A method for correcting tunnel deviation

Abstract

The present invention relates to the technical field of tunnels, and provides a tunnel deviation correction method. A first support assembly is assembled on the inner side of the lining on the over-excavated side within the deviation correction section range, a second support assembly is installed on the outer side of the first arch wall box body, the lining on the under-excavated side of the existing tunnel is demolished, and then the surrounding rock on the under-excavated side is excavated to the design contour line of the arch wall of the new tunnel. After slag cleaning, the remaining box body structure is assembled, and then the first temporary steel support and the second support assembly are demolished. The existing road surface and the bottom inverted arch of the existing tunnel are demolished to the design contour line of the inverted arch of the new tunnel, the lower surrounding rock on the under-excavated side is excavated to the design contour line of the inverted arch, and the inverted arch secondary lining of the new tunnel is constructed according to the design contour line of the inverted arch. After the inverted arch secondary lining reaches the strength, the remaining conventional structure is constructed. The present application realizes the precise adjustment of the tunnel axis, safely and quickly solves the problem that the axis of the existing tunnel deviates, and adopts a precast box body structure, which can reduce the on-site pouring time and improve the construction efficiency.

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:

[0008] S1. Obtain the deviation correction section range of the existing tunnel, and assemble the first support component on the inner side of the over-excavated side lining within the deviation correction section range; wherein, the first support component includes a first arch foot box body, a first arch wall box body, and a first temporary steel support. The first arch foot box body is fixedly connected to the existing road surface of the existing tunnel. The first arch wall box body is connected to the top of the first arch foot box body. One end of the first temporary steel support is lapped on the existing road surface, and the other end is connected to the inner wall of the first arch wall box body;

[0009] S2. Install a second support component on the outer side of the first arch wall box body; wherein, one end of the second support component is connected to the outer wall of the first arch wall box body, and the other end is connected to the over-excavated side lining;

[0010] S3. Demolish the under-excavated side lining of the existing tunnel, then excavate the surrounding rock on the under-excavated side to the arch wall design outline of the new tunnel. After clearing the slag, assemble the remaining box structure, and then demolish the first temporary steel support and the second support component; wherein, the first arch foot box body, the first arch wall box body, and the remaining box structure jointly enclose to form the arch wall lining structure of the new tunnel;

[0011] S4. Demolish the existing road surface and the bottom invert of the existing tunnel to the invert design outline of the new tunnel, and excavate the lower surrounding rock on the under-excavated side to the invert design outline;

[0012] S5. Construct the secondary lining of the invert of the new tunnel according to the invert design outline. After the secondary lining of the invert reaches the strength, construct the remaining conventional structure.

[0013] Preferably, the first temporary steel support is a corrugated steel plate, the second support component is an I-beam, the extending direction of the corrugated steel plate is consistent with the extending direction of the new tunnel, and the top of the corrugated steel plate is fixedly connected to the first arch wall box body.

[0014] Preferably, the model of the corrugated steel plate is obtained through the following steps:

[0015] S11. When it is determined that the lining structure of the existing tunnel is in a stable state, determine the lower limit value of the support force that the first support component needs to provide to the second support component;

[0016] S12. Obtain the sum of the self-weights of the first support component and the second support component, and determine the theoretical axial force received by the corrugated steel plate according to the sum of the self-weights and the lower limit value of the support force;

[0017] S13. Determine the model of the corrugated steel plate according to the theoretical axial force.

[0018] Preferably, step S11 specifically includes the following steps:

[0019] S111, equivalent the lining on the over-excavated side of the existing tunnel to a horizontal cantilever beam; wherein, the fixed end of the arch foot of the horizontal cantilever beam is point A, the other end is point B, and the intersection point of the I-beam and the lining on the over-excavated side is point C;

[0020] S112, obtain the intersection point B of the design contour line of the new tunnel and the design contour line of the existing tunnel; wherein, the lining on the over-excavated side is the lining structure section between point A and point B;

[0021] S113, calculate the vertical uniform pressure of the surrounding rock above the lining on the over-excavated side, and calculate the self-weight load of the lining on the over-excavated side;

[0022] S114, obtain the total vertical uniform load received by the lining on the over-excavated side according to the vertical uniform pressure of the surrounding rock above and the self-weight load;

[0023] S115, determine the lower limit value of the supporting force that the first support component needs to provide to the second support component at point C according to the total vertical uniform load.

