Construction methods of bridge-tunnel connection projects in mountainous areas

Abstract

The present invention belongs to the technical field of bridge and tunnel construction, and relates to a construction method for a bridge-tunnel connection project in a mountainous area, including: constructing the left and right tunnels of a tunnel to a preset length and excavating a crosswalk that runs through the two tunnels; using the high slope side in the first tunnel as a beam manufacturing site, the bottom slope side as a beam transport channel, and using the second tunnel as the main construction channel; prefabricating T-beams in the beam manufacturing site, and simultaneously carrying out tunnel penetration construction, and successively completing the penetration construction of the first tunnel and the second tunnel; after the first tunnel is penetrated, first transporting a plurality of T-beams to the outside of the first tunnel in sequence and erecting them on the piers of the first bridge, and then erecting a transverse sliding door machine between the first bridge and the opening of the second tunnel, and moving a plurality of T-beams transported from the first tunnel in sequence to the outside of the second tunnel, and erecting them on the piers of the second bridge. The present invention can solve the drawbacks of existing mountainous bridge-tunnel connection project construction, and T-beams can be erected without waiting for all tunnels to be penetrated, thereby improving the construction efficiency of mountainous bridge-tunnel connection projects.

Description

Technical Field

[0001] The invention belongs to the technical field of bridge and tunnel engineering construction, and specifically relates to a construction method for a bridge and tunnel connection engineering in a mountainous area. Background Art

[0002] With the rapid development of transportation, the development of mountain highways is increasing. In the construction of mountain highways, bridges and tunnels account for an increasingly high proportion. In addition, due to the complex terrain and undulating terrain in mountainous areas, bridges and tunnels are often required to connect in order to ensure the linear indicators of the route.

[0003] At present, in the construction of bridge-tunnel connection projects in mountainous areas, tunnel construction is usually carried out first. After the tunnel is fully penetrated, the T-beams required for bridge construction are transported from the beam manufacturing site to the tunnel entrance at the junction of the tunnel and the highway section, and then the T-beams are transported through the penetrated tunnel to the bridge construction area at the tunnel entrance at the other end of the tunnel for T-beam installation. Obviously, under this construction method of bridge-tunnel connection projects in mountainous areas, the transportation distance of T-beams is long, which will lead to high transportation costs and greater transportation safety risks. In addition, the T-beams of the bridge connected to the tunnel can only be transported and erected after the tunnel is fully penetrated, which leads to a long overall construction period for bridge-tunnel connection projects in mountainous areas.

[0004] In view of this, it is urgent to develop a construction method for bridge-tunnel connection projects in mountainous areas. Summary of the invention

[0005] In view of the deficiencies existing in the related technologies, the present invention provides a construction method for bridge-tunnel connection projects in mountainous areas, aiming to improve the construction efficiency of bridge-tunnel connection projects in mountainous areas and shorten the overall construction period of bridge-tunnel connection projects in mountainous areas.

[0006] The mountain bridge-tunnel connection engineering construction method of the present invention comprises the following steps:

[0007] Initial tunnel construction: starting from the junction of the tunnel to be constructed and the highway section, the length of the left and right tunnels of the tunnel to the road surface inside the tunnels should reach the preset length; a crosswalk connecting the left and right tunnels is excavated at the preset length position;

[0008] Regional planning: The high slope side of the road surface cross slope in the first tunnel is planned as the beam manufacturing site, and the bottom slope side is planned as the beam transportation channel; the second tunnel is planned as the main construction channel; the first tunnel is the right tunnel or the left tunnel, and the second tunnel is the left tunnel or the right tunnel different from the first tunnel; the construction vehicles of the beam manufacturing site are planned to enter from the first tunnel and drive along the beam transportation channel in one direction, and exit from the main construction channel via the crosswalk; the construction vehicles of the tunnel are planned to enter from the second tunnel and drive along the main construction channel, and enter the first tunnel where construction is to continue via the crosswalk, or enter the second tunnel where construction is to continue without passing through the crosswalk;

[0009] T-beam prefabrication: prefabrication of multiple T-beams in the beam manufacturing yard;

