Tunnel lining template, three-dimensional load loading device and loading test method

Abstract

The invention discloses a tunnel lining template, a three-dimensional load loading device and a loading test method.The tunnel lining template comprises an inner ring template, an outer ring template and two side template rings, the inner ring template is coaxially arranged in the outer ring template, an annular gap is formed between the inner ring template and the outer ring template, the two ends of the inner ring template and the two ends of the outer ring template are aligned, and the two side template rings are installed at the two ends of the annular gap; the two ends of the annular gap are blocked and enclosed to form an annular mold cavity; the outer ring template comprises a plurality of sealing rings and a plurality of sections of sub-template rings, the outer ring template is formed by sequentially splicing the plurality of sections of sub-template rings along the length direction, and one sealing ring is clamped between any two adjacent sections of sub-template rings; the sub-template ring comprises a plurality of sealing strips and a plurality of push plates, the sub-template ring is formed by sequentially splicing the plurality of push plates in the annular direction, one sealing strip is arranged between any two adjacent push plates, the structure is simple, and the device can be used for pouring and forming a tunnel lining and can also be used for applying a load to carry out a full-life-cycle three-dimensional load loading test on the tunnel lining.

Description

Technical Field

[0001] The invention belongs to the technical field of tunnel lining, and in particular relates to a tunnel lining template, a three-dimensional load loading device and a loading test method. Background Art

[0002] Numerical simulation methods are widely used in the study of tunnel lining structural performance, but the physical model of tunnel lining still has obvious advantages. It can comprehensively and intuitively reveal the evolution process of tunnel structure crack damage and the law of morphological decay, and is an important means to study the mechanical properties of tunnel lining. At present, all tunnel lining loading test devices are plane strain model devices, which cannot simulate the effect of longitudinal uneven loads in tunnels. There are two loading methods for existing tunnel lining loading test devices: the first is to indirectly load the tunnel model, that is, the load acts on the surrounding rock material at the outermost periphery, and the surrounding rock material transmits the force to the tunnel model after self-adjustment; the second loading method is that the load acts directly on the tunnel model, and the lining load in the non-loaded area is simulated by a spring with a certain stiffness. In actual engineering, it takes time for the tunnel support structure to increase with the increase of material strength, and the effect of the load has occurred when the support structure is low in strength. The existing devices are loaded after the lining model is cured, that is, after meeting the design strength requirements, and cannot simulate the load conditions of the tunnel support lining during the process of increasing strength.

[0003] The existing tunnel lining loading test device has the following main deficiencies:

[0004] The existing mountain tunnel model devices are mainly plane strain model devices, taking a certain section of the tunnel as the object and loading several key positions of the lining. Some model devices take into account the situation where the tunnel passes through unfavorable geological bodies such as sliding faults, but they mainly adjust the slip angle of the upper and lower plates of the fault through movable bearings and perform displacement loading controlled by the maximum fault displacement, but cannot simulate the high ground stress level of the surrounding rock at the same time; some devices realize the coupling of fault strike-slip dislocation and high ground stress, but the fault types that can be simulated are relatively single, generally strike-slip faults, and cannot simulate more complex three-dimensional stress conditions. The existing mountain tunnel model tests lack simulation devices for active faults with various dislocation forms under large-scale three-dimensional stress conditions.

[0005] At the same time, tunnel projects are affected by surrounding rock loads throughout their entire life cycle. Structural instability and other defects may occur during the construction and operation of the tunnel. In existing tunnel engineering model tests, lining model specimens are generally not subject to external forces during the maintenance process, and surrounding rock loads are applied after the maintenance is completed. This is inconsistent with the maintenance conditions of tunnel linings in actual projects. In actual projects, tunnel linings are immediately affected by surrounding rock loads during the maintenance process after the formwork trolley is removed. Summary of the invention

[0006] In order to solve the above technical problems, one of the objects of the present invention is to provide a tunnel lining template which has a simple structure and can be used as a tunnel lining casting mold and can also be used to perform three-dimensional load loading tests on tunnel linings throughout their life cycle.

[0007] In order to achieve the above-mentioned object, the technical solution of the present invention is as follows: a tunnel lining template, comprising an inner ring template, an outer ring template and two side template rings, wherein the inner ring template is coaxially arranged in the outer ring template, and an annular gap is provided between the two and the two ends are aligned, and the two side template rings are installed at the two ends of the annular gap to block the two ends of the annular gap and enclose to form an annular mold cavity;

[0008] The outer ring template includes a plurality of sealing rings and a plurality of sub-template rings, and the outer ring template is formed by sequentially splicing the plurality of sub-template rings along the length direction, and one sealing ring is sandwiched between any two adjacent sub-template rings;

[0009] The sub-template ring comprises a plurality of sealing strips and a plurality of push plates, and the sub-template ring is formed by sequentially splicing the plurality of push plates along the circumferential direction, and a sealing strip is arranged between any two adjacent push plates.

