CN117345266A - High-speed railway tunnel portal enlarged cavity buffer structure and construction method - Google Patents

High-speed railway tunnel portal enlarged cavity buffer structure and construction method Download PDF

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Publication number
CN117345266A
CN117345266A CN202310772589.6A CN202310772589A CN117345266A CN 117345266 A CN117345266 A CN 117345266A CN 202310772589 A CN202310772589 A CN 202310772589A CN 117345266 A CN117345266 A CN 117345266A
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China
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buffer structure
section
speed railway
lining
tunnel
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Inventor
喻渝
张红伟
罗禄森
胖涛
杨伟超
刘金松
袁伟
齐春
郑长青
何昌国
龙游昊
欧阳德惠
辜英晗
刘祥
蒋立
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China Railway Eryuan Engineering Group Co Ltd CREEC
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China Railway Eryuan Engineering Group Co Ltd CREEC
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Priority to CN202310772589.6A priority Critical patent/CN117345266A/en
Publication of CN117345266A publication Critical patent/CN117345266A/en
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    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
    • E21D9/14—Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/003—Linings or provisions thereon, specially adapted for traffic tunnels, e.g. with built-in cleaning devices
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/04—Lining with building materials
    • E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
    • E—FIXED CONSTRUCTIONS
    • E21—EARTH OR ROCK DRILLING; MINING
    • E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
    • E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
    • E21D11/38—Waterproofing; Heat insulating; Soundproofing; Electric insulating

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  • Engineering & Computer Science (AREA)
  • Mining & Mineral Resources (AREA)
  • Structural Engineering (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • General Life Sciences & Earth Sciences (AREA)
  • Geochemistry & Mineralogy (AREA)
  • Geology (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Environmental & Geological Engineering (AREA)
  • Lining And Supports For Tunnels (AREA)

Abstract

The invention relates to the field of high-speed train tunnel aerodynamics, in particular to a high-speed railway tunnel portal enlarged cavity buffer structure and a construction method. The buffer structure comprises a lining group, wherein a housing is arranged on the outer side of the lining group, the lining group comprises a plurality of lining rings which are arranged at intervals along the line direction, the cross-sectional area of the inner cavity of the lining ring is larger than or equal to that of the inner cavity of a standard section tunnel, ribs are arranged on the outer side of the lining ring along the circumferential direction of the lining ring, and the housing is supported by the ribs. The constant-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway can enable air fluid to undergo expansion and contraction for the same number of times as the number of lining rings, and can achieve better slowing down effect through shorter buffer structure length.

Description

High-speed railway tunnel portal enlarged cavity buffer structure and construction method
Technical Field
The invention relates to the field of high-speed train tunnel aerodynamics, in particular to a high-speed railway tunnel portal enlarged cavity buffer structure and a construction method.
Background
The construction of high-speed railways in China is rapidly developed, and the running speed of high-speed trains is continuously improved in order to shorten the traffic time between cities. High speed trains have become possible to run at speeds of 400km per hour and will be moving towards more speeds in the future. The increase in vehicle speed has led to a gradual prominence of tunnel aerodynamic problems.
When the high-speed train runs, micro air pressure waves exist at the tunnel portal, and along withThe continuous increase of the vehicle speed further highlights the danger of micro-air pressure waves to the surrounding environment. The energy of micro-air pressure wave is mainly in the infrasonic wave region, which can damage the building and human organs, when the energy is higher, the tunnel portal can also generate sonic boom phenomenon, and noise pollution is brought to the surrounding environment. The research shows that the micro-air pressure wave peak value of the tunnel portal is proportional to the third power of the speed of the vehicle, when the train passes through 100m at the speed of 400km/h 2 When the standard single-hole double-line tunnel is used, the micro-air pressure wave peak value at the tunnel opening 20m is 135Pa, which is far beyond the normal requirement (50 Pa).
At present, the arrangement of a buffer structure at the tunnel portal is a main means for reducing micro-air pressure waves. But the buffer structure of the prior tunnel portal is difficult to reduce the longitudinal length of the tunnel portal to be within the standard limit value. The buffering structure with short length and small cross section and capable of achieving good buffering effect is required to be solved under requirements of hole topography and engineering construction.
Disclosure of Invention
The invention aims at: aiming at the problem that the prior buffer structure of the tunnel portal is difficult to reduce the longitudinal length of the tunnel portal micro-air pressure wave to be within the standard limit value when a high-speed train runs at the speed of 400km per hour in the prior art, the buffer structure and the construction method for enlarging the cavity of the tunnel portal of the high-speed railway are provided.
