Shield tunnel invert block structure under steep longitudinal slope conditions

Abstract

This disclosure relates to the field of tunnel construction technology and provides a shield tunnel invert block structure under conditions of steep longitudinal slope. The shield tunnel invert block structure includes: multiple shield segments and multiple precast blocks. The shield segments include first segments and multiple second segments. The first segments have first fixing holes and second fixing holes, which are spaced apart circumferentially. The multiple precast blocks correspond one-to-one with the multiple shield segments. The precast blocks are disposed on the inner surface of the first segments and have fixing through holes penetrating the precast blocks vertically. The multiple precast blocks include adjacent first and second precast blocks. The fixing through holes of the first precast blocks are aligned with the first fixing holes and fixed with fastening bolts. The fixing through holes of the second precast blocks are aligned with the second fixing holes and fixed with fastening bolts. The shield tunnel invert block structure provided by this disclosure significantly reduces the risk of water leakage during tunnel operation.

Description

Technical Field

[0001] This disclosure relates to the field of tunnel construction technology, and in particular to a shield tunnel invert block structure under conditions of large longitudinal slope. Background Technology

[0002] During the construction of a circular shield tunnel, a platform needs to be set up at the bottom as a transportation channel to ensure the supply of segments, materials, etc., which is usually made by installing prefabricated tunnel segments.

[0003] However, for shield tunnels such as coal mine shafts (typically with a slope of 6° or more than 10.3%), the slope is much greater than that of conventional traffic tunnels, resulting in poor stability of the tunnel components and a high risk of downward swaying and instability.

[0004] Currently, the most common approach is to use inverted arch blocks instead of the aforementioned opening components. This means that the platform is set up during the shield assembly. However, since the inverted arch blocks are different in form from other segments, and they can only be located at the bottom of the shield, it should be noted that during the shield assembly process, both the inverted arch blocks and other segments are prefabricated blocks with fixed shapes and sizes. Because the inverted arch blocks can only be located at the bottom of the shield, the installation angle and position of the inverted arch blocks and other segments are fixed, which can easily lead to longitudinal joint penetration (i.e., "through joint"), greatly increasing the risk of water leakage during tunnel operation. Summary of the Invention

[0005] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, the present invention provides a shield tunnel inverted arch block structure under conditions of large longitudinal slope.

[0006] This application provides a shield tunnel invert block structure under a large longitudinal slope condition, comprising: multiple shield tunnel segments arranged sequentially in the longitudinal direction of the tunnel, each shield tunnel segment including a first segment and multiple second segments, the first segment and multiple second segments forming a ring, the first segment having a first fixing hole and a second fixing hole, both the first fixing hole and the second fixing hole being recessed from a portion of the inner surface of the first segment towards the outer surface, the first fixing hole and the second fixing hole being spaced apart circumferentially on the shield tunnel segment; multiple precast blocks, each precast block corresponding one-to-one with the multiple shield tunnel segments, the precast blocks being disposed on the inner surface of the first segment, each precast block having a fixing through hole penetrating the precast block in the vertical direction, the multiple precast blocks including adjacent first precast blocks and second precast blocks, the fixing through hole of the first precast block being aligned with the first fixing hole and fixed by a hoop bolt, the fixing through hole of the second precast block being aligned with the second fixing hole and fixed by a fastening bolt; wherein, the upper surfaces of the multiple precast blocks are coplanar.

[0007] According to the shield tunnel invert block structure under large longitudinal slope conditions provided in the embodiments of this application, the shield segment corresponding to the first precast block needs to be rotated at an angle relative to the shield segment corresponding to the second precast block, which realizes the misalignment of the joints between adjacent shield segments. Here, the joint refers to the joint between the first segment and the second segment, or the joint between the second segments, which avoids the phenomenon of longitudinal joint penetration and greatly reduces the risk of water leakage during tunnel operation.

[0008] In one possible implementation of this application, the first segment is further provided with a third fixing hole, and the third fixing hole, the first fixing hole and the second fixing hole are arranged at intervals in the circumferential direction of the shield segment.

