CN116006189A - Construction method for in-situ extension of existing highway tunnel and tunnel structure - Google Patents
Construction method for in-situ extension of existing highway tunnel and tunnel structure Download PDFInfo
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- CN116006189A CN116006189A CN202310158412.7A CN202310158412A CN116006189A CN 116006189 A CN116006189 A CN 116006189A CN 202310158412 A CN202310158412 A CN 202310158412A CN 116006189 A CN116006189 A CN 116006189A
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- 238000010276 construction Methods 0.000 title claims abstract description 52
- 238000011065 in-situ storage Methods 0.000 title claims abstract description 12
- 238000009412 basement excavation Methods 0.000 claims abstract description 29
- 229910000831 Steel Inorganic materials 0.000 claims description 103
- 239000010959 steel Substances 0.000 claims description 103
- 239000011435 rock Substances 0.000 claims description 21
- 238000003466 welding Methods 0.000 claims description 16
- 238000000034 method Methods 0.000 claims description 15
- 238000005422 blasting Methods 0.000 claims description 7
- 238000010008 shearing Methods 0.000 claims description 5
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims description 3
- 239000002699 waste material Substances 0.000 abstract description 3
- 238000001514 detection method Methods 0.000 description 7
- 230000002787 reinforcement Effects 0.000 description 5
- 239000011800 void material Substances 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000004035 construction material Substances 0.000 description 1
- 230000002349 favourable effect Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 238000009440 infrastructure construction Methods 0.000 description 1
- 238000004062 sedimentation Methods 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/20—Hydro energy
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Abstract
The invention relates to a construction method and a tunnel structure for in-situ extension of an existing highway tunnel, belongs to the technical field of tunnel design construction, and solves the problems of resource waste, large investment and high reconstruction and extension cost of the existing construction method. The construction method mainly comprises the following steps: removing the secondary lining of the existing tunnel arch part on the expanded digging side; constructing an advanced support of a newly built tunnel arch part at the expanding excavation side and an initial support of the newly built tunnel arch part; dismantling secondary lining of the existing tunnel arch wall at the expanded digging side; constructing an advanced support of a newly built tunnel arch wall at the expanding excavation side and an initial support of the newly built tunnel arch wall; constructing an inverted arch of the newly-built tunnel; and (5) constructing a secondary lining of the newly built tunnel. The invention effectively shortens the site construction time, reduces the reconstruction and expansion cost, and improves the quality and stability of the tunnel structure.
Description
Technical Field
The invention relates to the technical field of tunnel design construction, in particular to a construction method and a tunnel structure for in-situ extension of an existing highway tunnel.
Background
With the continuous growth of the economy in China, infrastructure construction is in the front of the world, and the quantity of automobile conservation is increasing, so that many operation highways cannot meet the requirement of traffic increase.
In order to meet the demand of traffic growth, the reconstruction and expansion of the existing expressway are imperative, and the reconstruction and expansion of the expressway are related to the reconstruction and expansion of the highway tunnel.
The existing highway tunnel reconstruction and expansion scheme mainly comprises the following modes: firstly, discarding the existing tunnel, and fully re-expanding and digging a new tunnel; second, the existing tunnel is low in utilization rate by starting from the bottom of the existing tunnel.
The highway tunnel reconstruction and expansion scheme has low utilization rate of the existing tunnel, causes larger resource waste, and has high reconstruction and expansion cost and long period.
Disclosure of Invention
In view of the above analysis, the present invention aims to provide a construction method and a tunnel structure for in-situ extension of an existing highway tunnel, which are used for solving the problems of resource waste, large investment and high reconstruction and extension cost of the existing construction method.
