Device for testing anti-shearing mechanical property of joint between shield tunnel segment rings

Abstract

The invention discloses a device for testing the shear-resistant mechanical property of a joint between shield tunnel segment rings, which can better provide the actual constraint on the segment, consider the synergistic shear-resistant effect and the influence of the longitudinal force of the joint of the whole ring of segment, and study the shear-resistant mechanical property of the joint between the segment rings. And a powerful means is provided for researching inter-ring deformation problems such as tunnel slab staggering. The device is suitable for carrying out inter-ring shear-resistant loading tests on whole-ring shield tunnel segments with different diameters.

Description

Technical Field

[0001] This invention belongs to the field of structural mechanical performance testing, and in particular relates to a device for testing the shear mechanical properties of the inter-segment joints of shield tunnel segments. Background Technology

[0002] The lining structure of a shield tunnel is an assembled structure composed of reinforced concrete segments connected by bolts. The presence of numerous joints significantly weakens the overall integrity of the lining structure. Extensive practical testing and research in shield tunnel engineering have demonstrated that segment joints have become a significant weak link in the overall internal lining structure of shield tunnels. The internal stress-deformation characteristics of these joints largely determine the overall stress-deformation and structural bearing capacity of the entire shield tunnel ring structure. Current research on the mechanical properties of segment joints mainly focuses on the bending mechanical properties of local segment joints and the shear mechanical properties of local segment ring joints. Research on the shear mechanical properties of inter-ring joints of the entire shield tunnel is limited, and misalignment between tunnel rings is a common problem encountered in shield tunnel construction in my country. Excessive misalignment often leads to segment cracking, negatively impacting the tunnel's waterproofing and durability, and affecting the safe construction and normal operation of shield tunnel projects. Therefore, conducting shear tests on inter-ring joints of shield tunnel segments in the entire shield tunnel is of great significance for exploring the shear mechanical properties and misalignment of shield tunnel segment structures.

[0003] Currently, many engineers and scholars have conducted various designs and studies on shear loading devices for inter-ring joints in shield tunnel segments. Surveys show that shear loading devices for inter-ring joints in shield tunnel segments mainly include local inter-ring joint loading devices and full-ring inter-ring joint loading devices. Local inter-ring joint loading devices primarily study the shear mechanical properties of individual inter-ring joint units, failing to reflect the synergistic shear resistance effect of full-ring joints. Existing full-ring inter-ring joint loading devices do not consider the influence of longitudinal forces between segment rings on the inter-ring shear mechanical properties. However, longitudinal forces exist between tunnel rings during both the construction and operation phases of the shield tunnel, and these forces change continuously with time and space. During construction, the longitudinal forces between segment rings are larger, decreasing during operation. The final residual longitudinal force during operation accounts for approximately 20.4% to 44% of the jacking force during the tunneling stage. Longitudinal force has a significant impact on improving the shear mechanical properties of segment ring joints. Therefore, when designing shear loading devices for segment ring joints, it is necessary to consider both the synergistic shear mechanical effect of the entire ring segment ring joint and the influence of longitudinal force on shear mechanical properties.

[0004] Existing tunnel joint testing loading devices can only perform shear loading tests on partial segment-to-segment joints or on full-ring segment-to-segment joints without considering longitudinal forces. They cannot account for the synergistic shear effect of the full-ring segment-to-segment joints or accurately reflect the influence of longitudinal forces on the shear mechanical properties of the full-ring segment-to-segment joints. However, in actual engineering projects, the longitudinal forces between segment rings are real and constantly change with time and space. Current tunnel joint testing devices cannot guarantee better provision of constraint conditions at the segment ends, nor do they fully consider the synergistic shear effect of the full-ring segment joints and the enhancing effect of longitudinal forces on shear performance, thus failing to accurately reflect the shear mechanical properties of tunnel segment-to-segment joints. Summary of the Invention

[0005] To address the limitations of existing tunnel joint testing loading devices, which can only perform shear loading tests on partial segment inter-ring joints or fail to consider longitudinal forces in full-ring segment inter-ring loading tests, thus failing to account for the synergistic shear resistance effect of full-ring segment inter-ring joints or accurately reflect the influence of longitudinal forces on the shear mechanical properties of full-ring segment inter-ring joints, this invention proposes a device for testing the shear mechanical properties of shield tunnel segment inter-ring joints. This device ensures that the tunnel joint testing device better provides the constraint conditions at the segment ends, fully considers the synergistic shear resistance effect of the full-ring segment and the enhancing effect of longitudinal forces on shear resistance, and accurately reflects the shear mechanical properties of tunnel segment inter-ring joints.