[0010] The beneficial effects of the above technical solution are: its structure is simple, and the outer ring template is spliced ​​by multiple sub-template rings, and the push plates adjacent to each other in the ring direction are sealed by sealing strips, and the two push plates adjacent to each other in the axial direction are sealed by sealing rings, so that the entire outer ring template is spliced ​​by multiple push plates in a sealed manner, wherein the outer ring template, the inner ring template and the two side template rings are assembled to form a mold cavity, and the mold cavity can be used to cast and form the tunnel lining. After the tunnel lining is formed, the inner ring template and the side template ring can be removed, and the connection between adjacent push plates can be released, and loads can be applied to the push plates to perform a three-dimensional load loading test on the tunnel lining throughout its life cycle.

[0011] The push plate described in the above technical solution is a strip plate, and a first connecting ear is protrudingly provided on the outer side of the mold cavity at the four side edges of each push plate corresponding to the first connecting ear, and a first connecting hole is provided at the first connecting ear. The two push plates adjacent to each other in the annular direction are bolted together by the first connecting ears on the long side to enclose a ring-shaped sub-template ring, and the two push plates adjacent to each other in the axial direction are bolted together by the first connecting ears at the corresponding positions thereon to connect multiple sections of the sub-template rings to form an outer ring template.

[0012] The beneficial effect of the above technical solution is that two adjacent push plates can be bolted together via the first connecting ears that are close to each other.

[0013] In the above technical solution, both ends of the inner ring template are provided with a plurality of second connecting ears convexly spaced along the circumferential direction on the inner side of the ring, and the second connecting ears are provided with second connecting holes penetrating therethrough. A plurality of third connecting holes are provided circumferentially spaced at the outer edge of the side template ring, and a plurality of fourth connecting holes are provided circumferentially spaced at the inner edge of the side template ring. The plurality of fourth connecting holes on the side template ring correspond one-to-one with the plurality of second connecting holes at the corresponding end of the inner ring template and are aligned with each other for bolt connection. The plurality of third connecting holes on the side template ring correspond one-to-one with the plurality of first connecting holes at the corresponding end of the outer ring template and are aligned with each other for bolt connection.

[0014] The beneficial effect of the above technical solution is that the outer ring template and the inner ring template are bolted to the side template ring for assembly.

[0015] The second object of the present invention is to provide a three-dimensional load loading device which has a simple structure and can be used to cast and shape tunnel linings, and can also perform three-dimensional load loading tests on tunnel linings throughout their life cycle.

[0016] In order to achieve the above-mentioned purpose, another technical solution of the present invention is as follows: a three-dimensional load loading device, comprising a positioning cylinder seat, a plurality of loading components and the tunnel lining formwork as described above, wherein the plurality of loading components correspond one-to-one to the plurality of push plates, the positioning cylinder seat is cylindrical, and operation windows are evenly distributed on its side walls, the tunnel lining formwork is axially placed in the middle of the positioning cylinder seat, and each push plate is connected to the positioning cylinder seat through the corresponding loading component on the outer side of the mold cavity, and the loading component is used to apply loading force to the corresponding push plate.

[0017] The beneficial effect of the above technical solution is that: in this way, the tunnel lining formwork can be placed in the positioning cylinder seat, and each push plate is connected to the inner wall of the positioning cylinder seat through a corresponding loading assembly. At this time, the tunnel lining formwork is supported in the positioning cylinder seat by multiple loading assemblies. Before pouring concrete into the mold cavity, a steel cage is first added to the mold cavity. After the pouring is completed, the tunnel lining formwork can be removed until only the push plates are left (people can reach into the positioning cylinder seat through the operating window to unsplice adjacent push plates). At this time, the loading assembly can apply load to the push plates, thereby conducting a full life cycle three-dimensional load loading test on the tunnel lining specimen.

[0018] The loading assembly in the above technical solution includes a universal part and a telescopic cylinder. The telescopic ends of the telescopic cylinder are connected to the corresponding position in the middle of the outer side of the push plate through the universal part, and the end of the telescopic cylinder away from its telescopic end is connected to the corresponding position of the inner wall of the positioning cylinder seat.

[0019] The beneficial effects of the above technical solution are: its structure is simple, so the inclination angle of the telescopic cylinder relative to the push plate can be adjusted as needed, and the telescopic cylinder is extended to apply load to the push plate. At this time, the outer side of the entire tunnel lining specimen can be subjected to loads from multiple points, and the load force at each point can be adjusted, the test operation flexibility is good, and the simulation effect is good.

[0020] The loading assembly in the above technical solution further comprises a clamping member, and the clamping member is provided at one end of the telescopic cylinder away from the telescopic end thereof, and an attachment portion for clamping by the clamping member is provided on the inner wall of the positioning cylinder seat.

[0021] The beneficial effect of the above technical solution is that the loading assembly is detachably connected to the inner wall of the positioning cylinder seat.