The aim of the invention is mainly realized by the following technical scheme:
on one hand, the invention provides a construction method for in-situ extension of an existing highway tunnel, which comprises the following steps:
step 1: carrying out advanced geological forecast on the expanded digging side;
step 2: removing the secondary lining of the existing tunnel arch part on the expanded digging side;
step 3: constructing an advanced support of a newly built tunnel arch part at the expanding excavation side and an initial support of the newly built tunnel arch part;
step 4: installing a temporary steel support;
step 5: dismantling secondary lining of the existing tunnel arch wall at the expanded digging side;
step 6: constructing an advanced support of a newly built tunnel arch wall at the expanding excavation side and an initial support of the newly built tunnel arch wall;
step 7: filling gaps of surrounding rocks behind the primary supports of the arch parts of the newly-built tunnels and the primary supports of the arch walls of the newly-built tunnels;
step 8: removing the temporary steel support;
step 9: constructing an inverted arch of the newly-built tunnel;
step 10: constructing a secondary lining of the newly built tunnel;
step 11: and (5) repeating the steps 1-10 in the longitudinal direction of the existing tunnel to finish the expansion of the tunnel.
Optionally, the step 3 includes the following steps:
step 31: constructing an advanced support of the arch part of the newly built tunnel at the expanding excavation side so as to ensure the stability of surrounding rock during the expanding excavation construction;
step 32: excavating arch surrounding rocks between the existing tunnel arch and the newly-built tunnel arch on the expanded excavation side;
step 33: shi Zuoxin constructing a tunnel arch primary support;
step 34: and connecting the primary support of the arch part of the newly constructed tunnel with the secondary lining of the existing tunnel.
Optionally, the step 34 includes the steps of:
step 341: arranging channel steel at the joint of the primary support of the arch part of the newly-built tunnel and the secondary lining of the existing tunnel, and arranging a backing plate in the channel steel;
step 342: contacting the end part of I-steel used for the initial support of the arch part of the newly constructed tunnel with a backing plate;
step 343: and welding the channel steel, the backing plate and the I-steel.
Optionally, the step 7 includes the steps of:
step 71: grouting holes are formed in the combination part of the secondary lining of the existing tunnel and the primary support of the newly built tunnel arch part;
step 72: grouting into the grouting holes.
Optionally, the step 9 includes the steps of:
step 91: removing the existing tunnel inverted arch at the expanding excavation side;
step 92: excavating surrounding rocks between an existing tunnel inverted arch and a newly constructed tunnel inverted arch;
step 93: and constructing an inverted arch of the new tunnel, and backfilling to enable the existing tunnel primary support at the reserved side, the primary support at the arch part of the new tunnel and the primary support at the arch wall of the new tunnel to be sealed into a ring.
Optionally, the step 5 is implemented in a blasting manner.
Optionally, the step 5 is implemented by mechanically shearing the reinforcing steel bars.
Optionally, the step 343 includes the following steps: the end part of the I-steel is welded with the backing plate, and then the backing plate is connected with the bottom wall of the channel steel.
Optionally, the step 343 includes the following steps: the end part of the I-steel is welded with the backing plate, and then the backing plate is connected with the side wall of the channel steel.
Optionally, the step 1 includes determining a location where the tunnel in-situ expansion is performed, including the following steps:
step 1: determining the limit of a newly built tunnel building;
step 2: and comparing the inner contours of the existing tunnel and the newly-built tunnel, and determining the junction position of the existing tunnel and the newly-built tunnel.
On the other hand, the invention also provides a tunnel structure which is reconstructed and expanded on the basis of the existing tunnel, and the tunnel structure is obtained by adopting the construction method.
The tunnel structure after reconstruction and expansion based on the existing tunnel comprises an existing tunnel section and an expansion tunnel section, wherein the existing tunnel section provides primary support for the expansion tunnel section; the existing tunnel section and the extended tunnel section are connected through a connecting piece.
Optionally, the connecting piece comprises a channel steel and a backing plate, wherein the channel steel is arranged along the longitudinal direction of the tunnel, and the backing plate is arranged in a groove of the channel steel.
Optionally, the opening of the channel steel faces the extension tunnel section, the end part of the I-steel used for the primary support of the extension tunnel section is contacted with the backing plate, and the channel steel, the backing plate and the end part of the I-steel are fixedly connected.