[0010] Tunnel penetration construction: carried out simultaneously with the T-beam prefabrication step; first complete the penetration construction of the first hole, and then complete the penetration construction of the second hole;

[0011] Bridge construction: During the execution of the initial tunnel construction steps, T-beam prefabrication steps, and tunnel penetration construction steps, the construction of multiple piers required for the bridge to be constructed is carried out; when the penetration construction of the first tunnel is completed, the multiple T-beams are transported in sequence to the outside of the first tunnel near the tunnel entrance of the bridge to be constructed; first, the multiple T-beams are erected on the piers of the first bridge connected to the first tunnel, thereby completing the construction of the expected length section of the first bridge; then, a sliding gantry is erected between the first bridge and the short roadbed outside the tunnel entrance of the second tunnel, and the multiple T-beams transported from the first tunnel are moved in sequence to the outside of the tunnel entrance of the second tunnel by using the sliding gantry, and the multiple T-beams are erected on the piers of the second bridge connected to the second tunnel, thereby completing the construction of the expected length section of the second bridge.

[0012] In some of the embodiments, the initial tunnel construction step further includes excavating outwards at the left tunnel side wall and the right tunnel side wall opposite to the crosswalk to form a tunnel widening area.

[0013] In some of the embodiments, in the initial construction step of the tunnel, the preset length is equal to 1 / 3 to 2 / 3 of the total length of the tunnel.

[0014] In some of the embodiments, the area planning step also includes planning the outer area of ​​the first hole opening close to the highway section as a temporary storage area for temporarily storing steel bars and corrugated pipes required for T-beam prefabrication.

[0015] In some of the embodiments, before executing the T-beam prefabrication step, the construction of the invert, the secondary lining, the drainage ditches on both sides and the cable trenches on both sides have been completed in the first hole at the beam fabrication site; the drainage ditches and the cable trenches are not connected to each other, and the drainage ditches on both sides are located between the cable trenches on both sides.

[0016] In some embodiments, the steps of prefabricating the T beam specifically include:

[0017] Multiple pedestals are arranged at intervals along the length direction of the first hole in the beam manufacturing yard, and the templates required for T-beam prefabrication are installed on each pedestal;

[0018] Concrete is transported into the formwork, and the concrete is poured layer by layer and section by section from low to high. After the concrete is poured, it is cured. When its strength reaches the preset requirements, the formwork is removed and the concrete is roughened.

[0019] Carry out prestressed steel strand threading and tensioning operations, including making prestressed steel strands and threading them, and adopting an intelligent tensioning system to carry out prestressed steel strand tensioning operations; the intelligent tensioning system includes a system host, an oil pump, and a jack;

[0020] Within 48 hours after the completion of the prestressed tendon threading and tensioning operation, the intelligent grouting system is used to carry out the hole grouting operation in the order of first bottom and then top; the intelligent grouting system includes an automatic feeding system, a high and low speed mixing slurry making system, a grouting system and a computing control system.

[0021] In some of the embodiments, both ends of the cable trenches on both sides in the first tunnel are blocked to serve as reservoirs for storing water for concrete curing and grouting of the channels required for T-beam prefabrication; transverse drainage ditches extending laterally and connected to the drainage ditches on both sides are excavated on the road surface at both ends of each pedestal to accommodate sewage after concrete curing and channel grouting and discharge it out of the tunnel through the drainage ditches on both sides.

[0022] In some of the embodiments, the first tunnel is equipped with lifting equipment, which includes two 80t gantry cranes and three 10t gantry cranes. The 80t gantry cranes are mainly used for lifting T-beams, and the 10t gantry cranes are mainly used for lifting formwork and materials. Two longitudinally extending tracks are laid on the road surface on both sides of the first tunnel, and the lifting equipment is connected to the two tracks and can move back and forth along the tracks. The construction vehicles in the beam manufacturing yard include material transport vehicles for transporting materials required for T-beam prefabrication and beam transport vehicles for transporting T-beams.

[0023] In some of the embodiments, in the steps of bridge construction, the construction of each pier includes the construction of abutments, pier bodies, tie beams, columns and cap beams; when erecting T-beams, a bridge erection machine is used to erect the T-beams on the constructed piers of the first bridge or the second bridge.

