Segment ring, segment prefabricated mold, segment ring wall back gap plugging and grouting filling implementation method

Abstract

The application discloses a segment ring, a segment prefabricated mold, a segment ring wall rear gap blocking and grouting filling implementation method, which comprises a hollow ring-shaped segment ring body and a plurality of grouting bags for post-grouting filling expansion. An inner recessed preset groove extending in a curve shape is arranged on the outer ring surface of the segment ring body. The plurality of grouting bags are sequentially folded in the preset groove along the extension direction of the preset groove, and the front and rear grouting bags are connected in a head-to-tail mode. The grouting bag is used for extruding the preset groove after post-grouting filling expansion, so as to block the gap between the segment ring and the tunnel surrounding rock. The segment ring can solve the problem of grouting leakage between the segment ring wall rear and the surrounding rock, reduce grouting material consumption, reduce resource waste, improve economic effect, enhance the filling degree and grouting effect of secondary grouting, enhance the overall bearing performance of the tunnel lining, and the high-pressure grouting environment can enhance the grouting effect of the surrounding rock cracks and improve the overall waterproof effect and construction quality of the tunnel.

Description

Technical Field

[0001] This invention relates to the field of prefabricated rail transit, and more particularly, to a segment ring. Furthermore, this invention also relates to a segment prefabrication mold for preparing the segment body of a tunnel segment within a segment ring. Moreover, this invention further relates to a method for sealing and grouting the back wall gaps of a segment ring using a segment ring. Background Technology

[0002] During the 14th Five-Year Plan period, the operational mileage of urban rail transit in my country will increase by more than 3,000 km. In regions such as Shandong, Chongqing, and Shenzhen, tunnel sections constructed using a shield-TBM dual-mode excavation method due to the presence of hard rock strata have become common. Furthermore, the mileage of tunnels constructed using TBMs in the railway and water conservancy sectors is also increasing year by year. However, because rock masses cannot deform and compress towards the shield and segments after excavation to seal the gap between the shield and the surrounding rock like soil, and because the sealing rings at the tail of the shield or TBM wear down with the tunnel excavation, gaps exist between the shield, segments, and surrounding rock. This leads to incomplete sealing during grouting behind the segments, allowing grout to flow out through the gaps via the shield head and screw conveyor with the tunnel lining debris, resulting in serious resource waste. Moreover, incomplete grouting behind the segments often leads to voids behind the lining wall, which are extremely costly and difficult to treat later. A rock shield tunnel project in China once suffered a problem where the shield sealing ring was worn down, and the grout injected behind the treatment wall leaked through the shield head, resulting in a cost of over 30 million yuan and causing great losses and material waste.

[0003] Currently, in response to the problems of leakage and compaction of grouting behind shield / TBM tunnel walls, technical personnel in the industry have proposed many new materials, structures, and methods. For example, the solutions mentioned in patents 202110711138.2 and 202010431384.8 have not solved the problem of sealing the gap between the shield sealing ring and the surrounding rock. For example, patents 201710449152.3 and 202011212997.9 propose gap sealing solutions such as setting grouting bags and sealing grouting pads behind the wall. Although these solutions solve the gap sealing problem under ideal conditions, the shield tail brush of the shield machine is in close contact with the tunnel segments, and the newly added sealing grouting strip or pad will be destroyed by the shield tail brush, so it is actually impossible to seal the gap between the shield and the surrounding rock. Summary of the Invention

[0004] This invention provides a method for sealing and grouting the gap behind the segment ring, segment prefabrication mold, and segment ring wall, in order to solve the technical problems of the prior art that "the problem of sealing the gap between the shield sealing ring and the surrounding rock is not solved, and the newly added sealing grouting strip or pad will be destroyed by the shield tail brush, and in fact cannot seal the gap between the shield and the surrounding rock".

[0005] The technical solution adopted in this invention is as follows:

[0006] A segment ring includes: a hollow annular segment ring body and a plurality of grouting bags for expansion after grouting filling; a pre-set groove is machined on the outer ring surface of the segment ring body and extends in a concave and curved manner; the plurality of grouting bags are folded sequentially in the pre-set groove along the extension direction of the pre-set groove, and the two grouting bags are connected end to end; the grouting bags are used to squeeze out of the pre-set groove after grouting filling and expansion to seal the gap between the segment ring and the surrounding rock of the tunnel.

[0007] Furthermore, the segment ring body is assembled from multiple segment bodies arranged sequentially along its circumference, and the pre-set grooves on the outer ring surface of the multiple segment bodies are smoothly connected to form a concave curved ring groove; a grouting bag is folded inside the pre-set groove on the outer ring surface of each segment body, and the grouting bag and the corresponding segment body are combined to form a tunnel segment as a segment ring unit.

