A construction method for shield cutting existing operating pipe gallery

Abstract

The invention relates to a construction method for shield cutting an existing operating pipe gallery, belongs to the field of underground engineering technology, solves the problems existing in the current shield cutting of the existing pipe gallery, and comprises the following steps: grouting and reinforcing soil in a shield crossing area below the existing pipe gallery; constructing a pipe shed in a pipe shed installation area of ​​a side wall of the existing pipe gallery, the pipe shed installation area being located at the upper periphery of a shield cutting cross-sectional area of ​​the existing structure; cutting vibration isolation joints on the side walls and middle partition walls corresponding to the shield cutting cross-sectional area and the pipe shed installation area, and cutting a first cutting joint in the side walls and middle partition walls below the vibration isolation joint; cutting a second cutting joint in a bottom plate area of ​​the existing pipe gallery corresponding to the shield crossing area; constructing a new bottom plate connected to the bottom plate of the existing pipe gallery as a whole at the periphery of the upper part of the pipe shed installation area; after the construction of the new bottom plate is completed, performing a shield underpass operation of a new tunnel, and adopting the method of the invention to ensure the safety of the existing pipe gallery and the smooth progress of the shield cutting.

Description

Technical Field

[0001] The present invention relates to the technical field of underground tunnel engineering, and in particular to a construction method for cutting an existing operating pipe gallery with a shield machine. Background Art

[0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art.

[0003] Subway tunnels are mostly constructed using the shield method. As construction progresses, the construction environment faced by tunnels becomes increasingly complex. Large-scale urban rail transit and integrated pipe corridor construction will inevitably bring about complex problems such as cross-crossing, parallelism, and overlapping between various structures. Existing underground structures often affect subway construction. For some underground structures that intrude into subway lines, they are often demolished by relocation or abandonment. For some important underground structures, especially large underground structures such as integrated pipe corridors, they often cannot be relocated and have to adjust the tunnel line. The adjustment of the tunnel line will inevitably cause changes in the project cost and engineering environment, leading to a series of new problems. In this regard, it is of great significance for shield tunnels to cross existing underground reinforced concrete structures at a negative distance. There are several difficulties in shield tunneling crossing existing underground structures at a negative distance: (1) Shield cutting existing underground structures will inevitably cause damage and settlement of existing structures, which will have a great impact on the safety of existing structures; (2) The strength of existing reinforced concrete structures is relatively large, and problems such as tool wear and steel bar entanglement are prone to occur during shield cutting. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a construction method for shield cutting of existing operating pipeline corridors, which avoids structural damage, settlement and other problems of the existing structure, while reducing the occurrence of tool wear, steel bar entanglement and other phenomena during shield cutting.

[0005] In order to achieve the above object, the present invention is implemented through the following technical solutions:

[0006] An embodiment of the present invention provides a construction method for shield cutting an existing operating pipe gallery, comprising the following steps:

[0007] Grouting reinforcement is carried out on the soil in the shield tunneling area under the existing pipe gallery;

[0008] The pipe shed is constructed in the pipe shed installation area of ​​the side wall of the existing pipe gallery. The pipe shed extends into the soil. The pipe shed installation area is located above and outside the existing structure shield cutting section area.

[0009] Cutting vibration isolation slits on the side walls and the middle partition wall corresponding to the shield cutting section area and the pipe shed installation area, and cutting a plurality of first cutting slits in the side walls and the middle partition wall area below the vibration isolation slits;

[0010] Cut a plurality of second cutting seams in the existing pipe gallery bottom plate area corresponding to the shield tunnel crossing area;

[0011] A new floor plate is constructed on the outer periphery of the upper part of the pipe shed installation area, which is located inside the existing pipe gallery and connected to the existing pipe gallery floor plate as a whole;

[0012] After the construction of the new base plate is completed, the shield cutting and underpass operation of the new tunnel will be carried out.

[0013] Optionally, the pipe rack is composed of multiple steel pipes, which pass through the side walls of the existing pipe gallery, and the multiple steel pipes are distributed in a fan shape.

[0014] Optionally, the vibration isolation joint adopts an arc-shaped joint that matches the cross-sectional area of ​​the shield cutting, and the vibration isolation joint runs through the side walls and the middle partition wall of the existing pipe gallery.

[0015] Optionally, after the construction of the vibration isolation joint is completed, a plurality of vibration reduction holes are drilled in the side wall and middle partition wall area below the vibration isolation joint.