Optionally, the backing plate is made of steel.
Optionally, the number of the channel steel is multiple, and the multiple channel steel is sequentially connected along the longitudinal direction of the tunnel.
Optionally, the bottom wall of the channel steel, the backing plate and the end part of the I-steel are welded.
Optionally, the side wall of the channel steel, the backing plate and the end part of the I-steel are welded.
Optionally, the width of the backing plate is greater than the width of the i-steel.
Optionally, the width of the backing plate is smaller than the width of the channel steel.
Optionally, the length of the channel steel is 60cm.
Compared with the prior art, the invention has at least one of the following beneficial effects:
(1) The construction method of the invention does not discard the existing tunnel, fully re-dig the new tunnel, and not start arching from the bottom of the existing tunnel, but keeps a part of the existing tunnel, and on one hand, maintains the stability of the un-digged side wall rock and improves the construction safety by taking the secondary lining of the single side part of the existing tunnel as the primary support of the extended tunnel; on the other hand, the existing tunnel resources can be fully utilized, the green development concept is implemented, the extension investment is saved, the site construction time is shortened, and the extension efficiency is improved.
(2) The invention ascertains the condition of the cavity behind the existing tunnel lining by carrying out advanced geological detection before construction, and decides whether to pre-reinforce or not according to the detection condition. The method can effectively save construction resources and improve construction safety.
(3) The invention adopts a subsection excavation method, and the construction process ensures the safety of the tunnel in the weak stratum.
(4) According to the invention, through reasonably selecting the connection points of the existing tunnel and the newly-built tunnel, on one hand, a part of original lining can be utilized to the maximum extent, the extension cost is reduced, and the extension period is shortened; on the other hand, the stability of the non-expanded excavation side wall rock can be maintained, and the construction safety is improved.
(5) The tunnel structure of the present invention does not fully re-excavate but utilizes a portion of the existing tunnel. Specifically, the tunnel structure comprises the existing tunnel section and the expanded tunnel section, wherein the existing tunnel section provides primary support for the expanded tunnel section, on one hand, the stability of the unexpanded side wall rock is maintained, and the construction safety is improved; on the other hand, the existing tunnel resources can be fully utilized, the green development concept is implemented, the reconstruction and expansion cost is reduced, the site construction time is shortened, and the expansion efficiency is improved.
(6) According to the invention, the pad is arranged at the joint of the primary support of the newly-built tunnel arch and the secondary lining of the existing tunnel, so that the contact area of the primary support of the newly-built tunnel arch and the secondary lining of the existing tunnel is increased, the pressure intensity is reduced, and the stress concentration is prevented from crushing the secondary lining of the existing tunnel.
(7) According to the invention, the channel steel is arranged, so that on one hand, the backing plate is prevented from shifting; on the other hand, the welding mode is increased, and the welding flexibility is improved. For example, the bottom wall of the channel steel can be welded with the backing plate and the I-steel, and the side wall of the channel steel can be welded with the backing plate and the I-steel, so that the connection between the primary support of the arch part of the newly-built tunnel and the secondary lining of the existing tunnel can be realized.
(8) According to the invention, the width of the backing plate is set to be larger than the width of the I-steel and smaller than the width of the channel steel, so that a gap can be formed between the backing plate and the side wall of the channel steel, and on one hand, the welding is convenient; on the other hand, the welding firmness of the channel steel, the backing plate and the I-steel is improved.
In the invention, the technical schemes can be mutually combined to realize more preferable combination schemes. Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.
Drawings
The drawings are only for purposes of illustrating particular embodiments and are not to be construed as limiting the invention, like reference numerals being used to refer to like parts throughout the several views.
FIG. 1 is a construction flow diagram of in-situ extension using existing tunnel unilateral lining;
FIG. 2 is a schematic diagram showing the tunnel reconstruction and expansion construction steps;
fig. 3 is an enlarged view of the junction of the existing tunnel secondary lining and the newly built tunnel primary support at a point a in fig. 2.
