A connection structure and method for connecting new and old integrated pipe corridors by the mined tunneling method

Abstract

The present invention discloses a connection structure for new and old integrated pipe galleries by the mined - tunneling method, which includes a newly built pipe gallery, an existing pipe gallery, a transfer beam, a circumferential connecting beam and a quick - set closing net. One end of the transfer beam is connected to the top plate of the newly built pipe gallery, and the other end of the transfer beam is in contact with the bottom plate of the existing pipe gallery. The quick - set closing net is arranged inside the transfer beam. One end of the circumferential connecting beam is connected to the quick - set closing net, and the other end of the circumferential connecting beam is connected to the steel bars implanted in the opening in the bottom plate of the existing pipe gallery. An opening is formed in the bottom plate of the existing pipe gallery for the connection between the existing pipe gallery and the newly built pipe gallery. The quick - set closing net is arranged around the opening of the existing pipe gallery and is connected to the inner side wall of the transfer beam. Part of the steel bars of the circumferential connecting beam connected to the existing pipe gallery are tied through the holes in the quick - set closing net, achieving the purpose of safe and rapid construction of the connection between the newly built integrated pipe gallery and the existing integrated pipe gallery under restricted conditions. The present invention also discloses a method for connecting new and old integrated pipe galleries by the mined - tunneling method.

Description

Technical Field

[0001] The invention belongs to the technical field of urban utility tunnel construction, and particularly relates to a connection structure and a connection method for new and old utility tunnels by the mined tunneling method. Background Art

[0002] Urban utility tunnels are usually constructed by the open cut method or the pipe jacking method. When the cross-section of the utility tunnel is too large and it passes through a road with dense traffic flow, the mined tunneling method is usually selected. When the new utility tunnel and the existing utility tunnel have a connection by the mined tunneling method, the stress of the supporting structure at the connection of the new and old tunnels is complex, and there are many cross-operation construction procedures. At the same time, after the existing tunnel is opened, the overall structure is extremely prone to deformation and has a high safety risk, which limits the construction efficiency and cannot achieve the purpose of safe and rapid construction. Summary of the Invention

[0003] Aiming at the deficiencies in the prior art, the purpose of the invention is to provide a connection structure and a connection method for new and old utility tunnels by the mined tunneling method with simple structure and convenient operation, so as to achieve the purpose of safe and rapid construction of the connection between the new utility tunnel and the existing utility tunnel under limited conditions.

[0004] To achieve the above purpose, the technical solution of the invention is: a connection structure for new and old utility tunnels by the mined tunneling method, including a new tunnel, an existing tunnel, a frame supporting beam, a ring connecting beam and a quick-setting closing net. One end of the frame supporting beam is connected to the top plate of the new tunnel, and the other end of the frame supporting beam is attached to the bottom plate of the existing tunnel. The quick-setting closing net is arranged inside the frame supporting beam. One end of the ring connecting beam is connected to the quick-setting closing net, and the other end of the ring connecting beam is connected to the steel bars implanted in the opening in the bottom plate of the existing tunnel by bonding.

[0005] Further, the existing tunnel is above the new tunnel. Frame supporting beams, ring connecting beams and quick-setting closing nets are arranged at the positions of the outer wall and the middle partition wall of the existing tunnel. The steel bars of the frame supporting beam are tied to the top plate of the new tunnel. After the concrete of the frame supporting beam is poured, its bottom is connected to the new tunnel, and its top is connected to the outer wall and the middle partition wall of the existing tunnel.

[0006] Further, an opening is made in the bottom plate of the existing tunnel for the connection between the existing tunnel and the new tunnel. The quick-setting closing net is arranged around the opening of the existing tunnel. The quick-setting closing net is connected to the inner side wall of the frame supporting beam. Part of the steel bars of the ring connecting beam connected to the existing tunnel are tied through the holes in the quick-setting closing net.