[0016] Optionally, the first cutting seam is arranged perpendicular to the existing pipe gallery bottom plate, the top end of the first cutting seam is connected to the vibration isolation seam, and the bottom end extends to the bottom surface of the existing pipe gallery.

[0017] Optionally, the plurality of second cutting slits are distributed in a grid pattern.

[0018] Optionally, the construction method of the new base plate is:

[0019] Micro steel pipe piles are driven into the corresponding positions of the arch feet of the new base plate, and the micro steel pipe piles pass through the existing base plate of the pipe gallery and extend into the soil;

[0020] Then, the steel bar structure of the new bottom plate is constructed, and the ends of the steel bar structure of the new bottom plate are tied and fixed to the existing steel bar structure of the existing pipe gallery bottom plate;

[0021] Then the new base slab is poured with concrete, and the micro steel pipe piles and the new base slab are cast as a whole.

[0022] Optionally, during the construction process of the shield tunneling through the existing pipeline gallery, only the wall of the lower half of the segment ring under the existing pipeline gallery is filled with pea gravel. After the shield tunneling is completed, the wall of the upper half of the segment ring under the existing pipeline gallery is filled with pea gravel.

[0023] Optionally, after the pea gravel filling is completed, grouting is performed on the wall of the segment ring below the existing pipe gallery.

[0024] Optionally, the construction method for grouting reinforcement of the soil in the shield tunnel crossing area under the existing pipe gallery is:

[0025] A grouting pipe is constructed on the bottom plate of the existing pipe gallery corresponding to the shield tunneling area, and the grouting pipe extends into the soil under the existing pipe gallery;

[0026] After the construction of the grouting pipe is completed, the soil in the shield crossing area under the existing pipeline corridor is grouting reinforced by using the backward grouting method through the grouting pipe.

[0027] The beneficial effects of the present invention are as follows:

[0028] 1. The construction method of the present invention first performs grouting reinforcement on the soil corresponding to the shield crossing area under the existing pipeline corridor, and then constructs a pipe shed on the periphery above the shield cutting cross-sectional area. The grouting reinforcement treatment of the soil increases the strength and stability of the shield crossing area and the surrounding strata, and reduces the damage to the existing pipeline corridor during the subsequent construction process. The setting of the pipe shed further prevents the settlement damage of the existing pipeline corridor during the shield passing, and ensures the stability and normal operation of the existing pipeline corridor. The structure of the shield cutting cross-sectional area and the upper existing pipeline corridor is cut off by the vibration isolation joint, so as to prevent the vibration during the shield cutting from being transmitted upward to the structure of the upper existing pipeline corridor and affecting the safety of the existing pipeline corridor, thereby avoiding the structural damage and settlement of the existing pipeline corridor and other problems, and providing effective protection for the existing pipeline corridor.

[0029] 2. The construction method of the present invention reduces the strength of the existing pipe gallery in the shield crossing area by cutting a first cutting seam on the side wall and the middle partition wall and cutting a second cutting seam on the bottom plate, thereby preventing a series of problems such as tool wear and steel bar entanglement caused by excessive structural strength when the shield cuts the reinforced concrete structure.

[0030] 3. The construction method of the present invention provides vibration reduction holes on the side walls and the middle partition wall below the vibration isolation joint, and the existing reinforced concrete structure of the corridor in the shield cross-sectional area is formed into a honeycomb shape through the vibration reduction holes, thereby reducing the strength of the reinforced concrete and effectively reducing the vibration during shield cutting.

[0031] 4. The construction method of the present invention is provided with micro steel pipe piles, which can provide a supporting reaction force for the settlement or damage and deformation of the existing pipeline corridor, restrain the settlement and deformation of the existing pipeline corridor, and prevent the existing pipeline corridor from excessive settlement when the shield passes through. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings in the specification, which constitute a part of the present invention, are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0033] Figure 1 is a flow chart of the construction method of embodiment 1 of the present invention;

[0034] Figure 2 This is a schematic diagram of grouting reinforcement in Example 1 of the present invention;

[0035] Figure 3 This is a schematic diagram of the pipe shed construction of Example 1 of the present invention;

[0036] Figure 4 This is a schematic diagram of the distribution of the vibration isolation slits and the first cutting slits in Example 1 of the present invention;