Reference numerals:
1-radar survey lines; 2 a-existing tunnel arch; 2 b-newly-built tunnel arch part; 3-steel columns; 4 a-existing tunnel archways; 4 b-newly-built tunnel arch walls; 5-secondary lining of the existing tunnel; 6 a-existing tunnel invert; 6 b-creating a tunnel inverted arch; 7-backing plate; 8-I-steel; 9-channel steel.
Detailed Description
The following detailed description of preferred embodiments of the invention is made in connection with the accompanying drawings, which form a part hereof, and together with the description of the embodiments of the invention, are used to explain the principles of the invention and are not intended to limit the scope of the invention.
Example 1
The invention discloses a construction method for expanding a tunnel of an existing highway in a complex weak stratum. The construction method utilizes the single-side lining of the existing tunnel as an initial support of the extension tunnel to carry out in-situ extension, can effectively ensure the safety of the tunnel extension construction, implements the green development concept, and can effectively save the construction cost.
Before the formal construction, the positions where the tunnel is to be expanded in situ, that is, the positions where the existing tunnel is reserved and from which the tunnel is to be expanded, are determined first. The method specifically comprises the following steps:
step 1: determining the limit of a newly built tunnel building;
step 2: and comparing the inner contours of the existing tunnel and the newly-built tunnel, and determining the junction position of the existing tunnel and the newly-built tunnel, namely the joint of the secondary lining of the existing tunnel and the primary support of the newly-built tunnel.
After the position for in-situ expansion is determined, construction is performed. As shown in fig. 1, the construction method of the present embodiment includes the steps of:
step 1: and carrying out advanced geological forecast on the expanded digging side.
Before construction, advanced geological detection is carried out on the side of the expansion excavation, and detection means such as geological radar and the like are adopted to detect the void condition behind the tunnel lining so as to determine whether pre-reinforcement measures are needed for the existing tunnel.
According to the embodiment, advanced geological detection is carried out before construction, the condition of a cavity behind an existing tunnel lining is ascertained, and whether pre-reinforcement is carried out or not is determined according to the detected condition. The method can effectively save construction resources and improve construction safety.
Specifically, in this embodiment, advanced geological detection is performed on the extended excavation side by using a geological radar detection means. As shown in fig. 2, in this embodiment, 3 radar lines 1 are arranged along the longitudinal direction of the tunnel at the arch, the waisted arch and the arch wall of the existing tunnel on the side of the expansion.
It should be noted that, in this embodiment, the reason why the radar line is disposed at the dome is that: on the one hand, the vault is the weakest place of construction; on the other hand, when the vault is used for lining, concrete spraying and other operations, construction materials are easy to fall off due to the action of gravity, construction defects occur, and the back of the lining is hollow.
In addition, the arches and walls are also locations prone to construction defects. According to the embodiment, the radar measuring lines are arranged at the three positions of the vault, the arch waist and the arch wall, so that the void situation behind the tunnel lining can be accurately known, and the guidance of whether pre-reinforcement measures need to be carried out on the existing tunnel is improved.
If pre-reinforcement is required, the reinforcement measures adopted in this embodiment are: and driving a grouting pipe into the void position, and then injecting concrete into the grouting pipe.
Step 2: and removing the secondary lining of the existing tunnel arch part 2a on the expanding and digging side.
Specifically, the method is realized by blasting, mechanically shearing the steel bars and the like.