[0009] In one possible implementation of this application, the third fixing hole, the first fixing hole, and the second fixing hole are evenly spaced around the shield tunnel segment.

[0010] In one possible implementation of this application, the shield tunnel invert block structure under steep longitudinal slope conditions includes: a leveling layer, which is disposed between the precast block and the first segment.

[0011] In one possible implementation of this application, the lower surface of the precast block is provided with a support portion.

[0012] In one possible implementation of this application, there are multiple support portions, which are spaced apart in the circumferential direction of the tunnel segment.

[0013] In one possible implementation of this application, the cross-sectional area of ​​the support portion is reduced in the direction of the precast block toward the first segment.

[0014] In one possible implementation of this application, the first precast block is provided with a first bent hole, one end of which penetrates the upper surface of the first precast block and the other end of which penetrates the side surface of the first precast block facing the second precast block. The second precast block is provided with a second bent hole, one end of which penetrates the upper surface of the second precast block and the other end of which penetrates the side surface of the second precast block facing the first precast block and is aligned with the first bent hole. The shield tunnel inverted arch block structure under the large longitudinal slope condition further includes: bent bolts, which are sequentially inserted into the first bent hole and the second bent hole.

[0015] In one possible implementation of this application, the prefabricated block includes a first side block, a middle block, and a second side block connected in sequence in the width direction, and the fixing through hole is provided in the middle block.

[0016] In one possible implementation of this application, the leveling layer is a cement mortar leveling layer. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the shield tunnel inverted arch block structure under a large longitudinal slope condition provided for some embodiments of this application;

[0020] Figure 2 for Figure 1 A schematic cross-sectional view of the shield tunnel inverted arch block structure shown in the figure;

[0021] Figure 3 for Figure 1 A top view of the multiple prefabricated blocks described herein;

[0022] Figure 4 for Figure 3 A top view of a prefabricated block shown in the image;

[0023] Figure 5 for Figure 3 The diagram shows a cross-sectional view of the locations of adjacent precast blocks.

[0024] Figure label:

[0025] 100. Shield tunnel invert block structure; 111. First segment; 1111. First fixing hole; 1112. Second fixing hole; 1113. Third fixing hole; 112. Second segment; 120. Precast block; 121. Fixing through hole; 122. First bend hole; 123. Second bend hole; 124. Support part; 130. Leveling layer; 140. Bent bolt. Detailed Implementation

[0026] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0027] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0028] During the construction of a circular shield tunnel, a platform needs to be set up at the bottom as a transportation channel to ensure the supply of segments, materials, etc., which is usually made by installing prefabricated tunnel segments.

[0029] However, for shield tunnels such as coal mine shafts (typically with a slope of 6° or more than 10.3%), the slope is much greater than that of conventional traffic tunnels, resulting in poor stability of the tunnel components and a high risk of downward swaying and instability.

[0030] Currently, the most common approach is to use inverted arch blocks instead of the aforementioned opening components. This means that the platform is set up during the shield assembly. However, since the inverted arch blocks are different in form from other segments, and they can only be located at the bottom of the shield, it should be noted that during the shield assembly process, both the inverted arch blocks and other segments are prefabricated blocks with fixed shapes and sizes. Because the inverted arch blocks can only be located at the bottom of the shield, the installation angle and position of the inverted arch blocks and other segments are fixed, which can easily lead to longitudinal joint penetration (i.e., "through joint"), greatly increasing the risk of water leakage during tunnel operation.

[0031] To resolve the above technical issues, please refer to Figures 1 to 5 This application provides a shield tunnel invert block structure 100 under a large longitudinal slope condition. The shield tunnel invert block structure 100 may include multiple shield segments and multiple precast blocks 120.

[0032] In this system, multiple shield tunnel segments are sequentially arranged along the longitudinal direction of the tunnel. The shield tunnel segments include a first segment 111 and multiple second segments 112. The first segment 111 and multiple second segments 112 are arranged in a ring shape. Both the second segments 112 and the first segment 111 are formed into arc-shaped segments. In the specific implementation process, the multiple second segments 112 can be arc-shaped segments of the same size or arc-shaped segments of different sizes. For example, the multiple second segments 112 include two standard blocks, two adjacent blocks and one capping block. The first segment 111, standard blocks, adjacent blocks, capping blocks, adjacent blocks and standard blocks are sequentially connected to form a ring-shaped shield tunnel segment. The multiple shield tunnel segments are sequentially arranged along the longitudinal direction of the tunnel to form the tunnel perimeter. The first segment 111 is located at the lower part of the shield tunnel segment.

