Tunnel deviation rectifying method

Abstract

The invention relates to the technical field of tunnels, and provides a tunnel deviation rectifying method which comprises the following steps: assembling a first supporting assembly on the inner side of an over-excavation side lining in a deviation rectifying section range, mounting a second supporting assembly on the outer side of a first arch wall box body, dismantling an under-excavation side lining of an existing tunnel, and then excavating surrounding rock on the under-excavation side to an arch wall design contour line of a newly-built tunnel. After slag is removed, the remaining box body structures are assembled, then the first temporary steel supports and the second supporting assemblies are dismantled, an existing road surface and a bottom inverted arch of the existing tunnel are dismantled to an inverted arch design contour line of the newly-built tunnel, lower surrounding rock on the undercut side is excavated to the inverted arch design contour line, and an inverted arch secondary lining of the newly-built tunnel is constructed according to the inverted arch design contour line; and after the inverted arch secondary lining reaches the strength, the remaining conventional structure is constructed. Accurate adjustment of the tunnel axis is achieved, the problem of deviation of the existing tunnel axis is safely and rapidly solved, the prefabricated box body structure is adopted, the cast-in-place time can be shortened, and the construction efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of tunnels, in particular to a tunnel deviation correction method. Background Art

[0002] During the tunnel construction process, due to the influence of various factors such as measurement errors, the tunnel axis will deviate. Especially for long tunnels, the measurement errors will gradually accumulate during the tunnel construction process. When excavating from both ends of the tunnel, if there are errors in the measurements at both ends, a large axis deviation will occur when the tunnel is penetrated. This penetration error may cause the tunnel to fail to dock normally, and additional processing is required, such as expansion excavation, adjustment of lining and other measures to make the tunnel meet the design requirements.

[0003] like Figure 1 As shown, the current tunnel deviation correction plan for the above problems is: construct temporary steel support 10 on the over-excavation side according to the design requirements, remove the secondary lining and initial support steel support (or grid steel frame) on the under-excavation side, excavate the surrounding rock on the under-excavation side to the design contour line, construct the initial support of the new composite lining, reserve a C20 pumping concrete pipeline on the over-excavation side, pump C20 concrete backfill on the over-excavation side, build the secondary lining of the arch wall, remove the existing road surface and the bottom invert to the design contour line of the new lining invert, and then excavate the surrounding rock of the invert part on the under-excavation side to the design contour line. Construct the secondary lining of the bottom invert according to the design contour line, and after the concrete of the secondary lining of the invert reaches the strength, construct the invert backfill, center ditch, and transverse water guide pipe according to the design drawings, and then construct the secondary lining concrete of the arch wall.

[0004] This construction plan has the following problems: (1) the temporary support structure occupies the space of the newly built composite lining, which means that the temporary support needs to be removed before the initial support is built, which poses a great construction risk; and (2) the newly built lining still adopts the composite lining form of the original design plan, which has a long construction period and poor timeliness of the support structure. On the one hand, it prolongs the construction period. On the other hand, the expansion of the under-excavated side will undoubtedly cause secondary disturbance to the surrounding rock. This composite lining has insufficient rigidity and poor timeliness, which poses a great construction risk.

[0005] In view of this, it is necessary to propose a tunnel deviation correction method to solve or at least alleviate the above defects. Summary of the invention

[0006] The main purpose of the present invention is to provide a tunnel deviation correction method to solve the technical problems of tunnel deviation correction schemes in the prior art, such as high construction risk, long construction period and poor timeliness.

[0007] To achieve the above object, the present invention provides a tunnel deviation correction method, comprising the following steps: S1, obtaining the deviation correction section range of the existing tunnel, and assembling the first support assembly on the inner side of the over-excavation side lining within the deviation correction section range; wherein the first support assembly includes a first arch foot box, a first arch wall box and a first temporary steel support, the first arch foot box is fixedly connected to the existing road surface of the existing tunnel, the first arch wall box is connected to the top of the first arch foot box, one end of the first temporary steel support is overlapped on the existing road surface, and the other end is connected to the inner wall of the first arch wall box; S2, installing a second support assembly on the outside of the first arch wall box; wherein one end of the second support assembly is connected to the outer wall of the first arch wall box, and the other end is connected to the over-excavation side lining; S3, dismantling the lining of the under-excavated side of the existing tunnel, excavating the surrounding rock of the under-excavated side to the arch wall design contour line of the new tunnel, assembling the remaining box structure after clearing the slag, and then dismantling the first temporary steel support and the second support assembly; wherein the first arch foot box, the first arch wall box and the remaining together form the arch wall lining structure of the new tunnel; S4, dismantling the existing road surface and bottom invert of the existing tunnel to the invert design contour line of the new tunnel, and excavating the lower surrounding rock of the undercut side to the invert design contour line; S5, constructing the secondary lining of the invert arch of the newly built tunnel according to the designed contour line of the invert arch, and constructing the remaining conventional structure after the secondary lining of the invert arch reaches the required strength.