[0006] According to a first aspect of the embodiments of this application, an apparatus for testing the shear mechanical properties of the interlocking joints of shield tunnel segments is provided, comprising: The fixing unit includes a steel beam fixing support, an I-beam, an upper segment fixing support, a lower segment fixing support, and a frame. The steel beam fixing support is installed on the frame, and the I-beam is vertically mounted on the top of the steel beam fixing support. The upper segment fixing support and the lower segment fixing support are respectively installed on the frame and the I-beam, and the two cooperate to fix the test segment. The loading unit includes a loading curved plate, a lower hydraulic jack, and a side hydraulic jack. The loading curved plate is used to provide a loading surface for the test tube segment. The lower hydraulic jack is used to adjust the height of the loading curved plate and apply shear force to the test tube segment. The side hydraulic jack is used to apply longitudinal force to the test tube segment. The reaction unit includes a reaction beam and a segment fixing plate. The segment fixing plate includes a polytetrafluoroethylene plate and a reaction plate. The reaction beam is slidably connected to the frame. The reaction plate is installed on the reaction beam to provide lateral reaction support for the test segment. The polytetrafluoroethylene plate is disposed between the reaction plate and the test segment.

[0007] Furthermore, it also includes a hydraulic jack control console, which is used to control the lower hydraulic jack and the side hydraulic jack.

[0008] Furthermore, the steel beam fixing support is provided with several holes of different heights, and the I-beam can be installed on the steel beam fixing support in a lifting and lowering manner through the holes of different heights.

[0009] Furthermore, the surface shape of the loading plate is matched with that of the test tube segment.

[0010] Furthermore, a sliding groove is provided between the frame and the reaction plate, allowing the reaction plate to slide freely on the frame. The reaction beam is connected to the frame by bolts to fix the reaction plate.

[0011] Furthermore, the upper segment fixing support and the lower segment fixing support are made of concrete, while the steel beam fixing support, I-beam, loading curved plate, reaction beam, and reaction plate are made of steel.

[0012] Furthermore, two grooves matching the dimensions of the lower hydraulic jack are made on the outer side of the loading plate.

[0013] According to a second aspect of the embodiments of this application, a method for testing the shear mechanical properties of the interlocking joints of shield tunnel segments is provided, comprising: Connect the two half-ring full-scale test segments together, place the connected test segments on the loading curved plate and the lower segment fixing support, and adjust the loading curved plate to the same height as the lower segment fixing support by controlling the lower hydraulic jack through the hydraulic jack control console. Place the upper segment fixing support on the upper part of one side of the fixed segment end, and adjust the I-beam to a suitable height so that it naturally contacts the upper part of the upper fixing support of the segment. Slide the reaction plate to a suitable position on the frame and make contact with the side of the test tube segment. Place a polytetrafluoroethylene plate between the contact points and fix it to the frame with bolts. Adjust the side hydraulic jacks according to the radius of the test tube segment using the hydraulic jack control console so that the center of the jacks corresponds to the center of the thickness of the test tube segment. The placement and position adjustment of the test tube segment are now complete, and it is ready to be loaded. First, a longitudinal force is applied by controlling the hydraulic jacks on the control side via the hydraulic jack console to load them to the set test longitudinal force; then, the shear force is applied step by step by the hydraulic jacks on the control console to complete the study of the shear mechanical properties of the ring-to-ring joint of the entire tunnel segment.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. Considering the size of the test tube segment, an adjustable longitudinal force loading mechanism is adopted. The position of the hydraulic jack and the reaction plate can be adjusted according to the radius and width of the test tube segment, so that the hydraulic jack and the reaction plate are in close contact with the side of the tube segment, thereby applying longitudinal force. It has a wide range of applications. Second, the whole-ring segment test was adopted to simulate the mutual influence between segments in actual tunnel lining, fully reflecting the synergistic shear resistance effect of the whole-ring segment joint, making the test more accurate and reasonable; Third, the test loading device provided by this patent can better provide constraints on the ends of tunnel segments and apply longitudinal forces between rings, making the test results more accurate and reliable.