In order to achieve the above purpose, the technical scheme adopted by the invention is as follows:
the utility model provides a high-speed railway tunnel portal constant cross section enlarges cavity buffer structure, is including setting up in the lining cutting group of standard section tunnel tip, the lining cutting group outside is provided with the housing, the lining cutting group includes a plurality of lining cutting rings that set up along the circuit direction interval, lining cutting ring intra-annular chamber cross sectional area is greater than or equal to standard section tunnel inner chamber cross sectional area, lining cutting ring outside is provided with the rib along lining cutting ring circumference, the rib supports the housing.
The utility model provides a high-speed railway tunnel portal equal cross-section enlarges cavity buffer structure, because lining ring intra-annular chamber cross-sectional area is greater than or equal to standard section tunnel inner chamber cross-sectional area, and the housing sets up the lining group outside for housing inner chamber cross-sectional area is also greater than standard section tunnel inner chamber cross-sectional area, has so set up the rise time that has prolonged the compression wave, thereby has reduced pressure gradient, thereby reaches the effect that reduces the micro-pneumatic pressure wave.
Meanwhile, the constant-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway has the advantages that due to the fact that air has certain viscosity, when the air with viscosity flows through the tunnel wall surface, the pressure reduction phenomenon can be generated. The lining rings are arranged at intervals along the direction of the line, so that the roughness of the inner wall of the tunnel portal is increased, and therefore, when a pressure wave passes through the constant-section enlarged tunnel, the pressure drop is larger, thereby reducing the initial compression wave and the pressure gradient generated when a train enters the tunnel, and further reducing the micro-air pressure wave at the tunnel outlet.
Based on the principle that: the lining rings are arranged at intervals along the line direction, ribs are arranged on the outer side of the lining rings along the circumferential direction of the lining rings, and the ribs support the housing, so that air fluid is subjected to expansion and contraction of the same number of times as the number of the lining rings, and the uniform-section expansion cavity buffer structure of the tunnel portal of the high-speed railway can achieve better buffer effect with shorter buffer structure length through multiple expansion and contraction.
Preferably, the lining ring width closest to the standard section tunnel is larger than the rest of lining ring widths in the line direction.
Preferably, the lining group comprises four lining rings, which are sequentially defined as a first lining ring, a second lining ring, a third lining ring and a fourth lining ring along the line direction, wherein the first lining ring is closest to the standard section tunnel, the width F1 of the first lining ring along the line direction is 4-6m, and the width F2 of the second lining ring, the third lining ring and the fourth lining ring along the line direction is 2-4m.
Preferably, in the direction of a line, the clearance distance F3 between the first lining ring and the standard section tunnel portal is 4-6m, and the clearance distance F4 between adjacent lining rings is 2-4m.
Preferably, a gap is provided between the rib and the corresponding lining ring.
Preferably, the housing covers the cavity open cut tunnel.
Preferably, the cover is a light-transmitting member.
The application discloses a cavity buffer structure is enlarged to equal cross-section in high-speed railway tunnel portal, pressure wave passes through cavity buffer structure is enlarged to equal cross-section in high-speed railway tunnel portal's pressure loss final value DeltaP Z The design comprises the following steps:
a1, obtaining a pressure loss value delta P when a pressure wave passes through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway based on the axial length L of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway, the equivalent diameter d of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and the average flow velocity of the pressure wave passing through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway;
a2, obtaining a local resistance coefficient xi of sudden expansion of the section of the buffer structure of the constant-section expansion cavity of the tunnel portal of the high-speed railway based on the section area of the inner cavity of the lining ring and the section area of the inner cavity of the housing 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 ；
A3, based on the sudden expansion of the section of the buffer structure of the constant section expansion cavity of the tunnel portal of the high-speed railway, the local resistance coefficient xi 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 Obtaining accumulated local pressure loss value delta P of constant-section enlarged cavity buffer structure of tunnel portal of high-speed railway j ；
A4, accumulating local pressure loss value delta P of cavity buffer structure enlarging constant section of tunnel portal of high-speed railway j The final local pressure loss delta P3 of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway is obtained by reducing;
a5, obtaining pressure waves through the high-speed railway tunnel hole based on pressure loss value delta P of pressure waves when the pressure waves pass through the high-speed railway tunnel hole constant section enlarged cavity buffer structure and final local pressure loss delta P3 of the high-speed railway tunnel hole constant section enlarged cavity buffer structureFinal value Δp of pressure loss in cavity buffer structure with enlarged mouth section Z 。
The application also discloses a construction method of the high-speed railway tunnel portal enlarged cavity buffer structure, which comprises the following steps:
s1, pouring a plurality of lining rings by using concrete, and forming the lining group;
s2, after the lining ring reaches the design strength, building a rib mould for pouring ribs on the outer side of the lining ring; the rib mould is enabled to be in ring protection with the lining ring corresponding to the inner side at a certain distance, and a bracket is arranged on the inner side of the rib mould and is connected with the lining ring;
s3, keeping the interval between the rib and the lining ring; and pouring the rib after the rib mould is built.
