynamic parameters for driving safety such as lift force, lateral force, pitching moment, yaw moment, and nodding moment. Among them, for the wind barrier with a length twice that of the vehicle head, its aerodynamic performance during wind resistance is not good during driving, and there are certain safety problems. The wind barriers with lengths of 4 and 6 times that of the vehicle head have similar wind resistance performance, and multiple driving aerodynamic parameters are similar. For example, the reduction rates of the amplitude of the aerodynamic load coefficient of the wind barrier with a length four times that of the vehicle head are 28.1% for the lift coefficient, 4.2% for the pitching moment, 65.2% for the yaw moment, and 25.2% for the nodding moment; the reduction rates of the amplitude of the aerodynamic load coefficient of the wind barrier with a length six times that of the vehicle head are 26.1% for the lift coefficient, 9.9% for the pitching moment, 67.7% for the yaw moment, and 25.2% for the nodding moment.

[0037] When the crosswind speed at the exit of the train from the tunnel is 20m / s, the total length of each section of the wind barrier is 25m, the widths of the four sections of the wind barrier blades are 4m, 3m, 2m, and 1m respectively, the height of each section is 3m, and five groups of wind barrier blades are installed in each section of the wind barrier.

[0038] Q = Av

[0039] Where: Q is the flow rate; A is the area; v is the incoming flow velocity.

[0040] For the incoming flow rate in the 20% ventilation rate section:

[0041] Q 1 = Av - nA 1 v = 25×3×20 - 5×12×20 = 300m 3 / s

[0042] For the incoming flow rate in the 40% ventilation rate section:

[0043] Q 2 = Av - nA 2 v = 25×3×20 - 5×9×20 = 600m 3 / s

[0044] For the incoming flow rate in the 60% ventilation rate section:

[0045] Q 3 = Av - nA 3 v = 25×3×20 - 5×6×20 = 900m 3 / s

[0046] For the incoming flow rate in the 80% ventilation rate section:

[0047] Q 4 = Av - nA 4 v = 25×3×20 - 5×3×20 = 1200m 3 / s

[0048] For the incoming flow rate in the 100% ventilation rate section

[0049] Q = Av = 25×3×20 = 1500m 3 / s

[0050] For the incoming flow rate in the 50% ventilation rate section

[0051] Q 5 = 0.5Av = 0.5×25×3×20 = 750m 3 / s

[0052] From the above calculations, it can be seen that compared with the tunnel exit without any wind barriers, the wind barrier in this embodiment can effectively reduce 60% of the incoming flow; compared with the wind barrier with a 50% ventilation rate for each section of the main flow, the ability to reduce the incoming flow is increased by 20%.

[0053] If there is no wind barrier set, the wind speed distribution in the transition section at the tunnel entrance shows a cliff-like decline longitudinally, which is the reason for the sudden change in the aerodynamic load of the train at this position. When a wind barrier is set, the longitudinal wind speed distribution decreases uniformly from the outside to the inside, and as the set distance of the wind barrier increases, the degree of dispersion around the wind speed distribution line becomes lower and the linearity becomes higher. For wind barriers with a length of 4 times the train head length and 6 times the train head length, their wind speed distributions and trends are similar. Considering that the wind barrier in this embodiment is used for the semi-fill and semi-excavated terrain at the tunnel entrance, to give full play to the windproof characteristics of the terrain, the wind barrier with a length of 4 times the train head length is selected in this embodiment.

[0054] In terms of structural design, a design and installation method similar to the frame structure is adopted, which is very flexible in spatial separation layout, has a light self-weight, saves materials, has good integrity and stiffness of the structure, and has good mechanical properties. While the mechanical properties of each component can be organically combined, they are relatively independent in spatial layout, which is convenient for construction, installation, and later maintenance and replacement.

[0055] The wind barrier in this embodiment can balance the engineering cost and the windproof effect, achieve a good windproof effect with a relatively moderate wind barrier length and wind barrier blade area, make full use of the favorable windproof terrain in the transition section of the tunnel entrance. The wind barrier in this embodiment occupies less lateral space and will not hinder the normal operation of the tunnel. Longitudinally, the spatial layout of each component is reasonable, which is convenient for construction, installation, and later maintenance and replacement. Moreover, the wind barrier in this embodiment is preferably made of steel structure, which is simple to manufacture and has good mechanical properties.

[0056] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wind barrier for a transition section of a tunnel entrance, wherein one side of the transition section of the tunnel entrance is a fill terrain and the other side is a cut terrain, characterized in that: The wind barrier comprises a plurality of wind barrier units arranged on one side of the tunnel portal transition section close to the excavated terrain; The wind barrier unit comprises a column (1), a force transmission beam (2), a wind barrier blade, a blade base (7) and a column base (8); The columns (1) are fixed on the ground along the length direction of the road via column bases (8), and two adjacent columns (1) are connected via force transmission beams (2). The wind barrier blades are arranged parallel to the columns (1), one end of the wind barrier blades is connected to the force transmission beam (2), and the other end is connected to the ground via a blade base (7).

2. A wind barrier for a tunnel portal transition section according to claim 1, characterized in that: The wind barrier blades between different columns (1) have different widths, and are used to form a wind barrier with successively increasing air permeability in a direction away from the tunnel opening (9); the wind barrier blades between different columns (1) are arranged at the same spacing.

3. A wind barrier for a tunnel portal transition section according to claim 2, characterized in that: The wind barrier unit includes at least four air permeabilities of 20%, 40%, 60% and 80%; The width of the wind barrier blades with a permeability of 20% is 3.5 to 4.5 m; the width of the wind barrier blades with a permeability of 40% is 2.5 to 3.5 m; the width of the wind barrier blades with a permeability of 60% is 1.5 to 2.5 m; and the width of the wind barrier blades with a permeability of 80% is 0.5 to 1.5 m.

4. A wind barrier for a tunnel portal transition section according to claim 1, characterized in that: The column (1) is an I-beam.

5. A wind barrier for a tunnel portal transition section according to claim 1, characterized in that: The height of the column (1) is 2.5 to 3.5 m, and is fixed to the column base (8) by welding.

6. A wind barrier for a tunnel portal transition section according to claim 1, characterized in that: The force transmission beam (2) has a length of 20 to 30 m and is fixed to the column (1) by welding.

7. A wind barrier for a tunnel portal transition section according to claim 1, characterized in that: Both ends of the wind barrier blade are connected to the force transmission beam (2) and the blade base (7) respectively through a plurality of bolts.

8. The wind barrier for a tunnel portal transition section according to claim 1, characterized in that: The blade base (7) and the column base (8) are both fixed on the ground by anchor bolts.

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