Construction method of highway tunnel suspended partition air supply duct

Abstract

The application provides a highway tunnel suspension type partition air supply duct construction method, and belongs to the technical field of highway tunnel construction. The method comprises the following steps: S1, measuring and laying out; S2, installing secondary lining steel bars; S3, installing a hanger pre-embedded part; S4, installing channel steel and foam filling; S5, pouring secondary lining concrete; S6, secondary lining demolding and foam filling cleaning; S7, installing the first horizontal partition of the bottom of a vertical head partition; S8, installing a vertical head partition; and S9, installing remaining horizontal partitions. The highway tunnel suspension type partition air supply duct construction method is convenient in material selection, high in safety, easy to operate, fast in construction progress, simple in structure of the constructed air supply duct, and light in weight.

Description

Technical Field

[0001] This invention belongs to the technical field of highway tunnel construction, and specifically discloses a construction method for a suspended diaphragm ventilation duct in a highway tunnel. Background Technology

[0002] With the rapid development of highway tunnel construction technology, the number of long highway tunnels designed and successfully implemented is also gradually increasing. To address the issues of construction progress and ventilation during operation of long tunnels, ventilation inclined shafts or ventilation vertical shafts are generally designed to increase the working face during construction and excavation, while also solving the problem of air supply and exhaust during operation. Typically, a connecting ventilation duct is set on the side of the ventilation inclined shaft or vertical shaft closest to the main tunnel, and an air supply outlet for supplying air to the main tunnel is set at the waist of the secondary lining arch. A 20-30m long air supply duct is set along the driving direction of the main tunnel from the air supply outlet. The bottom of this section of the air supply duct is a horizontal baffle, with the baffle height the same as the bottom height of the intersection. A vertical baffle is set at the upstream end in the driving direction. Through the horizontal baffle and the vertical baffle, the air supply direction is restricted to the driving direction.

[0003] Due to the special structure of the air supply duct and the relatively small amount of partition work, the traditional concrete air supply duct construction method is complicated, and the construction quality and the stress of the partition cannot be guaranteed, resulting in slow construction progress and high construction costs. Summary of the Invention

[0004] This invention provides a construction method for a suspended partition ventilation duct in a highway tunnel, which can improve both the construction quality and efficiency of the ventilation duct, thereby solving the technical problems of complex construction, slow construction progress, and high construction cost of traditional concrete ventilation duct construction methods.

[0005] The above-mentioned construction method for a suspended diaphragm ventilation duct in a highway tunnel includes the following steps;

[0006] S1, Measurement and layout

[0007] When constructing the secondary lining of the main tunnel within the length range of the air supply duct, before installing the secondary lining reinforcement, according to the construction progress of each secondary lining slab, measure and mark the intersection lines of the horizontal diaphragm and the vertical end diaphragm with the secondary lining on the surface of the positioned secondary lining trolley template according to the design parameters. Among them, the horizontal diaphragm intersects with the secondary lining at the two sides of the arch waist, and the vertical end diaphragm intersects with the secondary lining at the arch ring. The intersection lines are marked as the center line of the diaphragm thickness.

[0008] Meanwhile, based on the construction progress of each secondary lining plate, the pre-embedded position of the top of the threaded hanger is measured, and the center point of the threaded hanger projection is marked on the surface of the positioned secondary lining trolley template. The threaded hangers corresponding to the first horizontal partition plate are divided into three groups: threaded hanger I, threaded hanger II, and threaded hanger III. Threaded hangers I, threaded hanger II, and threaded hanger III are arranged sequentially from upstream to downstream along the direction of travel. The pre-embedded positions of threaded hangers I and threaded hangers II are located on both sides of the intersection line between the vertical end partition plate and the secondary lining. The threaded hangers corresponding to the remaining horizontal partition plates are threaded hangers III.