[0007] Further, the connection structure further includes double-ply steel sections. Double-ply steel sections are arranged at the positions of the outer wall and the middle partition wall of the existing tunnel during the primary support construction of the mined new tunnel. The double-ply steel sections are in a ring structure for supporting the existing tunnel.

[0008] Further, the existing utility tunnel is separated into a water supply chamber and an electric power chamber by a middle partition wall, and openings are formed at the bottoms of the water supply chamber and the electric power chamber to communicate with the newly built utility tunnel.

[0009] Based on the above-mentioned connection structure of the new and old utility tunnels by the mined tunneling method, the present invention also provides a connection method for the new and old utility tunnels by the mined tunneling method, and the connection method includes:

[0010] Step 1. Underpinning the foundation of the existing utility tunnel;

[0011] Step 2. Erecting an operation platform in the newly built utility tunnel;

[0012] Step 3. Constructing the frame-supported beam and part of the ring beam;

[0013] Step 4. Protecting the pipelines in the existing utility tunnel;

[0014] Step 5. Breaking the bottom slab of the existing utility tunnel;

[0015] Step 6. Strengthening the ring beam;

[0016] Step 7. Installing formwork and pouring concrete.

[0017] Further, the specific operation of the step 1. Underpinning the foundation of the existing utility tunnel is as follows: When the initial support construction of the mined tunneling of the newly built utility tunnel is carried out, double-ply steel sections are added at the positions of the outer side wall and the middle partition wall of the existing utility tunnel to support the existing utility tunnel. The double-ply steel section is a double-ply I20a steel frame, and the double-ply steel section is arranged in the initial support of the mined tunneling of the newly built utility tunnel; The specific operation of the step 2. Erecting an operation platform in the newly built utility tunnel is as follows: After the excavation support of the newly built utility tunnel and the construction of the bottom slab of the newly built utility tunnel are completed, the lining structure construction at the node of the newly built utility tunnel and the existing utility tunnel is started, and an operation platform is erected on the bottom slab of the newly built utility tunnel. The operation platform is erected by using a disc buckle type scaffold.

[0018] Further, the specific operation of the step 3. Constructing the frame-supported beam and part of the ring beam is as follows: After the steel bars of the side wall of the newly built utility tunnel are bound, the steel bars of the top slab and the frame-supported beam of the newly built utility tunnel are started to be bound. Frame-supported beams are arranged at the positions of the outer side wall and the middle partition wall of the existing utility tunnel. The steel bars of the frame-supported beam are bound on the top slab of the newly built utility tunnel. The top of the frame-supported beam is attached to the bottom slab of the existing utility tunnel. Quick-setting closing nets are arranged around the openings of the upper existing utility tunnel. The quick-setting closing nets are located inside the frame-supported beam, and the steel bars of part of the ring beam connected with the existing utility tunnel are bound through perforations in the quick-setting closing nets; When binding the steel bars in this part, the steel bars are bound from the inside of the mined tunneling to the outside in sequence. First, the steel bars that can play a bracing role are bound, then other steel bars are inserted, and then the concrete of the frame-supported beam part is poured; After the concrete of the frame-supported beam is poured, its bottom is connected to the newly built utility tunnel, and its top is connected to the outer side wall and the middle partition wall of the existing utility tunnel.

[0019] Further, the specific operation of the step 4. Protecting the pipelines in the existing utility tunnel is as follows:

[0020] 1) Before opening a hole in the water supply compartment of the existing pipe gallery, two temporary guiding piers are set at the positions below the water supply pipe and on both sides of the hole, and the original piers at the hole position are demolished; at the same time, the water supply pipes within 3 meters outside the demolition edge line of the existing pipe gallery floor are protected with geotextiles.