[0015] In summary, this loading device can better provide the actual constraints on the tunnel segments, considering the synergistic shear resistance effect of the segment joints and the influence of longitudinal forces, and study the shear mechanical properties of the segment joints. This provides a powerful tool for studying inter-ring deformation problems such as tunnel misalignment. This device is suitable for conducting inter-ring shear loading tests on tunnel segments of different diameters, providing a reference for the study of inter-ring deformation problems such as misalignment encountered in tunnel construction.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

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

[0018] Figure 1 This is a schematic diagram of a device for testing the shear mechanical properties of the inter-segment joint of shield tunnel segments according to the present invention, wherein (a) is an isometric view and (b) is a front view.

[0019] Figure 2 This is a schematic diagram of the longitudinal force loading structure of a hydraulic jack.

[0020] Figure 3 This is a schematic diagram of the segment fixing plate structure. Detailed Implementation

[0021] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application.

[0022] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The singular forms “a,” “the,” and “the” used in this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0023] It should be understood that although the terms first, second, third, etc., may be used in this application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, without departing from the scope of this application, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0024] To address the limitations of existing tunnel joint testing loading devices, which can only perform shear loading tests on partial segment inter-ring joints or fail to consider longitudinal forces in full-ring segment inter-ring loading tests, thus failing to account for the synergistic shear resistance effect of full-ring segment inter-ring joints or accurately reflect the influence of longitudinal forces on the shear mechanical properties of full-ring segment inter-ring joints, this invention proposes a device for testing the shear mechanical properties of shield tunnel segment inter-ring joints. This device ensures that the tunnel joint testing device better provides the constraint conditions at the segment ends, fully considers the synergistic shear resistance effect of the full-ring segment and the enhancing effect of longitudinal forces on shear resistance, and accurately reflects the shear mechanical properties of tunnel segment inter-ring joints.

[0025] like Figure 1 As shown, the device provided in this application for testing the shear mechanical properties of shield tunnel segment ring joints may include: The fixing unit includes a steel beam fixing support 1, an I-beam 2, an upper segment fixing support 7, a lower segment fixing support 8, and a frame 9. The steel beam fixing support 1 is installed on the frame 9. The I-beam 2 is vertically mounted on the top of the steel beam fixing support 1. The upper segment fixing support 7 and the lower segment fixing support 8 are respectively installed on the frame 9 and the I-beam 2, and the two cooperate to fix the test segment. The loading unit includes a loading curved plate 3, a lower hydraulic jack 4, and a side hydraulic jack 13. The loading curved plate 3 is used to provide a loading surface for the test tube segment. The lower hydraulic jack 4 is used to adjust the height of the loading curved plate 3 and apply shear force to the test tube segment. The side hydraulic jack 13 is used to apply longitudinal force to the test tube segment. The reaction unit includes a reaction beam 6 and a segment fixing plate. The segment fixing plate includes a polytetrafluoroethylene plate 11 and a reaction plate 12. The reaction beam 6 is slidably connected to the frame 9. The reaction plate 12 is installed on the reaction beam 6 to provide lateral reaction support for the test segment. The polytetrafluoroethylene plate 11 is disposed between the reaction plate 12 and the test segment.

[0026] In a specific implementation, the device also includes a hydraulic jack control console 10, which is used to control the lower hydraulic jack 4 and the side hydraulic jack 13.

[0027] In this device, the frame 9 is the main frame of the entire device, used to install and fix other components, and to provide stable support for the test; the steel beam fixing support 1 serves as the fixing foundation of the I-beam 2 and is connected to the I-beam 2 by bolts 5. In order to achieve the adjustability of the I-beam 2, multiple holes of different heights need to be set on the steel beam fixing support 1 so that the I-beam 2 can be installed at different heights.

