Vertical shaft type shield segment prototype loading test device and test method

Abstract

The invention provides a vertical shaft type shield segment prototype loading test device and test method, and relates to the technical field of shield tunnel engineering, the test device comprises a support supporting body and a reaction frame body, and the reaction frame body is provided with a radial loading assembly, a hoop loading assembly and a hoisting loading assembly; the test ring pipe piece is vertically placed, equivalent bending moment is applied in a graded mode through the radial loading assembly, equivalent axial force is applied in a graded mode through the hoop loading assembly, and lifting acting force is applied in a graded mode through the hoisting loading assembly so as to achieve self-weight balance. Compared with a flat-lying type test in the prior art, the test device is used for a standing type segment prototype loading test, and the actual stress state of a segment is simulated more truly; besides, dead-weight balance is realized by hoisting the loading assembly, the dead-weight counter-force effect of the duct piece provided by the stratum in the actual working condition can be accurately simulated, the problem of dead-weight counter-force concentration in the standing type duct piece prototype loading test is solved, and the actual stress state of the duct piece is simulated more truly.

Description

Technical Field

[0001] The invention relates to the technical field of shield tunnel engineering, and in particular to a shaft-type shield segment prototype loading test device and a test method. Background Art

[0002] In recent years, with the continuous advancement of my country's overall urban planning, influenced by factors such as environmental conditions along the route and ground transportation, it has gradually become a trend to use shield tunnel construction when transportation routes enter urban areas or cross large rivers. The segment is the permanent load-bearing structure of the shield tunnel, which is responsible for resisting soil pressure, groundwater pressure and some special loads. The mechanical properties of the shield segment are directly related to the overall stability, safety and durability of the tunnel structure.

[0003] Based on this, domestic and foreign methods mainly use numerical calculation analysis, scaled test and prototype loading test to carry out research on the mechanical properties of segments. For numerical calculation analysis, the calculation model greatly simplifies the segment structure, and the key calculation parameters of the model are difficult to obtain accurately, and the calculation results are difficult to truly reflect the mechanical state of the segment. The scaled test also simplifies the segment model. Due to issues such as the size and material properties of the scaled segment model, the test results are often quite different from the actual situation. The prototype loading test is a research method that can more truly reflect the mechanical properties of the segment at this stage.

[0004] At present, the prototype loading tests of the shield tunnel engineering technology are all based on the flat-lying tests carried out on the indoor laboratory platform. However, the accuracy of the test results of the flat-lying prototype loading test needs further review and evaluation because it cannot take into account the important influence of the deadweight of the segment structure on the mechanical state of the segment ring. Summary of the invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, the present invention aims to provide a shaft-type shield segment prototype loading test device and test method.

[0006] In a first aspect, the present invention provides a shaft-type shield segment prototype loading test device, comprising: A support body, wherein the support body is used to support a test ring segment group, wherein the test ring segment group includes at least one test ring segment distributed and arranged along a first direction and connected to each other, wherein the test ring segment is a shield segment, wherein each of the test ring segments is composed of a plurality of arc segments, and the direction of an axis extension line of the test ring segment is the first direction; and the first direction is a horizontal direction; A reaction frame body, wherein the reaction frame body comprises at least one reaction frame group distributed along the first direction, each reaction frame group is arranged corresponding to the test ring segment, each reaction frame group comprises at least one reaction frame, each reaction frame comprises two columns distributed along the second direction, the bottom ends of the two columns are connected to the support body, a first space is formed between the columns of each reaction frame group and the support body, the first space is used to place the test ring segment, and the second direction is perpendicular to the first direction; A load loading system, the load loading system comprising at least one loading mechanism corresponding to the reaction frame, each of the loading mechanisms comprising: A radial loading assembly, wherein the radial loading assembly is used to apply an equivalent bending moment to the test ring segment, wherein the equivalent bending moment is used to simulate the bending moment to which the shield segment is subjected in actual working conditions; A hoop loading assembly, wherein the hoop loading assembly is used to apply an equivalent axial force to the test ring segment, wherein the equivalent axial force is used to simulate the axial force to which the shield segment is subjected in actual working conditions; A hoisting and loading assembly, wherein the hoisting and loading assembly is used to apply a pulling force to the test ring segment to achieve deadweight balance of the test ring segment; A monitoring component is used to measure the structural internal force and deformation of the test ring segment.

[0007] According to the technical solution provided by the present invention, the test device is arranged in a vertical shaft structure, and the vertical shaft structure includes two vertical shaft walls distributed along the second direction, and the two columns of each reaction frame are connected to the corresponding vertical shaft walls at ends away from each other; the test ring segment group is assembled by a shield machine.