[0008] Preferably, the first temporary steel support is a corrugated steel plate, the second support assembly is an I-beam, the extension direction of the corrugated steel plate is consistent with the extension direction of the newly built tunnel, and the top of the corrugated steel plate is fixedly connected to the first arch wall box.

[0009] Preferably, the model of the corrugated steel plate is obtained by the following steps: S11, when determining that the lining structure of the existing tunnel is in a stable state, a lower limit value of the supporting force that the first supporting assembly needs to provide to the second supporting assembly; S12, obtaining the sum of the deadweights of the first support assembly and the second support assembly, and determining the theoretical axial force exerted on the corrugated steel plate according to the sum of the deadweights and the lower limit of the support force; S13, determining the model of the corrugated steel plate according to the theoretical axial force.

[0010] Preferably, the step S11 specifically includes the following steps: S111, the over-excavation side lining of the existing tunnel is equivalent to a horizontal cantilever beam; wherein the arch foot consolidation end point of the horizontal cantilever beam is point A, the other end point is point B, and the intersection point of the I-beam and the over-excavation side lining is point C; S112, obtaining an intersection point B of a design contour line of the newly built tunnel and a design contour line of the existing tunnel; wherein the over-excavation side lining is a lining structure section from point A to point B; S113, calculating the vertical uniformly distributed pressure of the surrounding rock above the over-excavation side lining, and calculating the deadweight load of the over-excavation side lining; S114, obtaining a vertically uniformly distributed total load on the overcut side lining according to the vertically uniformly distributed pressure of the upper surrounding rock and the deadweight load; S115: Determine the lower limit value of the support force that the first support assembly needs to provide to the second support assembly at point C according to the vertical uniformly distributed total load.

[0011] Preferably, determining the theoretical axial force exerted on the corrugated steel plate according to the sum of the deadweight and the lower limit of the supporting force in step S12 specifically comprises the following steps: S121, the first support assembly is equivalent to a secondary hyperstatic structure; wherein the first arch foot box and the first arch wall box are the first rod, the corrugated steel plate is the second rod, the first rod is connected to the existing ground at point 1, and the other end is point 2, the second rod is rigidly connected to the first rod at point 2, point 2 is acted upon by the lower limit of the support force perpendicular to the first rod, and the other end of the second rod is point 3 and is hinged to the existing ground; S122, calculating the deadweight load of the first supporting assembly; S123, inputting the deadweight load, the lower limit of the supporting force and the secondary hyperstatic structure into a structural mechanics solver to obtain a theoretical axial force on the corrugated steel plate under the action of the deadweight load and the lower limit of the supporting force.

[0012] Preferably, the step S13 specifically includes the following steps: S31, firstly select a type of corrugated steel plate according to construction experience, and use it as the current type of corrugated steel plate; S32, obtaining the allowable stress and net cross-sectional area of ​​the steel material of the current model of the corrugated steel plate, and calculating the calculated axial force of the current model of the corrugated steel plate according to the allowable stress and net cross-sectional area of ​​the steel material; S33, determining a safety factor of the corrugated steel plate according to the calculated axial force and the theoretical axial force; S34, determining whether the safety factor is greater than a preset threshold; S35, when the safety factor is greater than a preset threshold, determining that the current model of the corrugated steel plate meets the design requirements, and using the current model of the corrugated steel plate as the model of the corrugated steel plate; S36, when the safety factor is less than or equal to the preset threshold, it is determined that the current model of the corrugated steel plate does not meet the design requirements, a new model of the corrugated steel plate is selected and used as the current model of the corrugated steel plate, and then returns to step S32.

[0013] Preferably, the step S115 specifically includes the steps of: using the formula Determine the lower limit of the support force that the first support component needs to provide to the second support component at point C ;in, is the vertical uniformly distributed total load, is the length from point A to point C, is the distance from point C to point B.

[0014] Preferably, the step S113 of calculating the vertical uniformly distributed pressure of the surrounding rock above the overcut side lining comprises the following steps: Using formula Calculate the vertical uniform pressure q of the surrounding rock above the overcut side lining; where: is the bulk density of the surrounding rock mass, is the diameter of the existing tunnel chamber, is the lateral pressure coefficient, is the friction angle of the surrounding rock mass, It is the thickness of surrounding rock covering the top of the existing tunnel.

[0015] Preferably, the step between step S2 and step S3 further includes the step of: injecting foam concrete into the inner side of the over-excavation side lining through the first grouting hole reserved on the first arch foot box and the second grouting hole reserved on the first arch wall box; And / or the step between steps S3 and S4 also includes: continuing to inject foam concrete into the inner side of the over-excavation side lining through the second grouting hole reserved on the first arch wall box to fill the remaining cavity between the over-excavation side lining and the first arch wall box.

