Construction method of shield negative ring combined segment

Abstract

The application discloses a construction method of a shield negative ring combined segment, which comprises installation and removal of the shield negative ring combined segment; the installation method of the shield negative ring combined segment is as follows: installing a segment support cushion block in a shield tail shell of a shield machine; installing each segment symmetrically on the segment support cushion block according to the principle of from bottom to top, and assembling to form a segment ring; pushing out the segment ring from the shield tail of the shield machine through a propelling oil cylinder of the shield machine and pressing the segment ring on a counterforce frame after assembling one segment ring; when a cutter head of the shield machine fully contacts with a working face, the segment ring is tightly pressed, the segment support cushion block is removed, and the installation of the shield negative ring combined segment is completed. The application has the advantages of convenience in installation and removal, better stress effect and repeated use.

Description

Technical Field

[0001] This invention relates to the technical field of shield tunneling machine negative ring segments, and in particular to a construction method for shield tunneling machine negative ring combined segments. Background Technology

[0002] The negative ring segment of a tunnel boring machine (TBM) is a temporary segment installed between the TBM jacks and the reaction frame during the initial tunneling. Its function is to provide forward thrust for the initial tunneling. After the TBM has tunneled a certain distance, the friction between the positive ring segment and the ground can balance the propulsion reaction force. At this point, the negative ring segment loses its function and needs to be removed.

[0003] Currently, the commonly used negative ring segments are reinforced concrete segments or steel segments. Reinforced concrete segments are the most common due to their low cost; however, because of the heavy weight of concrete, steel plates must be welded to the internal and external connections of the negative ring to maintain its circular shape after assembly. During dismantling, holes need to be drilled in the segments for securing the hoist's wire ropes. Furthermore, concrete segments are generally dismantled individually, and the removal of the top segments significantly impacts the arch's stress. To maintain stability during dismantling, the remaining segments need to be connected and fixed to other stable structures to prevent instability. Therefore, negative ring dismantling is difficult, time-consuming, and can cause some downtime in tunnel boring. Moreover, concrete segments suffer significant damage during dismantling, especially the top segments, resulting in low reuse rates. While steel segments are easy to install and have high strength, their lighter weight makes them prone to floating, which can negatively affect the shield's attitude. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of the prior art by providing a construction method for a shield tunneling negative ring combined segment. By first hoisting reinforced concrete segments and then hoisting steel truss segments, a segment ring can be assembled, which has good stress-bearing effect. Furthermore, when dismantling the segment ring, the steel truss segments and reinforced concrete segments are hoisted out in sequence for recycling and repeated use.

[0005] The objective of this invention is achieved through the following technical solutions:

[0006] A construction method for a shield tunneling negative ring composite segment, characterized in that the construction method includes the installation and dismantling of the shield tunneling negative ring composite segment; wherein, the installation method of the shield tunneling negative ring composite segment is as follows:

[0007] (1) Install segment support pads inside the tail shell of the tunnel boring machine;

[0008] (2) Install each segment symmetrically on the segment support pad according to the principle of bottom to top, and assemble to form a segment ring; wherein, the segment ring is divided into an upper half ring and a lower half ring, the upper half ring is assembled from three steel truss segments, the lower half ring is assembled from three reinforced concrete segments, each of the longitudinal end faces of the steel truss segments is provided with a longitudinal steel plate, each of the circumferential end faces is provided with a circumferential steel plate, the steel truss segments include connected truss longitudinal connecting rods and truss circumferential connecting rods, the two ends of the truss longitudinal connecting rods are respectively connected to the two longitudinal steel plates, and the two ends of the truss circumferential connecting rods are respectively connected to the two circumferential steel plates;

[0009] (3) After each segment ring is assembled, the segment ring is pushed out of the shield tail of the tunnel boring machine by the propulsion cylinder of the tunnel boring machine and pressed tightly onto the reaction frame;

[0010] (4) When the cutterhead of the tunnel boring machine is in full contact with the working face, the segment ring is tightened, the segment support pad is removed, and the installation of the shield negative ring combined segment is completed.

[0011] The assembly method of the segment ring in step S2 is as follows: First, install the middle reinforced concrete segment, then symmetrically install the two sides of the reinforced concrete segment, and connect the three reinforced concrete segments together circumferentially; symmetrically install the two sides of the steel truss segment, and connect the side steel truss segment with the reinforced concrete segment on the same side; finally, install the middle steel truss segment, and connect the middle steel truss segment with the two sides of the steel truss segment, thereby completing the assembly of the segment ring.