[0037] Figure 5 This is a schematic diagram of the distribution of the second cutting seams in Example 1 of the present invention;

[0038] Figure 6 This is a schematic diagram of the construction of a new base plate according to Embodiment 1 of the present invention;

[0039] Figure 7 This is a schematic diagram of the distribution of the first pea gravel blown fill layer and the second pea gravel blown fill layer in Example 1 of the present invention;

[0040] Figure 8 This is a rendering of the effect after the construction of Example 1 of the present invention is completed;

[0041] Among them, 1. existing tunnel floor, 2. grouting pipe, 3. grouting reinforcement area, 4. side wall, 5. pipe shed, 6. vibration isolation joint, 7. first cutting joint, 8. vibration reduction hole, 9. second cutting joint, 10. middle partition wall, 11. new floor, 12. micro steel pipe pile, 13. steel structure, 14. new tunnel, 15. second bean gravel filling layer, 16. pipe segment ring, 17. first bean gravel filling layer. DETAILED DESCRIPTION

[0042] Example 1

[0043] This embodiment provides a construction method for shield cutting an existing operating pipe gallery, such as Figure 1 As shown, the following steps are included:

[0044] Step 1: Grouting is performed to reinforce the soil in the shield tunneling area under the existing pipe gallery to form a grouting reinforcement area 3.

[0045] Specifically, Figure 2 As shown, the following steps are included:

[0046] Step 1.1: construct multiple grouting pipes 2 in the existing pipe gallery bottom plate 1 area corresponding to the shield tunneling area, and the multiple grouting pipes 2 extend into the soil corresponding to the shield tunneling area under the existing pipe gallery. Preferably, the multiple grouting pipes 2 are distributed in a divergent manner.

[0047] Step 1.2: For each grouting pipe 2, a backward grouting process is used to grout the soil in the shield tunneling area under the existing pipe gallery to form a grouting reinforcement area 3.

[0048] The backward grouting process can adopt the existing grouting process, which will not be described in detail here.

[0049] Step 2: If Figure 3As shown, a pipe shed 5 is constructed in the pipe shed installation area of ​​the side wall 4 of the existing pipe gallery. The pipe shed 5 passes through the side wall 4 and extends into the soil. The pipe shed installation area is located above and outside the existing pipe gallery shield cutting cross-sectional area, avoiding the shield crossing area.

[0050] In this embodiment, the pipe rack installation area is an arc-shaped area, which is arranged on the upper periphery of the shield cutting cross-sectional area of ​​the existing structure. The pipe rack 5 is composed of multiple steel pipes. Both side walls 4 of the existing pipe gallery are constructed with the pipe rack 5, and the steel pipes extend into the soil outside the existing pipe gallery.

[0051] In this embodiment, for the pipe rack 5 on the same side, the multiple steel pipes in the pipe rack 5 are distributed in a fan shape.

[0052] When the shield passes through the existing pipeline corridor, the soil above the tunnel will collapse, reducing the supporting capacity of the soil around the new tunnel. The pipe roof 5 diverges outward in a fan shape, which can effectively avoid the new tunnel, so that the pipe roof 5 is supported on a more stable stratum, better playing a supporting role, further preventing the existing pipeline corridor from settlement damage, and ensuring the stability and normal operation of the existing pipeline corridor.

[0053] Step 3: If Figure 4 As shown, a vibration isolation slit 6 is cut on the side wall 4 and the middle partition wall 10 corresponding to the shield cutting cross-sectional area and the pipe roof installation area, and a plurality of first cutting slits 7 are cut in the side wall 4 and the middle partition wall 10 area below the vibration isolation slit 6 .

[0054] Specifically, the vibration isolation joint 6 is an arc-shaped joint that matches the shield cutting cross-sectional area. The arc-shaped joint is arranged on the upper periphery of the shield cutting cross-sectional area and below the pipe rack installation area. The two ends of the vibration isolation joint 6 extend to the bottom surface of the existing pipe gallery.

[0055] The vibration isolation seam 6 is arranged through the side wall 4 and the middle partition wall 10 in a direction parallel to the existing pipe gallery bottom plate 1 .

[0056] The vibration isolation joint 6 is arranged above the shield cutting cross-sectional area, which can isolate the shield cutting cross-sectional area and the structure of the existing pipeline corridor above the vibration isolation joint 6, preventing the vibration during shield cutting from being transmitted upward to the structure of the existing pipeline corridor above the vibration isolation joint 6, thereby avoiding the shield cutting affecting the safety of the existing pipeline corridor.