[0021] 2) Existing medium-voltage cables within 10 meters on each side of the opening edge line of the power compartment of the existing pipe gallery and within the opening range are all protected by φ150 insulated fiberglass cable side-opening buckle pipes; when breaking the floor of the power compartment of the existing pipe gallery, the brackets of the lower two layers of cables within 2 meters on each side outside the floor breaking edge line are demolished, and at the same time, the two layers of cables are lifted by fiberglass steel frames to ensure the construction space for pneumatic picks.

[0022] Further, the specific operation of step 5. Breaking the floor of the existing pipe gallery is as follows: When the concrete strength of the frame-supported beam reaches more than 90%, a hole is opened in the floor of the existing pipe gallery. The floor demolition is carried out inside the existing pipe gallery. Before opening the hole, measurement and lofting are carried out. The floor demolition spreads from the middle to the surrounding. The middle area is demolished by manual cooperation with a water mill drill, and the surrounding area is chiseled by manual pneumatic picks.

[0023] The specific operation of step 6. Reinforcing the ring beam is as follows: Since the new pipe gallery ring beam uses a quick-closing mesh embedded steel bar, the construction joint does not need to be roughened, but the existing pipe gallery should be roughened. Reinforcing bars are implanted in the existing pipe gallery within the opening of the existing pipe gallery. The embedded steel bars of the ring beam are connected to the reinforcing bar implantation of the existing pipe gallery by four-leg stirrups, and pouring pipes are embedded.

[0024] The specific operation of step 7. Installing the formwork and pouring the concrete is as follows: The formwork is installed on the side wall of the ring beam, and the adjacent ring beams are supported by formwork cross braces. After the formwork is fixed, the ring beam is poured with concrete; after curing, the formwork is removed to complete the connection construction.

[0025] The advantages of adopting the technical solution of the present invention are as follows:

[0026] 1. The connection method of the new and old integrated pipe galleries by the mined tunneling method provided by the present invention has a simple construction method, few process conversions, and reliable construction safety; the double-channel steel and the frame-supported beam are used for foundation underpinning to prevent the settlement and cracking of the existing pipe gallery during the construction process.

[0027] 2. The present invention protects the water supply pipe with guiding piers and geotextiles, and the medium-voltage cable is protected by insulated fiberglass cable side-opening buckle pipes. The floor of the existing pipe gallery is perforated in zones from the inside to the outside, which is safe and reasonable; the connection method of implanting reinforcing bars in the old pipe gallery and connecting the ring beam of the new pipe gallery with embedded steel bars prevents uneven settlement of the new and old pipe galleries and the influence on the rigidly connected pipelines in the gallery.

[0028] 3. The present invention uses a quick-closing and easy-to-use formwork for the secondary pouring of the ring connecting beam, which is beneficial to the horizontal embedding of steel bars, increases the shear resistance of the construction joint interface, and is conducive to exhaust, improving the construction quality of the concrete at the construction joint. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The present invention will be further described in detail below with reference to the drawings and specific embodiments:

[0030] Figure 1 Schematic diagram of the position of the double-rolled steel in the present invention;

[0031] Figure 2 Schematic diagram of the erection of the working platform in the present invention;

[0032] Figure 3 Schematic diagram of the construction of the transfer girder and the ring connecting beam in the present invention;

[0033] Figure 3-1 is Figure 3 Cross-sectional view along the 1-1 direction in

[0034] Figure 3-2 is Figure 3 Cross-sectional view along the 2-2 direction in

[0035] Figure 4 Schematic diagram of the protection of the water supply pipe in the present invention;

[0036] Figure 5 Schematic diagram of the protection of the medium-voltage cable in the present invention;

[0037] Figure 6 Schematic diagram of the hole breaking of the existing pipe gallery in the present invention;

[0038] Figure 7 Schematic diagram of the concrete construction of the connection between the new and old pipe galleries in the present invention;

[0039] Figure 8 Schematic diagram of the finished product of the connection between the new and old pipe galleries in the present invention;

[0040] Figure 8-1 is Figure 8 Cross-sectional view along the 1-1 direction in

[0041] Figure 8-2 is Figure 8 Cross-sectional view along the 2-2 direction in.