S4, erecting the housing after the ribs reach the design strength.
The construction method of the high-speed railway tunnel portal enlarged cavity buffer structure adopts a cast-in-situ structure, has good waterproof performance and integrity, is not easy to damage, and can be used for efficiently constructing the high-speed railway tunnel portal equal-section enlarged cavity buffer structure, so that a better slowing effect is achieved by a shorter buffer structure length.
Preferably, step S4 is specifically: and placing the housing on the rib by adopting a crane, and enabling the rib to support the housing, wherein the housing is subjected to sealing treatment with a line roadbed, a standard section tunnel and a lining ring farthest from the standard section tunnel.
In summary, due to the adoption of the technical scheme, the beneficial effects of the invention are as follows:
1. the utility model provides a high-speed railway tunnel portal equal cross-section enlarges cavity buffer structure, because lining ring intra-annular chamber cross-sectional area is greater than or equal to standard section tunnel inner chamber cross-sectional area, and the housing sets up the lining group outside for housing inner chamber cross-sectional area is also greater than standard section tunnel inner chamber cross-sectional area, has so set up the rise time that has prolonged the compression wave, thereby has reduced pressure gradient, thereby reaches the effect that reduces the micro-pneumatic pressure wave. Meanwhile, the constant-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway has the advantages that due to the fact that air has certain viscosity, when the air with viscosity flows through the tunnel wall surface, the pressure reduction phenomenon can be generated. The lining rings are arranged at intervals along the direction of the line, so that the roughness of the inner wall of the tunnel portal is increased, and therefore, when a pressure wave passes through the constant-section enlarged tunnel, the pressure drop is larger, thereby reducing the initial compression wave and the pressure gradient generated when a train enters the tunnel, and further reducing the micro-air pressure wave at the tunnel outlet. Based on the principle that: the lining rings are arranged at intervals along the line direction, ribs are arranged on the outer side of the lining rings along the circumferential direction of the lining rings, and the ribs support the housing, so that air fluid is subjected to expansion and contraction of the same number of times as the number of the lining rings, and the uniform-section expansion cavity buffer structure of the tunnel portal of the high-speed railway can achieve better buffer effect with shorter buffer structure length through multiple expansion and contraction.
2. The construction method of the high-speed railway tunnel portal expansion cavity buffer structure adopts a cast-in-situ structure, has the advantages of good waterproof performance and integrity, convenient implementation, simple structure and difficult damage, and can efficiently construct the high-speed railway tunnel portal uniform cross section expansion cavity buffer structure, so that a better slowing effect is achieved by a shorter buffer structure length.
Drawings
Fig. 1 is a schematic structural perspective view of a buffer structure for enlarging a cavity of a tunnel portal of a high-speed railway.
Fig. 2 is a schematic structural front view of the buffer structure for enlarging the cavity of the tunnel portal of the high-speed railway.
Fig. 3 is a schematic view of a longitudinal cross-section of the structure of the high-speed railway tunnel portal enlarged cavity buffer structure of the present invention.
FIG. 4 is a schematic view of a rib and lining ring arrangement of the present invention.
Icon: 1-a standard section tunnel; 11-a standard section tunnel inner cavity; 2-cavity open cut tunnel; 3-lining rings; 31-a first liner ring; 32-a second lining ring; 33-a third liner ring; 34-a fourth liner ring; 35-lining the ring lumen; 4-ribs; 5-a housing; 51-a housing lumen; 6-void; 7-line subgrade.
Detailed Description
The present invention will be described in detail with reference to the accompanying drawings.
The present invention will be described in further detail with reference to the drawings and examples, in order to make the objects, technical solutions and advantages of the present invention more apparent. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
Example 1
As shown in fig. 1-4, the equal-section enlarged cavity buffer structure for a tunnel portal of a high-speed railway in this embodiment comprises a lining group arranged at the end part of a standard section tunnel 1, a housing 5 is arranged at the outer side of the lining group, the lining group comprises a plurality of lining rings 3 arranged at intervals along the line direction, the section area of an inner cavity 35 of the lining ring is greater than or equal to the section area of an inner cavity 11 of the standard section tunnel, ribs 4 are arranged at the outer side of the lining ring 3 along the circumferential direction of the lining ring 3, the housing 5 is supported by the ribs 4, and a cavity open cut tunnel 2 of the buffer structure is jointly formed by the inner side of the lining ring 3 and the inner side of the housing 5
The lining ring inner cavity 35 is a cavity through which the train passes inside the lining ring 3.