[0008] Furthermore, each tunnel segment also includes a sealing strip, which is attached to the outer ring surface of the segment body along the extension direction of the pre-set groove to seal the grouting bag inside the pre-set groove.

[0009] Furthermore, each tunnel segment also includes multiple sets of fixing buckles; the multiple sets of fixing buckles are arranged sequentially at intervals along the extension direction of the pre-set groove, and the fixing end of each fixing buckle is pre-embedded in the segment body, and its opposite connecting end extends into the pre-set groove to connect and fix the grouting bag.

[0010] Furthermore, the grouting bag includes a bag body for expansion after grouting and a plurality of pull rings sequentially and spaced apart along the length of the bag body; the bag body is completely folded into the pre-set groove before grouting; the fixing buckle is in the shape of an inverted "U", with its closed end pre-embedded in the segment body, and its two opposite connecting sections extending into the pre-set groove to be tightened with the pull rings at the corresponding positions.

[0011] Furthermore, the grouting bag also includes a grouting pipe connected to the bag body for supplying grouting material into the bag body; a grouting hole penetrating the segment body is provided in the pre-set groove corresponding to the grouting pipe, and the grouting pipe is fixed to the inner ring surface of the segment body by fasteners after passing through the grouting hole; the segment body is also provided with a wall-mounted grouting hole penetrating the body for supplying grouting material to fill the gap between the segment ring and the surrounding rock of the tunnel between two adjacent grouting bags.

[0012] According to another aspect of the present invention, a prefabrication mold for prefabricating tunnel segments as described above is also provided. The prefabrication mold includes: an original tunnel segment prefabrication template extending in an arc, and a forming tube for forming a pre-set groove on the tunnel segment body; the forming tube is fixed to the arc surface of the original tunnel segment prefabrication template and extends in a curved shape along the arc surface extension direction of the original tunnel segment prefabrication template.

[0013] According to another aspect of the present invention, a method for sealing and grouting the gap behind the tunnel segment ring wall is also provided, comprising the following steps: tunnel segment preparation: using the segment prefabrication mold, grouting bag and multiple sets of fixing buckles as described above to prepare tunnel segments as described above; segment ring assembly and gap sealing performance test; segment ring assembly, gap sealing and grouting at the project site.

[0014] Furthermore, in the step "segment ring assembly and back wall gap sealing performance test", the "back wall gap sealing performance test" specifically includes the following: test of the smoothness of the connection between the pre-cast grooves of the tunnel segments in the same ring; test of the folding condition of the grouting bag; test of the fastening characteristics of the grouting bag pull buckle; test of the expansion characteristics of the grouting bag and the back wall gap sealing performance of the segment ring.

[0015] Furthermore, the step "On-site assembly of tunnel segments and sealing and grouting of gaps behind the tunnel wall" specifically includes the following steps: assembly of the N-ring tunnel segments with pre-installed grouting bags inside the tunnel; assembly of the N+1 ring tunnel segments, with the grouting bags of the N-ring tunnel segments being grouted and expanded until the gap between the tunnel segments and the surrounding rock is completely sealed; assembly of the N+2 ring tunnel segments, with the grouting bags of the N+1 ring tunnel segments being grouted and expanded until the gap between the tunnel segments and the surrounding rock is completely sealed; assembly of the N+3 ring tunnel segments, N... +2 ring segment grouting bag expansion until the gap between the segment ring and the tunnel surrounding rock is completely sealed. N ring and N+1 ring segment ring wall back gap is grouted and compacted. N+4 ring segment ring assembly. N+3 ring segment grouting bag expansion until the gap between the segment ring and the tunnel surrounding rock is completely sealed. N+1 ring and N+2 ring segment ring wall back gap is grouted and compacted. Repeat the above cycle until the construction of the segment ring wall back gap compaction and filling section is completed.

[0016] The present invention has the following beneficial effects:

[0017] To address the shortcomings of existing technologies and solutions, and specifically to prevent grout leakage behind the tunnel walls in TBM / shield tunnels, this invention proposes a segment ring. This segment ring incorporates multiple grouting bags arranged in a ring within a pre-set groove on the outer surface of the segment ring body. These bags expand after grouting to form a ring, effectively sealing the gap between the segment ring and the surrounding rock. This avoids grout leakage problems that occur during conventional TBM / shield tunnel construction, such as unsealed areas between the shield tail brush and the segment, and wear and tear on the components used to seal the gap between the segment and the surrounding rock. This reduces grouting material consumption, minimizes resource waste, and improves economic efficiency. Furthermore, the expanding rings between adjacent segment rings can create a sealed secondary grouting zone, providing the closed environment required for high-pressure grouting, thereby enhancing the fullness and effectiveness of the secondary grouting. The invention improves the grouting effect behind the tunnel wall, enhances the overall bearing capacity of the tunnel lining, and the high-pressure grouting environment can enhance the grouting effect of the surrounding rock fissures, thereby improving the overall waterproofing effect and construction quality of the tunnel. In addition, the pre-set groove adopts an innovative curved extension on the segment ring body. Compared with the straight arrangement, it can not only effectively avoid the problem of the shield tail brush falling into the pre-set groove and piercing the grouting bag in the straight arrangement, but also prevent the problem of non-sealing between the shield tail brush and the segment when the groove appears on the side of the segment adjacent to the surrounding rock in the same section. It can also raise the local segment ring by adjusting the diameter of the grouting bag expansion, eliminating the segment misalignment problem that is prone to occur when the TBM / shield turns, achieving the misalignment amount required by relevant specifications, and reducing the difficulty of segment misalignment repair. Therefore, the segment ring of the present invention has good application prospects.