[0009] S2, Install secondary lining reinforcement

[0010] S3, Install the embedded parts for the hanger rod

[0011] t1, As the secondary lining construction progresses, according to the measurement points of the threaded hangers in step S1, pre-embedded parts for threaded hangers are pre-embedded in the secondary lining reinforcement layer of each slab. The pre-embedded parts include the pre-embedded threaded rod and the matching pad, nut I and connector. The bottom end of the pre-embedded threaded rod is screwed into the connector, the pad passes through the pre-embedded threaded rod and is placed on top of the connector, the nut I passes through the pre-embedded threaded rod and presses the pad, the central axis of the connector is vertically aligned with the measurement point of the center point of the threaded hanger projection on the surface of the secondary lining trolley template, the bottom of the connector is pressed against the surface of the secondary lining trolley template, and the position where the bottom of the connector does not contact the surface of the secondary lining trolley template is sealed.

[0012] t2, Install two layers of reinforcing steel bars at the bottom of the pad. The two sets of upper reinforcing steel bars are close to the pad and symmetrically arranged on both sides of the connector. The two sets of lower reinforcing steel bars are close to the upper reinforcing steel bars and symmetrically arranged on both sides of the connector. The upper and lower reinforcing steel bars are perpendicular to each other. The reinforcing steel bars are firmly welded to the secondary lining steel bars through auxiliary steel bars. The contact positions of the reinforcing steel bars with the pad and the connector are fixed by spot welding.

[0013] S4, Install channel steel and foam filling

[0014] t1, according to the intersection line between the horizontal partition and the secondary lining marked on the surface of the secondary lining trolley template in step S1, channel steel is pre-embedded on both sides of each secondary lining plate. The channel steel is aligned with the intersection line between the horizontal partition and the secondary lining and is snapped onto the surface of the secondary lining trolley template. The channel steel and the secondary lining reinforcement are welded and fixed firmly by auxiliary reinforcement. The contact position between the channel steel and the surface of the secondary lining trolley template is fixed by spot welding to ensure that the channel steel and the trolley are in close contact. The channel steel joint between the two secondary lining plates is sealed by spot welding. The ends of the first and last channel steels are sealed tightly. The channel steel is disconnected at the intersection position between the bottom of the two sides of the vertical end partition.

[0015] t2, according to the vertical end plate and the intersection line of the secondary lining marked on the surface of the secondary lining trolley template in step S1, fix a rectangular foam on the surface of the secondary lining trolley template. The center line of the rectangular foam is aligned with the intersection line of the vertical end plate and the secondary lining. The two ends of the rectangular foam extend into the break of the channel steel. The break between the rectangular foam and the channel steel is sealed tightly.

[0016] S5, pouring secondary lining concrete

[0017] S6, Secondary lining demolding and cleaning of foam filling

[0018] After each lining trolley is demolded, the elevation of the embedded channel steel is remeasured, the blockage between the bottom of the connector and the surface of the lining trolley template is removed to expose the connector, and the rectangular foam and its fixings of the arch are removed to expose the arch reserved groove.

[0019] S7, Install the first horizontal partition at the bottom of the vertical head partition.

[0020] The construction platform is placed at the bottom of the vertical head plate, and the first horizontal plate is lifted and placed on the construction platform according to the design projection position of the first horizontal plate. The first horizontal plate is vertically lifted and supported to a height lower than the design height. The first horizontal plate is in a horizontal and stable state. Threaded hanger I is installed. The bottom end of threaded hanger I passes through the hanger hole on the first horizontal plate, and the top end is screwed into the connector to hold the bottom end of the pre-embedded threaded rod in the connector. Rubber pad, steel pad and nut II are installed at the bottom end of threaded hanger I.

[0021] S8, install vertical head stop partition.

[0022] The vertical stop plate is lifted and placed on the first horizontal plate, and erected against the threaded hanger I installed in step S7. The top of the vertical stop plate is aligned with the arch ring pre-reserved groove. Threaded hangers II and III are installed in the same way as threaded hanger I. The vertical stop plate and the first horizontal plate are lifted vertically upward while the bottom nuts II of threaded hangers I, II, and III are rotated upward to make the vertical stop plate enter the arch ring pre-reserved groove to the design position. At the same time, the two ends of the horizontal plate are adjusted to extend into the channel steel. The bottom of the vertical stop plate is sealed and connected to the first horizontal plate by welding.

[0023] S9, Install the remaining horizontal partitions

[0024] The second horizontal partition is lifted and placed on the construction platform and supported to the design height. Both ends of the second horizontal partition extend into the channel steel, and the horizontal partition is in a horizontal and stable state. Threaded rod III is installed in the same way as threaded rod I. The second horizontal partition is welded to the first horizontal partition to achieve a closed connection. The remaining horizontal partitions are installed in sections and continuously in the same way until the project is completed.