The inner cavity 11 of the standard section tunnel is a cavity through which the train passes inside the standard section tunnel 1.
The embodiment is characterized in that a cavity buffer structure is enlarged in a constant cross section of a tunnel portal of a high-speed railway, at least one end of a standard section tunnel 1 is provided with a cavity open cut tunnel 2, a housing 5 is arranged on the outer side of the cavity open cut tunnel 2, the cavity open cut tunnel 2 comprises a lining group arranged on the inner side of the housing 5, the lining group comprises at least three lining rings 3 arranged at intervals along the line direction, and the inner wall of each lining ring 3 is correspondingly arranged with the standard section tunnel 1.
The lining ring cavity 35 and the housing cavity 51 together form the cavity open cut tunnel 2.
Specifically, the rib 4 is a concrete member.
The cavity open cut tunnel 2 is arranged at both ends of the standard section tunnel 1, namely, the equal section expansion cavity buffer structure of the tunnel portal of the high-speed railway in the embodiment is additionally arranged at the outlet and inlet of the standard section tunnel 1.
In the same lining group, the width of the lining ring 3 closest to the standard section tunnel 1 is larger than the width of the rest lining rings 3 in the direction of the line.
The inner wall of the lining ring 3 is arranged corresponding to the standard section tunnel 1.
The lining group comprises four lining rings 3 corresponding to the standard section tunnel 1, which are sequentially defined as a first lining ring 31, a second lining ring 32, a third lining ring 33 and a fourth lining ring 34 along the line direction, wherein the first lining ring 31 is closest to the standard section tunnel 1, the width F1 of the first lining ring 31 along the line direction is 4-6m, preferably 5m, and the width F2 of the second lining ring 32, the third lining ring 33 and the fourth lining ring 34 along the line direction is 2-4m, preferably 3m.
In the direction of the line, the clearance distance F3 between the first lining ring 31 and the opening of the standard section tunnel 1 is 4-6m, the clearance distance F4 between the adjacent lining rings 32 is 2-4m, the distance between the center line of the first lining ring 31 and the opening of the standard section tunnel 1 is 6.5-8.5m, the distance between the center line of the second lining ring 32 and the center line of the first lining ring 31 is 6-8m, and the distances between the rest lining rings 3 and the last lining ring 3 are all 2-4m.
The radius of the rib 4 is several times of the section outer radius r of the standard section tunnel 1.
The longitudinal width of the rib 4 along the line is 0.4-0.6m, the outer radius of the rib 4 is 1.25r-1.35r along the circumferential direction, the inner radius of the rib 4 is 1.15r-1.25r along the circumferential direction, and r is the section outer radius r of the inner cavity 11 of the standard section tunnel.
And a cover shell 5 is arranged at the top of the open cut tunnel 2 section of the cavity, namely, the outside of the rib 4, and the length of the cover shell 5 starts from the entrance and the exit of the standard section tunnel 1 to the end point of the constant section expansion cavity buffer structure of the tunnel portal of the high-speed railway.
The cover shell 5 is a light-transmitting material member, and specifically, the cover shell 5 is made of toughened glass, light-transmitting polymer materials or other materials with better lighting performance and is used for covering the whole cavity open cut tunnel 2.
The application discloses a constant cross section expansion cavity buffer structure of high-speed railway tunnel portal, the principle of alleviating pressure gradient is specifically as follows:
since air has a certain viscosity, a pressure drop phenomenon occurs when the air having viscosity flows through the wall surface of the tunnel. The constant section expansion cavity buffer structure of the tunnel portal of the high-speed railway is arranged, and the roughness of the inner wall of the tunnel portal is increased, so that the pressure drop generated when a pressure wave passes through the constant section expansion type tunnel is larger, the initial compression wave and the pressure gradient generated when a train enters the tunnel are reduced, and the micro-air pressure wave at the tunnel portal is further reduced.