[0018] In this invention, a forming tube is fixed on the outer arc surface of the original tunnel segment prefabrication template of the existing tunnel segment mold. When the tunnel segments are prefabricated in the factory, a prefabrication groove for the grouting bag can be formed on the outer arc surface of the tunnel segment. This not only ensures that the grouting bag is not damaged and solves the above-mentioned technical problems, but also makes the overall structure of the tunnel segment prefabrication mold simple, easy to process and manufacture, and low in manufacturing cost.

[0019] In the method for sealing and grouting the gap behind the tunnel segment ring wall of the present invention, tunnel segments are prepared using the precast molds, grouting bags, and multiple sets of fixing buckles as described above. These tunnel segments are then used for on-site assembly of the segment rings and sealing and grouting the gap behind the wall. This method not only achieves the sealing of the gap between the segment ring and the surrounding rock, avoiding the problems of non-sealing between the shield tail brush and the segment, and grout leakage caused by wear of the components used to seal the gap between the segment and the surrounding rock during conventional TBM / shield tunnel construction, thus reducing grouting material consumption, minimizing resource waste, and improving economic efficiency; simultaneously, the expanding bag rings between adjacent segment rings can form a sealed secondary grouting zone, creating the closed environment required for high-pressure grouting. This enhances the fullness and grouting effect of the secondary grouting, improves the grouting effect behind the wall, and enhances the overall bearing capacity of the tunnel lining. Furthermore, the high-pressure grouting environment enhances the grouting effect in the surrounding rock fissures, improving the overall waterproofing effect and construction quality of the tunnel.

[0020] In addition to the objectives, features, and advantages described above, the present invention has other objectives, features, and advantages. The invention will now be described in further detail with reference to the figures. Attached Figure Description

[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0022] Figure 1 This is a schematic diagram of the segment ring space structure of a preferred embodiment of the present invention;

[0023] Figure 2 This is a planar layout diagram of the outer wall of the segment ring according to a preferred embodiment of the present invention;

[0024] Figure 3 yes Figure 2 Schematic diagram of the pre-installed grouting bag type on the outer annular surface of the central tube segment;

[0025] Figure 4 This is a schematic diagram showing the state of the gap between the outer wall of the segment and the surrounding rock after the pre-embedded tie and the bag are expanded;

[0026] Figure 5 This is a schematic diagram of the longitudinal section of the closed grouting between the two ring segments;

[0027] Figure 6 This is a schematic diagram of grouting to seal the gap between tunnel segments and the surrounding rock.

[0028] Figure 7 This is a schematic diagram of a precast segment mold according to a preferred embodiment of the present invention;

[0029] Figure 8 This is a schematic diagram showing the filling of the gap between the segment ring and the surrounding rock of the tunnel before the grouting bag expands;

[0030] Figure 9 This is a schematic diagram showing the filling of the gap between the segment ring and the surrounding rock of the tunnel after the grouting bag expands;

[0031] Figure 10 This is a flowchart of the TBM / shield tunnel segment wall backfilling and compaction grouting construction process.

[0032] Legend

[0033] 1. Tunnel segment; 11. Segment body; 111. Precast groove; 112. Grouting hole of the grouting bag; 113. Grouting hole behind the wall; 114. Main reinforcement of the segment; 115. Segment structural reinforcement; 12. Grouting bag; 121. Bag body; 122. Pull ring; 123. Grouting pipe of the grouting bag; 13. Fixing buckle; 14. Sealing tape; 2. Tunnel surrounding rock; 3. Segment prefabrication mold; 31. Original tunnel segment prefabrication template; 32. Forming pipe; 321. Reserved pull buckle hole. Detailed Implementation

[0034] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0035] Reference Figure 1-2 A preferred embodiment of the present invention provides a segment ring, comprising: a hollow annular segment ring body, and a plurality of grouting bags 12 for expansion after grouting filling. A pre-set groove 111, which is concave and extends in a curved shape, is machined on the outer annular surface of the segment ring body. The plurality of grouting bags 12 are sequentially folded into the pre-set groove 111 along the extension direction of the pre-set groove 111, with two grouting bags 12 connected end-to-end. The grouting bags 12 are used to squeeze out of the pre-set groove 111 after expansion during grouting filling, thereby sealing the gap between the segment ring and the surrounding rock 2 of the tunnel.