Step 3: and performing advanced support and preliminary support of an upper step (namely, a newly built tunnel arch part) on the newly built tunnel arch part 2b on the expanding and digging side. The method specifically comprises the following steps:
step 31: constructing an advanced support of a newly built tunnel arch part 2b on the expanding excavation side so as to ensure the stability of surrounding rock during expanding excavation construction;
step 32: excavating arch surrounding rock between the existing tunnel arch 2a and the newly built tunnel arch 2b on the expanding excavation side by adopting a blasting or mechanical excavation mode, wherein the expanding excavation footage is not more than 2-ring steel frames;
step 33: constructing an initial support of a newly built tunnel arch part 2b on the expanding and digging side;
step 34: and connecting the primary support of the newly built tunnel arch part 2b on the expanding and digging side with the secondary lining 5 of the existing tunnel.
As shown in fig. 3, step 34 includes the steps of:
step 341: and arranging channel steel 9 at the joint of the primary support of the newly-built tunnel arch part 2b and the secondary lining 5 of the existing tunnel, and arranging a backing plate 7 in the channel steel 9.
Specifically, the channel steel 9 is placed along the longitudinal direction of the tunnel (i.e. along the length direction of the tunnel), the opening of the channel steel 9 faces the newly-built tunnel side, and the backing plate 7 is also placed along the longitudinal direction of the tunnel and placed in the groove of the channel steel 9.
Step 342: the end of the I-steel 8 for the initial support of the newly built tunnel arch part 2b is contacted with the backing plate 7.
Step 343: and welding the channel steel 9, the backing plate 7 and the I-steel 8.
Step 343 is implemented in two ways: firstly, welding the end part of the I-steel 8 with the backing plate 7, and then connecting the backing plate 7 with the bottom wall of the channel steel 9; in the second mode, the end of the I-steel 8 is welded with the backing plate 7, and then the backing plate 7 is connected with the side wall of the channel steel 9.
In a preferred embodiment, the channel steel 9 should be closely attached to the concrete surface of the existing secondary lining 5 of the tunnel, and the gaps are closely filled with concrete pads or the like.
The small cross-sectional area of the i-steel 8 results in a large pressure on the contact surface between the primary support of the newly-built tunnel arch 2b and the existing tunnel secondary lining 5, which is liable to crush the existing tunnel secondary lining 5 locally. In this embodiment, the pad 7 is disposed at the junction between the primary support of the newly-built tunnel arch 2b and the existing tunnel secondary lining 5, so that the contact area between the primary support and the existing tunnel secondary lining is increased, and thus the pressure is reduced, and the stress concentration is prevented from crushing the existing tunnel secondary lining.
The benefit of adopting the channel steel in this embodiment is that: the channel steel is provided with side walls with two upright sides, and when the channel steel, the backing plate and the I-steel are welded, the welding mode is increased, and the welding flexibility is improved. For example, the bottom wall of the channel steel can be welded with the backing plate and the I-steel, and the side wall of the channel steel can be welded with the backing plate and the I-steel.
Step 4: and installing a temporary steel support.
Specifically, a steel column 3 is installed between one end of the newly formed primary support of the newly constructed tunnel arch and the bottom wall of the existing tunnel to form a temporary support.
According to the method, the temporary steel support is arranged between the existing tunnel pavement structure and the newly built tunnel arch primary support at the expanding excavation side, so that dislocation and deviation of the newly formed primary support can be prevented, stability of surrounding rocks is kept, and favorable conditions are provided for expanding excavation of side wall side surrounding rocks in the next step.
Step 5: and removing the secondary lining of the existing tunnel arch wall 4a on the expanded excavation side.
Specifically, the method is realized by blasting, mechanically shearing the steel bars and the like.
Step 6: and constructing an advanced support and an initial support of a lower step (namely the newly built tunnel arch wall) of the newly built tunnel arch wall 4b on the expanding and digging side. The method specifically comprises the following steps:
step 61: constructing an advanced support of a newly built tunnel arch wall 4b on the expanding excavation side so as to ensure the stability of surrounding rock during the expanding excavation construction;
step 62: excavating surrounding rocks between the existing tunnel arch wall 4a and the newly-built tunnel arch wall 4b by adopting a blasting or mechanical excavating mode, wherein the expanding excavation footage is not more than 2 rings of steel frames;
step 63: and constructing an initial support of the arch wall of the newly-built tunnel.