Specifically, in the buffer structure with the uniform-section enlarged cavity for the tunnel portal of the high-speed railway according to the embodiment, the sectional area of the lining ring inner cavity 35 is greater than or equal to the sectional area of the standard-section tunnel inner cavity 11, and the housing 5 is arranged outside the lining group, so that the sectional area of the housing inner cavity 51 is also greater than the sectional area of the standard-section tunnel inner cavity 11, and the rise time of compression waves is prolonged, so that the pressure gradient is reduced, and the effect of reducing micro-air pressure waves is achieved. Meanwhile, the constant-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway has the advantages that due to the fact that air has certain viscosity, when the air with viscosity flows through the tunnel wall surface, the pressure reduction phenomenon can be generated. The lining rings 3 are arranged at intervals along the line direction, so that the roughness of the inner wall of the tunnel portal is increased, and therefore, when a pressure wave passes through the constant-section enlarged tunnel, the pressure drop is larger, thereby reducing the initial compression wave and the pressure gradient generated when a train enters the tunnel, and further reducing the micro-air pressure wave at the tunnel outlet. Based on the principle that: because the lining rings 3 are arranged at intervals along the line direction, ribs 4 are arranged on the outer side of the lining rings 3 along the circumferential direction of the lining rings 3, and the ribs 4 support the housing 5, so that air fluid undergoes expansion and contraction for the same times as the number of the lining rings 3, and the expansion and contraction for multiple times are carried out, and the constant-section expansion cavity buffer structure for the tunnel portal of the high-speed railway can achieve better buffer effect with shorter buffer structure length.
The invention can achieve better slowing effect with shorter buffer structure length, so the buffer structure with the uniform section enlarged cavity of the tunnel portal of the high-speed railway occupies small longitudinal space, can fully utilize the stability and vegetation of the original ground surface of the tunnel portal, and is less limited by the topography of the portal. The invention adopts cast-in-situ structure, which has better waterproof performance and integrity and is not easy to damage.
Example 2
As shown in fig. 1-4, the equal-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway has the pressure wave passing through the pressure loss final value deltaP of the equal-section enlarged cavity buffer structure for the tunnel portal of the high-speed railway Z The design comprises the following steps:
a1, obtaining a pressure loss value delta P when a pressure wave passes through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway based on the axial length L of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway, the equivalent diameter d of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and the average flow velocity of the pressure wave passing through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway;
a2, obtaining a local resistance coefficient xi of sudden expansion of the section of the buffer structure of the constant section expansion cavity of the tunnel portal of the high-speed railway based on the section area of the inner cavity 35 of the lining ring and the section area of the inner cavity 51 of the housing 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 ；
A3, based on the sudden expansion of the section of the buffer structure of the constant section expansion cavity of the tunnel portal of the high-speed railway, the local resistance coefficient xi 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 Obtaining accumulated local pressure loss value delta P of constant-section enlarged cavity buffer structure of tunnel portal of high-speed railway j ；
A4, accumulating local pressure loss value delta P of cavity buffer structure enlarging constant section of tunnel portal of high-speed railway j Reducing to obtain constant-section enlarged cavity buffer of tunnel portal of high-speed railwayThe final local pressure loss Δp3 of the structure;
a5, obtaining a final pressure loss value delta P when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway based on the pressure loss value delta P when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and the final local pressure loss delta P3 of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway Z 。
Specifically, the darcy-weissebach formula is a formula for describing a phenomenon of pressure drop generated when a viscous fluid flows through a pipe, and the formula is shown in formula (1):
wherein deltaP is the pressure loss value when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway; l is the length of a pipeline, and the length of a cavity buffer structure is enlarged by taking the constant section of a tunnel portal of a high-speed railway; d is the diameter of the pipeline, and the equivalent diameter of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway is taken here; l/d is called the geometry factor of the pipeline; ρ is the air density; v is the average flow velocity in the tube; lambda is the along-the-path friction coefficient, the dimension is 1, and is not a constant, and is usually determined by test results or an empirical formula and is a function of the Reynolds number Re of the fluid and the relative roughness of the pipe wallThe value can be obtained by inquiring a moid graph, and the calculation formula is shown as formula (2) to formula (4) according to the different flowing modes of the fluid in the pipeline:
for circular tube laminar flow:
for the excessive rough area of the round tube:
for circlesTube turbulence roughness zone:
wherein: r is R e The Reynolds number is calculated as R e ρvd/μ, μ is the viscosity coefficient of air, 1.87×10 - 5 Pa.s。
The local loss calculation formula:
local resistance coefficient of sudden expansion of constant-section expansion cavity buffer structure section of high-speed railway tunnel portal: zeta type toy 1 ＝(1-A 1 /A 2 ) 2
Wherein A is 1 Taking the cross-sectional area of the lining ring inner cavity 35 as the cross-sectional area of the original inner cavity under the condition of suddenly expanding cross-section; a is that 2 The cross-sectional area of the inner cavity 51 of the housing is taken to enlarge the cross-sectional area of the rear cavity in the case of sudden expansion of the cross-section.