[0024] In some of the embodiments, during the bridge construction steps, relatively arranged guide rails are installed on the bridge deck of the first bridge and on the top surface of the short roadbed outside the second tunnel opening, and the sliding door machine is connected to the two guide rails and can move back and forth along the guide rails.

[0025] Based on the above technical scheme, the construction method of mountain bridge-tunnel connection project in the embodiment of the present invention can solve the problems of high cost and risk of long-distance transportation of T-beams and long overall construction period of mountain bridge-tunnel connection project during the construction of mountain bridge-tunnel connection project under the prior art, reduce the construction cost of mountain bridge-tunnel connection project, and do not have to wait for the entire tunnel to be penetrated before erecting the T-beam of the bridge connected to the tunnel, which significantly improves the construction efficiency of mountain bridge-tunnel connection project and shortens the overall construction period of mountain bridge-tunnel connection project. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0027] Figure 1 It is a flow chart of the construction method of the mountain bridge-tunnel connection project of the present invention;

[0028] Figure 2 It is a schematic diagram of the regional planning in the construction method of the mountain bridge-tunnel connection project of the present invention;

[0029] Figure 3 It is a layout diagram of the first tunnel in the mountain bridge-tunnel connection engineering construction method of the present invention;

[0030] Figure 4 It is a schematic diagram of T-beam prefabrication and transportation in the construction method of mountain bridge-tunnel connection engineering of the present invention;

[0031] Figure 5 It is a schematic diagram of T-beam erection in the construction method of mountain bridge-tunnel connection engineering of the present invention.

[0032] In the figure: 10, tunnel; 11, right tunnel; 12, left tunnel; 13, crosswalk; 14, tunnel widening area; 15, temporary storage area; 16, short roadbed; 17, drainage ditch; 18, cable trench; 19, track; 21, first tunnel; 21a, beam manufacturing site; 21b, beam transport channel; 21c, transverse drainage ditch; 22, second tunnel; 22a, main construction channel; 23, pedestal; 24, formwork; 25, lifting equipment; 26, beam transport vehicle; 30, T-beam; 31, first bridge; 40, sliding gantry crane. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0034] In the description of the present invention, it should be understood that the terms "center", "lateral", "longitudinal", "up", "down", "top", "bottom", "inside", "outside", "left", "right", "front", "back", "vertical", "horizontal", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0035] The terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first", "second", etc. may explicitly or implicitly include one or more of the features.

[0036] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0037] refer to Figure 1-Figure 5 As shown, the construction method of the mountain bridge-tunnel connection project of the present invention includes the steps of initial construction of the tunnel 10, regional planning, prefabrication of the T-beam 30, through-construction of the tunnel 10 and bridge construction.

[0038] The specific steps of the initial construction of the tunnel 10 are as follows: starting from the end where the tunnel 10 to be constructed connects with the highway section, the left tunnel 12 and the right tunnel 11 of the tunnel 10 are constructed simultaneously until the length of the road surface in the left tunnel 12 and the right tunnel 11 reaches a preset length; at the preset length position, a crosswalk 13 is excavated to pass through the left tunnel 12 and the right tunnel 11. It can be understood that the width of the crosswalk 13 should meet the needs of smooth passage of construction vehicles.