[0012] Bolt holes are provided on the circumferential steel plate, and screws are pre-embedded on the circumferential end face of the reinforced concrete tube segment. The circumferential connection between the reinforced concrete tube segment and the steel truss tube segment is realized through the cooperation between the screws on the circumferential end face of the reinforced concrete tube segment and the bolt holes on the circumferential steel plate.

[0013] The steel truss segments in the same segment ring are circumferentially connected by bolts.

[0014] The reinforced concrete segments in the same segment ring are circumferentially connected by circumferential connecting bolts.

[0015] The circumferential connecting rod of the truss is connected to the longitudinal steel plate through the diagonal rod of the truss.

[0016] The steel truss segment has several circumferential connecting rods arranged vertically, and the circumferential connecting rods are connected to each other by vertical truss rods.

[0017] Bolt holes are provided on the longitudinal steel plate, and the steel truss segment in one segment ring is longitudinally connected to the corresponding steel truss segment in another adjacent segment ring by bolts.

[0018] The reinforced concrete segment in one segment ring is longitudinally connected to the corresponding reinforced concrete segment in another adjacent segment ring by longitudinal connecting bolts.

[0019] The method for dismantling the shield tunnel negative ring combined segment is as follows:

[0020] (a) Install lifting rings symmetrically on the longitudinal connecting rods of the steel truss segments and secure them firmly;

[0021] (b) Cut off the connection between the shield negative ring combined segment and the reaction frame, and disconnect the connection between the middle steel truss segment and the adjacent steel truss segment in the circumferential direction and the adjacent steel truss segment in the longitudinal direction.

[0022] (c) Lift out the middle steel truss segment, and then lift and remove the steel truss segments on both sides in sequence;

[0023] (d) Fix the lifting ring to the upper end face reinforcement of the reinforced concrete segment and disconnect the connection between the side of the reinforced concrete segment and the circumferentially adjacent reinforced concrete segment and the longitudinally adjacent reinforced concrete segment.

[0024] (e) Lift out the reinforced concrete segments on both sides and lift and remove the middle reinforced concrete segment.

[0025] The advantages of this invention are:

[0026] Installation and dismantling are convenient; the installation of the upper ring only requires hoisting the steel truss segment into place and tightening the connecting bolts between the circumferential steel plates. The longitudinal connection is also made by bolts. During installation and dismantling, the steel wire rope can be fixed to the longitudinal connecting rod of the truss for hoisting. It is convenient to install and dismantle, and there is no need to temporarily drill lifting holes like concrete segments. The construction period is shortened, the impact on shield tunneling is small, and the situation inside and outside the segment can be observed at any time, which also makes the construction safer.

[0027] The upper half of the ring has better stress distribution; the steel truss segments are lightweight and have good overall stability. After installation, they can maintain good roundness and do not require additional steel plate welding for reinforcement (there is no need to cut the reinforcement steel plates during dismantling). During dismantling, the dismantling of the upper half of the ring has a much smaller impact on the stress of adjacent segments and the reinforced concrete segments of the lower half of the ring, thus improving the safety of the dismantling construction. The reinforced concrete segments of the lower half of the ring have high rigidity and heavy weight, which also avoids the adverse effects of the segments floating on the shield attitude.

[0028] It can be reused repeatedly; the steel truss segments of the upper half ring can be reused after dismantling, while the reinforced concrete segments of the lower half ring are only spliced ​​together by three pieces. The damage caused by the dismantling of the segments is much less than that caused by the conventional use of concrete segments for the entire ring, which improves the reuse rate of the segments. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the shield tunnel negative ring combined segment of the present invention;

[0030] Figure 2 This is a schematic diagram of the steel truss tube segment of the present invention. Implementation

[0031] The features and other related features of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, so as to facilitate understanding by those skilled in the art:

[0032] like Figure 1-2 As shown in the figure, the markings 1-12 represent: steel truss segment 1, reinforced concrete segment 2, bolt hole 3, longitudinal steel plate 4, circumferential steel plate 5, longitudinal connecting rod of truss 6, circumferential connecting rod of truss 7, diagonal rod of truss 8, vertical rod of truss 9, bolt 10, circumferential bolt hole 11, and longitudinal bolt hole 12.