Step 7: and filling gaps of surrounding rocks behind the primary supports of the arch parts of the newly-built tunnels and the primary supports of the arch walls of the newly-built tunnels. The method comprises the following steps:
step 71: grouting holes are formed in the combination part of the secondary lining 5 of the existing tunnel and the primary support of the arch part of the newly-built tunnel;
step 72: grouting is carried out in the grouting holes, and gaps of surrounding rocks behind the primary support are filled through grouting, so that the surrounding rocks are reinforced, sedimentation is reduced, and deformation is controlled.
Step 8: and removing the temporary steel support.
Step 9: and constructing an inverted arch of the newly built tunnel. The method comprises the following steps:
step 91: removing the existing tunnel inverted arch 6a at the expansion side by blasting, mechanically shearing the reinforcing steel bars and the like;
step 92: excavating surrounding rocks between the existing tunnel inverted arch 6a and the newly-built tunnel inverted arch 6 b;
step 93: shi Zuoxin the tunnel inverted arch 6b is built and backfilled with C15 concrete to enclose the existing tunnel primary support on the reserved side, the newly built tunnel arch primary support and the newly built tunnel arch wall primary support.
Step 10: and (5) constructing a secondary lining of the newly built tunnel.
After the primary support is closed into a ring, water-proof and drainage construction is carried out, and then secondary lining of the newly built tunnel is carried out.
Step 11: and (5) repeating the steps 1-10 in the longitudinal direction of the existing tunnel to finish the expansion of the tunnel.
Example two
The invention discloses a tunnel structure obtained by rebuilding and expanding an existing tunnel by adopting the construction method of the first embodiment.
As shown in fig. 2, the re-established tunnel structure includes an existing tunnel section and an established tunnel section, and the secondary lining of the existing tunnel section provides primary support for the established tunnel section.
The existing tunnel section and the extension tunnel section are connected through a connecting piece. As shown in fig. 3, the connector includes a channel steel and a pad plate, the channel steel is disposed along the longitudinal direction of the tunnel (i.e., along the length direction of the tunnel), and the pad plate is disposed in a groove of the channel steel.
The opening of the channel steel faces to the expanded tunnel section, the end part of the I-steel used for the primary support of the expanded tunnel section is contacted with the backing plate, and the channel steel, the backing plate and the end part of the I-steel are fixedly connected. The fixed connection may be, for example, welding. The backing plate may be made of steel, for example.
Specifically, the welding part of the channel steel, the backing plate and the I-steel can be the welding of the bottom wall of the channel steel, the backing plate and the end part of the I-steel, or the welding of the side wall of the channel steel, the backing plate and the end part of the I-steel.
In a specific embodiment, the number of the channel steel is multiple, and the channel steel is sequentially connected along the longitudinal direction of the tunnel. The length of the channel is illustratively 60cm.
Specifically, the width of the backing plate is larger than the width of the I-steel and smaller than the width of the channel steel, so that a gap is formed between the backing plate and the side wall of the channel steel, and on one hand, the welding is convenient; on the other hand, the welding firmness of the channel steel, the backing plate and the I-steel is improved.
The present invention is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present invention are intended to be included in the scope of the present invention.
Claims (10)
1. The construction method for in-situ extension of the existing highway tunnel is characterized by comprising the following steps of:
step 1: carrying out advanced geological forecast on the expanded digging side;
step 2: removing the secondary lining of the existing tunnel arch part on the expanded digging side;
step 3: constructing an advanced support of a newly built tunnel arch part at the expanding excavation side and an initial support of the newly built tunnel arch part;
step 4: installing a temporary steel support;
step 5: dismantling secondary lining of the existing tunnel arch wall at the expanded digging side;
step 6: constructing an advanced support of a newly built tunnel arch wall at the expanding excavation side and an initial support of the newly built tunnel arch wall;
step 7: filling gaps of surrounding rocks behind the primary supports of the arch parts of the newly-built tunnels and the primary supports of the arch walls of the newly-built tunnels;
step 8: removing the temporary steel support;
step 9: constructing an inverted arch of the newly-built tunnel;
step 10: constructing a secondary lining of the newly built tunnel;
step 11: and (5) repeating the steps 1-10 in the longitudinal direction of the existing tunnel to finish the expansion of the tunnel.