[0016] Preferably, the step S5 further includes the following steps: S6, continue pouring concrete into the first arch foot box, the first arch wall box and the remaining box structures.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present application achieves precise adjustment of the tunnel axis by retaining part of the existing lining on the over-excavation side and expanding and rebuilding the under-excavation side, thereby safely and quickly solving the problem of deviation of the existing tunnel axis; by adopting the first support assembly and the second support assembly, as well as the first arch foot box and the first arch wall box, a permanent and temporary combined support system (which can be used as a temporary support structure during construction and as a permanent lining structure for a newly built tunnel) can effectively improve the stability of the lining on the over-excavation side during construction, and has strong usability, and there is no need to formulate different correction plans according to the size of the tunnel axis deviation.

[0018] Secondly, compared with the composite lining form used in the tunnel lining of the prior art, the first arch foot box, the first arch wall box and the remaining box structure of the present application adopt a prefabricated box structure, which can reduce the on-site pouring time and improve construction efficiency. In addition, the expansion of the under-excavation side will undoubtedly cause secondary disturbance to the surrounding rock. The box structure of the present application adopts rigid support to effectively reduce the disturbance of the surrounding rock and improve construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0020] Figure 1 Schematic diagram of tunnel deviation correction scheme in the prior art; Figure 2 is a schematic diagram of a flow chart in one embodiment of the present invention; Figure 3 It is a schematic diagram of the structure after the construction of step S2 in one embodiment of the present invention; Figure 4 It is a schematic diagram of the structure after the construction of step S5 in one embodiment of the present invention; Figure 5 It is a schematic diagram of converting the over-excavation side lining of an existing tunnel into a horizontal cantilever beam in one embodiment of the present invention; Figure 6 It is a schematic diagram of an embodiment of the present invention in which the first supporting assembly is equivalent to a secondary hyperstatic structure; Figure 7 FIG. 4 is a schematic diagram of the axial force of the first rod and the second rod in one embodiment of the present invention.

[0021] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings in conjunction with the embodiments.

[0022] Description of Figure Numbers: 10. Temporary steel support on the over-excavation side; 20. Existing tunnel; 210. Existing road surface; 220. Lining on the over-excavation side; 230. Lining on the under-excavation side; 30. New tunnel; 310. Remaining box structure; 311. Second arch foot box; 312. Second arch wall box; 320. Secondary lining of the invert; 40. First support assembly; 410. First arch foot box; 420. First arch wall box; 430. First temporary steel support; 440. First rod; 450. Second rod; 50. Second support assembly. DETAILED DESCRIPTION

[0023] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0026] In addition, the descriptions of "right part", "middle part" and the like in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "right part" and "middle part" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0027] Please refer to the attached Figures 1 to 7 In one embodiment of the present invention, a tunnel deviation correction method includes the following steps: S1, obtaining the deviation correction section range of the existing tunnel 20, and assembling the first support assembly 40 on the inner side of the over-excavation side lining 220 within the deviation correction section range; wherein the first support assembly 40 includes a first arch foot box 410, a first arch wall box 420 and a first temporary steel support 430, the first arch foot box 410 is fixedly connected to the existing road surface 210 of the existing tunnel 20, the first arch wall box 420 is connected to the top of the first arch foot box 410, one end of the first temporary steel support 430 is overlapped on the existing road surface 210, and the other end is connected to the inner wall of the first arch wall box 420; S2, installing a second support assembly 50 on the outer side of the first arch wall box 420; wherein one end of the second support assembly 50 is connected to the outer wall of the first arch wall box 420, and the other end is connected to the over-excavation side lining 220; S3, dismantling the under-excavated side lining 230 of the existing tunnel 20, then excavating the surrounding rock of the under-excavated side to the arch wall design contour line of the new tunnel 30, assembling the remaining box structure 310 after slag removal, and then dismantling the first temporary steel support 430 and the second support assembly 50; wherein the first arch foot box 410, the first arch wall box 420 and the remaining together enclose the arch wall lining structure of the new tunnel 30; It should be noted that the demolition of the under-excavated side lining 230 should follow the top-down principle, and the longitudinal length of each demolition should not be greater than 5m. Static blasting or manual and mechanical demolition can be used during construction. Blasting with explosives and static blasting should not be used.

[0028] Furthermore, anchor rod through holes (not shown) may be reserved in the remaining box structure 310, and system anchor rods may be driven into the under-excavated side through the reserved anchor rod through holes to enhance the stability and safety of the overall structure.