[0042] The marks in the above figures are respectively: 1. New pipe gallery; 2. Existing pipe gallery; 3. Transfer girder; 4. Ring connecting beam; 5. Quick-closing and easy-to-use formwork; 6. Double-rolled steel; 8. Guide pier; 9. Original pier; 10. Bottom plate breaking edge line; 11. Water supply pipe; 12. Bracket. SPECIFIC EMBODIMENTS

[0043] In the present invention, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial direction", "plane direction", "circumferential direction", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. These are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0044] The object of the present invention is to provide a connection structure and connection method for a newly-built and existing integrated pipe gallery by the mined tunneling method to carry out the connection construction between the newly-built integrated pipe gallery and the existing operating integrated pipe gallery, so as to realize the connected operation of the new and old integrated pipe galleries. The object of the present invention is achieved through the following technical solutions:

[0045] The connection construction between the newly-built pipe gallery by the mined tunneling method and the existing pipe gallery includes processes such as the underpinning of the existing pipe gallery foundation, pipeline protection, the demolition of the pipe gallery floor slab, the reinforcement of the ring beam, and concrete pouring. First, an operation platform is erected in the newly-built pipe gallery, the primary support and the secondary lining frame support beam of the newly-built pipe gallery are constructed under the existing pipe gallery, part of the steel bars of the ring beam are pre-embedded using the quick-installing closing net, the pipelines in the existing pipe gallery are protected, the water jet drill and pneumatic pick are selected for drilling holes in zones when demolishing the intersection of the new and old pipe galleries, the ring beam at the intersection of the new and old pipe galleries is tied and reinforced, and finally the lining concrete is poured.

[0046] As Figures 1 to 8 shown, a connection structure for a newly-built and existing integrated pipe gallery by the mined tunneling method includes a newly-built pipe gallery 1, an existing pipe gallery 2, a frame support beam 3, a ring beam 4, and a quick-installing closing net 5. One end of the frame support beam 3 is connected to the top plate 01 of the newly-built pipe gallery 1, the other end of the frame support beam 3 is in contact with the bottom plate 21 of the existing pipe gallery 2, the quick-installing closing net 5 is arranged inside the frame support beam 3, one end of the ring beam 4 is connected to the quick-installing closing net 5, and the other end of the ring beam 4 is connected to the steel bars implanted in the opening in the bottom plate of the existing pipe gallery 2 by bonding.

[0047] The existing pipe gallery 2 is above the newly-built pipe gallery 1. Frame support beams 3, ring beams 4, and quick-installing closing nets 5 are arranged at the positions of the outer wall 22 and the middle partition wall 23 of the existing pipe gallery 2. The steel bars of the frame support beam 3 are tied to the top plate 01 of the newly-built pipe gallery 1. After the frame support beam 3 is concreted, its bottom is connected to the newly-built pipe gallery 1, and its top is connected to the outer wall 22 and the middle partition wall 23 of the existing pipe gallery 2.

[0048] An opening is made in the bottom plate of the existing pipe gallery 2 for the connection between the existing pipe gallery and the newly-built pipe gallery. The quick-installing closing net 5 is arranged around the opening in the existing pipe gallery. The quick-installing closing net 5 is connected to the inner side wall of the frame support beam 3, and part of the steel bars of the ring beam connected to the existing pipe gallery are tied by perforating and binding on the quick-installing closing net 5.

[0049] The connection structure further includes double - spliced steel sections 6. When the primary support construction of the newly - built pipe gallery by mined - tunneling is carried out, double - spliced steel sections 6 are arranged at the positions of the outer wall 22 and the middle partition wall 23 of the existing pipe gallery 2. The double - spliced steel sections 6 are in a ring structure and are used to support the existing pipe gallery 2.