[0025] In step S1, the threaded hangers corresponding to the first horizontal partition are arranged as follows: threaded hangers I and threaded hangers II are staggered; the number of threaded hangers II is odd, and the threaded hanger II in the middle position is located on the centerline of the tunnel; threaded hangers III are arranged in a rectangular pattern; the threaded hangers III corresponding to the remaining horizontal partitions are arranged in a rectangular pattern.

[0026] In step S2, the secondary lining reinforcement is installed according to the design parameters. High-strength mortar spacers are placed at the bottom of the secondary lining reinforcement, with a minimum of 4 spacers per meter. 2 Set up the reinforcement, distribute it evenly, and tie it firmly to ensure that the thickness of the protective layer of the bottom reinforcement is not less than 5cm. If there is a conflict between the position of the secondary lining reinforcement, high-strength mortar spacer and the embedded part of the threaded hanger according to the measurement point, the position of the secondary lining reinforcement and high-strength mortar spacer needs to be adjusted to ensure the accurate position of the embedded part.

[0027] In step S3, the area where the bottom of the connector does not contact the surface of the secondary lining trolley template is sealed tightly with foam and transparent tape;

[0028] In step S4, the break between the rectangular foam and the channel steel is sealed tightly with tape.

[0029] In step S7, after the secondary lining construction of the emergency parking lane adjacent to the air supply duct is completed, the template, widened side support and auxiliary support on the gantry of the parking lane folding trolley are removed, leaving only the main gantry of the trolley. The main gantry of the trolley is then returned to the construction position of the air supply duct and used as a construction platform.

[0030] The horizontal partition and vertical head partition are made of 8mm thick Q235A hot-rolled steel plate, and the horizontal partition is a rectangular plate; the threaded hanger and the pre-embedded threaded rod are made of precision rolled threaded steel.

[0031] The above-mentioned construction method for suspended partition ventilation ducts in highway tunnels also includes step S10, rust prevention treatment: all exposed parts of steel components are treated with hot-dip galvanizing for rust prevention.

[0032] The above-mentioned construction method for suspended diaphragm ventilation ducts in highway tunnels also includes step S111, sealing treatment.

[0033] The channel steel on both sides of the arch waist and the reserved groove of the arch ring are all filled with C20 micro-expansion concrete and compacted, with the filling surface flush with the surface of the secondary lining; all the hanger holes on the horizontal partitions are sealed with water-based neutral silicone weather-resistant sealant.

[0034] Compared with traditional concrete air duct construction methods, this invention has the following advantages:

[0035] 1. The above-mentioned construction method for suspended diaphragm ventilation ducts in highway tunnels is convenient in terms of material availability, high in safety, easy to operate, fast in construction, and the constructed ventilation duct has a simple structure and is lightweight.

[0036] 2. The threaded hangers and embedded threaded rods of the air supply duct are made of precision rolled threaded steel, and the overall stress of the air supply duct partition structure is reliable;

[0037] 3. The main gantry of the lining trolley in the emergency parking lane, which was not in use during the period of idleness, was used as a construction operation platform. This did not affect the passage of construction vehicles in the main tunnel, improved construction efficiency, saved construction costs, and ensured construction safety.

[0038] 4. The construction process of this invention is simple, speeds up the construction progress, and ensures the construction quality, and has extremely wide application value. Attached Figure Description

[0039] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0040] Figure 1 A process flow diagram for the construction method of suspended diaphragm ventilation ducts in highway tunnels;

[0041] Figure 2 This is a plan view of the suspended diaphragm ventilation duct in a highway tunnel.

[0042] Figure 3 for Figure 2 A magnified view of part A in the middle;

[0043] Figure 4 This is a longitudinal section layout diagram of a suspended diaphragm ventilation duct in a highway tunnel.

[0044] Figure 5 This is a cross-sectional layout diagram of the suspended diaphragm ventilation duct in a highway tunnel along the centerline of the connecting ventilation duct.

[0045] Figure 6 This is a cross-sectional layout diagram of the suspended diaphragm air supply duct in a highway tunnel along the position of the vertical head steel diaphragm.