[0029] S4, dismantling the existing road surface and bottom invert of the existing tunnel 20 to the invert design contour line of the newly built tunnel 30, and excavating the lower surrounding rock of the undercut side to the invert design contour line; S5, constructing the secondary lining 320 of the newly built tunnel 30 according to the designed contour line of the invert, and constructing the remaining conventional structures, such as the invert backfill layer, central ditch, transverse water pipe and other conventional structures after the secondary lining 320 of the invert reaches the required strength.

[0030] Specifically, the scope of the deviation correction section can be measured and determined in advance, and the first support assembly 40 is installed on the inner side of the over-excavation side lining 220 of the existing tunnel 20 to form an inner temporary support to ensure structural stability during construction. The first support assembly 40 is connected to the over-excavation side lining 220 through the second support assembly 50 to form an internal and external coordinated support system, and then the original secondary lining on the under-excavation side is removed, and the surrounding rock is excavated according to the contour line of the new tunnel 30 to expand the tunnel section. After the slag is cleared, the remaining box structure 310 is installed, and together with the first arch foot box 410 and the first arch wall box 420, a new arch wall lining structure is enclosed to complete the replacement of the main lining structure. Then the existing road surface and inverted arch are removed, and the lower surrounding rock is excavated to the design contour to ensure the construction space of the inverted arch. The secondary lining 320 of the inverted arch is constructed according to the design to form a complete tunnel bottom structure. After the new structure reaches the strength, the first temporary steel support 430 and the second support assembly 50 are gradually removed to achieve a smooth transfer of load from the temporary system to the permanent structure.

[0031] As a preferred example, please see the attached Figure 4 The remaining box structure 310 includes a second arch foot box 311 and three second arch wall boxes 312 assembled in sequence. The second arch foot box 311 and the first arch foot box 410 are relatively arranged on the left and right sides of the tunnel. The second arch wall box 312 can preferably adopt a standard box form, which can effectively reduce the construction difficulty and project cost.

[0032] Preferably, the correction can be carried out along the longitudinal direction of the tunnel according to the correction section range, and the construction sequence of each mold is carried out according to steps S1 to S5 until the normal tunnel section is constructed to complete the correction of the correction section range.

[0033] In the present application, by retaining part of the existing lining on the over-excavation side and expanding and reconstructing the under-excavation side, the tunnel axis is accurately adjusted, and the problem of deviation of the axis of the existing tunnel 20 is solved safely and quickly; by adopting the first support assembly 40 and the second support assembly 50, as well as the first arch foot box 410 and the first arch wall box 420, a permanent and temporary combined support system (which can be used as a temporary support structure during construction and as a permanent lining structure of the newly built tunnel 30) can be effectively improved. The stability of the lining 220 on the over-excavation side during construction can be effectively improved, and it has strong usability, and there is no need to formulate different correction plans according to the deviation size of the tunnel axis.

[0034] Secondly, compared with the composite lining form used in the tunnel lining of the prior art, the first arch foot box 410, the first arch wall box 420 and the remaining box structure 310 of the present application adopt a prefabricated box structure, which can reduce the on-site pouring time and improve construction efficiency. In addition, the expansion of the under-excavation side will undoubtedly cause secondary disturbance to the surrounding rock. The box structure of the present application adopts rigid support to effectively reduce the disturbance of the surrounding rock and improve construction safety.

[0035] As a preferred embodiment, the first temporary steel support 430 is a corrugated steel plate, the second support assembly 50 is an I-beam, the extension direction of the corrugated steel plate is consistent with the extension direction of the newly built tunnel 30, and the top of the corrugated steel plate is fixedly connected to the first arch wall box 420.

[0036] Specifically, the extension direction of the corrugated steel plate is consistent with the extension direction of the newly-built tunnel 30, which can significantly improve its longitudinal bending stiffness and form a continuous longitudinal support system. The corrugated steel plate and I-beam are both prefabricated components and can be quickly assembled, thus shortening the construction period.

[0037] Preferably, if Figure 3 As shown, an assembly groove (not shown) is provided on the inner side of the first arch wall box 420, and a bevel is provided on the upper edge of the assembly groove to facilitate assembly, and is used to connect with the top of the corrugated steel plate. The corrugated steel plate is used as the first temporary steel support 430, one end of which is overlapped on the existing pavement 210, and the other end is overlapped in the assembly groove. Furthermore, a channel steel is provided on the upper end of the corrugated steel plate as a connecting flange, which is connected to the first arch wall box 420 by bolts.

[0038] Furthermore, connecting rod supports may be provided between the first arch foot box 410 and the corrugated steel plate, and between the first arch wall box 420 and the corrugated steel plate, so as to enhance the stability of the overall structure.