[0008] According to the technical solution provided by the present invention, the reaction frame also includes two top inclined beams, one end of the two top inclined beams are connected, and the other end is respectively connected to the two columns away from the support body end of the bearing, and a first angle is formed between the two top inclined beams, and the first angle opens toward the test ring segment.

[0009] According to the technical solution provided by the present invention, the hoisting and loading assembly includes a hoisting steel strand arranged around the outer wall of the test ring segment close to the support body side of the bearing, and also includes a hoisting drive unit arranged on the two top inclined beams, the two hoisting drive units are respectively connected to the two ends of the hoisting steel strand, and the two hoisting drive units can synchronously apply a force along a third direction to the test ring segment, and the third direction is perpendicular to the first direction and the second direction.

[0010] According to the technical solution provided by the present invention, the radial loading assembly includes a horizontal loading part arranged on both sides of the test ring segment along the second direction, and a vertical loading part arranged on both sides of the test ring segment along the third direction, the horizontal loading part is used to apply a horizontal force to the test ring segment along the second direction, and the vertical loading part is used to apply a vertical force to the test ring segment along the third direction.

[0011] According to the technical solution provided by the present invention, the hoop loading assembly includes at least one hoop loading part, each of the hoop loading parts includes a hoop steel strand wound around the test ring segment, one end of the hoop steel strand is connected to the outer wall of the test ring segment, and the other end is connected to a hoop driving part, and the hoop driving part is used to apply tensioning force to the hoop steel strand.

[0012] According to the technical solution provided by the present invention, the support body includes a base, the top surface of the base is provided with an arc-shaped groove, the arc-shaped groove has an arc-shaped surface matching the test ring segment, two steel rails are provided on the arc-shaped surface, the two steel rails are symmetrically distributed on both sides of the test ring segment along the second direction, and the extension direction of the steel rails is the first direction; the steel rails are used to support the test ring segment.

[0013] According to the technical solution provided by the present invention, a notch is provided on the top of the rail, and the notch is used for the hoop steel strand and the hoisting steel strand to pass through.

[0014] According to the technical solution provided by the present invention, polyethylene plates are adhered to both ends of the test ring segment group along the first direction to reduce the frictional resistance at the boundary positions of the test ring segments.

[0015] In a second aspect, the present invention provides a shaft-type shield segment prototype loading test method, using the shaft-type shield segment prototype loading test device as described above, comprising the following steps: Obtaining the gravity magnitude and actual load set of the test ring segment, wherein the actual load set includes the top load, the lateral top load, the load difference between the lateral top and the lateral bottom, and the horizontal resistance of the triangular stratum that the shield segment is subjected to in actual working conditions; The radial concentrated load and the hoop uniformly distributed load are calculated based on the actual load set; Starting the hoisting loading assembly according to the gravity, applying a counter-gravity force to the test ring segment in stages, wherein the counter-gravity force is equal in magnitude to the gravity and opposite in direction to the gravity; Starting the radial loading assembly according to the magnitude of the radial concentrated load to apply radial loads to the test ring segment in stages, and starting the hoop loading assembly according to the magnitude of the hoop uniform load to apply hoop uniform loads to the outer wall of the test ring segment in stages in the circumferential direction; The structural internal forces and deformations of the test ring segments are recorded.

[0016] In summary, the present invention proposes a prototype loading test device for shaft-type shield segments, including a support body for supporting the test ring segments and a reaction frame body placed on both sides of the test ring segments, and a load loading system including a radial loading component, a hoop loading component, and a hoisting loading component is provided on the reaction frame body; the test ring segments are placed vertically, and their axes are in the horizontal direction, and an equivalent bending moment is applied to the test ring segments by the radial loading component, an equivalent axial force is applied to the test ring segments by the hoisting loading component, and a pulling force is applied to the test ring segments by the hoisting loading component to achieve self-weight balance. The present invention is a standing segment prototype loading test, which simulates the actual stress state of the segments more realistically compared with the flat-lying test of the prior art; in addition, the present invention achieves self-weight balance through the hoisting loading component, which can accurately simulate the self-weight reaction force of the segments provided by the stratum in actual working conditions, solves the problem of self-weight reaction force concentration in the standing segment prototype loading test, and more realistically simulates the actual stress state of the segments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a prototype loading test device for a shaft-type shield segment provided in Example 1 of the present invention; Figure 2 A top view of the test ring segment and the shield segment provided in Example 1 of the present invention in the shaft structure; Figure 3 This is a flow chart of the shaft shield segment prototype loading test method provided in Example 2 of the present invention.