[0022] The clamping member described in the above technical solution includes a clamping bolt and a clamping nut, the attachment portion is a mesh-shaped groove arranged on the inner wall of the positioning cylinder seat, and the cross-section of the mesh-shaped groove is T-shaped, the clamping nut is threadedly connected to the clamping bolt, and the heads of the clamping bolts are inserted into the mesh-shaped groove, the threaded end of the clamping bolt is swingably connected to the end of the telescopic cylinder away from its telescopic end through a movable hinge support, the clamping nut is tightened to clamp the clamping bolt at the corresponding position of the mesh-shaped groove, or the clamping nut is loosened to release the clamping bolt relative to the positioning cylinder seat, and the operation windows are all arranged at the mesh of the mesh-shaped groove.

[0023] The beneficial effect of the above technical solution is that the position of each clamping member on the inner wall of the positioning cylinder seat can be flexibly adjusted.

[0024] The mesh grooves in the above technical solution include multiple axial grooves and multiple annular grooves, the cross-sections of the axial grooves and the annular grooves are both T-shaped, the multiple axial grooves are axially arranged on the inner wall of the positioning cylinder seat and are distributed at intervals along the annular direction, the two ends of each axial groove pass through the two ends of the positioning cylinder seat, and the multiple annular grooves are coaxially arranged on the inner wall of the positioning cylinder seat and are distributed at intervals along the axial direction.

[0025] The beneficial effect of the above technical solution is that the position of the clamping member on the inner wall of the positioning cylinder seat can be adjusted axially along the axial groove, and can also be adjusted circumferentially along the annular groove.

[0026] The above technical solution also includes a moving seat, which has a lifting frame, and the lifting frame has multiple horizontally arranged positioning rods, and multiple positioning rods extend into the inner ring template to lift the inner ring template. The lifting frame is used to adjust the height of the tunnel lining template, and the moving seat is used to drive the lifting frame to drive the tunnel lining template to move axially in and out of the positioning cylinder seat.

[0027] The beneficial effect of the above technical solution is that: in this way, the entire moving seat can move the inner ring template into the outer ring template or move it out of the outer ring template like a forklift, and can flexibly adjust the position of the inner ring template in the outer ring template.

[0028] A third object of the present invention is to provide a method for conducting a full life cycle three-dimensional load loading test on a tunnel lining using the above-mentioned three-dimensional load loading device.

[0029] In order to achieve the above object, the technical solution of the present invention is as follows: A loading test method, using the three-dimensional load loading device as described above to perform the test, comprises the following steps:

[0030] Step 1: Obtain the annular and axial stresses at key positions of the tunnel lining in the active fault section through engineering measurements or numerical simulations, so as to determine the loading angles and loading targets of each loading component and determine the maintenance loading plan;

[0031] Step 2: Match the outer ring template with a plurality of loading components, and install the plurality of loading components at corresponding positions on the inner wall of the positioning cylinder seat;

[0032] Step 3: insert the inner ring template into the outer ring template, and make the inner ring template coaxial with the positioning cylinder seat, then insert the steel cage of the tunnel lining into the annular gap between the inner ring template and the outer ring template, and finally install the side ring templates at both ends of the annular gap;

[0033] Step 4: After pouring concrete into the mold cavity and curing to a suitable age, the side formwork ring is removed, and the inner ring formwork is taken out. At the same time, the connection between adjacent push plates is disconnected, and a load test is applied to the tunnel lining specimen according to the curing loading plan;

[0034] Step 5: After the test is completed, take out the tunnel lining specimen and record the final crack damage of the lining.

[0035] The beneficial effect of the above technical solution is that the loading test can be carried out directly during the maintenance stage of the tunnel lining, and its simulation effect is good, which can basically realize the three-dimensional load loading test of the tunnel lining at any stage of the whole life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a vertical view of the tunnel lining template described in Example 1 of the present invention;

[0037] Figure 2 It is one of the partial views of the tunnel lining template described in Example 1 of the present invention;

[0038] Figure 3This is a second partial view of the tunnel lining template described in Example 1 of the present invention;

[0039] Figure 4 It is a vertical view of the three-dimensional load applying device described in Example 2 of the present invention;

[0040] Figure 5 It is a vertical view of the positioning cylinder seat described in Example 2 of the present invention;

[0041] Figure 6 It is a schematic end view of the three-dimensional load applying device described in Example 2 of the present invention;

[0042] Figure 7 It is a schematic diagram of the connection between the recording assembly and the push plate described in Example 2 of the present invention;

[0043] Figure 8 It is a schematic diagram of the structure of the clamping member and the mesh-shaped groove clamping in Example 2 of the present invention;

[0044] Fig. 9 This is a vertical view of the three-dimensional load loading device of Example 2 of the present invention when a moving seat is provided;

[0045] Fig.10 It is a schematic diagram of the cooperation between the plurality of positioning rods and the positioning cylinder seat in Embodiment 2 of the present invention;

[0046] Fig.11 It is a schematic diagram of partitions of the three-dimensional load loading device described in Example 3 of the present invention;

[0047] Fig.12 A schematic diagram of the loading and stressing of the tunnel lining specimen in Example 3 of the present invention;

[0048] Fig.13 Schematic diagram of setting strain gauges on the tunnel lining specimen described in Example 3 of the present invention.