[0028] In specific implementation, the lower segment fixing support 8 is used to fix the lower part of the test segment. The loading curved plate 3 is adjusted in height by the lower hydraulic jack 4. After it is at the same height as the lower segment fixing support 8, it provides support and loading surface for the test segment. Its surface shape matches the test segment. The cooperation between the lower segment fixing support 8 and the loading curved plate 3 ensures stable support and uniform force transmission during the test. The upper segment fixing support 7 is installed below the I-beam 2 and cooperates with the lower segment fixing support 8 to fix and constrain the test segment, ensuring the stability of the segment position during loading. A sliding groove is provided between the frame 9 and the reaction plate 12, so that the reaction plate 12 can slide freely on the frame 9. The reaction beam 6 has bolt holes with the frame 9. Bolts 5 can be used to connect the reaction beam 6 to the frame 9 to fix the reaction plate 12.

[0029] After the reaction plate 12 slides to a suitable position on the frame 9 via the reaction beam 6, it contacts the side of the test tube segment. The friction of the tube segment sidewall is reduced by the polytetrafluoroethylene plate 11, which prevents the test tube segment from being subjected to additional bending moment. It is fixed with bolts to provide lateral reaction force support for the test.

[0030] like Figure 2 As shown, the side hydraulic jack 13 can slide along the sliding groove. When applying longitudinal force to the test tube segment, the side hydraulic jack 13 can be slid to a suitable position on the side of the tube segment and then the position of the side hydraulic jack 13 can be kept unchanged. The side hydraulic jack 13 is fixed with bolts 5.

[0031] like Figure 3 As shown, the segment fixing plate is mainly used to provide reaction force. After the test segment is assembled onto the instrument, the reaction plate 12 slides along the sliding groove of the frame 9 so that the polytetrafluoroethylene plate 11 is fully in contact with the side of the test segment. The reaction beam 6 is connected to the frame 9 using bolts 5 to fix the reaction plate 12. When the side hydraulic jack 13 applies longitudinal force to the side of the test segment, the polytetrafluoroethylene plate 11 provides reaction force. At the same time, the polytetrafluoroethylene plate 11 can also slide along the sliding groove.

[0032] In practice, the position of the side hydraulic jack 13 can be adjusted by the hydraulic jack control console 10 according to the radius of the test tube segment, so that the center of the jack roughly corresponds to the center of the thickness of the test tube segment, ensuring that the point of force application is accurate.

[0033] The polytetrafluoroethylene plate 11 is placed between the reaction plate 12 and the test tube segment. Utilizing its low coefficient of friction, it reduces the friction between the side wall of the tube segment and the reaction plate 12, ensuring that the test tube segment mainly bears the shear force and reducing the influence of other additional forces.

[0034] In the specific implementation, the upper segment fixing support 7 and the lower segment fixing support 8 are made of concrete, while the steel beam fixing support 1, the I-beam 2, the loading curved plate 3, the reaction beam 6, and the reaction plate 12 are made of steel. Two grooves of the appropriate size for the lower hydraulic jack 4 are made on the outer side of the loading curved plate 3 to allow the lower hydraulic jack 4 to better transmit force, first transmitting force to the loading curved plate 3, and then transmitting force from the loading curved plate to the test segment.

[0035] Based on the above-mentioned device, this application also provides a method for testing the shear mechanical properties of the interlocking joints of shield tunnel segments, which may include: First, connect the two half-ring full-scale test segments with bolts. Place the connected test segments on the loading curved plate 3 and the lower segment fixing support 8. The loading curved plate 3 is adjusted to the same height as the lower segment fixing support 8 by controlling the lower hydraulic jack 4 through the hydraulic jack control console 10. Then, place the upper segment fixing support 7 on the upper part of one side of the fixed segment end. Then, adjust the I-beam 2 to a suitable height so that it naturally contacts the upper part of the upper fixing support 7 of the segment. Finally, use bolts 5 to connect it to the steel beam fixing support 1. Slide the reaction plate 12 to a suitable position on the frame 9 and make contact with the side of the test tube segment. Place a polytetrafluoroethylene plate 11 between the contact points to reduce friction on the side wall of the tube segment and reduce or avoid additional bending moments on the test tube segment. Finally, fix it to the frame 9 with bolts 5. Adjust the side hydraulic jack 13 according to the radius of the test tube segment through the hydraulic jack control console 10 so that the center of the jack roughly corresponds to the center of the thickness of the test tube segment. The placement and position adjustment of the test tube segment are completed, and it is ready to be loaded.