[0018] The text annotations in the figure represent: 1. Support body; 11. Base; 111. Arc groove; 112. Rail; 113. First groove; 2. Test ring segment group; 21. Test ring segment; 3. Reaction frame; 31. Column; 32. Top inclined beam; 33. Top horizontal beam; 34. Top vertical beam; 4. Radial loading assembly; 41. Triangular bracket; 42. Horizontal loading beam; 43. Horizontal drive unit; 44. Top loading unit; 441. Top loading beam; 442. Top drive unit; 45. Bottom loading unit; 451. Bottom drive unit; 5. Hoop loading assembly; 51. Hoop steel strand; 52. Hoop beam; 6. Hoisting loading assembly; 61. Hoisting steel strand; 62. Hoisting drive unit; 8. Shaft structure; 81. Shaft wall. DETAILED DESCRIPTION

[0019] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0020] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0021] Example 1 As mentioned in the background technology, the present invention proposes a prototype loading test device for shaft shield segments, such as Figure 1 and Figure 2 As shown, including: The support body 1 is used to support a test ring segment group 2. The test ring segment group 2 includes at least one test ring segment 21 distributed and arranged along a first direction and connected to each other. The test ring segment 21 is a shield segment. Each test ring segment 21 is composed of a plurality of arc segments. The direction of the axis extension line of the test ring segment 21 is the first direction. The first direction is a horizontal direction. Among them, Figure 1 As shown, the first direction is the front-rear direction perpendicular to the paper surface. Optionally, the test ring segment group 2 includes three test ring segments 21, and two adjacent test ring segments 21 are connected by bolts. A reaction frame body, the reaction frame body includes at least one reaction frame group distributed along the first direction, each reaction frame group is arranged corresponding to the test ring segment 21, each reaction frame group includes at least one reaction frame 3, each reaction frame 3 includes two columns 31 distributed along the second direction, the bottom ends of the two columns 31 are connected to the support body 1, and a first space is formed between the columns 31 of each reaction frame group and the support body 1, and the first space is used to place the test ring segment 21, and the second direction is perpendicular to the first direction; The second direction is a horizontal direction. Optionally, the reaction frame group includes two reaction frames 3, that is, each test ring segment 21 corresponds to two reaction frames 3; The load loading system includes at least one loading mechanism corresponding to the reaction frame 3, and each loading mechanism includes: A radial loading component 4, the radial loading component 4 is used to apply an equivalent bending moment to the test ring segment 21, and the equivalent bending moment is used to simulate the bending moment to which the shield segment is subjected in actual working conditions; A hoop loading assembly 5, the hoop loading assembly 5 is used to apply an equivalent axial force to the test ring segment 21, and the equivalent axial force is used to simulate the axial force to which the shield segment is subjected in actual working conditions; A hoisting and loading assembly 6, which is used to apply a pulling force to the test ring segment 21 to achieve self-weight balance of the test ring segment 21; Among them, under actual working conditions, the shield segment will be subjected to bending moment due to various factors such as surrounding soil and water pressure, uneven settlement, temperature change, etc., and the surrounding soil and water pressure, the pressure inside the tunnel, and the interaction force between the shield segments, etc., will generate axial force in the axial direction of the shield segment; in the test, the equivalent bending moment and equivalent axial force are applied to the test ring segment 21 through the radial loading component 4 and the hoop loading component 5 to simulate the stress condition of the shield segment in actual working conditions, so as to test and evaluate the performance of the segment; A monitoring component, the monitoring component is used to measure the structural internal force and deformation of the test ring segment 21; Optionally, the monitoring component is a strain gauge, and multiple strain gauges are arranged on the inner and outer surfaces of the test ring segment 21 to measure the structural internal force and deformation of the test ring segment 21. The obtained structural internal force and deformation are used to optimize the segment structure design and evaluate the safety of the segment. This is a prior art and will not be described in detail here.

[0022] The present invention is a standing segment prototype loading test. Compared with the lying test in the prior art, it simulates the actual stress state of the segment more realistically. The present invention provides equivalent bending moment and equivalent axial force to the test ring segment 21 through the radial loading component 4 and the hoop loading component 5. The two sets of loading components are loaded independently, and the operation is simple. In addition, the present invention realizes the self-weight balance of the test ring segment 21 through the hoisting loading component 6, which can accurately simulate the self-weight reaction force of the segment provided by the formation in the actual working condition, solves the problem of self-weight reaction force concentration in the standing segment prototype loading test, and more realistically simulates the actual stress state of the segment.

[0023] In a preferred embodiment, the test device is arranged in a shaft structure 8, the shaft structure 8 includes two shaft walls 81 distributed along the second direction, and the two columns 31 of each reaction frame 3 are connected to the corresponding shaft walls 81 at ends away from each other; the test ring segment group 2 is assembled by a shield machine.