[0049] In the figure: 1. tunnel lining template; 11. inner ring template; 111. second connecting ear; 1111. second connecting hole; 12. outer ring template; 121. sealing ring; 122. sub-template ring; 1221. sealing strip; 1222. push plate; 12221. first connecting ear; 12222. first connecting hole; 13. side template ring; 131. third connecting hole; 132. fourth connecting hole; 2. positioning cylinder seat; 21. operating window; 22. mesh groove; 221. axial groove; 222. annular groove; 23. support seat; 3. loading assembly; 31. universal joint; 32. telescopic cylinder; 33. clamping member; 331. clamping bolt; 332. clamping nut; 333. pad; 34. hinge support; 4. moving seat; 41. lifting frame; 42. positioning rod; 5. tunnel lining specimen; 6. strain gauge. DETAILED DESCRIPTION

[0050] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention. The present invention is described in more detail by way of example with reference to the accompanying drawings in the following paragraphs. The advantages and features of the present invention will become clearer according to the following description and claims. It should be noted that the drawings are all in a very simplified form and are not in precise proportions, and are only used to conveniently and clearly assist in explaining the purpose of the embodiments of the present invention.

[0051] Example 1

[0052] like Figure 1 As shown, this embodiment provides a tunnel lining template, including an inner ring template 11, an outer ring template 12 and two side template rings 13, the inner ring template 11 is coaxially placed in the outer ring template 12, and there is an annular gap between the two and the two ends are aligned, the two side template rings 13 are installed at the two ends of the annular gap to block the two ends of the annular gap and enclose to form an annular mold cavity; the outer ring template 12 includes a plurality of sealing rings 121 and a plurality of sub-template rings 122, and the outer ring template 12 is formed by splicing a plurality of sub-template rings 122 in sequence along the length direction, and a sealing ring 121 is sandwiched between any two adjacent sub-template rings 122; the sub-template ring 122 includes a plurality of sealing strips 1221 and a plurality of push plates 1222, and the sub-template ring 122 is composed of a plurality of The push plates 1222 are spliced ​​in sequence along the annular direction, and a sealing strip 1221 is arranged between any two adjacent push plates 1222. The structure is simple, and the outer ring template is spliced ​​by multiple sub-template rings, and the push plates adjacent in the annular direction are sealed by sealing strips, and the push plates adjacent in the axial direction are sealed by sealing rings, so that the entire outer ring template is sealed by multiple push plates. The outer ring template, the inner ring template and the two side template rings are assembled to form a mold cavity, and the mold cavity can be used to cast and form the tunnel lining. After the tunnel lining is formed (that is, the tunnel lining specimen 5 is obtained), the inner ring template and the side template ring can be removed, and the adjacent push plates can be disconnected, and loads are applied to the push plates to perform a three-dimensional load loading test on the tunnel lining throughout its life cycle.

[0053] like Figure 2 and Figure 3As shown, the push plate 1222 in the above technical solution is a strip plate, and a first connecting ear 12221 is protrudingly provided on the outer side of the mold cavity at the four sides of each push plate 1222, and a penetrating first connecting hole 12222 is provided at the first connecting ear 12221. The two push plates 1222 adjacent to each other in the annular direction are bolted together by the first connecting ears 12221 on the long side to enclose the annular sub-template ring 122, and the two push plates 1222 adjacent to each other in the axial direction are bolted together by the first connecting ears 12221 at the corresponding positions thereon to connect multiple sections of the sub-template rings 122 to form an outer ring template 12, so that the two adjacent push plates can be bolted together through the first connecting ears close to each other.

[0054] like Figure 2 and Figure 3 As shown, in the above technical solution, both ends of the inner ring template 11 correspond to a plurality of second connecting ears 111 convexly provided along the annular interval on the inner side of the ring, and the second connecting ears 111 are provided with second connecting holes 1111 penetrating therethrough, and a plurality of third connecting holes 131 are provided annularly spaced at the outer edge of the side template ring 13, and a plurality of fourth connecting holes 132 are provided annularly spaced at the inner edge of the side template ring 13, and the plurality of fourth connecting holes 132 on the side template ring 13 correspond one-to-one with the plurality of second connecting holes 1111 at the corresponding end of the inner ring template 11 and are aligned with each other for bolting, and the plurality of third connecting holes 131 on the side template ring 13 correspond one-to-one with the plurality of first connecting holes 12222 at the corresponding end of the outer ring template 12 and are aligned with each other for bolting, so that the outer ring template and the inner ring template are bolted to the side template ring for assembly.

[0055] The push plates described in this embodiment are all straight strip-shaped plates with a certain curvature in width.