[0057] After the vibration isolation slits 6 of the side wall 4 and the middle partition wall 10 are cut, a plurality of first cutting slits 7 are cut in the side wall 4 and the middle partition wall 10 below the vibration isolation slits 6 .

[0058] In this embodiment, the first cutting seam 7 is a straight seam perpendicular to the existing pipe gallery bottom plate 1, and multiple first cutting seams 7 are distributed along the longitudinal direction of the existing pipe gallery, and the longitudinal direction of the existing pipe gallery is the length direction of the existing pipe gallery.

[0059] The top end of the first cutting slit 7 is communicated with the vibration isolation slit 6, and the bottom end of the first cutting slit 7 extends to the bottom surface of the existing pipe gallery.

[0060] After the first cutting seam 7 is cut, a plurality of vibration-damping holes 8 are drilled in the corresponding side walls 4 and middle partition walls 10 above the existing pipe gallery floor 1 below the vibration-damping seam 6. The reinforced concrete structures of the side walls 4 and middle partition walls 10 within the shield cross-sectional area are formed into a honeycomb shape through the vibration-damping holes 8, thereby reducing the strength of the reinforced concrete and effectively reducing the vibration during shield cutting.

[0061] By setting the first cutting seam 7 and the vibration-damping hole 8, the steel bars of the side wall 4 and the middle partition wall 10 in the shield cross-sectional area can be cut off, which greatly reduces the reinforced concrete strength of the side wall 4 and the middle partition wall 10, and prevents a series of problems such as tool wear and steel bar entanglement due to excessive structural strength when the shield cuts the side wall 4 and the middle partition wall 10.

[0062] Step 4: Cut a plurality of second cutting seams 9 in the existing pipe gallery floor 1 area corresponding to the shield tunneling crossing area.

[0063] After the side wall 4 and the middle partition wall 10 corresponding to the shield cutting cross-sectional area are partially processed, the existing pipe gallery floor 1 area corresponding to the shield crossing area is processed, and multiple second cutting seams 9 are cut in the existing pipe gallery floor 1 area corresponding to the shield crossing area.

[0064] Preferably, Figure 5 As shown, the plurality of second cutting seams 9 include a plurality of first straight seams distributed longitudinally along the existing pipe gallery and a plurality of second straight seams distributed transversely along the existing pipe gallery, and the first straight seams and the second straight seams are vertically intersected to form a mesh distribution.

[0065] By setting the second cutting seam 9, the strength of the existing tunnel floor 1 area corresponding to the shield crossing area can be reduced, preventing a series of problems such as tool wear and steel bar entanglement due to excessive structural strength when the shield cuts the existing tunnel floor 1.

[0066] Step 5: construct a new base plate 11 located in the existing pipe gallery and connected to the existing pipe gallery base plate 1 as a whole on the outer periphery of the upper part of the pipe rack installation area.

[0067] In this embodiment, the newly built bottom plate 11 is an arc bottom plate matching the shield cutting cross-sectional area, and its position corresponds to the position of the shield crossing area, such as Figure 6 As shown, the construction method is:

[0068] Step 5.1: Construct multiple micro steel pipe piles 12 at the corresponding positions of the arch feet on both sides of the new base plate 11. Preferably, two micro steel pipe piles 12 are constructed at the arch foot positions on each side. The micro steel pipe piles 12 pass through the existing tunnel base plate 1 and extend into the soil under the existing tunnel. The micro steel pipe piles 12 extend in a direction away from the shield crossing area, so that the micro steel pipe piles 12 can avoid the shield crossing area.

[0069] Step 5.2: Chisel away the existing pipe gallery floor 1 in the set areas on both sides of the shield crossing area to expose the steel structure 13 of the existing pipe gallery floor 1, tie up the steel structure of the newly built floor 11, and tie and fix the ends of the steel structure of the newly built floor 11 to the exposed steel structure 13 of the existing pipe gallery floor 1.

[0070] Step 5.3: After setting up the formwork, the new base plate 11 is poured with concrete. The ends of the micro steel pipe piles 12 are embedded in the new base plate 11 and concrete is injected into the micro steel pipe piles 12. At this time, the micro steel pipe piles 12 and the new base plate 11 are cast as a whole.