[0024] The shaft structure 8 is a square shield starting shaft, and the bottom of the shaft structure 8 includes a shaft bottom plate of reinforced concrete, on which two embedded steel plates are embedded, and the embedded steel plates are arranged on both sides of the support body 1 along the second direction, and the embedded steel plates are used to connect with the columns 31 of the reaction frame 3. Each reaction frame 3 is in contact with the shaft wall 81 of the shaft structure 8, and the existing shaft structure 8 and the support body 1 of the shield project are used as the test platform, and the existing shield negative ring segment is used as the test ring segment 21, so that the prototype loading test is carried out without affecting the on-site shield construction, thereby reducing the segment prototype loading test cost.

[0025] The present invention starts excavation by means of a shield machine, and assembles shield segments in a shaft structure 8 to form a plurality of shield segments connected by bolts, selects three shield segments in the middle as a test ring segment group 2, and removes the bolts between the test ring segment group 2 and other shield segments; therefore, the test ring segment 21 is the shield segment, and the present invention uses a shield machine to complete the assembly, restores the actual assembly form of the shield segments, and uses the construction site as a test site, avoiding the problem of difficulty in finding a site, and can truly reflect the mechanical properties of the segments.

[0026] Specifically, each column 31 and the shaft wall 81 are connected through a column support assembly, and the column support assembly is arranged in the middle of the column 31. The column support assembly includes a column plate arranged at the end of the column 31 away from the test ring segment 21, a threaded screw threadedly connected to the column plate, a ball head connected to the end of the threaded screw away from the column plate, and a shaft wall plate arranged at the end of the shaft wall 81 close to the test ring segment 21; wherein, the extension direction of the threaded screw is the second direction, and its length can be adjusted telescopically; after adjustment, the ball head abuts against the shaft wall plate, and when the column 31 is subjected to a horizontal force, the ball head can ensure that the force can be evenly transmitted to the shaft structure 8 to avoid unbalanced loading.

[0027] In the prior art, since the diameter of the test ring segment 21 is relatively large and the weight of each segment is about 15 tons, even a lying test requires finding a sufficiently large space and using lifting equipment to complete the assembly of the test ring segment 21. This method has assembly errors and will have a significant impact on the mechanical state of the segment ring. The present invention uses a shield machine to complete the assembly, avoiding assembly errors, and uses the construction site as a test site, avoiding the problem of difficulty in finding a site, and can truly reflect the mechanical properties of the segment.

[0028] In a preferred embodiment, polyethylene plates are attached to both ends of the test ring segment group 2 along the first direction to reduce the friction resistance at the boundary positions of the test ring segment 21 .

[0029] Among them, the polyethylene plate is pasted in the annular seam. Since the test ring segment 21 will be deformed under the load loading of the load loading system, the polyethylene plate is used to prevent the shield segments on both sides of the test ring segment group 2 from interfering with it.

[0030] In a preferred embodiment, the reaction frame 3 also includes two top inclined beams 32, one end of the two top inclined beams 32 is connected, and the other end is respectively connected to the two columns 31 away from the end of the support body 1, and a first angle is formed between the two top inclined beams 32, and the opening of the first angle is toward the test ring segment 21.

[0031] Among them, the reaction frame 3 structure is a gate-shaped steel frame, which is installed between the test ring segment 21 and the shaft wall 81, and includes a column 31, two top inclined beams 32, a top cross beam 33, and a top vertical beam 34. Among them, the extension direction of the top cross beam 33 is the second direction, and its two ends are respectively connected to the corresponding top inclined beams 32. The extension direction of the top vertical beam 34 is the vertical direction, one end of which is connected to the connection between the two top inclined beams 32, and the other end is connected to the top cross beam 33. The adjacent components are connected by high-strength bolts; the top cross beam 33 and the top inclined beam 32 form a triangular structure, which improves the stability of the reaction frame 3.

[0032] In a preferred embodiment, the support body 1 includes a base 11, and an arc-shaped groove 111 is opened on the top surface of the base 11. The arc-shaped groove 111 has an arc-shaped surface matching the test ring segment 21. Two steel rails 112 are provided on the arc-shaped surface. The two steel rails 112 are symmetrically distributed on both sides of the test ring segment 21 along the second direction, and the extension direction of the steel rails 112 is the first direction; the steel rails 112 are used to support the test ring segment 21.

[0033] Among them, a shield starting base is cast on the bottom plate of the shaft as a base 11, and the extension direction of the base 11 is a first direction. The base 11 includes a first base, a second base and a third base which are sequentially distributed along a second direction, with gaps between them. The top surfaces of the three bases all have curved surfaces, which together form an arc-shaped curved surface. Steel rails 112 are provided on the first base and the third base. In addition to supporting the test ring segment 21, the steel rails 112 are also used for the travel of the shield machine.

[0034] In a preferred embodiment, the lifting and loading assembly 6 includes a lifting steel strand 61 which is arranged around the outer wall of the test ring segment 21 near the side of the support body 1, and also includes a lifting drive unit 62 which is arranged on two top inclined beams 32. The two lifting drive units 62 are respectively connected to the two ends of the lifting steel strand 61. The two lifting drive units 62 can synchronously apply a force along a third direction to the test ring segment 21, and the third direction is perpendicular to the first direction and the second direction.