[0050] The existing pipe gallery 2 is separated into a water supply chamber 24 and an electric power chamber 25 by the middle partition wall 23. Openings are formed at the bottoms of the water supply chamber 24 and the electric power chamber 25 to communicate with the newly - built pipe gallery.

[0051] During the construction of the urban utility tunnel, when the newly - built utility tunnel uses the shallow - buried mined - tunneling method to carry out the under - crossing connection construction with the existing utility tunnel, the foundation of the existing pipe gallery is passively underpinned by the primary - support steel structure and the secondary - lining frame - supported beam. Reasonably select the floor - breaking equipment, set up the operation platform for construction, and use the quick - installation closing net as the construction joint joint surface to pour the connecting ring beam of the new and old pipe galleries, so as to achieve the purpose of safe and rapid construction of the connection between the newly - built utility tunnel and the existing utility tunnel under restricted conditions.

[0052] Based on the above - mentioned connection structure of the mined - tunneling method for new and old utility tunnels, the present invention also relates to a connection method for new and old utility tunnels by the mined - tunneling method. The connection method includes:

[0053] Step 1. Underpinning the foundation of the existing pipe gallery. The specific operation is as follows: When the primary support 17 of the newly - built pipe gallery is constructed by mined - tunneling, double - spliced steel sections 6 are added at the positions of the outer wall and the middle partition wall of the existing pipe gallery to support the existing pipe gallery. The double - spliced steel sections 6 are double - spliced I20a steel frames, and the double - spliced steel sections 6 are arranged in the primary support of the newly - built pipe gallery.

[0054] Step 2. Set up an operation platform in the newly - built pipe gallery. The specific operation is as follows: After the excavation and support of the newly - built pipe gallery and the construction of the bottom slab of the newly - built pipe gallery are completed, the lining structure construction at the node of the newly - built pipe gallery and the existing pipe gallery is started. An operation platform is set up on the bottom slab of the newly - built pipe gallery. The operation platform is set up with a disk - type fastener scaffold. The operation platform includes vertical poles 71, horizontal bars 72, safety nets 73, diagonal braces 74, disk fasteners 75 and ladders 76. The vertical poles 71 and the horizontal bars 72 are connected by the disk fasteners 75 to form a multi - layer and multi - row frame support structure. The diagonal braces 74 are obliquely connected to the vertical poles 71 or the horizontal bars 72 through the disk fasteners 75. The safety nets 73 are wrapped on the outside of the upper part of the frame support structure. During construction, the staff are located in the space surrounded by the safety nets. A support plate 76 for the construction personnel to stand on is also provided on the frame support structure. The support plate 76 is fixedly connected to the vertical poles 71 and the horizontal bars 72, and the safety nets 73 are located above the support plate 76.

[0055] Step 3. Construct the transfer girders and partial loop connecting girders. The specific operations are as follows: After the steel bars of the side wall of the newly built pipe gallery are tied, start tying the steel bars of the top slab and transfer girders of the newly built pipe gallery. Set transfer girders 3 at the positions of the outer side wall 22 and the middle partition wall 23 of the existing pipe gallery 2. The steel bars of the transfer girders are tied on the top slab of the newly built pipe gallery. The top of the transfer girders is fitted to the bottom slab of the existing pipe gallery. Set quick-setting closing nets around the openings of the upper existing pipe gallery. The quick-setting closing nets are located inside the transfer girders. Tie the steel bars of the partial loop connecting girders connected to the existing pipe gallery through the holes in the quick-setting closing nets. When tying the steel bars in this part, the steel bars are tied from the inside of the mined tunnel outwards. First, tie the steel bars that can act as a shoulder pole, then insert other steel bars, and then pour concrete for the transfer girder part. After the transfer girder 3 is concreted, its bottom is connected to the newly built pipe gallery 1, and its top is connected to the outer side wall 22 and the middle partition wall 23 of the existing pipe gallery 2.