[0036] To address the shortcomings of existing technologies and solutions, and specifically the problem of grout leakage behind the tunnel walls in TBM / shield tunnels, this invention proposes a segment ring. This segment ring incorporates multiple grouting bags 12 arranged in a ring within a pre-set groove 111 on the outer surface of the segment ring body. The grouting bags 12 expand after grouting to form a bag ring, thereby sealing the gap between the segment ring and the surrounding rock 2. This avoids the grout leakage problems that occur during conventional TBM / shield tunnel construction, such as unsealed areas between the shield tail brush and the segment, and wear of the components used to seal the gap between the segment and the surrounding rock on the tunnel boring machine. This reduces grouting material consumption, minimizes resource waste, and improves economic efficiency. Furthermore, the expanding bag rings between adjacent segment rings can form a sealed secondary grouting zone, creating the closed environment required for high-pressure grouting, thus enhancing the fullness and effectiveness of the secondary grouting. This invention improves the grouting effect behind the tunnel wall, enhances the overall bearing capacity of the tunnel lining, and the high-pressure grouting environment can enhance the grouting effect of the surrounding rock fissures, thereby improving the overall waterproofing effect and construction quality of the tunnel. In addition, the pre-set groove 111 adopts an innovative curved extension on the segment ring body. Compared with the straight arrangement, it can not only effectively avoid the problem of the shield tail brush falling into the pre-set groove 111 and piercing the grouting bag 12 that exists in the straight arrangement, but also prevent the problem of non-sealing between the shield tail brush and the segment when the groove appears on the side of the segment adjacent to the surrounding rock at the same cross section. It can also raise the local segment ring by adjusting the expansion diameter of the grouting bag 12, eliminating the segment misalignment problem that is prone to occur when the TBM / shield turns, achieving the misalignment amount required by relevant specifications, and reducing the difficulty of segment misalignment repair. Therefore, the segment ring of this invention has good application prospects.

[0037] Optionally, such as Figure 1 and Figure 2 As shown, the tunnel segment ring body is assembled from multiple tunnel segment bodies 11 arranged sequentially along its circumference, and the pre-set grooves 111 on the outer ring surface of the multiple tunnel segment bodies 11 are smoothly connected to form a concave curved ring groove. A grouting bag 12 is folded inside the pre-set groove 111 on the outer ring surface of each tunnel segment body 11, and the grouting bag 12 and the corresponding tunnel segment body 11 combine to form the tunnel segment 1, which serves as the tunnel segment ring unit. In this optional scheme, such as... Figure 2 As shown, the pre-set groove 111 extends in a wavy line along the outer arc surface of the segment body 11, which effectively avoids the problems of the shield tail brush piercing the grout bag and the groove appearing on the side of the segment adjacent to the surrounding rock, resulting in a lack of sealing between the shield tail brush and the segment, which exist in the straight arrangement scheme. In addition, the multiple pre-set grooves 111 on the outer ring surface of multiple segments 11 are smoothly connected in sequence to form a concave curved ring groove, so as to ensure that after the subsequent grouting of the grouting bag 12, all the grouting bags 12 in the same ring are connected to form a bag ring, thereby ensuring the sealing effect of the gap between the segment ring and the tunnel surrounding rock 2 wall.

[0038] Optionally, to prevent the pre-installed grouting bags 12 (folded state) behind the tunnel segment 1 from being damaged by the steel wire shield tail brush during construction, a pre-installation space, i.e., a pre-installation groove 111, needs to be provided on the outer arc surface (adjacent to the tunnel surrounding rock) of the segment body 11. In this optional scheme, if... Figure 3 As shown, the cross-sectional shape of the pre-set groove 111 is semi-circular, semi-elliptical, or square. In this optional scheme, the cross-sectional shape of the pre-set groove 111 is semi-circular. When the groove space required when the grouting bag 12 is folded is greater than the space provided by the semi-circular steel pipe, or when the groove is too deep and affects the bearing capacity of the tunnel segment 11, the semi-circular steel pipe can be replaced with a semi-elliptical steel pipe, a rectangular steel groove, etc., to ensure that the structural bearing capacity of the tunnel segment 1 meets the engineering and specification requirements.