[0035] Among them, optionally, the lifting drive part 62 is a hollow cylinder, the third direction is the vertical direction, and a fixed steel plate is welded at the horizontal boundary position of the test ring segment 21 corresponding to the top inclined beam 32. The fixed steel plate is arranged at the ends of the two top inclined beams 32 that are far away from each other. The fixed steel plate is placed horizontally, and the lifting drive part 62 is arranged in the middle above the fixed steel plate. A through hole is opened in the center of the fixed steel plate and the top inclined beam 32 and its corresponding position. The lifting steel strand 61 passes through the through holes of the top inclined beam 32 and the fixed steel plate and is connected to the hollow cylinder. Through the synchronous action of the two hollow cylinders, the test ring segment 21 can be moved up and down in the vertical direction.

[0036] In a preferred embodiment, the radial loading assembly 4 includes a horizontal loading part arranged on both sides of the test ring segment 21 along the second direction, and a vertical loading part arranged on both sides of the test ring segment 21 along the third direction. The horizontal loading part is used to apply a horizontal force to the test ring segment 21 along the second direction, and the vertical loading part is used to apply a vertical force to the test ring segment 21 along the third direction.

[0037] Wherein, the horizontal loading part comprises: A triangular bracket 41 is arranged in the middle of the column 31 near the end of the test ring segment 21. The triangular bracket 41 includes a horizontal bracket and an oblique bracket. One end of the horizontal bracket is connected to the column 31, and the other end is connected to the high end of the oblique bracket. The low end of the oblique bracket is connected to the column 31. A horizontal loading beam 42, which is disposed on the outer wall of the test ring segment 21, and extends in a vertical direction and is tangent to the outer wall of the test ring segment 21; The horizontal driving part 43 is placed horizontally on the horizontal support. Optionally, the horizontal driving part 43 is a jack, the bottom of the jack is connected to the column 31 through a flange, and the top of the jack is in contact with the horizontal loading beam 42.

[0038] Wherein, the vertical loading part comprises: A top loading part 44, the top loading part 44 comprises a top loading beam 441 disposed on the top of the test ring segment 21, the top loading beam 441 is tangent to the top of the test ring segment 21, and further comprises a top driving part 442, the bottom of the top driving part 442 is connected to the top cross beam 33, and the other end is in contact with the top loading beam 441, and optionally, the top driving part 442 is a hydraulic jack; The bottom loading part 45 includes a bottom loading beam arranged at the bottom of the test ring segment 21, the bottom loading beam is tangent to the bottom of the test ring segment 21, and also includes a bottom driving part 451. Optionally, the bottom driving part 451 is a hydraulic jack, which is retractable and used to apply a load to the bottom of the test ring segment 21. The second base is provided with a first groove 113. In the initial state, the hydraulic jack is placed in the first groove 113. When a load is applied to the test ring segment 21, the piston rod of the hydraulic jack extends out of the first groove 113 and abuts against the bottom loading beam.

[0039] When the test ring segment group 2 includes multiple test ring segments 21, it includes multiple radial loading assemblies 4, all horizontal loading beams 42 on the left side of the test ring segment group 2 are integrated into one, and all horizontal loading beams 42 on the right side, all top loading beams 441 and all bottom loading beams are respectively integrated into one, and the first groove 113 is strip-shaped, and all bottom driving parts 451 are placed in the first groove 113.

[0040] Furthermore, a limiting groove is provided on the top crossbeam 33, the limiting groove opening faces the test ring segment 21 side, and its extension direction is the first direction, a slide groove is provided on the bottom wall of the limiting groove, and the extension direction of the slide groove is the first direction, and a buckle slider matching the slide groove is provided on the top of the hydraulic jack, and the buckle slider can drive the hydraulic jack to slide in the slide groove, and after it is in place, it is fixed to the slide groove through the buckle structure of the buckle slider. A limiting baffle is provided at the opening of the limiting groove, and a limiting opening is provided on the limiting baffle. When the hydraulic jack is not extended, it is placed in the limiting groove. When a load is applied to the test ring segment 21, the piston of the hydraulic jack is abutted against the top of the test ring segment 21 through the limiting opening. The limiting baffle avoids the risk of the hydraulic jack falling.

[0041] In a preferred embodiment, the hoop loading assembly 5 includes at least one hoop loading part, each hoop loading part includes a hoop steel strand 51 wound around the test ring segment 21, one end of the hoop steel strand 51 is connected to the outer wall of the test ring segment 21, and the other end is connected to the hoop driving part, which is used to apply tension to the hoop steel strand 51.