[0039] The specific steps of regional planning are: planning the high slope side of the road surface transverse slope in the first hole 21 of the tunnel 10 as the beam manufacturing site 21a, and planning the bottom slope side of the road surface transverse slope in the first hole 21 of the tunnel 10 as the beam transportation channel 21b, that is, the high slope side of the transverse slope in the first hole 21 will be used for beam manufacturing and the bottom slope side will be used for beam transportation, so as to facilitate the transportation of beams in the tunnel 10 with limited height; planning the second hole 22 of the tunnel 10 as the main construction channel 22a. Among them, the first hole 21 is the right hole 11 or the left hole 12, and the second hole 22 is the left hole 12 or the right hole 11 different from the first hole 21. Furthermore, the construction vehicles of the beam manufacturing site 21a are planned to enter from the hole of the first hole 21 close to the highway section, and travel one-way along the beam transportation channel 21b, and then exit the tunnel 10 from the main construction channel 22a via the crosswalk 13. The construction vehicles of tunnel 10 are planned to enter from the entrance of the second tunnel 22 close to the highway section and travel along the main construction channel 22a. Then, the construction vehicles of tunnel 10 either drive into the first tunnel 21 where construction continues via the crosswalk 13 to continue construction of the remaining length of the first tunnel 21 toward the direction of the bridge to be constructed, or directly drive into the second tunnel 22 where construction continues without passing through the crosswalk 13 to continue construction of the remaining length of the second tunnel 22 toward the direction of the bridge to be constructed. It can be understood that the construction vehicles of tunnel 10 return along the original route after completing the construction work.

[0040] The specific steps of prefabricating the T-beams 30 are as follows: prefabricate multiple T-beams 30 in the beam-making yard 21a of the first hole 21 of the tunnel 10, that is, utilize the space inside the constructed part of the first hole 21 of the tunnel 10 to prefabricate multiple T-beams 30 required for the bridge to be constructed in the bridge-tunnel connection project, thereby saving construction land and saving the cost of building the beam-making yard 21a.

[0041] The specific steps of the through construction of the tunnel 10 are to be carried out simultaneously with the steps of prefabrication of the T-beam 30, that is, when the T-beam 30 is prefabricated, the tunnel construction of the remaining length of the tunnel 10 in the direction of the bridge to be constructed is carried out simultaneously; first, the through construction of the first hole 21 is completed, and then the through construction of the second hole 22 is completed. It can be understood that the through construction of the first hole 21 and the second hole 22 can be carried out successively, in parallel or alternately, but the through construction of the first hole 21 should be completed first to meet the needs of the subsequent transportation of the T-beam 30 in the first hole 21 and the erection of the bridge, so that the construction resources can be optimally allocated and the various construction links are closely connected.

[0042] The specific steps of bridge construction are: during the execution of the initial construction step of the tunnel 10, the prefabrication step of the T-beam 30, and the through-construction step of the tunnel 10, the construction of multiple bridge piers required for the bridge to be constructed is carried out; when the through-construction of the first tunnel 21 is completed, the prefabricated multiple T-beams 30 are transported in sequence to the outside of the opening of the first tunnel 21 near the bridge to be constructed; first, multiple T-beams 30 are erected on the constructed piers of the first bridge 31 connected to the first tunnel 21, and the erection of the T-beams 30 required for each section of the first bridge 31 is completed, thereby completing the construction of the expected length section of the first bridge 31; then, a horizontal sliding door machine is erected between the first bridge 31 and the short roadbed 16 outside the opening of the second tunnel 22 40, specifically, one side of the sliding gantry 40 in the length direction is supported on the bridge deck of the first bridge 31, and the other side is supported on the short roadbed 16 outside the opening of the second tunnel 22 near the second bridge to be constructed. It can be understood that the sliding gantry 40 is equipped with an electric gantry vehicle that can move back and forth along its length direction, and the electric gantry vehicle can be used to hoist and place the parts to be installed; the sliding gantry 40 is used to sequentially hoist and transfer the multiple T beams 30 transported from the first tunnel 21 to the outside of the opening of the second tunnel 22, and the multiple T beams 30 are erected on the constructed piers of the second bridge connected to the second tunnel 22, completing the erection of the T beams 30 required for each joint of the second bridge, and then completing the construction of the expected length section of the second bridge. The specific method of erecting the T beams 30 is well known to those skilled in the art, and will not be repeated here; after the T beams 30 are erected, it is necessary to carry out the transverse connection of the T beams 30, lay the bridge deck steel mesh, pour the bridge deck concrete, and other construction to finally complete the bridge construction.