[0039] Preferably, the diameter of the semi-circular steel pipe can be adjusted according to the shield diameter and the relevant backwall clearance width parameters of the shield machine, so as to ensure that the grouting bag 12, set according to the corresponding clearance parameters to be sealed, can be folded into the pre-set groove 111 when unfilled, thus preventing the tail shield brush from puncturing the bag. Figure 3 As shown.

[0040] Optionally, such as Figure 3 As shown, the tunnel segment 1 also includes a sealing strip 14, which is attached to the outer ring surface of the segment body 11 along the extension direction of the pre-set groove 111 to seal the grouting bag 12 within the pre-set groove 111. In this optional scheme, the stretchable and deformable sealing strip 14, i.e., tape, is used to seal the grouting bag 12 within the semi-circular pre-set groove 111, preventing the grouting bag 12 from being damaged due to it exceeding the outer surface of the segment body 11 during transportation, assembly, and advancement. In actual design, the two ends of the tape do not need to be permanently fixed; it is only necessary to meet the fixing requirements of the grouting bag 12 during transportation and assembly. The adhesive force of the tape should not be too large to avoid affecting the expansion of the grouting bag 12, resulting in incomplete gap sealing, which in turn affects the secondary wall grouting.

[0041] Optionally, such as Figure 2As shown, each tunnel segment 1 also includes multiple sets of fixing buckles 13. These sets of fixing buckles 13 are arranged sequentially at intervals along the extension direction of the pre-set groove 111, with the fixing end of each fixing buckle 13 pre-embedded within the segment body 11, and its opposite connecting end extending into the pre-set groove 111 to connect and fix the grouting bag 12. In this optional embodiment, two sets of fixing buckles 13 are respectively located at both ends of the pre-set groove 111 to tighten and fix both ends of the grouting bag 12, while the remaining sets of fixing buckles 13 are arranged sequentially at intervals along the length direction of the pre-set groove 111. In actual design, attention should be paid to ensuring that the pre-installed fixing buckles 13 inside the segment body 11 are locked to both ends of the grouting bag 12 to prevent the grouting bag 12 from detaching at the ends during grouting, which would prevent it from connecting and sealing with the grouting bag 12 of the connected segment to form a ring. At the same time, the middle position of the grouting bag 12 should also be tightened to ensure that the position of the grouting bag 12 is fixed, and to prevent the grouting bag 12 from detaching from the pre-installed groove 111 due to gravity after grouting, which would affect the sealing effect between the segment and the surrounding rock.

[0042] Optionally, such as Figure 4-6 As shown, the grouting bag 12 includes a bag body 121 for expansion after grouting, and a plurality of pull rings 122 sequentially and spaced along the length of the bag body 121. Before grouting, the bag body 121 is completely folded into the pre-set groove 111. The fixing buckle 13 is inverted "U" shape, with its closed end pre-embedded in the segment body 11, and its two opposite connecting sections extending into the pre-set groove 111 to tighten with the corresponding pull rings 122. In this optional solution, such as... Figure 4 As shown, the segment body 11 includes segment main reinforcement 114 and segment structural reinforcement 115 for binding to form the segment skeleton. The closed end of the fixing buckle 13 is fastened to the nearest segment main reinforcement 114 to enhance the stability of the pre-embedded fixing buckle 13.

[0043] Furthermore, such as Figure 6As shown, the grouting bag 12 also includes a grouting pipe 123 connected to the bag body 121 for supplying grouting material into the bag body 121. A grouting hole 112 is provided in the pre-set groove 111 corresponding to the grouting pipe 123, penetrating the segment body 11. After passing through the grouting hole 112, the grouting pipe 123 is fixed to the inner ring surface of the segment body 11 by fasteners. The segment body 11 also has a wall-mounted grouting hole 113 penetrating the body, for supplying grouting material to fill the gap between the segment ring and the surrounding rock 2 of the tunnel between two adjacent grouting bags 12. In actual design, at 1 / 3 of the length of the pre-set groove 111, avoiding the wall-mounted grouting hole 113, a grouting hole 112 with a diameter of Φ10~30mm is reserved in the segment body 11 for later use by the grouting pipe 123. After the tunnel segment 1 is prefabricated and cured, when the grouting bag 12 is installed, the bag grouting pipe 123 is connected to the inner ring surface of the segment body 11 through the reserved bag grouting hole 112, so as to facilitate bag grouting after the segment is assembled in the tunnel, so as to seal the gap between the segment and the surrounding rock.

[0044] In this optional scheme, after the tunnel segments are poured with concrete, demolded, and cured, rubber bags matching the length of each tunnel segment 1 are folded and placed in the pre-set groove 111. The selected grouting bags 12 must have the deformation capacity to ensure that they can expand to form a columnar body with a maximum diameter of 15cm and can resist the compression of rock blocks without breaking. Figure 4 As shown.