[0042] Among them, since the internal force of the test ring segment 21 is relatively large, each test ring segment 21 is loaded with multiple hoop loading parts. Optionally, each test ring segment 21 uses 4 hoop loading parts. A layer of rubber skin is sleeved on the outside of the hoop steel strand 51, and lubricating grease is filled between the rubber skin and the hoop steel strand 51. Each hoop loading part also includes a hoop beam 52, which extends radially outward from the outer wall of the test ring segment 21, and a steel strand passing hole is provided in the middle of the hoop beam 52; the hoop driving part is arranged on the hoop beam 52, and the hoop driving part is optionally a hollow cylinder. One end of the hoop steel strand 51 is fixed to the hoop beam 52 by a steel strand tool anchor tool, and the other end is wrapped around the test ring segment 21 for a circle, and is connected to the hollow cylinder after passing through the steel strand passing hole. Since the width of the test ring segment 21 is limited, it is impossible to place multiple hollow cylinders, so two hollow cylinders are placed at 180-degree diagonal positions.

[0043] In a preferred embodiment, a slot is formed on the top of the steel rail 112 , and the slot is used for the hoop steel strand 51 and the hoisting steel strand 61 to pass through.

[0044] Among them, the number of notches is the same as the number of hoop steel strands 51 surrounding the outside of the test ring segment 21 and the number of lifting steel strands 61 wound around the outer wall of the test ring segment 21. Optionally, each test ring segment 21 is wrapped with 4 hoop steel strands 51 and one lifting steel strand 61, so the number of notches corresponding to each test ring segment 21 is 5.

[0045] Example 2 Based on Example 1, the present invention provides a test method for a shaft-type shield segment prototype loading test device, such as Figure 3 As shown, the following steps are included: S100. Obtaining the gravity magnitude and actual load set of the test ring segment 21, the actual load set including the top load, lateral top load, load difference between the lateral top and lateral bottom, and horizontal resistance of the triangular stratum received by the shield segment in actual working conditions; Wherein, before step S100, the following steps are also included: S010. Construct the shield starting shaft, and pre-embed the steel plate at the corresponding position of the shaft bottom plate; S020. Cast the shield starting base as the base 11 on the shaft bottom plate, and reserve a first groove 113 on the second base of the base 11, install the rail 112 on the first base and the third base, and install the bottom drive unit 451 in the first groove 113; S030. Prefabricate the test ring segment 21, set monitoring components inside and outside the test ring segment 21, and paste polyethylene plates on both ends of the test ring segment group 2; S040. The shield begins to excavate, assembling the test ring segment 21 and other shield segments in the shaft structure 8, and connecting the adjacent segment ring longitudinal seams with bolts; S050. Install the reaction frame body and load loading system; S060. After the test ring segment 21 is no longer affected by the thrust of the shield machine, unscrew the connecting bolts between the test ring segment 21 and the adjacent shield segment and start the test.

[0046] Optionally, before the shield machine is assembled, the weight of each segment can be obtained by a weighing device, and then the gravity of the test ring segment 21 can be calculated based on the number of segments required for assembling the test ring segment 21. The test personnel input the gravity into the control unit of the test device.

[0047] Furthermore, obtaining the actual load set includes the following steps: S101. Obtaining the centroid radius of the test ring segment 21 and the soil and water information of the tunnel where the shaft structure 8 is located; Among them, the centroid radius can be calculated by measuring the inner diameter and outer diameter of the test ring segment 21, and the soil information and water information can be obtained through hydrogeological survey. The soil information includes soil type, overburden thickness, stratum properties, loose zone width, etc. The water information includes radial water pressure along the tunnel, net water head height at the top of the tunnel, etc.

[0048] S102. Obtaining an actual load set according to the centroid radius, soil information and water information; Among them, the actual load set can be obtained by searching the relevant specifications according to the centroid radius, soil information and water information; S200. Calculate the radial concentrated load and the hoop uniform load according to the actual load set; calculate the hoop uniform load according to the actual load set by the following formula: Formula (1) In the formula, F h is the uniform load distributed around the hoop, q c is the lateral top load; q s is the load difference between the lateral top and lateral bottom; q k It is the horizontal resistance of triangular strata.

[0049] Among them, the magnitude of radial concentrated load includes the magnitude of horizontal concentrated load and the magnitude of vertical concentrated load. The magnitude of vertical concentrated load and horizontal concentrated load are calculated according to the actual load set. The magnitude of horizontal concentrated load and vertical concentrated load can be obtained by the following formula: Formula (2) in: Formula (3) Where: F z is the vertical concentrated load; F s is the horizontal concentrated load; q d is the top load; q c is the lateral top load; q s is the load difference between the lateral top and lateral bottom; q k is the horizontal resistance of the triangular stratum; R is the centroid radius; In addition: The above formula involves a , b , c , d They are all coefficients, which serve to simplify the formula.