2. The method according to claim 1, wherein the step 3 comprises the steps of:
step 31: constructing an advanced support of the arch part of the newly built tunnel at the expanding excavation side so as to ensure the stability of surrounding rock during the expanding excavation construction;
step 32: excavating arch surrounding rocks between the existing tunnel arch and the newly-built tunnel arch on the expanded excavation side;
step 33: shi Zuoxin constructing a tunnel arch primary support;
step 34: and connecting the primary support of the arch part of the newly constructed tunnel with the secondary lining of the existing tunnel.
3. The construction method according to claim 2, wherein the step 34 comprises the steps of:
step 341: arranging channel steel at the joint of the primary support of the arch part of the newly-built tunnel and the secondary lining of the existing tunnel, and arranging a backing plate in the channel steel;
step 342: contacting the end part of I-steel used for the initial support of the arch part of the newly constructed tunnel with a backing plate;
step 343: and welding the channel steel, the backing plate and the I-steel.
4. The construction method according to claim 1, wherein the step 7 comprises the steps of:
step 71: grouting holes are formed in the combination part of the secondary lining of the existing tunnel and the primary support of the newly built tunnel arch part;
step 72: grouting into the grouting holes.
5. The construction method according to claim 1, wherein the step 9 comprises the steps of:
step 91: removing the existing tunnel inverted arch at the expanding excavation side;
step 92: excavating surrounding rocks between an existing tunnel inverted arch and a newly constructed tunnel inverted arch;
step 93: and constructing an inverted arch of the new tunnel, and backfilling to enable the existing tunnel primary support at the reserved side, the primary support at the arch part of the new tunnel and the primary support at the arch wall of the new tunnel to be sealed into a ring.
6. The construction method according to claim 1, wherein the step 5 is implemented by blasting.
7. The construction method according to claim 1, wherein the step 5 is performed by mechanically shearing the reinforcing steel bars.
8. A method according to claim 3, wherein said step 343 comprises the steps of: the end part of the I-steel is welded with the backing plate, and then the backing plate is connected with the bottom wall of the channel steel.
9. A method according to claim 3, wherein said step 343 comprises the steps of: the end part of the I-steel is welded with the backing plate, and then the backing plate is connected with the side wall of the channel steel.
10. A tunnel structure after reconstruction and expansion based on an existing tunnel, characterized in that it is constructed by the construction method according to any one of claims 1-9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310158412.7A CN116006189A (en) | 2023-02-23 | 2023-02-23 | Construction method for in-situ extension of existing highway tunnel and tunnel structure |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202310158412.7A CN116006189A (en) | 2023-02-23 | 2023-02-23 | Construction method for in-situ extension of existing highway tunnel and tunnel structure |
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| CN116006189A true CN116006189A (en) | 2023-04-25 |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119244251A (en) * | 2024-12-04 | 2025-01-03 | 湖南省交通规划勘察设计院有限公司 | A construction method for widening one side of an existing tunnel |
| CN119266831A (en) * | 2024-09-13 | 2025-01-07 | 保利长大工程有限公司 | A large-span tunnel expansion construction technology |
-
2023
- 2023-02-23 CN CN202310158412.7A patent/CN116006189A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN119266831A (en) * | 2024-09-13 | 2025-01-07 | 保利长大工程有限公司 | A large-span tunnel expansion construction technology |
| CN119244251A (en) * | 2024-12-04 | 2025-01-03 | 湖南省交通规划勘察设计院有限公司 | A construction method for widening one side of an existing tunnel |
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