[0039] Furthermore, a connection port (not shown) can be set at the outer upper edge of the first arch wall box 420 with a longitudinal spacing of 40 cm for connecting an I-beam, that is, one end of the I-beam is connected to the overlap joint, and the other end is connected to the over-excavation side lining 220.

[0040] Furthermore, the bottom opening of the corrugated steel plate can be 200 80cm, with an interval of 5m, as the exit of the escape passage, it has both escape and rescue functions to ensure construction safety.

[0041] Furthermore, a groove may be formed in the existing road surface 210, and the arch foot end of the first arch foot box 410 may be connected in the groove. Those skilled in the art may make a selection according to actual needs.

[0042] As a preferred embodiment, the model of the corrugated steel plate is obtained by the following steps: S11, when it is determined that the lining structure of the existing tunnel 20 is in a stable state, the lower limit value of the supporting force that the first supporting assembly 40 needs to provide to the second supporting assembly 50; S12, obtaining the sum of the deadweights of the first support assembly 40 and the second support assembly 50, and determining the theoretical axial force exerted on the corrugated steel plate according to the sum of the deadweights and the lower limit of the support force; S13, determining the model of the corrugated steel plate according to the theoretical axial force.

[0043] It is worth noting that in the process of tunnel deviation correction, since it is necessary to remove the lining 230 of the under-excavated side of the existing tunnel 20 and then excavate the surrounding rock of the under-excavated side to the arch wall design contour line of the new tunnel 30, after the under-excavated side lining 230 is removed, the original annular closed lining structure of the existing tunnel 20 is destroyed. If the supporting force provided by the first support assembly 40 and the second support assembly 50 is insufficient, safety problems are likely to occur. In addition, the main load-bearing components of the first support assembly and the second support assembly 50 are corrugated steel plates. If the corrugated steel plate model is blindly selected, there may be excessive consideration of safety, resulting in material waste and increased construction costs, or the selected corrugated steel plate model may not meet safety requirements, resulting in safety hazards. Therefore, it is of great significance to quickly determine the design with the best performance and the lowest cost to avoid material waste and construction costs caused by excessive design, while meeting the expected safety reserve.

[0044] In this embodiment, the minimum support force requirement of the first support assembly 40 for the second support assembly 50 is determined through structural stability analysis to prevent structural instability due to insufficient support. The weight of the support assembly is superimposed on the lower limit of the support force to calculate the theoretical axial force that the corrugated steel plate needs to bear, and then the model of the corrugated steel plate is selected according to the axial force value, which can avoid blind empirical selection, determine the lower limit of the support force and the axial force through theoretical calculation, reduce material redundancy, reduce engineering costs and meet safety requirements.

[0045] In addition, during the structural design stage, the model calculation process of the corrugated steel plate can serve as an important basis for evaluating the feasibility and rationality of the design scheme. The calculation data can be used to determine whether the selected corrugated steel plate can meet the support requirements of the surrounding rock and the secondary lining that has not been removed, and potential problems in the design can be discovered in time and optimized and adjusted to avoid safety hazards in actual use.

[0046] As a preferred implementation, the step S11 specifically includes the following steps: S111, the over-excavation side lining 220 of the existing tunnel 20 is equivalent to a horizontal cantilever beam; wherein the arch foot consolidation end point of the horizontal cantilever beam is point A, the other end point is point B, and the intersection point of the I-beam and the over-excavation side lining 220 is point C; S112, obtaining the intersection point B of the design contour line of the newly built tunnel 30 and the design contour line of the existing tunnel 20; wherein the over-excavation side lining 220 is the lining structure section from point A to point B; S113, calculating the vertical uniformly distributed pressure of the surrounding rock above the over-excavation side lining 220, and calculating the deadweight load of the over-excavation side lining 220; Furthermore, the step S113 of calculating the vertical uniformly distributed pressure of the surrounding rock above the overcut side lining 220 specifically includes the following steps: Using formula Calculate the vertical uniform pressure q of the surrounding rock above the overcut side lining 220; where: is the bulk density of the surrounding rock mass, is the diameter of the chamber of the existing tunnel 20, is the lateral pressure coefficient, is the friction angle of the surrounding rock mass, It is the thickness of surrounding rock covering the top of the existing tunnel 20.

[0047] S114, obtaining a vertically uniformly distributed total load on the overcut side lining 220 according to the vertically uniformly distributed pressure of the upper surrounding rock and the deadweight load; S115 , determining the lower limit value of the support force that the first support assembly 40 needs to provide to the second support assembly 50 at point C according to the vertical uniformly distributed total load.

[0048] Furthermore, the step S115 specifically includes the steps of: using the formula Determine the lower limit of the support force that the first support assembly 40 needs to provide to the second support assembly 50 at point C ;in, is the vertical uniformly distributed total load, is the length from point A to point C, is the distance from point C to point B.