[0046] Figure 7 An elevation view of the threaded hanger construction structure;

[0047] Figure 8 This is a plan view of the threaded hanger construction structure;

[0048] Figure 9 This is a detailed drawing of the embedded part for the threaded hanger rod.

[0049] In the diagram: 1-Horizontal steel partition; 2-Vertical end steel partition; 3.1-Threaded hanger I; 3.2-Threaded hanger II; 3.3-Threaded hanger III; 4-Embedded threaded rod; 5-Plate; 6-Nut I; 7-Connector; 8-Reinforcing steel bar; 9-Channel steel; 10-Arch ring reserved groove; 11-Rubber pad; 12-Steel pad; 13-Nut II; 101-Secondary lining; 102-Secondary lining reinforcement; 103-Air supply duct; 104-Air supply outlet; 105-Tunnel centerline; 106-Connecting ventilation duct. Detailed Implementation

[0050] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0051] This embodiment takes a highway tunnel as an example to provide specific steps and parameters for the construction method of a suspended diaphragm ventilation duct in a highway tunnel.

[0052] S1, Measurement and Setting Out

[0053] When constructing the secondary lining 101 of the main tunnel within the length range of the air supply duct, before installing the secondary lining reinforcement 102, according to the construction progress of each secondary lining plate, the intersection lines of the horizontal steel partition 1 and the vertical end steel partition 2 with the secondary lining 101 are measured and marked on the surface of the positioned secondary lining trolley template according to the design parameters. Among them, the horizontal steel partition 1 intersects with the secondary lining 101 at the two sides of the arch waist, and the vertical end steel partition 2 intersects with the secondary lining 101 at the arch ring. The intersection lines are marked as the center line of the steel partition thickness.

[0054] Simultaneously, based on the construction progress of each secondary lining 101, the pre-embedded position of the top of the threaded hanger is measured, and the center point of the threaded hanger projection is marked on the surface of the positioned secondary lining trolley template. Among them, the threaded hangers corresponding to the first horizontal steel partition are divided into three groups: threaded hanger I 3.1, threaded hanger II 3.2, and threaded hanger III 3.3. Threaded hangers I 3.1, threaded hanger II 3.2, and threaded hanger III 3.3 are arranged sequentially from upstream to downstream along the travel direction. The pre-embedded positions of threaded hangers I 3.1 and threaded hangers II 3.2 are located on both sides of the intersection line between the vertical end steel partition 2 and the secondary lining 101. The threaded hangers corresponding to the remaining horizontal partitions are threaded hangers III 3.3. There are 5 threaded hangers II3.2. The third threaded hanger II3.2 is located on the tunnel centerline. The 4 threaded hangers I3.1 and 5 threaded hangers II3.2 are staggered at 1.0m intervals. The center points of the projections of threaded hangers I3.1 and threaded hangers II3.2 are arranged 3cm apart from the centerline of the vertical end steel diaphragm 2, for a total of 9 hangers. Threaded hangers III3.3 are arranged in pairs with the tunnel centerline as the centerline, at 2.0m intervals laterally and 1.0m intervals longitudinally.

[0055] S2. Install secondary lining reinforcement.

[0056] Install the secondary lining reinforcement 102 according to the design parameters. High-strength mortar spacers should be placed at the bottom of each secondary lining reinforcement 102, with a minimum of 4 spacers per meter. 2 The reinforcement should be set up, evenly distributed, and securely tied to ensure that the thickness of the protective layer for the bottom layer of reinforcement is not less than 5cm. If there is a conflict between the positions of the secondary lining reinforcement 102, the high-strength mortar spacers, and the embedded parts of the threaded hangers, the positions of the secondary lining reinforcement 102 and the high-strength mortar spacers should be adjusted appropriately to ensure the accurate positioning of the embedded parts.

[0057] S3. Install the embedded parts for the hanger rod.