[0033] Example: Figure 1-2 As shown, this embodiment relates to a construction method for a shield tunneling negative ring composite segment, which mainly includes the installation and removal of the shield tunneling negative ring composite segment:

[0034] The installation method for shield tunneling negative ring combined segments is as follows:

[0035] 1. Debug the tunnel boring machine's propulsion system and segment installation system to ensure stable operation.

[0036] 2. Install segment support pads inside the tail shell of the tunnel boring machine to facilitate segment positioning.

[0037] 3. Install each segment symmetrically from bottom to top, paying attention to deviation control: First, hoist the lower reinforced concrete segment 2, then hoist the upper steel truss segment 1. Specifically, first install the middle reinforced concrete segment 2, then symmetrically install the two sides of the reinforced concrete segment 2, and connect the three reinforced concrete segments 2 together in a ring; then symmetrically install the two sides of the steel truss segment 1, and connect the side steel truss segment 1 with the reinforced concrete segment 2 on the same side; finally, install the middle steel truss segment 1, and connect the middle steel truss segment 1 with the two sides of the steel truss segment 1, thus completing the segment ring connection.

[0038] Among them, such as Figure 1-2As shown, steel truss segments 1 and reinforced concrete segments 2 are assembled together to form a segment ring. The segment ring is divided into an upper half ring and a lower half ring. The upper half ring is assembled from three steel truss segments 1, and the lower half ring is assembled from three reinforced concrete segments 2. The longitudinal end faces and the circumferential end faces of the steel truss segments 1 are both steel plates with bolt holes 3. The steel plates located on the longitudinal end faces of the steel truss segments 1 are longitudinal steel plates 4, and the steel plates located on the circumferential end faces of the steel truss segments 1 are circumferential steel plates 5. The longitudinal steel plates 4 and the circumferential steel plates 5 are connected together. The steel truss segment 1 also includes truss circumferential connecting rods 7, truss longitudinal connecting rods 6, and truss diagonal rods 8. The truss circumferential connecting rods 7 and truss longitudinal connecting rods 6 are connected to each other, and the two ends of the truss longitudinal connecting rods 6 are respectively connected to two longitudinal steel plates 4. The two ends of the truss circumferential connecting rods 7 are respectively connected to two circumferential steel plates 5. The truss circumferential connecting rods 7 are connected to the longitudinal steel plates 4 through the truss diagonal rods 8. In this embodiment, there are two truss circumferential connecting rods 7 on the steel truss segment 1 in the vertical direction. The two truss circumferential connecting rods 7 are connected to each other through truss vertical rods 9. Each truss circumferential connecting rod 7 is connected to three truss longitudinal connecting rods 6. The upper half of the steel truss segment 1 exhibits high overall structural stability. As long as the stress on individual members meets requirements, the stability is maintained. Specifically, the pressure transmission between rings first reaches the circumferential steel plate 5 on the circumferential end face of the steel truss segment 1. Then, it is transmitted through the circumferential connecting rods 7 to the longitudinal connecting rods 6 and the diagonal rods 8. Finally, the pressure is evenly distributed through the longitudinal connecting rods 6 and the diagonal rods 8 and transmitted to the longitudinal steel plate 4 on the longitudinal end face of the steel truss segment 1. This avoids excessive local stress and ensures high stability. Furthermore, the longitudinal connecting rods 6 can also serve as lifting points.

[0039] like Figure 1-2 As shown, bolts 10 are pre-embedded on the circumferential end face of the reinforced concrete segment 2. The circumferential connection between the reinforced concrete segment 2 and the steel truss segment 1 is achieved through the engagement between the bolts 10 on the circumferential end face of the reinforced concrete segment 2 and the bolt holes 3 on the circumferential steel plate 5. The steel truss segments 1 within the same segment ring are circumferentially connected by bolts, which engage with the bolt holes 3 on the circumferential steel plate 5. The steel truss segments 1 in one segment ring are longitudinally connected to the corresponding steel truss segments 1 in another adjacent segment ring by bolts, which engage with the bolt holes 3 on the longitudinal steel plate 4.

[0040] like Figure 1As shown, the reinforced concrete segment 2 is provided with circumferential bolt holes 11 and longitudinal bolt holes 12. The reinforced concrete segments 2 within the same segment ring are circumferentially connected by circumferential connecting bolts, which mate with the circumferential bolt holes 11 on the reinforced concrete segment 2. The reinforced concrete segment 2 in one segment ring is longitudinally connected to the corresponding reinforced concrete segment 2 in another adjacent segment ring by longitudinal connecting bolts, which mate with the longitudinal bolt holes 12 on the reinforced concrete segment 2.