Local pressure loss of sudden expansion of constant-section expansion cavity buffer structure section of high-speed railway tunnel portal: ΔP 1 ＝0.5ξ 1 ρv 2
Local resistance coefficient of sudden reduction of section of constant-section enlarged cavity buffer structure of tunnel portal of high-speed railway: zeta type toy 2 ＝0.5(1-A 3 /A 4 )
Wherein A is 3 Taking the cross-sectional area of the lining ring inner cavity 35 as the cross-sectional area of the inner cavity after shrinkage under the condition of sudden shrinkage of the cross-section; a is that 4 The cross-sectional area of the inner cavity 51 of the housing is taken as the cross-sectional area of the original inner cavity in the case of sudden reduction of the cross-section.
Local pressure loss caused by sudden reduction of section of constant-section enlarged cavity buffer structure at tunnel portal of high-speed railway: ΔP 2 ＝0.5ξ 2 ρv 2
The constant cross section of the tunnel portal of the high-speed railway enlarges the buffer structure of cavity and accumulates the local pressure loss: ΔP j ＝0.5ξ 1 ρv 2 n 1 +0.5ξ 2 ρv 2 n 2
Wherein DeltaP j Accumulating a local pressure loss value for the cavity buffer structure with the uniform cross section of the tunnel portal of the high-speed railway; n is n 1 The expansion times are experienced for the air flow to pass through the constant-section expansion cavity buffer structure of the tunnel portal of the high-speed railway; n is n 2 The cavity buffer structure is expanded for the air flow to pass through the constant section of the tunnel portal of the high-speed railway for the times of shrinkage.
The following illustrates the slow down effect of this application a high-speed railway tunnel portal constant cross section enlarges cavity buffer structure:
taking the velocity of flow when the train passes through the constant section enlarged cavity buffer structure of the tunnel portal of the high-speed railway as v=30m/s, and the viscosity coefficient mu=1.87×10 of air -5 Pa.s, equivalent diameter d=12.6m of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway, and the calculated Reynolds number is:
R e ＝ρvd/μ＝2.14×10 -7
calculating the friction coefficient along the path according to a formula (4), wherein k is absolute roughness, and taking the total thickness of the lining ring 3 and the ribs 4 as 1.1+0.7=1.8m; d is the equivalent diameter of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and is 12.6m, and the along-line friction coefficient lambda=0.4 is calculated.
The length L=14m of the cavity buffer structure is enlarged according to the constant section of the tunnel portal of the high-speed railway; air density of 1kg/m 3 The method comprises the steps of carrying out a first treatment on the surface of the The pressure drop when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway is calculated according to the formula (1):
local drag coefficient ζ of abrupt expansion of cross section 1 ＝0.168，ξ 2 =0.295, since the cavity buffer structure with the uniform section expansion of the cavity high-speed railway tunnel portal causes the air fluid to undergo expansion and contraction for 4 times, the local pressure loss is accumulated: ΔP j ＝0.5ξ 1 ρv 2 n 1 +0.5ξ 2 ρv 2 n 2 ＝75.6×4+132.75×4＝833.4Pa。
Considering that the constant section of the high-speed train passing through the tunnel portal of the high-speed railway enlarges the cavity buffer junctionWhen the structure is constructed, new compression waves are formed at the abrupt section position. Therefore, the accumulated local pressure loss is multiplied by a reduction coefficient n=0.3, which is an empirical value. The final local pressure loss was 250Pa. The pressure 450Pa of the compression wave reduced by the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway can be determined by combining the local pressure loss and the along-the-way pressure drop, namely the final value delta P of the pressure loss of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway passing through the constant-section enlarged cavity of the tunnel portal of the high-speed railway Z ＝200+250＝450Pa。
When the pressure wave passes through the cavity buffer structure with the enlarged cross section of the tunnel portal of the high-speed railway, the pressure drop of 450Pa can be generated, which shows that the cavity buffer structure with the enlarged cross section of the tunnel portal of the high-speed railway can well reduce the initial compression wave, thereby reducing the micro-air pressure wave at the tunnel portal.
Example 3
As shown in fig. 1-4, this embodiment discloses a construction method of the high-speed railway tunnel portal enlarged cavity buffer structure according to embodiment 1 or 2, which includes the following steps:
s1, pouring a plurality of lining rings 3 by using concrete, and forming the lining group;
s2, after the lining ring 3 reaches the design strength, building a rib mould for pouring the ribs 4 on the outer side of the lining ring 3; the rib mould is kept at a certain distance from the lining ring 3 corresponding to the inner side, and a bracket is arranged on the inner side of the rib mould and is connected with the lining ring 3;
s3, maintaining the interval between the rib 4 and the lining ring 3 correspondingly; after the rib mold is built, the ribs 4 are poured.