[0043] The above-mentioned illustrative embodiment solves the problem of high transportation cost and high transportation risk caused by long-distance transportation of T-beams 30 in the construction of mountain bridge-tunnel connection projects under the prior art by manufacturing beams in the tunnel 10 and directly transporting them to the outside of the tunnel 10 for bridge construction, thereby saving construction land, saving the cost of building the beam manufacturing site 21a, reducing the input of manpower and material resources, and thus reducing the construction cost of the bridge-tunnel project in the mountain area; through the phased construction of the tunnel 10, reasonable planning of the area in the tunnel 10, the prefabrication of the T-beams 30 and the simultaneous construction of the tunnel 10, and the construction of the bridge piers at the same time as the tunnel 10 construction, the various construction links of the mountain bridge-tunnel connection project are well coordinated, so there is no need to wait for the tunnel 10 to be fully penetrated before the T-beam 30 of the bridge connected to the tunnel 10 can be erected, thereby improving the construction efficiency of the mountain bridge-tunnel connection project, shortening the overall construction period of the mountain bridge-tunnel connection project, and thus meeting the development trend of efficient construction of mountain bridge-tunnel connection projects.

[0044] refer to Figure 2As shown, in some embodiments, the initial construction step of the tunnel 10 also includes excavating outwards at the side walls of the left tunnel 12 and the right tunnel 11 opposite to the crosswalk 13 to form a tunnel widening area 14; through the setting of the tunnel widening area 14, each construction vehicle has a larger turning space at the crosswalk 13, which facilitates smooth passage of vehicles.

[0045] refer to Figure 2 As shown, in some embodiments, in the initial construction step of the tunnel 10, the preset length is equal to 1 / 3 to 2 / 3 of the total length of the tunnel 10; technical personnel in this field can combine the construction time required for the beam manufacturing site 21a, the production capacity and utilization rate of the template 24 and the pedestal 23 required for the production of the T-beam 30, the construction time of the first hole 21, etc., to specifically set the preset length in the initial construction step of the tunnel 10, so as to optimize the overall construction period of the bridge-tunnel connection project in the mountainous area.

[0046] refer to Figure 2 As shown, in some embodiments, the area planning step also includes planning the area outside the hole of the first hole 21 close to the highway section as a temporary storage area 15; specifically, without affecting the smooth entry of construction vehicles into the first hole 21, a larger area is reserved outside the hole of the first hole 21 close to the highway section as a temporary storage area 15; the temporary storage area 15 is used to temporarily store the steel bars and corrugated pipes required for the prefabrication of T-beams 30, so as to facilitate the nearby transportation of beam making materials.

[0047] refer to Figure 3 As shown, in some embodiments, before the step of prefabrication of the T beam 30 is performed, the construction of the invert and the secondary lining has been completed in the first hole 21 where the beam manufacturing yard 21a is located, thereby ensuring the structural stability and safety of the first hole 21 of the tunnel 10 when the T beam 30 is prefabricated later; and the construction of the drainage side ditches 17 on both sides and the cable trenches 18 on both sides has also been completed in the first hole 21 where the beam manufacturing yard 21a is located, the drainage side ditches 17 and the cable trenches 18 on both sides are not connected to each other, and the drainage side ditches 17 on both sides are located between the cable trenches 18 on both sides. In addition, since the first hole 21 is not yet through when the T beam 30 is prefabricated, in addition to using the existing exhaust equipment of the tunnel 10 for ventilation and oxygen supply, two movable high-power exhaust fans are added and arranged at a position of about 20m from the opening of the first hole 21 to replace the air in the hole, ensuring that the oxygen concentration in the tunnel 10 is between 19.5%vol-20.9%vol, the hydrogen sulfide content shall not be greater than 10mg / m3, and the carbon monoxide concentration shall not be greater than 20mg / m3.