[0058] As the secondary lining construction progresses, based on the measurement points of the threaded hangers in step S1, pre-embedded parts are pre-embedded in the upper part of the threaded hangers in each secondary lining reinforcement layer. The pre-embedded parts include the pre-embedded threaded rod 4 and the matching pad 5, nut I6 and connector 7. The pre-embedded threaded rod 4 is a Ф25 precision rolled threaded steel bar. The bottom end of the pre-embedded threaded rod 4 is screwed into the connector 7 by half its length. The pad 5 passes through the pre-embedded threaded rod 4 and is placed on top of the connector 7. The nut I6 passes through the pre-embedded threaded rod 4 and presses the pad 5. The central axis of the connector 7 is vertically aligned with the measurement point of the center point of the threaded hanger on the surface of the secondary lining trolley template. The bottom of the connector 7 rests against the trolley. The part of the bottom of the connector 7 that does not contact the surface of the secondary lining trolley template is sealed tightly with foam and transparent tape to prevent concrete slurry from clogging the connector 7.

[0059] The bottom of the pad 5 is reinforced with two layers of reinforcing steel bars 8, which are Ф25 steel bars. The two upper reinforcing steel bars are close to the pad 5 and symmetrically arranged on both sides of the connector 7. The two lower reinforcing steel bars are close to the upper reinforcing steel bars and symmetrically arranged on both sides of the connector 7. The upper and lower reinforcing steel bars are perpendicular to each other and arranged in a cross shape. Each Ф25 reinforcing steel bar 8 is 50cm long. The four reinforcing steel bars 8 are firmly welded to the secondary lining steel bars 102 by auxiliary steel bars. The contact points between the reinforcing steel bars and the pad 5 and the connector 7 are fixed by spot welding.

[0060] S4. Install channel steel and foam filling.

[0061] As the secondary lining construction progresses, based on the intersection line between the horizontal steel partition 1 and the secondary lining 101 marked on the surface of the secondary lining trolley template in step S1, channel steel 9 (model 10# channel steel) is pre-embedded on both sides of each secondary lining 101 plate. The lower 1 / 3 height of the channel steel 9 is aligned with the intersection line between the horizontal steel partition 1 and the secondary lining 101 and then snapped onto the surface of the secondary lining trolley template. The channel steel 9 is then firmly welded to the secondary lining reinforcement 102 using auxiliary reinforcement. The contact points between the channel steel 9 and the surface of the secondary lining trolley template are fixed by spot welding to ensure tight contact between the channel steel 9 and the trolley. The channel steel joints between the two secondary lining 101 plates are sealed by spot welding, and the ends of the first and last channel steels are tightly sealed. A 5cm gap is left at the intersection of the channel steel 9 and the bottom of the vertical end steel partition 2 on both sides.

[0062] According to the intersection line of the vertical end steel partition 2 and the secondary lining 101 marked on the surface of the secondary lining trolley template in step S1, a 5×5cm rectangular foam is pre-embedded. The center line of the rectangular foam is aligned with the intersection line and fixed on the surface of the secondary lining trolley template by tape. The bottom ends of both sides of the rectangular foam extend 3cm into the broken part of the channel steel 9 and are sealed tightly by tape.

[0063] S5, Pouring secondary lining concrete

[0064] During the concrete pouring process, care should be taken to protect the embedded channel steel 9, foam filling and threaded hanger embedded parts to prevent them from shifting due to excessive vibration.

[0065] S6. Secondary lining demolding and cleaning of foam filling.

[0066] After each linerboard is demolded, the elevation of the embedded channel steel 9 is promptly re-measured, and all foam and transparent tape at the bottom of connector 7 are removed to expose connector 7. The rectangular foam filler and fixing tape of the arch ring are removed to expose the arch ring reserved groove 10.

[0067] S7. Install the first horizontal steel partition at the bottom of the vertical head steel partition 2.

[0068] After the secondary lining construction of the emergency parking lane adjacent to the air supply duct is completed, the template, widened side support and auxiliary support on the gantry of the parking lane folding trolley are removed, leaving only the main gantry of the trolley. The main gantry of the trolley is then moved back to the construction position of the air supply duct. Square timber and wooden planks are laid on the top of the main gantry of the trolley and tied firmly with wire to serve as a construction platform.

[0069] Calculate the length of each threaded rod, which is made of Ф25 precision rolled threaded steel.