[0056] Step 4. Protect the pipelines in the existing pipe gallery. The specific operations are as follows:

[0057] 1. Before opening a hole in the water supply compartment of the existing pipe gallery, set two temporary guiding piers 8 under the water supply pipe 11 and on both sides of the opening, and remove the original pier 9 at the opening position. At the same time, protect the water supply pipe within 3 meters outside the demolition edge line 10 of the existing pipe gallery bottom slab with geotextile.

[0058] 2. Protect all existing medium-voltage cables within 10 meters on both sides of the opening edge line and within the opening range of the power compartment of the existing pipe gallery with φ150 insulated fiberglass cable edge-opening buckling pipes. When breaking the bottom slab of the power compartment of the existing pipe gallery, remove the brackets 12 of the lower two layers of cables within 2 meters on both sides of the bottom slab demolition edge line 10, and at the same time use fiberglass steel frames to lift the two layers of cables to ensure the construction space for pneumatic picks.

[0059] Step 5. Break the bottom slab of the existing pipe gallery. The specific operations are as follows: When the concrete strength of the transfer girder reaches more than 90%, open a hole in the bottom slab of the existing pipe gallery. The bottom slab demolition is carried out inside the existing pipe gallery. Before opening the hole, conduct measurement and lofting. The bottom slab demolition spreads from the middle to the surrounding. The middle area is demolished by manual cooperation with a water mill drill, and the surrounding area is chiseled by manual pneumatic picks. The middle area is the demolition range 13 of the water mill drill, and the surrounding area is the demolition range 14 of the pneumatic pick.

[0060] Step 6. Strengthen the loop connecting girders. The specific operations are as follows: Since the loop connecting girders of the newly built pipe gallery use pre-embedded steel bars with quick-setting closing nets, the construction joints do not need to be roughened, but the existing pipe gallery should be roughened. Carry out steel bar planting in the existing pipe gallery within the opening of the existing pipe gallery. The pre-embedded steel bars of the loop connecting girders are connected to the steel bar planting of the existing pipe gallery by four-limb hoops, and pouring pipes are pre-embedded.

[0061] Step 7. Install the formwork and pour the concrete. The specific operations are as follows: Install formwork 15 on the side walls of the ring connecting beams, and support between adjacent ring connecting beams through formwork cross braces 16. After the formwork is fixed, pour concrete into the ring connecting beams; after curing, remove the formwork to complete the connection construction.

[0062] In the present invention, the existing pipe gallery foundation is passively underpinned by the primary support type steel structure and the secondary lining transfer beam. A reasonable floor punching device is selected, an operation platform is built for construction, and the quick-closing mesh is used as the construction joint joint surface for pouring the connecting ring beam of the new and old pipe galleries, greatly improving the safety and stability of the existing comprehensive pipe gallery structure. The connection construction between the new and old comprehensive pipe galleries is safe and fast, realizing the connection and operation of the new and old comprehensive pipe galleries. Therefore, the connection construction of the new and old comprehensive pipe galleries by the mined tunneling method has practical significance.

[0063] The present invention has great practicality and economy. Taking the connection construction of a certain urban comprehensive pipe gallery by the mined tunneling method as an example, through the use of the connection structure and connection method of the new and old comprehensive pipe galleries by the mined tunneling method for the integrated construction of the new pipe gallery and the existing pipe gallery, the construction efficiency of the connection construction can be greatly improved, and with a low-cost investment, the comprehensive pipe gallery construction project can be excellently completed, achieving good economic benefits.

[0064] The key points of the present invention are the underpinning of the double-rolled steel and the transfer beam, the connection of the ring beam structure, the protection of the pipelines in the existing pipe gallery, and the floor breaking method, which are applicable to the connection project between the similar shallow-buried mined tunneling method comprehensive pipe gallery and the existing pipe gallery.