[0048] refer to Figure 4 As shown, in some embodiments, the steps of prefabricating the T beam 30 specifically include:

[0049] In the beam manufacturing yard 21a, multiple pedestals 23 are arranged at intervals along the length direction of the first hole 21, and the distance between two adjacent pedestals 23 can be 5m; in order to reduce the impact on the concrete panel of the tunnel 10, the pedestal 23 uses cast C30 concrete as the longitudinal main beam, and 5# channel steel is welded on both sides as the installation groove of the stop grout strip, and rubber rods or rubber strips are installed in the channel steel to prevent grout leakage; It can be understood by those skilled in the art that the pedestal 23 needs to be pre-cambered to ensure the molding quality of the T-beam 30 after prefabrication; the template 24 required for the prefabrication of the T-beam 30 is installed on each pedestal 23, and the steel bars and corrugated pipes required for the prefabrication of the T-beam 30 are installed in the template 24;

[0050] Concrete is transported to the template 24, and the concrete is poured layer by layer and section by section from low to high. The material feeding of the upper layer should be carried out after the lower layer of concrete is vibrated and compacted. The layers and sections should be continuously poured before the concrete begins to set. After the concrete is poured, it is cured in time, and the curing time is guaranteed to be more than 7 days. Since the beam manufacturing site 21a is located in the tunnel 10, the environment is relatively stable, and the curing time is sufficient to make the concrete surface wet. After the concrete strength reaches the preset requirements, the template 24 is removed and the concrete is roughened.

[0051] After the concrete strength reaches more than 85% of the design value and the concrete age is not less than 7 days, the prestressed bundle tensioning operation is carried out; the prestressed bundle tensioning operation includes: hole inspection to ensure that the hole is unobstructed and complete; making prestressed steel bundles and performing bundle tensioning operations; using an intelligent tensioning system to perform prestressed tensioning operations, when the steel bundles are tensioned, both ends are tensioned symmetrically at the same time, and a dual control method of tensioning force and elongation is adopted; the intelligent tensioning system includes a system host, an oil pump, and a jack; the specific implementation method of the prestressed bundle tensioning operation is well known to those skilled in the art and will not be repeated here;

[0052] Within 48 hours after the completion of the prestressed tendon threading and tensioning operation, the intelligent grouting system shall be used to carry out the hole grouting operation in the order of first bottom and then top; the hole shall be flushed before grouting to ensure that the hole is unobstructed and moistened so that the cement slurry can be well combined with the hole wall; the grouting should be carried out until the other end of the hole is full and slurry is discharged, and the exhaust hole shall discharge cement slurry with the same consistency as the specified consistency; the intelligent grouting system includes an automatic feeding system, a high and low speed mixing slurry making system, a grouting system and a computing control system; the specific implementation methods of the hole grouting operation are well known to those skilled in the art and will not be elaborated here.

[0053] It should be noted that due to the low sunlight and slow water loss in tunnel 10, concrete curing is easier than in traditional open-air conditions. The time for concrete to reach the design strength will be significantly shortened, and the time for prestressing tensioning operations and duct grouting operations will also be significantly shortened.

[0054] The above exemplary embodiment realizes the manufacture of the T-beam 30 in the tunnel 10 and can shorten the prefabrication time of the T-beam 30 , which is beneficial to improving the construction efficiency.

[0055] refer to Figure 3 , Figure 4 As shown, in some embodiments, due to the limited space in the tunnel 10, water for construction is transported to the first hole 21 by a water truck, and the two ends of the cable trench 18 on both sides of the first hole 21 are blocked to serve as a water reservoir; the main water used for prefabrication of the T-beam 30 is water for concrete curing and grouting of the channel, and a small water pump is used to connect the water pipe to pump water from the water reservoir as needed. A transverse drainage ditch 21c extending transversely and connected to the drainage side ditches 17 on both sides is excavated on the road surface at both ends of each pedestal 23, which is used to accommodate sewage after concrete curing and grouting of the channel, and to discharge the sewage outside the tunnel 10 through the drainage side ditches 17 on both sides. A sedimentation tank is usually provided outside the tunnel 10 to precipitate the sewage and discharge it outside the construction access road culvert. This exemplary embodiment meets the water and drainage needs when making beams in the tunnel 10 by setting the transverse drainage ditch 21c, using the cable trenches 18 on both sides and the drainage side ditches 17 on both sides.