[0045] After the segment ring assembly is completed, the grouting bags 12 behind the segment ring wall are gradually filled with grout through the grouting pipes 123 (one-time grouting). The grouting volume of each grouting bag 12 is based on the pre-calculated grouting volume required to compress and seal the gap between the segment ring and the tunnel surrounding rock. The grouting material is ordinary mortar with added quick-setting agent or self-expanding polyurethane grout, which is sufficient to make the grouting bag 12 reach the predetermined expansion diameter. Figure 5 As shown. After the initial setting of the mortar in the grout bag, grouting is then performed to fill the gap between the tunnel surrounding rock 2 and the segment rings, i.e., secondary grouting. The grouting material used is the conventional backwall grouting material currently used in TBM / shield tunnels. The final grouting effect is as follows. Figures 5-6 .

[0046] Reference Figure 7 A preferred embodiment of the present invention also provides a segment prefabrication mold for prefabricating the segment body 11 as described above. The segment prefabrication mold 3 includes: an original tunnel segment prefabrication template 31 extending in an arc, and a forming tube 32 for forming a pre-set groove 111 on the segment body 11. The forming tube 32 is fixed to the arc surface of the original tunnel segment prefabrication template 31 and extends in a curved shape along the arc surface extension direction of the original tunnel segment prefabrication template 31.

[0047] like Figure 7 As shown, in order to prevent the pre-installed grouting bags 12 (in a folded state) before the tunnel segment 1 is assembled from being damaged by the steel wire shield tail brush that plays a sealing role during construction, a pre-installed space for the bags, namely the pre-installed groove 111, needs to be provided on the outer arc surface (adjacent to the tunnel surrounding rock) of the tunnel segment 1. Therefore, in order to reduce the workload, difficulty and cost of modifying existing molds, in this invention, a forming tube 32 is fixed on the outer arc surface of the original tunnel segment prefabrication template 31 of the existing tunnel segment mold. When the segments are prefabricated in the factory, the pre-installed groove 111 for the grouting bags 12 can be formed on the outer arc surface of the tunnel segment 1. This not only ensures that the grouting bags 12 are not damaged and solves the above-mentioned technical problems, but also makes the overall structure of the segment prefabrication mold 3 simple, easy to process and prepare, and low in preparation cost.

[0048] Optionally, the two forming pipes 32 on the two sets of prefabricated molds 3 for forming two adjacent tunnel segments 1 of the same ring are smoothly connected to ensure that after the subsequent grouting bag 12 is grouted and expanded, the grouting bags 12 of the two adjacent tunnel segments 1 of the same ring can be connected to form an arc, thereby ensuring the sealing effect of the gap between the segment ring and the surrounding rock of the tunnel 2.

[0049] Furthermore, such as Figure 7 As shown, the forming tube 32 is welded and fixed to the original tunnel segment prefabrication template 31, and a reserved buckle hole 321 is provided on it at the position of the fixing buckle 13 of the tunnel segment 1 for the fixing buckle 13 to pass through.

[0050] Reference Figure 1 , Figure 8-9 A preferred embodiment of the present invention also provides a method for sealing and grouting the gap behind the segment annular wall, comprising the following steps:

[0051] Tunnel segment 1 preparation: Tunnel segment 1 as described above is prepared using the segment prefabrication mold 3, grouting bag 12 and multiple sets of fixing buckles 13 as described above;

[0052] Testing of segment ring assembly and back wall gap sealing performance;

[0053] On-site segment ring assembly, backfilling and grouting.

[0054] In the method for sealing and grouting the gap behind the tunnel segment ring wall of the present invention, the tunnel segment 1 is prepared by using the precast mold 3, grouting bag 12 and multiple sets of fixing buckles 13 as described above. Then, the tunnel segment 1 is used for on-site assembly of the segment ring and sealing and grouting the gap behind the wall. Thus, the method of the present invention can not only achieve the sealing of the gap between the segment ring and the surrounding rock 2 of the tunnel, avoiding the problems of non-sealing between the shield tail brush and the segment and grout leakage caused by wear of the structure used to seal the gap between the segment and the surrounding rock on the shield machine during conventional TBM / shield tunnel construction, but also reduce the consumption of grouting materials, reduce resource waste and improve economic efficiency. At the same time, the expanded bag ring between two adjacent segment rings can also form a sealed secondary grouting area, forming the closed environment required for high-pressure grouting, thereby enhancing the fullness and grouting effect of secondary grouting, improving the grouting effect behind the wall, and enhancing the overall bearing capacity of the tunnel lining. Moreover, the high-pressure grouting environment can enhance the grouting effect of the surrounding rock fissures, and improve the overall waterproofing effect and construction quality of the tunnel.