[0050] Among them, the load directions applied by the horizontal loading parts on both sides to the test ring segment 21 along the second direction are opposite, and the load magnitudes are equal to the horizontal concentrated load magnitude; the load directions applied by the top loading part 44 and the bottom loading part 45 to the test ring segment 21 along the third direction are opposite, and the load magnitudes are equal to the magnitude of the vertical concentrated load.

[0051] S300. Start the hoisting loading assembly 6 according to the gravity, and apply the anti-gravity force to the test ring segment 21 in stages, the magnitude of the anti-gravity force is equal to the gravity, and the direction is opposite to the gravity direction; Among them, after the test ring segment group 2, the reaction frame body and the load loading system are assembled, the gravity of the test ring segment 21 is obtained through the control unit, and the horizontal concentrated load size and the vertical concentrated load size, as well as the hoop uniform load size are calculated. The control unit sends a hoisting instruction to each hoisting and loading component 6. After receiving the hoisting instruction, all hoisting and loading components 6 synchronously pull the hoisting steel strand 61 through the hollow cylinders of each hoisting and loading component 6 to achieve the self-weight balance of the test ring segment 21; S400. According to the magnitude of the radial concentrated load, the radial loading assembly 4 is started to apply the radial load to the test ring segment 21 in stages, and according to the magnitude of the hoop uniform load, the hoop loading assembly 5 is synchronously started to apply the hoop uniform load to the outer wall of the test ring segment 21 in stages in the circumferential direction; After the hoisting and loading assembly 6 lifts the test ring segment group 2, the test ring segment group 2 is separated from the rail 112, and then the radial loading assembly 4 and the hoop loading assembly 5 apply load to the test ring segment 21 to simulate the stress condition of the shield segment in actual working conditions. Specifically, after the hoisting is completed, the hoisting and loading assembly 6 sends a hoisting completion signal to the control unit. After receiving the signal, the control unit sends a start signal to the top drive unit 442, the bottom drive unit 451, the horizontal drive unit 43 and the hoop drive unit. After receiving the signal, the top drive unit 442, the bottom drive unit 451, the horizontal drive unit 43 and the hoop drive unit perform graded loading on the test ring segment 21.

[0052] S500. Record the internal force and deformation of the test ring segment 21.

[0053] In summary, the present invention has the following beneficial effects: By using the existing shaft structure 8 and the support body 1 of the shield engineering as the test platform and the existing shield segments as the test objects, the prototype loading test is carried out without affecting the on-site shield construction, thus reducing the cost of the segment prototype loading test; This test is a standing segment prototype loading test. The test ring segment 21 is assembled by a shield machine. It can solve the problem that the existing lying segment prototype loading test cannot consider the effect of the deadweight of the segment structure and the assembly error on the mechanical state of the segment ring, and more realistically simulate the actual stress condition of the segment. The self-weight balance of the test ring segment 21 is achieved by hoisting the loading assembly 6, which can accurately simulate the self-weight reaction of the segment provided by the stratum in the actual working condition, and solve the problem of self-weight reaction concentration in the standing segment prototype loading test; The load on the reaction frame 3 is much smaller than the reaction frame 3 used in the laboratory flat-lying segment loading test, and the shaft structure 8 can be used as a support. Therefore, the internal force of the reaction frame 3 is relatively small, the construction cost is low, and the structure is simple.

[0054] The above description is only a preferred embodiment of the present invention and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present invention is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in the present invention (but not limited to) to form a technical solution.

Claims

1. A prototype loading test device for shaft-type shield segments, characterized in that: include: A support body (1), the support body (1) being used to support a test ring segment group (2), the test ring segment group (2) comprising at least one test ring segment (21) distributed and arranged along a first direction and connected to each other, the test ring segment (21) being a shield segment, each of the test ring segments (21) being composed of a plurality of arc segments, the direction of an axis extension of the test ring segment (21) being the first direction, and the first direction being a horizontal direction; A reaction frame body, the reaction frame body comprising at least one reaction frame group distributed along the first direction, each reaction frame group being arranged corresponding to the test ring segment (21), each reaction frame group comprising at least one reaction frame (3), each reaction frame (3) comprising two columns (31) distributed along the second direction, the bottom ends of the two columns (31) being connected to the support body (1), a first space being formed between the columns (31) of each reaction frame group and the support body (1), the first space being used to place the test ring segment (21), and the second direction being perpendicular to the first direction; A load loading system, the load loading system comprising at least one loading mechanism corresponding to the reaction frame (3), each of the loading mechanisms comprising: A radial loading assembly (4), the radial loading assembly (4) being used to apply an equivalent bending moment to the test ring segment (21), the equivalent bending moment being used to simulate the bending moment to which the shield segment is subjected in actual working conditions; A hoop loading assembly (5), the hoop loading assembly (5) being used to apply an equivalent axial force to the test ring segment (21), the equivalent axial force being used to simulate the axial force to which the shield segment is subjected in actual working conditions; A hoisting and loading assembly (6), the hoisting and loading assembly (6) being used to apply a pulling force to the test ring segment (21) to achieve deadweight balance of the test ring segment (21); A monitoring component is used to measure the structural internal force and deformation of the test ring segment (21).