[0065] The above has made an exemplary description of the present invention in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A connection structure for a new and old integrated utility tunnel using the mined - tunneling method, characterized in that: It includes a newly built pipe gallery (1), an existing pipe gallery (2), a transfer beam (3), a connecting beam (4) and a quick installation net (5). One end of the transfer beam (3) is connected to the top slab (01) of the newly built pipe gallery (1), and the other end of the transfer beam (3) is in contact with the bottom slab (21) of the existing pipe gallery (2). The quick installation net (5) is arranged inside the transfer beam (3). One end of the connecting beam (4) is connected to the quick installation net (5), and the other end of the connecting beam (4) is connected to the steel bars implanted in the opening in the bottom slab of the existing pipe gallery (2).

2. The connecting structure of the mined new and old integrated pipe corridors according to claim 1, characterized in that: The existing pipe gallery (2) is above the newly built pipe gallery (1). At the positions of the outer wall (22) and the middle partition wall (23) of the existing pipe gallery (2), transfer beams (3), connecting beams (4) and quick installation nets (5) are arranged. The steel bars of the transfer beam (3) are tied to the top slab (01) of the newly built pipe gallery (1). After the transfer beam (3) is concreted, its bottom is connected to the newly built pipe gallery (1), and its top is connected to the outer wall (22) and the middle partition wall (23) of the existing pipe gallery (2).

3. The connecting structure of the mined new and old integrated utility tunnels according to claim 2, characterized in that: Openings are made in the bottom slab of the existing pipe gallery (2) for the connection between the existing pipe gallery and the newly built pipe gallery. The quick installation net (5) is arranged around the opening in the existing pipe gallery. The quick installation net (5) is connected to the inner side wall of the transfer beam (3). Part of the steel bars of the connecting beam connected to the existing pipe gallery are tied through holes in the quick installation net (5).

4. The connecting structure of the new and old integrated pipe corridors by the mined method according to claim 3, characterized in that: The connection structure further includes double - spliced steel sections (6). During the initial support construction of the newly built pipe gallery by mining, double - spliced steel sections (6) are arranged at the positions of the outer wall (22) and the middle partition wall (23) of the existing pipe gallery (2). The double - spliced steel sections (6) are of an annular structure for supporting the existing pipe gallery (2).

5. A connecting structure for a new and old integrated pipe gallery by the mining method according to any one of claims 2 to 4, characterized in that: The existing pipe gallery (2) is separated into a water supply chamber (24) and an electric power chamber (25) by the middle partition wall (23). Openings are made at the bottoms of the water supply chamber (24) and the electric power chamber (25) to communicate with the newly built pipe gallery.

6. A connection method for new and old integrated pipe corridors by the mined - tunneling method, characterized in that: Based on a connection structure of a newly - built and existing integrated pipe gallery by the mining method according to any one of claims 1 to 5, the connection method includes: Step 1. Underpinning the foundation of the existing pipe gallery; Step 2. Erecting an operation platform in the newly built pipe gallery; Step 3. Constructing the transfer beam and part of the connecting beam; Step 4. Protecting the pipelines in the existing pipe gallery; Step 5. Breaking the bottom slab of the existing pipe gallery; Step 6. Strengthening the connecting beam; Step 7. Installing formwork and concreting.

7. The connection method of the new and old integrated pipe gallery by the mined - tunneling method according to claim 6, characterized in that: The specific operation of Step 1. Underpinning the foundation of the existing pipe gallery is as follows: During the initial support construction of the newly built pipe gallery by mining, double - spliced steel sections (6) are added at the positions of the outer wall and the middle partition wall of the existing pipe gallery for supporting the existing pipe gallery. The double - spliced steel sections (6) are double - spliced I20a steel frames and are arranged in the initial support of the newly built pipe gallery by mining. The specific operation of Step 2. Erecting an operation platform in the newly built pipe gallery is as follows: After the excavation and support of the newly built pipe gallery and the construction of the bottom slab of the newly built pipe gallery are completed, the lining structure construction at the node between the newly built pipe gallery and the existing pipe gallery is started. An operation platform is erected on the bottom slab of the newly built pipe gallery, and the operation platform is erected with a disc - type scaffold.