[0055] Optionally, such as Figure 10 As shown, the "testing of sealing performance of the gap behind the wall" in the step "assembly of segment rings and sealing performance of the gap behind the wall" specifically includes the following:

[0056] The smoothness of the connection of the pre-cast grooves of the tunnel segments in the same ring is tested to ensure that after the subsequent grouting of the grouting bags 12 expands, all the grouting bags 12 in the same ring are connected to form a bag ring, thereby ensuring the sealing effect of the gap between the segment ring and the tunnel surrounding rock 2 wall.

[0057] The folding condition of the grouting bag is checked. When the grouting bag 12 is folded, it is always within the pre-set groove 111 to avoid it from being punctured by the shield tail brush and causing the grouting bag 12 to fail.

[0058] The fastening characteristics of the grouting bag buckle were tested, and the grouting bag 12 was reliably fixed to the tunnel segment 1 to prevent the grouting bag 12 from loosening and causing the gap sealing failure.

[0059] The expansion characteristics of the grouting bag and the sealing performance of the gap behind the segment ring wall were tested. The reliability of using the grouting bag 12 to seal the gap between the segment ring and the surrounding rock 2 of the tunnel to carry out secondary grouting and compaction filling was verified.

[0060] In this optional solution, by setting the above steps, it can be ensured that all tunnel segments 1 delivered to the project site are qualified and meet the construction requirements. This solves the technical problems existing in the prior art, such as "the problem of sealing the gap between the shield sealing ring and the surrounding rock has not been solved, and the newly added sealing grouting strip or pad will be destroyed by the shield tail brush, and in fact cannot seal the gap between the shield and the surrounding rock".

[0061] Optionally, such as Figure 10As shown, tunnel segments 1 that have passed factory inspection and meet the following requirements—smooth connection between the grouting bag 12 and the pre-set groove 111, complete placement of the grouting bag 12 within the pre-set groove 111 when folded, reliable connection and fixation between the grouting bag 12 and the tunnel segment body 11, and reliable expansion and sealing performance of the grouting bag 12 in the gap between the tunnel segment ring and the surrounding rock 2—are transported to the project site. The step "Project Site Segment Ring Assembly and Backwall Gap Sealing and Grouting" specifically includes the following steps:

[0062] The N-ring segments with pre-filled grouting bags 12 are assembled inside the annular cavity;

[0063] N+1 ring segment assembly, N ring segment grouting bag 12 grouting expansion until the gap between the segment ring and the tunnel surrounding rock 2 is completely sealed at the grouting bag 12 position;

[0064] N+2 ring segment assembly, N+1 ring segment grouting bag 12 grouting expansion until the gap between the segment ring and the tunnel surrounding rock 2 is completely sealed at the grouting bag 12 position.

[0065] N+3 ring segment assembly, N+2 ring segment grouting bag 12 grouting expansion until the gap between the segment ring and the surrounding rock 2 of the tunnel is completely sealed at the grouting bag 12 position, and secondary grouting to fill the gap behind the segment ring wall between N ring and N+1 ring.

[0066] N+4 ring segment assembly, N+3 ring segment grouting bag 12 grouting expansion until the gap between the segment ring and the surrounding rock 2 of the tunnel is completely sealed at the position of grouting bag 12, and the gap behind the segment ring wall between N+1 ring and N+2 ring segment is densely filled by secondary grouting.

[0067] Repeat the above cycle until the construction of the dense grouting and filling section behind the segment ring wall is completed.