[0033] The first segment 111 is provided with a first fixing hole 1111 and a second fixing hole 1112. The first fixing hole 1111 and the second fixing hole 1112 are both formed by a portion of the inner surface of the first segment 111 recessed towards the outer surface. The first fixing hole 1111 and the second fixing hole 1112 are arranged at intervals around the circumference of the shield segment.

[0034] Multiple precast blocks 120 correspond one-to-one with multiple shield tunnel segments. The precast blocks 120 are located on the inner surface of the first tunnel segment 111. Each precast block 120 has a fixing through hole 121 that penetrates through the precast block in the vertical direction. The multiple precast blocks 120 include adjacent first precast blocks and second precast blocks. The fixing through hole 121 of the first precast block is aligned with the first fixing hole 1111 and fixed by a hoop bolt. The fixing through hole 121 of the second precast block is aligned with the second fixing hole 1112 and fixed by a hoop bolt. The upper surfaces of the multiple precast blocks 120 are coplanar for the passage of the shield tunneling equipment.

[0035] It should be noted that, taking the fixing through hole 121 located at the center of the precast block 120 (i.e., the center of the length and width of the precast block 120) as an example, since the fixing through hole 121 of the first precast block is aligned with the first fixing hole 1111, and the fixing through hole 121 of the second precast block is aligned with the second fixing hole 1112, and the first fixing hole 1111 and the second fixing hole 1112 are spaced apart in the circumferential direction, and the upper surfaces of the multiple precast blocks 120 are coplanar, the first fixing hole 1111 of the first segment 111 corresponding to the first precast block extends in the vertical direction, and the second... The second fixing hole 1112 of the first segment 111 corresponding to the precast block extends in the vertical direction. In order to meet the position requirements of the first precast block and the second precast block, the shield segment corresponding to the first precast block needs to be rotated at an angle relative to the shield segment corresponding to the second precast block so that the first fixing hole 1111 corresponding to the fixing through hole 121 of the first precast block and the second fixing hole 1112 corresponding to the fixing through hole 121 of the second precast block are arranged opposite to each other in the longitudinal direction, thereby satisfying that the upper surface of the first precast block and the upper surface of the second precast block are coplanar.

[0036] It can be understood that the shield segment corresponding to the first precast block needs to be rotated at an angle relative to the shield segment corresponding to the second precast block, which achieves the misalignment of the joints between adjacent shield segments. The joints refer to the joints between the first segment 111 and the second segment 112, or the joints between the second segments 112. This avoids the phenomenon of longitudinal joint penetration, which greatly reduces the risk of water leakage during tunnel operation.

[0037] Taking a tunnel segment and precast block 120 as an example, the number of adjacent precast blocks 120 can be the first precast block 120 and the second precast block 120, or the second precast block 120 and the third precast block 120, or the third precast block 120 and the fourth precast block 120, or the fourth precast block 120 and the fifth precast block 120.

[0038] That is, the joints between the first and second shield tunnel segments can be staggered, the joints between the second and third shield tunnel segments can also be staggered, the joints between the third and fourth shield tunnel segments can also be staggered, and the joints between the fourth and fifth shield tunnel segments can also be staggered.

[0039] In some embodiments of this application, the first tunnel segment 111 is further provided with a third fixing hole 1113, and the third fixing hole 1113, the first fixing hole 1111 and the second fixing hole 1112 are arranged at intervals in the circumferential direction of the shield tunnel segment.

[0040] It is understandable that by setting the third fixing hole 1113, the fixing through hole 121 can be directly opposite the first fixing hole 1111, the second fixing hole 1112, or the third fixing hole 1113. This increases the selection of the rotation angle of the shield tunnel segments, allowing the joints of the connected shield tunnel segments to be misaligned at different angles, further reducing the risk of water leakage during tunnel operation.