[0056] Example 2

[0057] like Figure 4As shown, this embodiment provides a three-dimensional load loading device, including a positioning cylinder seat 2, a plurality of loading components 3 and a tunnel lining template 1 as described in Example 1, wherein the plurality of loading components 3 correspond to the plurality of push plates 1222 one by one, the positioning cylinder seat 2 is cylindrical, and operation windows 21 are evenly distributed on its side wall, the tunnel lining template 1 is axially placed in the middle of the positioning cylinder seat 2, and each push plate 1222 is connected to the positioning cylinder seat 2 through the corresponding loading component 3 corresponding to the outer side of the mold cavity, and the loading component 3 is used to apply load to the corresponding push plate 1222. Load, so that the tunnel lining formwork can be placed in the positioning cylinder seat, and each push plate is connected to the inner wall of the positioning cylinder seat through the corresponding loading assembly. At this time, the tunnel lining formwork is supported in the positioning cylinder seat by multiple loading assemblies. Before pouring concrete into the mold cavity, a steel cage is first added to the mold cavity. After the pouring is completed, the tunnel lining formwork can be removed until only the push plates are left (people can reach into the positioning cylinder seat through the operating window to unsplice adjacent push plates). At this time, the loading assembly can apply load to the push plates, thereby conducting a three-dimensional load loading test on the tunnel lining specimen throughout its life cycle.

[0058] like Figure 7 As shown, the loading assembly 3 in the above technical solution includes a universal member 31 and a telescopic cylinder 32. The telescopic ends of the telescopic cylinder 32 are connected to the corresponding position of the middle part of the outer side of the push plate 1222 through the universal member 31. The end of the telescopic cylinder 32 away from its telescopic end is connected to the corresponding position of the inner wall of the positioning cylinder seat 2. Its structure is simple, so that the inclination angle of the telescopic cylinder relative to the push plate can be adjusted as needed, and the telescopic cylinder is extended to apply load to the push plate. At this time, the outer side of the entire tunnel lining specimen can be subjected to load from multiple points, and the load force at each point can be adjusted. Its test operation flexibility is good and the simulation effect is good. Among them, the telescopic cylinder can be a hydraulic cylinder.

[0059] The loading assembly 3 in the above technical solution also includes a clamping member 33, and the clamping member 33 is provided at one end of the telescopic cylinder 32 away from its telescopic end. An attachment portion for clamping by the clamping member 33 is provided on the inner wall of the positioning cylinder seat 2, so that the loading assembly and the inner wall of the positioning cylinder seat are detachably connected.

[0060] like Figure 5-Figure 8As shown, the clamping member 33 in the above technical scheme includes a clamping bolt 331 and a nut 332, the attachment portion is a mesh groove 22 arranged on the inner wall of the positioning cylinder seat 2, and the cross-section of the mesh groove 22 is T-shaped, the nut 332 is threadedly connected to the clamping bolt 331, and the head of the clamping bolt 331 is inserted into the mesh groove 22, the threaded end of the clamping bolt 331 is swingably connected to the end of the telescopic cylinder 32 away from its telescopic end through a movable hinge support 34, tighten the nut 332 to clamp the clamping bolt 331 at the corresponding position of the mesh groove 22, or loosen the nut 332 to release the clamping bolt 331 relative to the positioning cylinder seat 2, and the operating window 21 is arranged at the mesh of the mesh groove 22, so that the position of each clamping member on the inner wall of the positioning cylinder seat can be flexibly adjusted.

[0061] The clamping member in this embodiment may further be provided with a pad 333, and the pad 333 has a certain curvature, and a hole is provided in the middle of the pad 33 for the clamping bolt 331 to pass through, and the pad is squeezed by the clamping nut to abut against the inner wall of the positioning cylinder seat to improve the clamping effect of the clamping member on the inner wall of the positioning cylinder seat (the side of the pad facing away from the clamping nut is covered with grooves to form a friction surface).

[0062] like Figure 5 As shown, the mesh groove 22 in the above technical solution includes a plurality of axial grooves 221 and a plurality of annular grooves 222, the cross-sections of the axial grooves 221 and the annular grooves 222 are both T-shaped, and the plurality of axial grooves 221 are axially arranged on the inner wall of the positioning cylinder seat 2 and are distributed in an annular direction at intervals, and both ends of each axial groove 221 pass through the two ends of the positioning cylinder seat 2, and the plurality of annular grooves 222 are coaxially arranged on the inner wall of the positioning cylinder seat 2 and are distributed in an axial direction at intervals, so that the position of the clamping member on the inner wall of the positioning cylinder seat can be adjusted axially along the axial groove, and can also be adjusted in an annular direction along the annular groove.

[0063] In this embodiment, a plurality of support seats 23 may be provided at intervals along the length direction of the lower end of the positioning cylinder seat 2 to support the positioning cylinder seat 2 to be suspended in the air.

[0064] like Fig. 9 and Fig.10As shown, the above technical solution also includes a moving seat 4, which has a lifting frame 41, and the lifting frame 41 has multiple horizontally arranged positioning rods 42, and multiple positioning rods 42 extend into the inner ring template 11 to lift the inner ring template 11, and the lifting frame 41 is used to adjust the height of the tunnel lining template 1, and the moving seat 4 is used to drive the lifting frame 41 to drive the tunnel lining template 1 to move axially in and out of the positioning cylinder seat 2, so that the entire moving seat can move the inner ring template into the outer ring template, or move it out of the outer ring template like a forklift, and can flexibly adjust the position of the inner ring template in the outer ring template.