[0049] Specifically, Figure 5 As shown, the over-excavation side lining 220 is equivalent to a horizontal cantilever beam, with the arch foot consolidation end point A as the fixed support, the free end as point B, and the intersection point C of the I-beam and the over-excavation side lining 220 as the key stress point. The range of the over-excavation side lining 220, i.e., the AB section, can be determined through the intersection point B of the design contour lines of the new tunnel 30 and the existing tunnel 20.

[0050] The vertical pressure of the surrounding rock is the uniformly distributed load generated by the rock mass at the top of the tunnel, acting on the top of the lining. At the same time, the uniformly distributed load generated by the weight of the lining structure's own materials is superimposed to form a vertical uniformly distributed total load, which serves as the basis for the cantilever beam force analysis. Based on the cantilever beam model, the support force to be applied at point C is calculated to determine the lower limit of the support force that the first support assembly 40 needs to provide to the second support assembly 50 at point C to prevent the structure from being damaged due to excessive load.

[0051] As a preferred embodiment, the step S12 of determining the theoretical axial force on the corrugated steel plate according to the sum of the deadweight and the lower limit of the supporting force specifically includes the following steps: S121, the first support assembly 40 is equivalent to a secondary hyperstatic structure; wherein the first arch foot box 410 and the first arch wall box 420 are the first rod 440, the corrugated steel plate is the second rod 450, the first rod 440 is connected to the existing ground at point 1, and the other end point is point 2, the second rod 450 and the first rod 440 are rigidly connected at point 2, point 2 is acted upon by the lower limit of the support force perpendicular to the first rod 440, and the other end point of the second rod 450 is point 3 and is hinged to the existing ground; S122, calculating the deadweight load of the first supporting assembly 40; S123, inputting the deadweight load, the lower limit of the supporting force and the secondary hyperstatic structure into a structural mechanics solver to obtain a theoretical axial force on the corrugated steel plate under the action of the deadweight load and the lower limit of the supporting force.

[0052] Specifically, there are 3 degrees of freedom constraints in the consolidation of point 1, 3 degrees of freedom constraints in the rigid connection of point 2, and 2 degrees of freedom constraints in the hinge of point 3, so the first support assembly 40 is a secondary hyperstatic structure. In this embodiment, by introducing a structural mechanics solver, the self-weight load, the lower limit of the support force, and the secondary hyperstatic structure are input into the structural mechanics solver to obtain the theoretical axial force on the corrugated steel plate under the action of the self-weight load and the lower limit of the support force.

[0053] Furthermore, the step S13 specifically includes the following steps: S131, firstly select a type of corrugated steel plate according to construction experience, and use it as the current type of corrugated steel plate; S132, obtaining the allowable stress and net cross-sectional area of ​​the steel material of the current model of the corrugated steel plate, and calculating the calculated axial force of the current model of the corrugated steel plate according to the allowable stress and net cross-sectional area of ​​the steel material; S133, determining a safety factor of the corrugated steel plate according to the calculated axial force and the theoretical axial force; S134, determining whether the safety factor is greater than a preset threshold; S135, when the safety factor is greater than a preset threshold, determining that the current model of the corrugated steel plate meets the design requirements, and using the current model of the corrugated steel plate as the model of the corrugated steel plate; S136, when the safety factor is less than or equal to the preset threshold, it is determined that the current model of the corrugated steel plate does not meet the design requirements, a new model of the corrugated steel plate is selected and used as the current model of the corrugated steel plate, and then returns to step S132.

[0054] Specifically, the first arch foot box 410 and the first arch wall box 420 can adopt conventional structural dimensions, and based on construction experience or similar engineering cases, a corrugated steel plate model is initially selected as a candidate to narrow the selection range and improve efficiency. For example, the total height of the first arch foot box 410 and the first arch wall box 420 is h1, the longitudinal length is b1, and the thickness is t1. The current model of corrugated steel plate has a wave height of h2, a thickness of t2, a single wavelength L, and a longitudinal length of b2. The length coefficient of the current model of corrugated steel plate is K2=1+2 h2 / L, net cross-sectional area A=K2 t2 b2; Using formula Calculate the axial force of the current model of corrugated steel plate ,in, is the allowable stress of steel; Using formula Get the safety factor of the corrugated steel plate ,in, is the theoretical axial force.

[0055] When the safety factor is greater than a preset threshold, it is determined that the current model of the corrugated steel plate meets the design requirements, and the current model of the corrugated steel plate is used as the model of the corrugated steel plate; wherein the preset threshold is preferably set to 1.5.

[0056] When the safety factor is less than or equal to the preset threshold, it is determined that the current model of corrugated steel plate does not meet the design requirements, and a new model of corrugated steel plate is selected and used as the current model of corrugated steel plate, and then returns to step S132. That is, a larger model of steel plate needs to be reselected to increase the safety factor, and the process returns to step S132 until the conditions are met.