[0070] All air supply duct steel partitions are made of 8mm thick Q235A hot-rolled steel plates. Horizontal steel partitions 1 are manufactured in sections with a horizontal length of 2m and a vertical length of 2m. Specifically, the first horizontal steel plate at the bottom of the vertical end-plate steel partition 2 is manufactured with a horizontal length of 2.25m and a vertical length of 2. All horizontal steel partitions 2 have 5cm diameter holes drilled at the pre-embedded positions of the threaded hangers from step 1 for installing the threaded hangers. Vertical end-plate steel partitions 2 are manufactured according to the designed shape.

[0071] The construction platform is positioned at the bottom of the vertical end steel partition 2. The first 2.25m wide horizontal steel partition 1 is then placed on the construction platform according to the design projection position. The first horizontal steel partition is vertically lifted and supported to a height 5cm lower than the design height, ensuring the first horizontal steel partition is in a stable horizontal state. Four threaded hangers I3.1 are installed on the outside of the vertical end steel partition 1. The bottom ends of the hangers pass through the corresponding hanger holes in the first horizontal steel partition, and the top ends are screwed into connector 7, holding the bottom end of the pre-embedded threaded rod 4 inside connector 7. The rubber pad 11, steel pad 12, and nut II13 that are matched to the bottom end of the threaded hanger I3.1 are then installed.

[0072] S8. Install vertical headrest steel partitions.

[0073] The vertical stop steel partition 2 is lifted and placed onto the first horizontal steel partition, standing upright against the four already installed threaded hangers I 3.1. The top of the vertical stop steel partition 2 is aligned with the arch ring pre-reserved groove 10, at which point the vertical stop steel partition 2 passes through the break in the channel steel 9. The five threaded hangers II 3.2 and eight threaded hangers III 3.3 on the inner side of the vertical stop steel partition 2 are installed sequentially, along with the matching rubber pads 11, steel pads 12, and nuts II 13 at the bottom of the hangers. The vertical stop steel partition 2 and the first horizontal steel partition are vertically raised 5cm, while simultaneously rotating and fixing the nuts II 13 at the bottom of the 17 hangers upwards, so that the vertical stop steel partition 1 enters the arch ring pre-reserved groove 10 to the designed position. At the same time, both ends of the first horizontal steel partition extend into the channel steel 9. The bottom of the vertical stop steel partition 1 and the first horizontal steel partition are sealed together by welding.

[0074] S9. Install the remaining horizontal steel partitions.

[0075] The second horizontal steel partition is lifted and placed on the construction platform, and supported to the designed height. Both ends of the second horizontal steel partition extend into the channel steel 9, ensuring it is horizontal and stable. The bottom ends of the eight threaded hangers III3.3 corresponding to the second horizontal steel partition are passed through the corresponding hanger holes on the second horizontal steel partition, and the top ends are screwed into the embedded connector 7, pressing against the bottom end of the embedded threaded rod 4 inside the connector 7. The rubber pad 11, steel pad 12, and nut II 13 at the bottom of the threaded hanger III3.3 are installed. The second horizontal steel partition is then welded to the first horizontal steel partition for a closed connection. Following the above method, the remaining horizontal steel partitions 2 are installed in sections and continuously until completion.

[0076] S10, Rust prevention treatment

[0077] All exposed parts of steel components shall be hot-dip galvanized for rust prevention. The minimum coating amount and coating thickness shall meet the requirements of "Technical Requirements and Test Methods for Hot-Dip Galvanized Coatings of Steel Components with Metallic Coatings" (GB / T 13912-2020).

[0078] S11, Sealing treatment

[0079] The channel steel 9 on both sides of the arch waist and the reserved groove 10 of the arch ring are all filled with C20 micro-expansion concrete and compacted, with the filling surface flush with the surface of the secondary lining 101. All hanger holes on the horizontal steel diaphragm 2 are sealed with 5mm thick water-based neutral silicone weather-resistant sealant.