[0065] The lower end of the movable seat is provided with a plurality of rollers, and the lifting frame can adopt a screw drive member vertically arranged on the movable seat, and the positioning rod is arranged at the driving end of the lifting frame.

[0066] Example 3

[0067] This embodiment provides a loading test method, which uses the three-dimensional load loading device as described in Example 2 to perform the test, and includes the following steps:

[0068] Step 1: Obtain the annular and axial stresses at key positions of the tunnel lining of the active fault section through engineering measurement or numerical simulation, so as to determine the loading angle and loading target of each loading component 3 and determine the maintenance loading plan;

[0069] Step 2: Match the outer ring template 12 with a plurality of loading components 3, and install the plurality of loading components 3 at corresponding positions on the inner wall of the positioning cylinder seat 2;

[0070] Step 3: insert the inner ring template 11 into the outer ring template 12, and make the inner ring template 11 coaxial with the positioning cylinder seat 2, then insert the steel cage of the tunnel lining into the annular gap between the inner ring template 11 and the outer ring template 12, and finally install the side ring templates at both ends of the annular gap;

[0071] Step 4: After pouring concrete into the mold cavity and curing to a suitable age, the side template ring 13 is removed, and the inner ring template 11 is taken out. At the same time, the connection between the adjacent push plates 1222 is disconnected, and a load test is applied to the tunnel lining specimen according to the curing loading plan;

[0072] Step 5: After the test is completed, take out the tunnel lining specimen and record the final crack damage of the lining.

[0073] This method can directly carry out loading tests on tunnel lining specimens during the maintenance stage. It has good simulation effect and can basically realize three-dimensional load loading tests on tunnel linings at any stage of their entire life cycle.

[0074] like Fig.11 and Fig.12 As shown, the sub-template ring 122 in this embodiment has seven sections (which can be regarded as seven zones, which are zone A, zone B, zone C, zone D, zone E, zone F and zone G along the length direction), wherein the loading components corresponding to zone A and zone G are perpendicular to the corresponding push plates to clamp the two ends of the tunnel lining specimen in the positioning cylinder seat. In addition, no loading component is provided in the upper half of zone C, and no loading component is provided in the lower half of zone E. At this time, empty zones are formed above zone C and below zone E, and the corresponding inclined planes between the two empty zones constitute a fault plane, while the remaining loading components have the same inclination angles, see for details. Fig.11 shown.

[0075] in accordance with Fig.11 and Fig.12 As shown, the loading test method in this embodiment may specifically include the following steps:

[0076] Step 1: Determine the loading scheme: Fig.11 As shown in the figure, the annular stress F1 and axial stress F2 of the key position of the tunnel lining of the active fault section are obtained through engineering measurement or numerical simulation, so as to determine the loading angle a and loading target F of each movable loading unit and determine the maintenance loading plan. The active fault section tunnel is mainly divided into seven areas (A-G), that is, the tunnel lining template is assembled in 7 sections, and the BF area mainly simulates the forced deformation area, among which the upper part of the C area and the lower part of the E area are the empty areas, and the load form is that there is no load applied on the empty side; the A area and the G area are normal areas, and the load is applied according to the normal section of the tunnel. The loading unit is installed perpendicular to the tunnel lining specimen. The schematic diagram of the mechanical mechanism of tunnel forced deformation is shown in the figure. Fig.12 shown.

[0077] Step 2: Assemble the three-dimensional load loading device: Assemble the tunnel lining template, put the steel cage inside it, and clamp each loading component in the positioning cylinder seat according to the design scheme of step 1 (such as Fig.11 As shown), at this time, the telescopic cylinder does not apply a loading force to the push plate;

[0078] Step 3: lining pouring and curing load application: remove the longitudinal sealing strip of the vault, pour C35 concrete into the mold cavity, pour in layers and vibrate during the pouring process to eliminate bubbles and voids in the concrete. After the pouring is completed, wait for 5-8 hours for the concrete to finally set, remove the bolts between all the arc push plates, remove the template rings on both sides as well as the sealing strips and sealing rings, and apply the load according to the curing loading plan. The load is continuously applied during the formation of the lining concrete strength. The load application angle of the A and G areas is 90°, and the load target F is directly applied, and the load target F=f1; the upper part of the C area and the lower part of the E area are de-hollow areas, and the loading unit is not installed (the push plate of the de-hollow area can be removed); the loading of the non-de-hollow area in the five areas of the B-F area requires moving the clamping piece along the axial groove in the positioning cylinder seat, so that the angle between each loading component and the positioning cylinder seat is adjusted to the corresponding loading angle a, and the loading component is tightened and clamped with the mesh groove after it is in place. Finally, each loading unit applies the corresponding load target F. The schematic diagram of the loading unit installation is shown in Fig.12 As shown. The loading angle a and the load target F of each loading unit are:

[0079] a=arctan(F2 / F1),

[0080]

[0081] Wherein F2 is the hoop stress, and F1 is the axial stress (in order to avoid the error between the oil pressure of the telescopic cylinder of the loading assembly and the actual applied load affecting the test loading, a strain gauge may be sandwiched between the push plate and the tunnel lining specimen for load monitoring, as described in step 4 below);

[0082] Step 4: Laying out strain gauges: Curing the tunnel lining specimens to a suitable age for 21-28 days until the concrete reaches the designed strength, removing the inner ring formwork, taking out the tunnel lining specimens, and installing strain gauges on the outer wall of the tunnel lining specimens at the corresponding positions inside and outside each section of Zone A-G, wherein 22 sets of strain gauges 6 are symmetrically arranged on the inner side of the tunnel lining specimens in each zone, and 14 sets of strain gauges 6 are symmetrically arranged on the outer side of the tunnel lining specimens in each zone (such as Fig.13 As shown in the figure, all strain gauges are arranged circumferentially using single strain gauges. After the strain gauges are set up, the tunnel lining specimen is returned to its original position to avoid breaking the wire during the movement.

[0083] Step 5: Perform destructive test loading: According to the relevant test procedures and model test requirements, design a suitable loading scheme. The test load application process is as follows: Divide the numerical simulation value of the secondary lining ultimate load by the similarity ratio C qis the basic value J (obtained according to the similarity theory, which belongs to the prior art and will not be elaborated here). In the test, all loading units apply pressure at the same time. The first-level load is 0.1 times the basic value, that is, 0.1J. The load is applied gradually in proportion, that is, the pressure is gradually increased with a loading gradient of 0.1J. Each level of loading is maintained for 10 minutes, and then the strain value is read and the development of cracks in the tunnel lining specimen is recorded. The load is loaded until the tunnel lining specimen is destroyed, and one test loading is completed.

[0084] Step 6, post-test processing: After the test is completed, first remove all strain gauges inside the tunnel lining specimen, release the loading of all loading components, and move the tunnel lining specimen out of the positioning cylinder seat through the moving seat, and record the final crack damage of the tunnel lining specimen to complete a test process.

[0085] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any ordinary technician in the industry can smoothly implement the present invention as shown in the drawings and described above. However, any equivalent changes, modifications and evolutions made by technicians familiar with the profession without departing from the scope of the technical solution of the present invention using the technical content disclosed above are all equivalent embodiments of the present invention. At the same time, any equivalent changes, modifications and evolutions made to the above embodiments based on the essential technology of the present invention are still within the protection scope of the technical solution of the present invention.

Claims

1. A tunnel lining template, characterized in that: It comprises an inner ring template (11), an outer ring template (12) and two side template rings (13), wherein the inner ring template (11) is coaxially arranged inside the outer ring template (12), and an annular gap is provided between the two and the two ends are aligned, and the two side template rings (13) are installed at the two ends of the annular gap to block the two ends of the annular gap and enclose to form an annular mold cavity; The outer ring template (12) comprises a plurality of sealing rings (121) and a plurality of sub-template rings (122), and the outer ring template (12) is formed by sequentially splicing the plurality of sub-template rings (122) along the length direction, and a sealing ring (121) is sandwiched between any two adjacent sub-template rings (122); The sub-template ring (122) comprises a plurality of sealing strips (1221) and a plurality of push plates (1222), and the sub-template ring (122) is formed by splicing the plurality of push plates (1222) in sequence along a circumferential direction, and a sealing strip (1221) is provided between any two adjacent push plates (1222).

2. The tunnel lining formwork according to claim 1, characterized in that: The push plate (1222) is a strip plate, and each of the push plates (1222) is provided with a first connecting ear (12221) protruding from the outer side of the mold cavity at the four side edges thereof, and a first connecting hole (12222) is provided at the first connecting ear (12221). The two push plates (1222) adjacent to each other in the annular direction are bolted together through the first connecting ears (12221) on the long sides to enclose the annular sub-template ring (122), and the two push plates (1222) adjacent to each other in the axial direction are bolted together through the first connecting ears (12221) at the corresponding positions thereon to connect multiple sections of the sub-template rings (122) to form an outer ring template (12).

3. The tunnel lining formwork according to claim 2, characterized in that: Both ends of the inner ring template (11) are provided with a plurality of second connecting ears (111) convexly spaced along the annular direction on the inner side of the ring, and the second connecting ears (111) are provided with a second connecting hole (1111) penetrating therethrough; a plurality of third connecting holes (131) are provided at annular direction on the outer edge of the side template ring (13); a plurality of fourth connecting holes (132) are provided at annular direction on the inner edge of the side template ring (13); the plurality of fourth connecting holes (132) on the side template ring (13) correspond one-to-one with the plurality of second connecting holes (1111) at the corresponding end of the inner ring template (11) and are aligned with each other for bolt connection; the plurality of third connecting holes (131) on the side template ring (13) correspond one-to-one with the plurality of first connecting holes (12222) at the corresponding end of the outer ring template (12) and are aligned with each other for bolt connection.