2. The shaft shield segment prototype loading test device according to claim 1 is characterized in that: The test device is arranged in a shaft structure (8), the shaft structure (8) comprising two shaft walls (81) distributed along the second direction, the two columns (31) of each reaction frame (3) being connected to the corresponding shaft wall (81) at ends away from each other; the test ring segment group (2) is assembled and formed by a shield machine.

3. The shaft shield segment prototype loading test device according to claim 1 is characterized in that: The reaction frame (3) further comprises two top inclined beams (32), one end of the two top inclined beams (32) being connected, and the other end being respectively connected to the ends of the two columns (31) away from the support body (1), and a first angle is formed between the two top inclined beams (32), and the opening of the first angle is toward the test ring segment (21).

4. The shaft shield segment prototype loading test device according to claim 3 is characterized in that: The hoisting loading assembly (6) comprises a hoisting steel strand (61) arranged around the outer wall of the test ring segment (21) near the side of the support body (1), and also comprises a hoisting drive unit (62) arranged on the two top inclined beams (32), the two hoisting drive units (62) are respectively connected to the two ends of the hoisting steel strand (61), and the two hoisting drive units (62) can synchronously apply a force along a third direction to the test ring segment (21), and the third direction is perpendicular to the first direction and the second direction.

5. The shaft shield segment prototype loading test device according to claim 4 is characterized in that: The radial loading assembly (4) comprises horizontal loading parts arranged on both sides of the test ring segment (21) along the second direction, and vertical loading parts arranged on both sides of the test ring segment (21) along the third direction, the horizontal loading parts being used to apply a horizontal force to the test ring segment (21) along the second direction, and the vertical loading parts being used to apply a vertical force to the test ring segment (21) along the third direction.

6. The shaft shield segment prototype loading test device according to claim 4 is characterized in that: The hoop loading assembly (5) comprises at least one hoop loading part, each of the hoop loading parts comprises a hoop steel strand (51) wound around the test ring segment (21), one end of the hoop steel strand (51) is connected to the outer wall of the test ring segment (21), and the other end is connected to a hoop driving part, and the hoop driving part is used to apply a tensioning force to the hoop steel strand (51).

7. The shaft shield segment prototype loading test device according to claim 6 is characterized in that: The support body (1) comprises a base (11), the top surface of the base (11) is provided with an arc-shaped groove (111), the arc-shaped groove (111) has an arc-shaped curved surface matching the test ring segment (21), two steel rails (112) are provided on the arc-shaped curved surface, the two steel rails (112) are symmetrically distributed on both sides of the test ring segment (21) along the second direction, and the extension direction of the steel rails (112) is the first direction; the steel rails (112) are used to support the test ring segment (21).

8. The shaft shield segment prototype loading test device according to claim 7 is characterized in that: A notch is provided on the top of the steel rail (112), and the notch is used for the hoop steel strand (51) and the hoisting steel strand (61) to pass through.

9. The shaft shield segment prototype loading test device according to claim 1 is characterized in that: Polyethylene plates are adhered to both ends of the test ring segment group (2) along the first direction, so as to reduce the frictional resistance at the boundary positions of the test ring segment (21).

10. A shaft shield segment prototype loading test method, using the shaft shield segment prototype loading test device according to any one of claims 1 to 9, characterized in that: The steps include: Obtaining the gravity magnitude and actual load set of the test ring segment (21), wherein the actual load set includes the top load, the lateral top load, the load difference between the lateral top and the lateral bottom, and the horizontal resistance of the triangular stratum that the shield segment is subjected to in actual working conditions; The radial concentrated load and the hoop uniformly distributed load are calculated based on the actual load set; According to the magnitude of the gravity, a hoisting loading assembly (6) is started to apply a counter-gravity force to the test ring segment (21) in stages, wherein the magnitude of the counter-gravity force is equal to the magnitude of the gravity and the direction is opposite to the direction of the gravity; Starting a radial loading assembly (4) according to the magnitude of the radial concentrated load to apply a radial load in stages to the test ring segment (21), and synchronously starting a hoop loading assembly (5) according to the magnitude of the hoop uniformly distributed load to apply a hoop uniformly distributed load in stages in the circumferential direction to the outer wall of the test ring segment (21); The structural internal force and deformation of the test ring segment (21) are recorded.

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