[0071] The micro steel pipe piles 12 can provide a supporting reaction force for the settlement or damage and deformation of the existing pipe gallery, restrict the settlement and deformation of the existing pipe gallery, and prevent the existing pipe gallery from excessive settlement when the shield passes through.

[0072] The newly built base plate 11 is connected to the existing pipe gallery base plate 1 through a steel bar structure to form a whole, thereby ensuring the integrity and stability of the existing pipe gallery.

[0073] Step 6: After the concrete in the newly built base plate 11 and the micro steel pipe piles 12 reaches the set strength, the shield cutting and passing operation of the newly built tunnel 14 begins.

[0074] In this embodiment, when the shield machine cuts and passes under, in order to reduce vibration, the earth bin is constructed using the existing full bin method during shield construction. The earth bin pressure needs to be reasonably controlled during underpass excavation to ensure uniform passage during underpass excavation. When the shield machine cuts an existing pipe gallery, the deformation and vibration of the existing pipe gallery needs to be monitored in real time. The monitoring method can be the existing method, which will not be described in detail here. If the deformation or vibration of the existing pipe gallery is large, the excavation parameters need to be adjusted in real time to ensure the structural stability of the existing pipe gallery.

[0075] When cutting and passing under the existing pipe gallery, synchronous grouting needs to be stopped to prevent cement slurry from flowing into the gap under the newly built bottom plate 11 during synchronous grouting, and then entering the shield cutting section area to affect the shield construction.

[0076] like Figure 7As shown, when the shield machine is under the existing pipe gallery, for the pipe segment ring 16 under the existing pipe gallery, in the process of cutting and under the cutting, in order to prevent the pipe segment from sinking and causing defects such as misalignment, the wall of the lower half of the constructed pipe segment ring 16 is filled with pea gravel to form a first pea gravel filling layer 17. In this embodiment, the grouting holes on the pipe segment can be used for pea gravel filling. After the shield machine is through, the wall of the upper half of the pipe segment ring 16 under the existing pipe gallery is filled with pea gravel to form a second pea gravel filling layer 15. In this embodiment, the grouting holes on the pipe segment can be used for pea gravel filling.

[0077] After the pea gravel filling is completed, low-pressure grouting is carried out on the walls of the entire ring of all segment rings under the existing pipeline corridor through the grouting holes on the segments. The pressure range of the low-pressure grouting is 0.1Mpa-0.2Mpa. At this time, a closed space has been formed on the upper part of the segment, and the cement slurry will not flow into the new tunnel formed by the shield and affect the shield construction.

[0078] In addition, low-pressure grouting after the completion of pea gravel filling can effectively control the grouting pressure, prevent the existing pipeline corridor from being lifted due to excessive grouting pressure, and reduce the risk of the existing pipeline corridor floating.

[0079] After the shield tunneling construction is completed, the new tunnel 14 and the existing pipeline corridor are as follows Figure 8 shown.

[0080] The construction method of this embodiment effectively controls the damage and settlement of the existing pipeline corridor structure caused by the shield cutting the existing pipeline corridor through grouting reinforcement, pipe shed 5 and micro steel pipe piles 12, thereby providing effective protection for the existing pipeline corridor.

[0081] Specifically, through the grouting reinforcement treatment of the soil, the strength and stability of the shield crossing area and the surrounding strata are increased, and the damage to the existing pipeline corridor during the subsequent construction process is reduced. The setting of the pipe shed 5 can further prevent the settlement damage of the existing pipeline corridor during the shield crossing, and ensure the stability and normal operation of the existing pipeline corridor. The micro steel pipe piles 12 can provide support reaction force for the settlement or damage and deformation of the existing pipeline corridor, restrain the settlement and deformation of the existing pipeline corridor, prevent the existing pipeline corridor from excessive settlement when the shield passes through, avoid structural damage and settlement of the existing pipeline corridor, and provide effective protection for the existing pipeline corridor.

[0082] In the construction method of this embodiment, the provision of the first cutting seam 7, the second cutting seam 9, the vibration isolation seam 6 and the vibration reduction hole 8 greatly weakens the strength of the existing reinforced concrete structure of the corridor in the shield crossing area, thereby ensuring the smooth progress of the shield cutting.