[0036] First, a longitudinal force is applied by controlling the hydraulic jack 13 on the control side through the hydraulic jack control console 10 to load it to the set test longitudinal force; then, the shear force is applied step by step by the hydraulic jack 4 under the control of the hydraulic jack control console 10 to complete the study of the shear mechanical properties of the ring-to-ring joint of the entire ring segment.

[0037] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the disclosure herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein.

[0038] It should be understood that this application is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope.

Claims

1. A device for testing the shear mechanical properties of the inter-segment joints of shield tunnel segments, characterized in that, include: The fixing unit includes a steel beam fixing support (1), an I-beam (2), an upper segment fixing support (7), a lower segment fixing support (8), and a frame (9). The steel beam fixing support (1) is installed on the frame (9). The I-beam (2) is installed on the top of the steel beam fixing support (1) in a liftable manner. The upper segment fixing support (7) and the lower segment fixing support (8) are respectively installed on the frame (9) and the I-beam (2), and the two cooperate to fix the test segments. The loading unit includes a loading curved plate (3), a lower hydraulic jack (4), and a side hydraulic jack (13). The loading curved plate (3) is used to provide a loading surface for the test tube segment. The lower hydraulic jack (4) is used to adjust the height of the loading curved plate (3) and apply shear force to the test tube segment. The side hydraulic jack (13) is used to apply longitudinal force to the test tube segment. The reaction unit includes a reaction beam (6) and a segment fixing plate. The segment fixing plate includes a polytetrafluoroethylene plate (11) and a reaction plate (12). The reaction beam (6) is slidably connected to the frame (9). The reaction plate (12) is installed on the reaction beam (6) to provide lateral reaction support for the test segment. The polytetrafluoroethylene plate (11) is disposed between the reaction plate (12) and the test segment.

2. The apparatus according to claim 1, characterized in that, It also includes a hydraulic jack control console (10) for controlling the lower hydraulic jack (4) and the side hydraulic jack (13).

3. The apparatus according to claim 1, characterized in that, The steel beam fixed support (1) is provided with several holes of different heights, and the I-beam (2) can be installed on the steel beam fixed support (1) in a lifting and lowering manner through the holes of different heights.

4. The apparatus according to claim 1, characterized in that, The surface shape of the loading plate (3) is matched with the test tube segment.

5. The apparatus according to claim 1, characterized in that, A sliding groove is provided between the frame (9) and the reaction plate (12) so that the reaction plate (12) can slide freely on the frame (9). The reaction beam (6) is connected to the frame (9) by bolts to fix the reaction plate (12).

6. The apparatus according to claim 1, characterized in that, The upper segment fixing support (7) and the lower segment fixing support (8) are made of concrete, while the steel beam fixing support (1), the I-beam (2), the loading curved plate (3), the reaction beam (6), and the reaction plate (12) are made of steel.

7. The apparatus according to claim 1, characterized in that, Two grooves matching the size of the lower hydraulic jack (4) are made on the outside of the loading plate (3).

8. A method for testing the shear mechanical properties of the inter-segment joints of shield tunnel segments, characterized in that, include: Connect the two half-ring full-scale test segments together, place the connected test segments on the loading curved plate (3) and the lower segment fixing support (8), and adjust the loading curved plate (3) to the same height as the lower segment fixing support (8) by controlling the lower hydraulic jack (4) through the hydraulic jack control console (10). Place the upper segment fixing support (7) on the upper part of one side of the fixed segment end, and adjust the I-beam (2) to a suitable height so that it naturally contacts the upper part of the upper segment fixing support (7). Slide the reaction plate (12) to a suitable position on the frame (9) and make contact with the side of the test tube segment. Place a polytetrafluoroethylene plate (11) between the contact points and fix it to the frame (9) with bolts. Adjust the side hydraulic jack (13) through the hydraulic jack control console (10) according to the radius of the test tube segment so that the center of the jack corresponds to the center of the thickness of the test tube segment. The placement and position adjustment of the test tube segment are completed and ready for loading. First, a longitudinal force is applied, and the hydraulic jack (13) is controlled by the hydraulic jack control console (10) to load it to the set test longitudinal force; then, the hydraulic jack (4) is controlled by the hydraulic jack control console (10) to apply shear force step by step, and the shear mechanical properties of the ring-to-ring joint of the whole ring segment are studied.

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