[0056] refer to Figure 3 , Figure 4 As shown, in some embodiments, the first tunnel 21 is equipped with lifting equipment 25, and the lifting equipment 25 includes two 80t gantry cranes and three 10t gantry cranes; among them, the 80t gantry crane is mainly used for lifting the prefabricated T-beam 30, and the 10t gantry crane is mainly used for lifting the template 24 and materials required for the prefabrication of the T-beam 30; due to the limited space in the tunnel 10, the lifting equipment 25 can be customized according to needs. Two longitudinally extending tracks 19 are laid on the road surface on both sides of the first tunnel 21, and the two tracks 19 are located between the drainage ditches 17 on both sides. The lifting equipment 25 is connected to the two tracks 19 and can move back and forth along the tracks 19. The construction vehicles in the beam manufacturing yard 21a include material transport vehicles for transporting materials required for the prefabrication of T-beams 30, beam transport vehicles 26 for transporting T-beams 30, etc.

[0057] refer to Figure 5 As shown, in some embodiments, in the steps of bridge construction, the construction of each pier includes the construction of abutments, pier bodies, tie beams, columns and cap beams; when the T-beam 30 is erected, a bridge erection machine is used to erect the T-beam 30 on the constructed piers of the first bridge 31 or the second bridge; the construction method of the piers and the method of erecting the T-beam 30 using a bridge erection machine are well known to those skilled in the art and will not be elaborated here.

[0058] refer to Figure 5As shown, in some embodiments, during the steps of bridge construction, relatively arranged guide rails are installed on the bridge deck of the first bridge 31 and on the top surface of the short roadbed 16 outside the opening of the second tunnel 22, and the sliding door machine 40 is connected to the two guide rails and can move back and forth along the guide rails; thereby, the position of the sliding door machine 40 relative to the opening is adjustable, which facilitates the transportation and erection of the T-beam 30 required for the second bridge.

[0059] In summary, the construction method of mountain bridge-tunnel connection project of the present invention solves the problems of high cost and risk of long-distance transportation of T-beams 30 and long overall construction period of mountain bridge-tunnel connection project during the construction of mountain bridge-tunnel connection project under the prior art, through the phased construction of tunnel 10, reasonable planning of the area within tunnel 10, synchronization of prefabrication of T-beams 30 within tunnel 10 with the construction of tunnel 10, and simultaneous construction of bridge piers during the construction of tunnel 10. It reduces the construction cost of mountain bridge-tunnel connection project, and there is no need to wait for the tunnel 10 to be fully penetrated before erecting the T-beam 30 of the bridge connected to the tunnel 10, which significantly improves the construction efficiency of mountain bridge-tunnel connection project, shortens the overall construction period of mountain bridge-tunnel connection project, and can meet the development trend of efficient construction of mountain bridge-tunnel connection project.

[0060] Finally, it should be noted that: the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0061] The above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. The construction method of bridge-tunnel connection engineering in mountainous areas is characterized by: The following steps are involved: Initial construction of the tunnel: starting from the end where the tunnel to be constructed meets the highway section, the left and right tunnels of the tunnel are constructed simultaneously until the length of the road surface inside the tunnel reaches a preset length, which is equal to 1 / 3 to 2 / 3 of the total length of the tunnel; a crosswalk that runs through the left and right tunnels is excavated at the preset length position, and the left and right tunnel side walls opposite to the crosswalk are excavated outwards to form a tunnel widening area; Area planning: the high slope side of the road surface cross slope in the first tunnel is planned as the beam manufacturing site, and the bottom slope side is planned as the beam transport channel; the second tunnel is planned as the main construction channel; the first tunnel is the right tunnel or the left tunnel, and the second tunnel is the left tunnel or the right tunnel different from the first tunnel; the construction vehicles of the beam manufacturing site are planned to enter from the first tunnel and drive along the beam transport channel in one direction, and exit from the main construction channel via the crosswalk; the construction vehicles of the tunnel are planned to enter from the second tunnel and drive along the main construction channel, and enter the first tunnel where construction is to be continued via the crosswalk, or enter the second tunnel where construction is to be continued without passing through the crosswalk; T-beam prefabrication: prefabrication of multiple T-beams in the beam fabrication yard; Tunnel penetration construction: carried out simultaneously with the T-beam prefabrication step; first completing the penetration construction of the first tunnel, and then completing the penetration construction of the second tunnel; Bridge construction: During the execution of the initial tunnel construction step, T-beam prefabrication step, and tunnel penetration construction step, the construction of multiple piers required for the bridge to be constructed is carried out; when the penetration construction of the first tunnel is completed, the multiple T-beams are transported in sequence to the outside of the first tunnel near the tunnel entrance of the bridge to be constructed; first, the multiple T-beams are erected on the piers of the first bridge connected to the first tunnel, thereby completing the construction of the expected length section of the first bridge; then, a transverse sliding gantry is erected between the first bridge and the short roadbed outside the tunnel entrance of the second tunnel, and the multiple T-beams transported from the first tunnel are moved in sequence to the outside of the tunnel entrance by using the transverse sliding gantry, and the multiple T-beams are erected on the piers of the second bridge connected to the second tunnel, thereby completing the construction of the expected length section of the second bridge.