[0041] In this embodiment, the upper half-ring steel truss segment 1 is lightweight and has good overall stability. After installation, it maintains good roundness and does not require additional steel plate welding for reinforcement (thus eliminating the need to cut the reinforcement steel plates during dismantling). During dismantling, the removal of the upper half-ring steel truss segment 1 significantly reduces the stress impact on adjacent segments and the lower half-ring reinforced concrete segment 2, improving the safety of the dismantling operation. The lower half-ring reinforced concrete segment 2 has high rigidity and weight, which also prevents the segment from floating and adversely affecting the shield's attitude.

[0042] 5. After each segment is assembled, the tunnel segment ring is pushed out of the shield tail of the tunnel boring machine by the propulsion cylinder of the tunnel boring machine and pressed tightly onto the reaction frame.

[0043] 6. When advancing the segment ring, timely reinforcement is necessary to prevent the top from sinking or becoming out of round. The eccentric force of the jacking should also be considered.

[0044] 7. Once the cutterhead of the tunnel boring machine is in full contact with the tunnel face and generates sufficient thrust, the segment ring is tightened and the force is stable. At this point, the segment support pads can be removed to complete the installation of the negative ring.

[0045] The method for dismantling the shield tunnel negative ring composite segment is as follows:

[0046] 1. Remove tracks, pipes, lines, etc. from the site to prevent damage during hoisting.

[0047] 2. Inspect and tighten the longitudinal and circumferential connecting bolts of the lower reinforced concrete pipe segment 2.

[0048] 3. Install lifting rings symmetrically on the longitudinal connecting rods 6 of the upper steel truss segment 1 and fix them firmly.

[0049] 4. Disconnect the negative ring from the reaction frame.

[0050] 5. Remove the bolt connections between the middle steel truss segment 1 and the front and rear rings, as well as between it and adjacent segments in the circumferential direction.

[0051] 6. Lift out the middle steel truss segment 1 and place it stably on the temporary site with sleepers underneath.

[0052] 7. Following the same method, sequentially hoist and dismantle the steel truss segments 1 on both sides (at the arch shoulders).

[0053] 8. Fix the lifting ring to the upper end reinforcement of the lower reinforced concrete segment 2, and remove the connecting bolts between the reinforced concrete segment 2 and other segments in the circumferential and longitudinal directions.

[0054] 9. Following the order of first the two sides and then the middle, hoist and dismantle the three lower reinforced concrete segments 2 one by one.

[0055] 10. Transport each segment to the storage site by flatbed truck.

[0056] The beneficial technical effects of this embodiment are as follows:

[0057] Installation and dismantling are convenient; the installation of the upper ring only requires hoisting the steel truss segment into place and tightening the connecting bolts between the circumferential steel plates. The longitudinal connection is also made by bolts. During installation and dismantling, the steel wire rope can be fixed to the longitudinal connecting rod of the truss for hoisting. It is convenient to install and dismantle, and there is no need to temporarily drill lifting holes like concrete segments. The construction period is shortened, the impact on shield tunneling is small, and the situation inside and outside the segment can be observed at any time, which also makes the construction safer.

[0058] The upper half of the ring has better stress distribution; the steel truss segments are lightweight and have good overall stability. After installation, they can maintain good roundness and do not require additional steel plate welding for reinforcement (there is no need to cut the reinforcement steel plates during dismantling). During dismantling, the dismantling of the upper half of the ring has a much smaller impact on the stress of adjacent segments and the reinforced concrete segments of the lower half of the ring, thus improving the safety of the dismantling construction. The reinforced concrete segments of the lower half of the ring have high rigidity and heavy weight, which also avoids the adverse effects of the segments floating on the shield attitude.

[0059] It can be reused repeatedly; the steel truss segments of the upper half ring can be reused after dismantling, while the reinforced concrete segments of the lower half ring are only spliced ​​together by three pieces. The damage caused by the dismantling of the segments is much less than that caused by the conventional use of concrete segments for the entire ring, which improves the reuse rate of the segments.

[0060] Although the above embodiments have described the concept and embodiments of the present invention in detail with reference to the accompanying drawings, those skilled in the art will recognize that various improvements and modifications can still be made to the present invention without departing from the scope of the claims, and therefore will not be elaborated here.