S4, erecting the housing 5 after the ribs 4 reach the design strength.
Specifically:
s1, pouring a plurality of lining rings 3 corresponding to the radius of the standard section tunnel 1 by using concrete;
s2, after the lining ring 3 reaches the design strength, building a rib mould for pouring the ribs 4 at the middle position of the outer side of the lining ring 3; the rib mould is kept at a certain distance from the lining ring 3 corresponding to the inner side, and a bracket is arranged on the inner side of the rib mould and is connected with the lining ring 3;
s3, maintaining the interval between the rib 4 and the lining ring 3 correspondingly; after the rib mold is built, the ribs 4 are poured.
S4, after the ribs 4 reach the design strength, placing the cover shell 5 on the ribs 4 by adopting a crane, and enabling the ribs 4 to support the cover shell 5, wherein the cover shell 5 is subjected to sealing treatment with the circuit roadbed 7, the standard section tunnel 1 and the lining ring 3 farthest from the standard section tunnel 1.
The construction method of the high-speed railway tunnel portal enlarged cavity buffer structure adopts a cast-in-situ structure, has good waterproof performance and integrity, is not easy to damage, and can be used for efficiently constructing the high-speed railway tunnel portal equal-section enlarged cavity buffer structure, so that a better slowing effect is achieved by a shorter buffer structure length.
Specifically, step S4 specifically includes:
the constant-section enlarged cavity buffer structures are arranged at the entrance and the exit of the tunnel, so that the initial compression wave and the pressure change rate generated when a train enters the tunnel can be effectively reduced, the micro-air pressure wave peak value at the tunnel portal is reduced, and the influence of the micro-air pressure wave peak value on the surrounding environment is reduced;
the invention has convenient implementation and simple structure, can relieve micro-air pressure waves at the tunnel portal with shorter buffer structure length, and is less limited by the topography of the tunnel portal.
The method comprises the steps that a constant-section enlarged cavity buffer cavity open cut tunnel structure is arranged at an outlet and an inlet of a standard section tunnel, the clearance area of the constant-section enlarged cavity buffer structure of a constant-section enlarged cavity open cut tunnel 2 type high-speed railway tunnel portal is 1.2-1.3 times that of the standard section tunnel, the constant-section buffer cavity open cut tunnel structure is in a constant-section form, and the length is 26-32m;
the constant cross section enlarged cavity buffer structure of the constant cross section enlarged cavity open cut tunnel 2 type high-speed railway tunnel portal comprises a lining ring 3, ribs 4 and a housing 5, wherein the projection of the lining ring 3 in the line direction is consistent with that of a standard tunnel lining; the specific operation steps are as follows:
1. casting a plurality of lining rings 3 corresponding to the radius of the standard section tunnel 1 by using concrete;
2. after the lining ring 3 reaches the design strength, building a rib mould for pouring the ribs 4 at the middle position outside the lining ring 3; and the rib mould is kept at a certain distance from the inner side corresponding lining ring 3, and the inner side of the rib mould is provided with a bracket which is connected with the lining ring 3.
3. Maintaining the spacing between the ribs 4 and the corresponding lining rings 3. After the rib mold is built, the ribs 4 are poured.
4. After the rib 4 reaches the design strength, the housing 5 is made of toughened glass or other materials with better lighting performance and is used for covering the whole buffer structure with the uniform section enlarged cavity of the tunnel portal of the high-speed railway. The specific operation is as follows: the cover 5 is placed on the rib 4 by using a crane, and the rib 4 plays a supporting role on the cover 5. The closure 5 should be sealed with the route base 7, the tunnel wall and the last lining ring 3 so that the closure 5 covers the lining group.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.

Claims (10)

1. The utility model provides a high-speed railway tunnel portal constant cross section enlarges cavity buffer structure, its characterized in that, including setting up in the lining cutting group of standard section tunnel (1) tip, the lining cutting group outside is provided with housing (5), lining cutting group includes a plurality of lining cutting ring (3) that set up along the circuit direction interval, lining cutting ring inner chamber (35) sectional area is greater than or equal to standard section tunnel inner chamber (11) sectional area, lining cutting ring (3) outside is provided with rib (4) along lining cutting ring (3) circumference, rib (4) support housing (5).
2. The buffer structure of the constant section enlarged cavity of the tunnel portal of the high-speed railway according to claim 1, wherein the width of the lining ring (3) closest to the standard section tunnel (1) is larger than the width of the rest lining rings (3) along the line direction.