[0057] This embodiment can avoid waste of materials and construction caused by over-design or potential safety hazards caused by insufficient design, while taking into account both economy and safety. By verifying experience in selection, it can reduce the arbitrariness of human judgment and improve design reliability.

[0058] This application also provides a specific example to illustrate the selection process of corrugated steel plate, as follows: like Figure 6 and Figure 7As shown, the first arch foot box 410 and the first arch wall box 420 adopt conventional sizes, taking h1=0.4m, longitudinal length b1=1.0m, thickness t1=0.01m, wave height of the corrugated steel plate h2=0.15m, thickness t2=0.01m, single wavelength L=0.4m, longitudinal length b2=1m, the sum of the circumferential lengths of the first arch foot box 410 and the first arch wall box 420 = 6.0m, and the width of the corrugated steel plate along the radial direction of the tunnel =6.0m, the angle between the first arch foot box 410 and the first arch wall box 420 and the existing ground is θ1=60°, the angle between the corrugated steel plate and the existing ground is θ2=60°, the lining weight ρ=7850kg / m³, the lower limit of the support force F=1535KN is obtained by the above formula, the theoretical axial force is 1768.9KN, the corrugated steel plate is selected as Q235 steel, the allowable stress of steel is 190MPa, and the safety factor is calculated according to the above formula =1.88 is greater than the preset threshold of 1.5, so the current corrugated steel plate can meet the requirements.

[0059] As a preferred embodiment, the step between step S2 and step S3 further includes: injecting foam concrete into the inner side of the over-excavation side lining 220 through the first grouting hole reserved on the first arch foot box 410 and the second grouting hole reserved on the first arch wall box 420; And / or the step between steps S3 and S4 also includes the following steps: continuing to inject foam concrete into the inner side of the over-excavation side lining 220 through the second grouting hole reserved on the first arch wall box 420 to fill the remaining cavity between the over-excavation side lining 220 and the first arch wall box 420.

[0060] The over-excavation side cavity is backfilled with foam concrete, which has a simple construction process, low material cost, and a short construction period. It can also evenly transfer the structural stress of the over-excavation side lining 220 to the first support assembly 40 and the second support assembly 50, and has a high practical value.

[0061] Furthermore, the step S5 further includes the following steps: S6, continue to pour concrete into the first arch foot box 410, the first arch wall box 420 and the remaining box structure 310. After the concrete is filled, the bearing capacity of the box to the surrounding rock pressure and construction load can be significantly enhanced, as well as the structural strength of the permanent lining structure in the later stage. The concrete grade and the addition of materials such as steel fiber can be adjusted according to the surrounding rock geological conditions.

[0062] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A tunnel deviation correction method, characterized in that: The following steps are involved: S1, obtaining the deviation correction section range of the existing tunnel, and assembling the first support assembly on the inner side of the over-excavation side lining within the deviation correction section range; wherein the first support assembly includes a first arch foot box, a first arch wall box and a first temporary steel support, the first arch foot box is fixedly connected to the existing road surface of the existing tunnel, the first arch wall box is connected to the top of the first arch foot box, one end of the first temporary steel support is overlapped on the existing road surface, and the other end is connected to the inner wall of the first arch wall box; S2, installing a second support assembly on the outside of the first arch wall box; wherein one end of the second support assembly is connected to the outer wall of the first arch wall box, and the other end is connected to the over-excavation side lining; S3, dismantling the lining of the under-excavated side of the existing tunnel, excavating the surrounding rock of the under-excavated side to the arch wall design contour line of the new tunnel, assembling the remaining box structure after clearing the slag, and then dismantling the first temporary steel support and the second support assembly; wherein the first arch foot box, the first arch wall box and the remaining together form the arch wall lining structure of the new tunnel; S4, dismantling the existing road surface and bottom invert of the existing tunnel to the invert design contour line of the new tunnel, and excavating the lower surrounding rock of the undercut side to the invert design contour line; S5, constructing the secondary lining of the invert arch of the newly built tunnel according to the designed contour line of the invert arch, and constructing the remaining conventional structure after the secondary lining of the invert arch reaches the required strength.

2. The tunnel deviation correction method according to claim 1, characterized in that: The first temporary steel support is a corrugated steel plate, the second support assembly is an I-beam, the extension direction of the corrugated steel plate is consistent with the extension direction of the newly built tunnel, and the top of the corrugated steel plate is fixedly connected to the first arch wall box.