8. The connecting method of the new and old integrated pipe gallery by the subsurface excavation method as described in claim 6, characterized in that: The specific operation of step 3, constructing the transfer girders and partial loop connecting girders, is as follows: After the steel bars of the side wall of the newly built pipe gallery are tied, the steel bars of the top slab and transfer girders of the newly built pipe gallery are tied. Transfer girders (3) are set at the positions of the outer wall (22) and the middle partition wall (23) of the existing pipe gallery (2). The steel bars of the transfer girders are tied on the top slab of the newly built pipe gallery. The top of the transfer girder is in contact with the bottom slab of the existing pipe gallery. Quick-setting closing nets are set around the openings of the upper existing pipe gallery. The quick-setting closing nets are located inside the transfer girders. The steel bars of the partial loop connecting girders connected to the existing pipe gallery are tied through the perforations in the quick-setting closing nets. When tying the steel bars in this part, the steel bars are tied from the inside of the mined tunnel to the outside. First, tie the steel bars that can act as a shoulder pole, then insert other steel bars, and then pour concrete for the transfer girder part. After the transfer girder (3) is concreted, its bottom is connected to the newly built pipe gallery (1), and its top is connected to the outer wall (22) and the middle partition wall (23) of the existing pipe gallery (2).

9. The connecting method of the new and old integrated pipe corridors by the mined - tunneling method according to claim 6, wherein: The specific operation of step 4, protecting the pipelines in the existing pipe gallery, is as follows: 1) Before opening a hole in the water supply chamber of the existing pipe gallery, two temporary guiding piers (8) are set at the positions below the water supply pipe (11) and on both sides of the hole, and the original pier (9) at the hole position is removed; at the same time, the water supply pipes within 3 meters outside the demolition edge line (10) of the existing pipe gallery bottom slab are protected with geotextiles; 2) For the existing medium-voltage cables within 10 meters on each side of the opening edge line and within the opening range of the power cable chamber of the existing pipe gallery, φ150 insulated fiberglass cable edge-opening buckle pipes are used for protection; When demolishing the bottom slab of the power cable chamber of the existing pipe gallery, the brackets (12) of the lower two layers of cables within 2 meters on each side outside the bottom slab demolition edge line (10) are removed, and at the same time, the two layers of cables are lifted with fiberglass steel frames to ensure the construction space for pneumatic picks.

10. A connection method for the new and old integrated utility tunnels by the mined tunneling method as claimed in claim 6, characterized in that: The specific operation of step 5, demolishing the bottom slab of the existing pipe gallery, is as follows: When the concrete strength of the transfer girder reaches more than 90%, a hole is opened in the bottom slab of the existing pipe gallery. The bottom slab demolition is carried out inside the existing pipe gallery. Before opening the hole, measurement and lofting are carried out. The bottom slab demolition spreads from the middle to the surrounding. The middle area is demolished manually with the cooperation of a water mill drill, and the surrounding area is chiseled manually with a pneumatic pick; The specific operation of step 6, strengthening the loop connecting girders, is as follows: Since the loop connecting girders of the newly built pipe gallery use pre-buried steel bars with quick-setting closing nets, the construction joints do not need to be roughened, but the existing pipe gallery should be roughened. Reinforcing bars are implanted in the existing pipe gallery within the opening of the existing pipe gallery. The pre-buried steel bars of the loop connecting girders are connected to the implanted reinforcing bars of the existing pipe gallery with four-leg stirrups, and pouring pipes are pre-buried; The specific operation of step 7, installing formwork and pouring concrete, is as follows: Formwork (15) is installed on the side walls of the loop connecting girders. The adjacent loop connecting girders are supported by formwork cross braces (16). After the formwork is fixed, concrete is poured for the loop connecting girders; after curing, the formwork is removed to complete the connection construction.

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