3. The buffer structure of the constant section enlarged cavity of the tunnel portal of the high-speed railway according to claim 2, wherein the lining group comprises four lining rings (3), which are sequentially defined as a first lining ring (31), a second lining ring (32), a third lining ring (33) and a fourth lining ring (34) along the line direction, wherein the first lining ring (31) is closest to the standard section tunnel (1), the width F1 of the first lining ring (31) along the line direction is 4-6m, and the width F2 of the second lining ring (32), the third lining ring (33) and the fourth lining ring (34) along the line direction is 2-4m.
4. A constant section enlarged cavity buffer structure for a tunnel portal of a high-speed railway according to claim 3, wherein the clearance distance F3 between the first lining ring (31) and the portal of the standard section tunnel (1) is 4-6m, and the clearance distance F4 between adjacent lining rings (32) is 2-4m.
5. The buffer structure of the constant section enlarged cavity of the tunnel portal of the high-speed railway according to claim 1, wherein a gap (6) is arranged between the rib (4) and the corresponding lining ring (3).
6. The constant-section enlarged cavity buffer structure of a tunnel portal of a high-speed railway according to claim 1, wherein the cover (5) covers the lining group.
7. The buffer structure of the constant-section enlarged cavity of the tunnel portal of the high-speed railway according to claim 1, wherein the housing (5) is a light-transmitting material member.
8. The buffer structure for the uniform cross-section enlarged cavity of the tunnel portal of the high-speed railway according to claim 1, wherein the pressure wave passes through the final value deltap of the pressure loss of the buffer structure for the uniform cross-section enlarged cavity of the tunnel portal of the high-speed railway Z The design comprises the followingThe steps are as follows:
a1, obtaining a pressure loss value delta P when a pressure wave passes through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway based on the axial length L of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway, the equivalent diameter d of the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and the average flow velocity of the pressure wave passing through the equal section enlarged cavity buffer structure of the tunnel portal of the high-speed railway;
a2, obtaining a local resistance coefficient xi of sudden expansion of the section of the buffer structure of the constant-section expansion cavity of the tunnel portal of the high-speed railway based on the section area of the inner cavity (35) of the contracted lining ring and the section area of the inner cavity (51) of the housing 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 ；
A3, based on the sudden expansion of the section of the buffer structure of the constant section expansion cavity of the tunnel portal of the high-speed railway, the local resistance coefficient xi 1 And the local resistance coefficient xi of sudden reduction of the constant-section enlarged cavity buffer structure section of the tunnel portal of the high-speed railway 2 Obtaining accumulated local pressure loss value delta P of constant-section enlarged cavity buffer structure of tunnel portal of high-speed railway j ；
A4, accumulating local pressure loss value delta P of cavity buffer structure enlarging constant section of tunnel portal of high-speed railway j The final local pressure loss delta P3 of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway is obtained by reducing;
a5, obtaining a final pressure loss value delta P when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway based on the pressure loss value delta P when the pressure wave passes through the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway and the final local pressure loss delta P3 of the constant-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway Z 。
9. A construction method for the constant cross-section enlarged cavity buffer structure of the tunnel portal of the high-speed railway according to any one of claims 1 to 8, which is characterized by comprising the following steps:
s1, pouring a plurality of lining rings (3) by using concrete, and forming the lining group;
s2, after the lining ring (3) reaches the design strength, building a rib mould for pouring the ribs (4) on the outer side of the lining ring (3); the rib mould is kept at a certain distance from the lining ring (3) corresponding to the inner side, and a bracket is arranged on the inner side of the rib mould and is connected with the lining ring (3);
s3, maintaining the interval between the rib (4) and the corresponding lining ring (3); pouring ribs (4) after the rib mould is built;
s4, erecting the housing (5) after the ribs (4) reach the design strength.
10. The construction method according to claim 9, wherein step S4 specifically comprises: and placing the housing (5) on the rib (4) by adopting a crane, and enabling the rib (4) to support the housing (5), wherein the housing (5) is subjected to sealing treatment with the circuit roadbed (7), the standard section tunnel (1) and the lining ring (3) farthest from the standard section tunnel (1).
CN202310772589.6A 2023-06-27 2023-06-27 High-speed railway tunnel portal enlarged cavity buffer structure and construction method Pending CN117345266A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310772589.6A CN117345266A (en) 2023-06-27 2023-06-27 High-speed railway tunnel portal enlarged cavity buffer structure and construction method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310772589.6A CN117345266A (en) 2023-06-27 2023-06-27 High-speed railway tunnel portal enlarged cavity buffer structure and construction method

Publications (1)

Publication Number Publication Date
CN117345266A true CN117345266A (en) 2024-01-05

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Country Link
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