[0080] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A construction method for a suspended diaphragm ventilation duct in a highway tunnel, characterized in that, Includes the following steps; S1, Measurement and layout When constructing the secondary lining of the main tunnel within the length range of the air supply duct, before installing the secondary lining reinforcement, according to the construction progress of each secondary lining slab, measure and mark the intersection lines of the horizontal diaphragm and the vertical end diaphragm with the secondary lining on the surface of the positioned secondary lining trolley template according to the design parameters. Among them, the horizontal diaphragm intersects with the secondary lining at the two sides of the arch waist, and the vertical end diaphragm intersects with the secondary lining at the arch ring. The intersection lines are marked as the center line of the diaphragm thickness. Meanwhile, based on the construction progress of each secondary lining plate, the pre-embedded position of the top of the threaded hanger is measured, and the center point of the threaded hanger projection is marked on the surface of the positioned secondary lining trolley template. The threaded hangers corresponding to the first horizontal partition plate are divided into three groups: threaded hanger I, threaded hanger II, and threaded hanger III. Threaded hangers I, threaded hanger II, and threaded hanger III are arranged sequentially from upstream to downstream along the direction of travel. The pre-embedded positions of threaded hangers I and threaded hangers II are located on both sides of the intersection line between the vertical end partition plate and the secondary lining. The threaded hangers corresponding to the remaining horizontal partition plates are threaded hangers III. S2, Install secondary lining reinforcement S3, Install the embedded parts for the hanger rod t1, As the secondary lining construction progresses, according to the measurement points of the threaded hangers in step S1, pre-embedded parts for threaded hangers are pre-embedded in the secondary lining reinforcement layer of each slab. The pre-embedded parts include the pre-embedded threaded rod and the matching pad, nut I and connector. The bottom end of the pre-embedded threaded rod is screwed into the connector, the pad passes through the pre-embedded threaded rod and is placed on top of the connector, the nut I passes through the pre-embedded threaded rod and presses the pad, the central axis of the connector is vertically aligned with the measurement point of the center point of the threaded hanger projection on the surface of the secondary lining trolley template, the bottom of the connector is pressed against the surface of the secondary lining trolley template, and the position where the bottom of the connector does not contact the surface of the secondary lining trolley template is sealed. t2, Install two layers of reinforcing steel bars at the bottom of the pad. The two sets of upper reinforcing steel bars are close to the pad and symmetrically arranged on both sides of the connector. The two sets of lower reinforcing steel bars are close to the upper reinforcing steel bars and symmetrically arranged on both sides of the connector. The upper and lower reinforcing steel bars are perpendicular to each other. The reinforcing steel bars are firmly welded to the secondary lining steel bars through auxiliary steel bars. The contact positions of the reinforcing steel bars with the pad and the connector are fixed by spot welding. S4, Install channel steel and foam filling t1, according to the intersection line between the horizontal partition and the secondary lining marked on the surface of the secondary lining trolley template in step S1, channel steel is pre-embedded on both sides of each secondary lining plate. The channel steel is aligned with the intersection line between the horizontal partition and the secondary lining and is snapped onto the surface of the secondary lining trolley template. The channel steel and the secondary lining reinforcement are welded and fixed firmly by auxiliary reinforcement. The contact position between the channel steel and the surface of the secondary lining trolley template is fixed by spot welding to ensure that the channel steel and the trolley are in close contact. The channel steel joint between the two secondary lining plates is sealed by spot welding. The ends of the first and last channel steels are sealed tightly. The channel steel is disconnected at the intersection position between the bottom of the two sides of the vertical end partition. t2, according to the vertical end plate and the intersection line of the secondary lining marked on the surface of the secondary lining trolley template in step S1, fix a rectangular foam on the surface of the secondary lining trolley template. The center line of the rectangular foam is aligned with the intersection line of the vertical end plate and the secondary lining. The two ends of the rectangular foam extend into the break of the channel steel. The break between the rectangular foam and the channel steel is sealed tightly. S5, pouring secondary lining concrete S6, Secondary lining demolding and cleaning of foam filling After each lining trolley is demolded, the elevation of the embedded channel steel is remeasured, the blockage between the bottom of the connector and the surface of the lining trolley template is removed to expose the connector, and the rectangular foam and its fixings of the arch are removed to expose the arch reserved groove. S7, Install the first horizontal partition at the bottom of the vertical head partition. The construction platform is placed at the bottom of the vertical head plate, and the first horizontal plate is lifted and placed on the construction platform according to the design projection position of the first horizontal plate. The first horizontal plate is vertically lifted and supported to a height lower than the design height. The first horizontal plate is in a horizontal and stable state. Threaded hanger I is installed. The bottom end of threaded hanger I passes through the hanger hole on the first horizontal plate, and the top end is screwed into the connector to hold the bottom end of the pre-embedded threaded rod in the connector. Rubber pad, steel pad and nut II are installed at the bottom end of threaded hanger I. S8, install vertical head stop partition. The vertical stop plate is lifted and placed on the first horizontal plate, and erected against the threaded hanger I installed in step S7. The top of the vertical stop plate is aligned with the arch ring pre-reserved groove. Threaded hangers II and III are installed in the same way as threaded hanger I. The vertical stop plate and the first horizontal plate are lifted vertically upward while the bottom nuts II of threaded hangers I, II, and III are rotated upward to make the vertical stop plate enter the arch ring pre-reserved groove to the design position. At the same time, the two ends of the horizontal plate are adjusted to extend into the channel steel. The bottom of the vertical stop plate is sealed and connected to the first horizontal plate by welding. S9, Install the remaining horizontal partitions The second horizontal partition is lifted and placed on the construction platform and supported to the design height. Both ends of the second horizontal partition extend into the channel steel, and the horizontal partition is in a horizontal and stable state. Threaded rod III is installed in the same way as threaded rod I. The second horizontal partition is welded to the first horizontal partition to achieve a closed connection. The remaining horizontal partitions are installed in sections and continuously in the same way until the project is completed.