[0083] Specifically, the first cutting seam 7 and the second cutting seam 9 reduce the strength of the existing reinforced concrete structure of the tunnel corresponding to the shield crossing area, preventing a series of problems such as tool wear and steel bar entanglement due to excessive structural strength when the shield cuts the reinforced concrete structure. The shield cutting cross-sectional area and the existing tunnel upper structure above the vibration isolation seam 6 are cut off by the vibration isolation seam 6, preventing the vibration during shield cutting from being transmitted upward to the existing tunnel upper structure above the vibration isolation seam 6, thereby affecting the safety of the existing tunnel. The reinforced concrete structure in the shield cross-sectional area is made into a honeycomb shape by the vibration reduction holes 8, reducing the strength of the reinforced concrete and effectively reducing the vibration during shield cutting.

[0084] The above description is only the preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A construction method for shield cutting an existing operating pipe gallery, characterized in that: The following steps are involved: Grouting reinforcement is carried out on the soil in the shield tunneling area under the existing pipe gallery; The pipe shed is constructed in the pipe shed installation area of ​​the side wall of the existing pipe gallery. The pipe shed extends into the soil. The pipe shed installation area is located above and outside the existing structure shield cutting section area. Cutting vibration isolation slits on the side walls and the middle partition wall corresponding to the shield cutting section area and the pipe shed installation area, and cutting a plurality of first cutting slits in the side walls and the middle partition wall area below the vibration isolation slits; Cut a plurality of second cutting seams in the existing pipe gallery bottom plate area corresponding to the shield tunnel crossing area; A new floor plate is constructed on the outer periphery of the upper part of the pipe shed installation area, which is located inside the existing pipe gallery and connected to the existing pipe gallery floor plate as a whole; After the construction of the new base plate is completed, the shield cutting and underpass operation of the new tunnel will be carried out.

2. A construction method for shield cutting an existing operating pipe gallery as claimed in claim 1, characterized in that: The pipe rack is composed of multiple steel pipes, which pass through the side walls of the existing pipe gallery and are distributed in a fan shape.

3. A construction method for shield cutting an existing operating pipe gallery as claimed in claim 1, characterized in that: The vibration isolation joint adopts an arc-shaped joint that matches the shield cutting cross-sectional area, and the vibration isolation joint runs through the side wall and the middle partition wall of the existing pipe gallery.

4. A construction method for shield cutting an existing operating pipe gallery as claimed in claim 1, characterized in that: After the construction of the vibration isolation joint is completed, multiple vibration reduction holes are drilled in the side walls and middle partition areas below the vibration isolation joint.

5. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 1, characterized in that: The first cutting seam is arranged perpendicular to the existing pipe gallery bottom plate, the top end of the first cutting seam is connected to the vibration isolation seam, and the bottom end of the first cutting seam extends to the bottom surface of the existing pipe gallery.

6. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 1, characterized in that: The plurality of second cutting slits are distributed in a mesh shape.

7. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 1, characterized in that: The construction method of the newly built base plate is: Micro steel pipe piles are driven into the corresponding positions of the arch feet of the new base plate, and the micro steel pipe piles pass through the existing base plate of the pipe gallery and extend into the soil; Then, the steel bar structure of the new bottom plate is constructed, and the ends of the steel bar structure of the new bottom plate are tied and fixed to the existing steel bar structure of the existing pipe gallery bottom plate; Then the new base slab is poured with concrete, and the micro steel pipe piles and the new base slab are cast as a whole.

8. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 1, characterized in that: During the construction process of the shield tunneling through the existing pipeline gallery, only the wall of the lower half of the segment ring under the existing pipeline gallery is filled with pea gravel. After the shield tunneling is completed, the wall of the upper half of the segment ring under the existing pipeline gallery is filled with pea gravel.

9. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 8, characterized in that: After the pea gravel filling is completed, grouting is carried out on the wall of the segment ring below the existing pipeline gallery.

10. A construction method for shield cutting an existing operational pipe gallery as claimed in claim 1, characterized in that: The construction method for grouting reinforcement of the soil in the shield tunneling area under the existing pipe gallery is: A grouting pipe is constructed on the bottom plate of the existing pipe gallery corresponding to the shield tunneling area, and the grouting pipe extends into the soil under the existing pipe gallery; After the construction of the grouting pipe is completed, the soil in the shield crossing area under the existing pipeline corridor is grouting reinforced by using the backward grouting method through the grouting pipe.

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