2. The construction method for bridge-tunnel connection engineering in mountainous areas according to claim 1 is characterized in that: The step of area planning also includes planning the outer area of ​​the opening of the first tunnel close to the highway section as a temporary storage area for temporarily storing steel bars and corrugated pipes required for T-beam prefabrication.

3. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 1 is characterized in that: Before executing the step of prefabrication of the T-beam, the construction of the invert, the second lining, the drainage ditches on both sides and the cable trenches on both sides has been completed in the first hole at the beam fabrication site; the drainage ditches and the cable trenches are not connected to each other, and the drainage ditches on both sides are located between the cable trenches on both sides.

4. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 3 is characterized in that: The steps of prefabricating the T beam specifically include: Arrange a plurality of pedestals at intervals along the length direction of the first hole in the beam manufacturing yard, and install a template required for T-beam prefabrication on each of the pedestals; Concrete is transported into the template, and the concrete is poured layer by layer and section by section from low to high by feeding and vibrating; after the concrete is poured, it is cured, and after its strength reaches the preset requirements, the template is removed and the concrete is roughened; Performing prestressed steel strand threading and tensioning operations, including making prestressed steel strands and performing strand threading operations, and using an intelligent tensioning system to perform prestressed steel strand tensioning operations; the intelligent tensioning system includes a system host, an oil pump, and a jack; Within 48 hours after the completion of the prestressed tendon threading and tensioning operation, the intelligent grouting system is used to carry out the channel grouting operation in the order of first bottom and then top; the intelligent grouting system includes an automatic feeding system, a high and low speed mixing slurry making system, a grouting system and a computing control system.

5. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 4 is characterized in that: The two ends of the cable trenches on both sides of the first tunnel are sealed to serve as reservoirs for storing water for concrete curing and grouting of the channels required for T-beam prefabrication; transverse drainage ditches extending laterally and connected to the drainage ditches on both sides are excavated on the road surface at both ends of each of the pedestals to accommodate sewage after concrete curing and channel grouting and discharge it out of the tunnel through the drainage ditches on both sides.

6. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 4 is characterized in that: The first tunnel is equipped with lifting equipment, including two 80t gantry cranes and three 10t gantry cranes. The 80t gantry cranes are mainly used for lifting T-beams, and the 10t gantry cranes are mainly used for lifting formwork and materials. Two longitudinally extending tracks are laid on the road surface on both sides of the first tunnel. The lifting equipment is connected to the two tracks and can move back and forth along the tracks. The construction vehicles in the beam manufacturing yard include material transport vehicles for transporting materials required for T-beam prefabrication and beam transport vehicles for transporting T-beams.

7. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 1 is characterized in that: In the steps of bridge construction, the construction of each pier includes the construction of abutments, pier bodies, tie beams, columns and cap beams; when the T-beams are erected, a bridge erection machine is used to erect the T-beams on the constructed piers of the first bridge or the second bridge.

8. The construction method for bridge-tunnel connection engineering in mountainous area according to claim 1 is characterized in that: In the steps of bridge construction, relatively arranged guide rails are installed on the bridge deck of the first bridge and the top surface of the short roadbed outside the second tunnel opening, and the sliding door machine is connected to the two guide rails and can move back and forth along the guide rails.

Images