[0041] Furthermore, the third fixing hole 1113, the first fixing hole 1111, and the second fixing hole 1112 are evenly spaced around the shield tunnel segment.

[0042] In the specific implementation process, the included angle between the third fixing hole 1113 and the first fixing hole 1111 can be 5°, and the included angle between the first fixing hole 1111 and the second fixing hole 1112 is also 5°. In this way, the misalignment angle between two adjacent shield tunnel segments can be 5° or 10°. The construction personnel can choose the appropriate misalignment angle according to the actual situation.

[0043] Furthermore, a fourth fixing hole may be provided on the first segment 111. The fourth fixing hole, the third fixing hole 1113, the first fixing hole 1111, and the second fixing hole 1112 are evenly spaced around the shield segment.

[0044] In some embodiments of this application, please refer to Figure 3 The shield tunnel invert block structure 100 under the condition of large longitudinal slope can also include a leveling layer 130, which is located between the precast block 120 and the first segment 111.

[0045] In the specific implementation process, the leveling layer 130 can be a cement mortar leveling layer 130. Therefore, by setting the leveling layer 130, the unevenness of the contact surface between the precast block 120 and the first segment 111 can be avoided, ensuring the stability of the connection between the precast block 120 and the first segment 111.

[0046] In some embodiments of this application, the lower surface of the precast block 120 is provided with a support portion 124.

[0047] It should be noted that, taking the leveling layer 130 as a cement mortar leveling layer 130 as an example, by setting the support part 124, it can be ensured that the upper transport load can be effectively transferred to the shield tunnel segment structure during the cement mortar solidification period, ensuring uninterrupted construction and improving efficiency.

[0048] In the specific implementation process, there are multiple support parts 124, which are spaced apart in the circumferential direction of the shield tunnel segment. Specifically, there can be 2, 3 or 4 support parts 124.

[0049] In this way, by setting multiple support parts 124, the load transfer between the precast block 120 and the first segment 111 can be further guaranteed during the solidification of cement mortar.

[0050] Furthermore, in the direction of the precast block 120 toward the first segment 111, the cross-sectional area of ​​the support portion 124 is reduced.

[0051] In the specific implementation process, the contact surface between the support part 124 and the first segment 111 can be set with an arc. This can ensure the load transfer between the precast block 120 and the first segment 111, avoid the support part 124 occupying too much area of ​​the leveling layer 130, and avoid the situation of scratches between the support part 124 and the first segment 111.

[0052] In some embodiments of this application, the first precast block is provided with a first bent hole 122, one end of the first bent hole 122 penetrates the upper surface of the first precast block, and the other end penetrates the side surface of the first precast block facing the second precast block. The second precast block is provided with a second bent hole 123, one end of the second bent hole 123 penetrates the upper surface of the second precast block, and the other end penetrates the side surface of the second precast block facing the first precast block and is aligned with the first bent hole 122. The shield tunnel inverted arch block structure 100 under the condition of large longitudinal slope also includes: bent bolts 140, which are sequentially inserted into the first bent hole 122 and the second bent hole 123.

[0053] Thus, by setting mutually cooperating bent bolts 140, first bent holes 122 and second bent holes 123, the first precast block and the second precast block are connected and fixed in the longitudinal direction.

[0054] It is understandable that, in the specific implementation process, adjacent precast blocks 120 can be fixedly connected by means of bent bolts 140, first bent holes 122 and second bent holes 123.

[0055] Among them, the 140 bent bolts can be M30 bolts, the bolt product grade is C, the bolt sleeve is made of polyamide material, and the pull-out force is not less than 350kN; the mechanical performance grade of the bolt is 6.8, the mechanical performance grade of the nut is 6.0, the washer is a steel washer, and the hardness grade is Hv=100.

[0056] In the specific implementation process, in the width direction of the precast block 120, the precast block 120 includes a first side block, a middle block and a second side block connected in sequence. The fixed through hole 121 is provided in the middle block. The first bent hole 122 and the second bent hole 123 can be provided in the first side block or the second side block, or the first side block and the second side block are provided with two sets of first bent holes 122 and second bent holes 123.