Claims

1. A construction method for a shield tunneling negative ring combined segment, characterized in that... The construction method includes the installation and removal of the shield tunnel negative ring composite segments; wherein, the installation method of the shield tunnel negative ring composite segments is as follows: (1) Install segment support pads inside the tail shell of the tunnel boring machine; (2) Install each segment symmetrically on the segment support pad according to the principle of bottom to top, and assemble to form a segment ring; wherein, the segment ring is divided into an upper half ring and a lower half ring, the upper half ring is assembled from three steel truss segments, the lower half ring is assembled from three reinforced concrete segments, each of the longitudinal end faces of the steel truss segments is provided with a longitudinal steel plate, each of the circumferential end faces is provided with a circumferential steel plate, the steel truss segments include connected truss longitudinal connecting rods and truss circumferential connecting rods, the two ends of the truss longitudinal connecting rods are respectively connected to the two longitudinal steel plates, and the two ends of the truss circumferential connecting rods are respectively connected to the two circumferential steel plates; (3) After each segment ring is assembled, the segment ring is pushed out of the shield tail of the tunnel boring machine by the propulsion cylinder of the tunnel boring machine and pressed tightly onto the reaction frame; (4) When the cutterhead of the tunnel boring machine is in full contact with the working face, the segment ring is tightened, the segment support pad is removed, and the installation of the shield negative ring combined segment is completed.

2. The construction method of the shield tunnel negative ring combined segment as described in claim 1, characterized in that... The assembly method of the segment ring in step (2) is as follows: First, install the middle reinforced concrete segment, then symmetrically install the two sides of the reinforced concrete segment, and connect the three reinforced concrete segments together circumferentially; symmetrically install the two sides of the steel truss segment, and connect the side steel truss segment with the same side of the reinforced concrete segment; finally, install the middle steel truss segment, and connect the middle steel truss segment with the two sides of the steel truss segment, thereby completing the assembly of the segment ring.

3. The construction method of the shield tunnel negative ring combined segment as described in claim 2, characterized in that... Bolt holes are provided on the circumferential steel plate, and screws are pre-embedded on the circumferential end face of the reinforced concrete tube segment. The circumferential connection between the reinforced concrete tube segment and the steel truss tube segment is realized through the cooperation between the screws on the circumferential end face of the reinforced concrete tube segment and the bolt holes on the circumferential steel plate.

4. The construction method of a shield tunnel negative ring combined segment as described in claim 3, characterized in that... The steel truss segments in the same segment ring are circumferentially connected by bolts.

5. The construction method of a shield tunneling negative ring combined segment as described in claim 2, characterized in that... The reinforced concrete segments in the same segment ring are circumferentially connected by circumferential connecting bolts.

6. The construction method of a shield tunnel negative ring combined segment as described in claim 1, characterized in that... The circumferential connecting rod of the truss is connected to the longitudinal steel plate through the diagonal rod of the truss.

7. The construction method of a shield tunnel negative ring combined segment as described in claim 1, characterized in that... The steel truss segment has several circumferential connecting rods arranged vertically, and the circumferential connecting rods are connected to each other by vertical truss rods.

8. The construction method of a shield tunnel negative ring combined segment as described in claim 1, characterized in that... Bolt holes are provided on the longitudinal steel plate, and the steel truss segment in one segment ring is longitudinally connected to the corresponding steel truss segment in another adjacent segment ring by bolts.

9. The construction method of a shield tunneling negative ring combined segment as described in claim 1, characterized in that... The reinforced concrete segment in one segment ring is longitudinally connected to the corresponding reinforced concrete segment in another adjacent segment ring by longitudinal connecting bolts.

10. The construction method of a shield tunnel negative ring combined segment as described in claim 1, characterized in that... The method for dismantling the shield tunnel negative ring combined segment is as follows: Symmetrical lifting rings are installed on the longitudinal connecting rods of the steel truss segments and secured firmly. Cut off the connection between the shield tunnel negative ring combined segment and the reaction frame, and disconnect the connection between the middle steel truss segment and the adjacent steel truss segment in the circumferential direction, as well as the connection between the middle steel truss segment and the adjacent steel truss segment in the longitudinal direction. The middle steel truss segment is lifted out, and the steel truss segments on both sides are lifted and removed in sequence. Fix the lifting ring to the upper end face reinforcement of the reinforced concrete tube segment, and disconnect the connection between the side of the reinforced concrete tube segment and the circumferentially adjacent reinforced concrete tube segment and the longitudinally adjacent reinforced concrete tube segment. The reinforced concrete segments on both sides are lifted out, and the reinforced concrete segment in the middle is lifted and removed.

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