2. The construction method for suspended diaphragm ventilation ducts in highway tunnels according to claim 1, characterized in that, In step S1, the arrangement of the threaded hangers corresponding to the first horizontal partition is as follows: Threaded hanger I and threaded hanger II are arranged alternately; The number of threaded hangers II is odd, and the middle threaded hanger II is located on the centerline of the tunnel; Threaded hanger III is arranged in a rectangular shape; The threaded hangers III corresponding to the remaining horizontal partitions are arranged in a rectangular pattern.

3. The construction method for suspended diaphragm ventilation ducts in highway tunnels according to claim 1, characterized in that, In step S2, the second lining steel bars are installed according to the design parameters, the bottom of the second lining steel bars is provided with high-strength mortar pads, and the number of the pads is not less than 4 / m 2 The setting is performed, the distribution is uniform, and the binding is firm, so that the thickness of the bottom layer steel bar protection layer is not less than 5 cm. If there is a conflict between the positions of the secondary lining steel bars, high-strength mortar spacers and the embedded parts of the threaded hangers, the positions of the secondary lining steel bars and high-strength mortar spacers need to be adjusted to ensure the accurate position of the embedded parts.

4. The construction method for suspended diaphragm ventilation duct in highway tunnels according to claim 1, characterized in that, In step S3, the area where the bottom of the connector does not contact the surface of the secondary lining trolley template is sealed tightly with foam and transparent tape; In step S4, the break between the rectangular foam and the channel steel is sealed tightly with tape.

5. The construction method for a suspended diaphragm ventilation duct in a highway tunnel according to claim 1, characterized in that, In step S7, after the secondary lining construction of the emergency parking lane adjacent to the air supply duct is completed, the template, widened side support and auxiliary support on the gantry of the parking lane folding trolley are removed, leaving only the main gantry of the trolley. The main gantry of the trolley is then returned to the construction position of the air supply duct and used as a construction platform.

6. The construction method for a suspended diaphragm ventilation duct in a highway tunnel according to any one of claims 1-5, characterized in that, The horizontal partition and the vertical head partition are made of 8mm thick Q235A hot-rolled steel plate, and the horizontal partition is a rectangular plate; The threaded hanger and the embedded threaded rod are made of precision rolled threaded steel.

7. The construction method for a suspended diaphragm ventilation duct in a highway tunnel according to claim 6, characterized in that, It also includes step S10, rust prevention treatment. All exposed parts of the steel components are treated with hot-dip galvanizing for rust prevention.

8. The construction method for a suspended diaphragm ventilation duct in a highway tunnel according to claim 7, characterized in that, It also includes step S111, sealing treatment. The channel steel on both sides of the arch waist and the reserved groove of the arch ring are all filled with C20 micro-expansion concrete, and the filling surface is flush with the surface of the secondary lining. All hanger holes on the horizontal partitions are sealed with water-based neutral silicone weather-resistant sealant.

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