[0057] In the specific construction process, the precast block 120 uses C35 or higher grade concrete. Its transverse length is determined in combination with the width requirements of the transport vehicles during construction and is less than the transverse length of the first segment 111. The longitudinal length corresponds to the ring width of the shield segment, and a 10mm gap is set at both ends to meet the assembly requirements of the invert arch block for curved construction. The height must meet the clearance requirements of the shield tunnel and a leveling layer 130 of a certain thickness is reserved.

[0058] After the cement mortar of the first segment 111 and the precast block 120 reaches the design strength, additional grouting is performed through the two transverse ends of the precast block 120 and the longitudinal 20mm gap to fill the holes and the gaps between the precast blocks 120 in the longitudinal direction, ensuring the compactness and uniform stress between the first segment 111 and the precast block 120, and meeting the requirements of tunnel operation.

[0059] After the tunnel lining segments are assembled and the precast blocks 120 are installed, a plain concrete layer is poured on top of the precast blocks 120 for leveling. A crack-resistant steel mesh with a diameter of Φ6mm and a spacing of 150×150mm is installed on the surface of the plain concrete layer. Expansion joints are provided in the concrete layer, with a joint width of 20mm and a maximum length of 20m along the longitudinal direction of the tunnel lining.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0061] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments described herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A shield tunnel invert block structure under steep longitudinal slope conditions, characterized in that, include: Multiple shield tunnel segments are arranged sequentially along the longitudinal direction of the tunnel. Each shield tunnel segment includes a first segment and multiple second segments. The first segment and multiple second segments are arranged in a ring. The first segment is provided with a first fixing hole and a second fixing hole. Both the first fixing hole and the second fixing hole are recessed from a portion of the inner surface of the first segment toward the outer surface. The first fixing hole and the second fixing hole are arranged at intervals in the circumferential direction of the shield tunnel segment. Multiple precast blocks, each corresponding to a shield tunnel segment, are disposed on the inner surface of the first segment. Each precast block has a fixing through hole extending through the precast block in the vertical direction. The multiple precast blocks include adjacent first and second precast blocks. The fixing through hole of the first precast block is aligned with the first fixing hole and fixed by a hoop bolt. The fixing through hole of the second precast block is aligned with the second fixing hole and fixed by a fastening bolt. The first precast block is provided with a first bent hole, one end of which penetrates the upper surface of the first precast block and the other end of which penetrates the side surface of the first precast block facing the second precast block. The second precast block is provided with a second bent hole, one end of which penetrates the upper surface of the second precast block and the other end of which penetrates the side surface of the second precast block facing the first precast block and is aligned with the first bent hole. The shield tunnel invert block structure under the condition of steep longitudinal slope also includes: A bent bolt, wherein the bent bolt is sequentially inserted into the first bent hole and the second bent hole; The upper surfaces of the multiple prefabricated blocks are coplanar.

2. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 1, characterized in that, The first segment is also provided with a third fixing hole, and the third fixing hole, the first fixing hole and the second fixing hole are arranged at intervals around the shield segment.

3. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 2, characterized in that, The third fixing hole, the first fixing hole, and the second fixing hole are evenly spaced around the circumference of the shield tunnel segment.

4. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 1, characterized in that, include: A leveling layer is provided between the precast block and the first segment.

5. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 4, characterized in that, The lower surface of the precast block is provided with a support.

6. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 5, characterized in that, The number of the support parts is multiple, and the multiple support parts are arranged at intervals in the circumferential direction of the shield tunnel segment.

7. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 5, characterized in that, In the direction of the precast block toward the first segment, the cross-sectional area of ​​the support portion decreases.

8. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 1, characterized in that, In the width direction of the prefabricated block, the prefabricated block includes a first side block, a middle block and a second side block connected in sequence, and the fixing through hole is provided in the middle block.

9. The shield tunnel invert block structure under steep longitudinal slope conditions according to claim 4, characterized in that, The leveling layer is a cement mortar leveling layer.

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