3. The tunnel deviation correction method according to claim 2, characterized in that: The model of the corrugated steel plate is obtained by the following steps: S11, when determining that the lining structure of the existing tunnel is in a stable state, a lower limit value of the supporting force that the first supporting assembly needs to provide to the second supporting assembly; S12, obtaining the sum of the deadweights of the first support assembly and the second support assembly, and determining the theoretical axial force exerted on the corrugated steel plate according to the sum of the deadweights and the lower limit of the support force; S13, determining the model of the corrugated steel plate according to the theoretical axial force.

4. The tunnel deviation correction method according to claim 3, characterized in that: The step S11 specifically includes the following steps: S111, the over-excavation side lining of the existing tunnel is equivalent to a horizontal cantilever beam; wherein the arch foot consolidation end point of the horizontal cantilever beam is point A, the other end point is point B, and the intersection point of the I-beam and the over-excavation side lining is point C; S112, obtaining an intersection point B of a design contour line of the newly built tunnel and a design contour line of the existing tunnel; wherein the over-excavation side lining is a lining structure section from point A to point B; S113, calculating the vertical uniformly distributed pressure of the surrounding rock above the over-excavation side lining, and calculating the deadweight load of the over-excavation side lining; S114, obtaining a vertically uniformly distributed total load on the overcut side lining according to the vertically uniformly distributed pressure of the upper surrounding rock and the deadweight load; S115: Determine the lower limit value of the support force that the first support assembly needs to provide to the second support assembly at point C according to the vertical uniformly distributed total load.

5. The tunnel deviation correction method according to claim 3, characterized in that: Determining the theoretical axial force exerted on the corrugated steel plate according to the sum of the deadweight and the lower limit of the supporting force in step S12 specifically includes the following steps: S121, the first support assembly is equivalent to a secondary hyperstatic structure; wherein the first arch foot box and the first arch wall box are the first rod, the corrugated steel plate is the second rod, the first rod is connected to the existing ground at point 1, and the other end is point 2, the second rod is rigidly connected to the first rod at point 2, point 2 is acted upon by the lower limit of the support force perpendicular to the first rod, and the other end of the second rod is point 3 and is hinged to the existing ground; S122, calculating the deadweight load of the first supporting assembly; S123, inputting the deadweight load, the lower limit of the supporting force and the secondary hyperstatic structure into a structural mechanics solver to obtain a theoretical axial force on the corrugated steel plate under the action of the deadweight load and the lower limit of the supporting force.

6. The tunnel deviation correction method according to claim 4, characterized in that: The step S13 specifically includes the following steps: S31, firstly select a type of corrugated steel plate according to construction experience, and use it as the current type of corrugated steel plate; S32, obtaining the allowable stress and net cross-sectional area of ​​the steel material of the current model of the corrugated steel plate, and calculating the calculated axial force of the current model of the corrugated steel plate according to the allowable stress and net cross-sectional area of ​​the steel material; S33, determining a safety factor of the corrugated steel plate according to the calculated axial force and the theoretical axial force; S34, determining whether the safety factor is greater than a preset threshold; S35, when the safety factor is greater than a preset threshold, determining that the current model of the corrugated steel plate meets the design requirements, and using the current model of the corrugated steel plate as the model of the corrugated steel plate; S36, when the safety factor is less than or equal to the preset threshold, it is determined that the current model of the corrugated steel plate does not meet the design requirements, a new model of the corrugated steel plate is selected and used as the current model of the corrugated steel plate, and then returns to step S32.

7. The tunnel deviation correction method according to claim 4, characterized in that: The step S115 specifically includes the steps of: using the formula Determine the lower limit of the support force that the first support component needs to provide to the second support component at point C ;in, is the vertical uniformly distributed total load, is the length from point A to point C, is the distance from point C to point B.

8. The tunnel deviation correction method according to claim 4, characterized in that: The step S113 of calculating the vertical uniformly distributed pressure of the surrounding rock above the overcut side lining specifically includes the following steps: Using formula Calculate the vertical uniform pressure q of the surrounding rock above the overcut side lining; where: is the bulk density of surrounding rock mass, is the diameter of the existing tunnel chamber, is the lateral pressure coefficient, is the friction angle of the surrounding rock mass, It is the thickness of surrounding rock covering the top of the existing tunnel.

9. The tunnel deviation correction method according to claim 1, characterized in that: The step between step S2 and step S3 also includes the step of: injecting foam concrete into the inner side of the over-excavation side lining through the first grouting hole reserved on the first arch foot box and the second grouting hole reserved on the first arch wall box; And / or the step between steps S3 and S4 also includes: continuing to inject foam concrete into the inner side of the over-excavation side lining through the second grouting hole reserved on the first arch wall box to fill the remaining cavity between the over-excavation side lining and the first arch wall box.

10. The tunnel deviation correction method according to any one of claims 1 to 9, characterized in that: The step S5 further includes the following steps: S6, continue pouring concrete into the first arch foot box, the first arch wall box and the remaining box structures.

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