[0068] In this alternative solution, the above construction steps are simple and easy to implement, and the construction quality of the dense grouting filling section behind the segment ring wall is good, which can effectively solve the above-mentioned technical problems existing in the prior art.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A segment ring, characterized in that, include: Hollow annular segment ring body, and multiple grouting bladders (12) for expansion after grouting filling. A pre-set groove (111) is machined on the outer ring surface of the segment ring body, which is concave and extends in a curved shape. Multiple grouting bags (12) are folded sequentially into the pre-set groove (111) along the extension direction of the pre-set groove (111), and the two grouting bags (12) are connected end to end. The grouting bags (12) are used to fill and expand after grouting and squeeze out of the pre-set groove (111) to seal the gap between the segment ring and the surrounding rock (2) of the tunnel. The segment ring body is assembled from multiple segment bodies (11) arranged sequentially along its circumference, and the pre-set grooves (111) on the outer ring surface of the multiple segment bodies (11) are smoothly connected to form a concave curved ring groove; a grouting bag (12) is folded inside the pre-set groove (111) on the outer ring surface of each segment body (11), and the grouting bag (12) and the corresponding segment body (11) are combined to form a tunnel segment (1) as a segment ring unit. Each tunnel segment (1) also includes multiple sets of fixing buckles (13); multiple sets of fixing buckles (13) are arranged sequentially at intervals along the extension direction of the pre-set groove (111), and the fixing end of each fixing buckle (13) is pre-embedded in the segment body (11), and its opposite connecting end extends into the pre-set groove (111) to connect and fix the grouting bag (12); two sets of fixing buckles (13) are respectively set at both ends of the pre-set groove (111) to tighten and fix the two ends of the grouting bag (12), and the remaining sets of fixing buckles (13) are arranged sequentially at intervals along the length direction of the pre-set groove (111); The grouting bag (12) includes a bag body (121) for expansion after grouting and a plurality of pull rings (122) connected sequentially and at intervals along the length of the bag body (121); the bag body (121) is completely folded into the pre-set groove (111) before grouting; the fixing buckle (13) is in the shape of an inverted "U", its closed end is pre-embedded in the segment body (11), and its two opposite connecting sections extend into the pre-set groove (111) to be tightened with the pull rings (122) at the corresponding positions; The grouting bag (12) also includes a bag grouting pipe (123) connected to the bag body (121) for grouting material to enter the bag body (121); a bag grouting hole (112) is provided in the pre-set groove (111) corresponding to the bag grouting pipe (123) and penetrates the segment body (11); after the bag grouting pipe (123) passes through the bag grouting hole (112), it is fixed to the inner ring surface of the segment body (11) by fasteners; the segment body (11) is also provided with a wall-mounted grouting hole (113) that penetrates the body and is used for grouting material to fill the gap between the segment ring and the surrounding rock (2) between the adjacent two ring grouting bags (12).

2. The segment ring according to claim 1, characterized in that, Each tunnel segment (1) also includes a sealing strip (14), which is attached to the outer ring surface of the segment body (11) along the extension direction of the pre-set groove (111) to seal the grouting bag (12) inside the pre-set groove (111).

3. A precast segment mold, characterized in that, For prefabricating the segment body (11) as described in claim 2, the segment prefabrication mold (3) includes: The original tunnel segment prefabrication template (31) extends in an arc, and the forming tube (32) is used to form the pre-set groove (111) on the segment body (11). The forming tube (32) is fixed on the arc surface of the original tunnel segment prefabrication template (31) and extends in a curved shape along the arc surface extension direction of the original tunnel segment prefabrication template (31). The forming tube (32) is welded and fixed to the original tunnel segment prefabrication template (31), and a reserved buckle hole (321) is provided on it at the position of the fixing buckle (13) of the tunnel segment (1) for the fixing buckle (13) to pass through.

4. A method for sealing and grouting the gap behind the segment annular wall, characterized in that, Includes the following steps: Tunnel segment (1) preparation: Tunnel segment (1) is prepared using the segment prefabrication mold (3), grouting bag (12) and multiple sets of fixing buckles (13) as described in claim 3. Testing of segment ring assembly and back wall gap sealing performance; On-site segment ring assembly, backfilling and grouting.

5. The method for sealing and grouting the gap behind the segment annular wall according to claim 4, characterized in that, In the step "Segment Ring Assembly and Backwall Gap Sealing Performance Test", the "Backwall Gap Sealing Performance Test" specifically includes: the following: Smoothness test of the connection between pre-installed slots for tunnel segments in the same ring tunnel; Inspection of the folding condition of the grouting bag; Inspection of the fastening properties of the grouting bag buckles; Inspection of the expansion characteristics of the grouting bag and the sealing performance of the gap behind the segment ring wall.

6. The method for sealing and grouting the gap behind the segment annular wall according to claim 4, characterized in that, The step "On-site segment ring assembly, back wall gap sealing, and grouting" specifically includes the following steps: The N-ring segments with pre-filled grouting bags (12) are assembled inside the annular cavity; The N+1 ring segment is assembled, and the N ring segment grouting bag (12) is grouted and expanded until the gap between the segment ring and the tunnel surrounding rock (2) is completely sealed at the position of the grouting bag (12). The N+2 ring segment is assembled, and the N+1 ring segment grouting bag (12) is grouted and expanded until the gap between the segment ring and the tunnel surrounding rock (2) is completely sealed at the position of the grouting bag (12). The N+3 ring segment is assembled, and the N+2 ring segment grouting bag (12) is grouted and expanded until the gap between the segment ring and the tunnel surrounding rock (2) is completely sealed. The gap between the N ring and the N+1 ring segment ring wall is filled with secondary grouting. The N+4 ring segments are assembled, and the N+3 ring segments are grouted and expanded to the position of the grouting bag (12) until the gap between the segment ring and the surrounding rock (2) of the tunnel is completely sealed. The gap between the N+1 ring and the N+2 ring segments behind the wall is filled with grout in a second time. Repeat the assembly pattern of the previous segment ring until the construction of the grouting and filling section behind the segment ring wall is completed.

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