4. A three-dimensional load loading device, characterized in that: It comprises a positioning cylinder seat (2), a plurality of loading components (3) and a tunnel lining template (1) as claimed in any one of claims 1 to 3, wherein the plurality of loading components (3) correspond one to one with the plurality of push plates (1222), the positioning cylinder seat (2) is cylindrical, and operation windows (21) are evenly distributed on its side walls, the tunnel lining template (1) is axially placed in the middle of the positioning cylinder seat (2), and the outer side of each push plate (1222) corresponding to the mold cavity is connected to the positioning cylinder seat (2) through the corresponding loading component (3), and the loading component (3) is used to apply a loading force to the corresponding push plate (1222).

5. The three-dimensional load applying device according to claim 4, characterized in that: The loading assembly (3) comprises a universal member (31) and a telescopic cylinder (32), the telescopic ends of the telescopic cylinder (32) being connected to a position corresponding to the middle of the outer side of the push plate (1222) through the universal member (31), and the end of the telescopic cylinder (32) away from the telescopic end is connected to a corresponding position of the inner wall of the positioning cylinder seat (2).

6. The three-dimensional load applying device according to claim 5, characterized in that: The loading assembly (3) further comprises a clamping member (33), the clamping member (33) being arranged at one end of the telescopic cylinder (32) away from the telescopic end thereof, and an attachment portion for clamping by the clamping member (33) being arranged on the inner wall of the positioning cylinder seat (2).

7. The three-dimensional load applying device according to claim 6, characterized in that: The clamping member (33) comprises a clamping bolt (331) and a clamping nut (332); the attachment portion is a mesh-shaped groove (22) arranged on the inner wall of the positioning cylinder seat (2); and the cross-section of the mesh-shaped groove (22) is T-shaped; the clamping nut (332) is threadedly connected to the clamping bolt (331); and the head of the clamping bolt (331) is inserted into the mesh-shaped groove (22); the thread of the clamping bolt (331) is The end is rotatably connected to the end of the telescopic cylinder (32) away from the telescopic end thereof through a movable hinge support (34), the clamping nut (332) is tightened to clamp the clamping bolt (331) at the corresponding position of the mesh groove (22), or the clamping nut (332) is loosened to release the clamping bolt (331) relative to the positioning cylinder seat (2), and the operating window (21) is arranged at the mesh of the mesh groove (22).

8. The three-dimensional load applying device according to claim 7, characterized in that: The mesh-shaped groove (22) comprises a plurality of axial grooves (221) and a plurality of annular grooves (222); the cross-sections of the axial grooves (221) and the annular grooves (222) are both T-shaped; the plurality of axial grooves (221) are axially arranged on the inner wall of the positioning cylinder seat (2) and are distributed at intervals along the annular direction; the two ends of each axial groove (221) pass through the two ends of the positioning cylinder seat (2); the plurality of annular grooves (222) are coaxially arranged on the inner wall of the positioning cylinder seat (2) and are distributed at intervals along the axial direction.

9. The three-dimensional load applying device according to claim 4, characterized in that: The invention also comprises a movable seat (4), wherein the movable seat (4) has a lifting frame (41), and the lifting frame (41) has a plurality of horizontally arranged positioning rods (42), and the plurality of positioning rods (42) extend into the inner ring template (11) to lift the inner ring template (11), and the lifting frame (41) is used to adjust the height of the tunnel lining template (1), and the movable seat (4) is used to drive the lifting frame (41) to drive the tunnel lining template (1) to move axially to enter and exit the positioning cylinder seat (2).

10. A loading test method, characterized in that: The test is carried out using the three-dimensional load loading device as described in any one of claims 4 to 9, which comprises the following steps: Step 1: Obtain the annular and axial stresses at key positions of the tunnel lining in the active fault section through engineering measurements or numerical simulations, thereby determining the loading angles and loading targets of each loading component (3) and determining the maintenance loading plan; Step 2: matching the outer ring template (12) with a plurality of loading components (3), and installing the plurality of loading components (3) at corresponding positions on the inner wall of the positioning cylinder seat (2); Step 3: insert the inner ring template (11) into the outer ring template (12), and make the inner ring template (11) and the positioning cylinder seat (2) coaxially distributed, then insert the steel cage of the tunnel lining into the annular gap between the inner ring template (11) and the outer ring template (12), and finally install the side ring templates at both ends of the annular gap; Step 4: After pouring concrete into the mold cavity and curing to a suitable age, the side template ring (13) is removed, and the inner ring template (11) is taken out, and the connection between adjacent push plates (1222) is disconnected, and a load test is applied to the tunnel lining specimen according to the curing loading plan; Step 5: After the test is completed, take out the tunnel lining specimen and record the final crack damage of the lining.

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