[0024] Preferably, the specific steps of determining the theoretical axial force received by the corrugated steel plate according to the sum of the self-weights and the lower limit value of the supporting force in step S12 are as follows:

[0025] S121, equivalent the first support component to a secondary statically indeterminate structure; wherein, the first arch foot box body and the first arch wall box body are the first members, the corrugated steel plate is the second member, the end point where the first member is connected to the existing ground is point 1, the other end point is point 2, the second member is rigidly connected to the first member at point 2, and a supporting force with a lower limit value perpendicular to the first member acts at point 2. The other end point of the second member is point 3 and is hinged to the existing ground;

[0026] S122, calculate the self-weight load of the first support component;

[0027] S123, input the self-weight load, the lower limit value of the supporting force and the secondary statically indeterminate structure into a structural mechanics solver to obtain the theoretical axial force received by the corrugated steel plate under the action of the self-weight load and the lower limit value of the supporting force.

[0028] Preferably, step S13 specifically includes the following steps:

[0029] S31, first select a type of corrugated steel plate according to construction experience and use it as the current type of corrugated steel plate;

[0030] S32, obtain the allowable stress and net cross-sectional area of the steel of the current type of corrugated steel plate, and calculate the calculated axial force of the current type of corrugated steel plate according to the allowable stress and net cross-sectional area of the steel;

[0031] S33. Determine the safety factor of the corrugated steel plate according to the calculated axial force and the theoretical axial force;

[0032] S34. Judge whether the safety factor is greater than a preset threshold value;

[0033] S35. When the safety factor is greater than the preset threshold value, determine that the current type of corrugated steel plate meets the design requirements, and use the current type of corrugated steel plate as the type of the corrugated steel plate;

[0034] S36. When the safety factor is less than or equal to the preset threshold value, determine that the current type of corrugated steel plate does not meet the design requirements, reselect a type of corrugated steel plate, and use it as the current type of corrugated steel plate, and then return to step S32.

[0035] Preferably, step S115 specifically includes the steps of: using the formula to determine the lower limit value of the supporting force that the first support component needs to provide to the second support component at point C ; where is the total vertical uniform load, is the length from point A to point C, is the length from point C to point B.

[0036] Preferably, calculating the vertical uniform pressure of the surrounding rock above the lining on the over-excavated side in step S113 specifically includes the following steps:

[0037] Using the formula to calculate the vertical uniform pressure q of the surrounding rock above the lining on the over-excavated side; where is the unit weight of the surrounding rock mass, is the chamber diameter of the existing tunnel, is the lateral pressure coefficient, is the internal friction angle of the surrounding rock, is the thickness of the overlying surrounding rock at the top of the existing tunnel.

[0038] Preferably, between step S2 and step S3, there is also the step of: injecting foamed concrete into the inner side of the lining on the over-excavated side through the first grouting hole reserved on the first arch foot box body and the second grouting hole reserved on the first arch wall box body;

[0039] and / or between step S3 and S4, there is also the step of: continuously injecting foamed concrete into the inner side of the lining on the over-excavated side through the second grouting hole reserved on the first arch wall box body to fill the remaining cavity between the lining on the over-excavated side and the first arch wall box body.

[0040] Preferably, after step S5, the following steps are also included:

[0041] S6. Continue to pour concrete into the first springing box body, the first arch wall box body and the remaining box body structures.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] In this application, by retaining a part of the existing lining on the over-excavated side and expanding and reconstructing the under-excavated side, the accurate adjustment of the tunnel axis is realized, and the problem of deviation of the existing tunnel axis is solved safely and quickly; by adopting the first support assembly and the second support assembly, and the first springing box body and the first arch wall box body adopting a temporary and permanent combined support system (which can be used as a temporary support structure during construction and also as a permanent lining structure of the newly built tunnel), the stability of the lining on the over-excavated side during construction can be effectively improved, and it has strong usability, and different rectification schemes do not need to be formulated according to the size of the tunnel axis deviation.

[0044] Secondly, compared with the composite lining form adopted by the tunnel lining in the prior art, the first springing box body, the first arch wall box body and the remaining box body structures in this application adopt precast box body structures, which can reduce the on-site pouring time and improve the construction efficiency. In addition, the expansion of the under-excavated side will undoubtedly cause secondary disturbance to the surrounding rock. The box body structure in this application adopts rigid support, which can effectively reduce the disturbance of the surrounding rock and improve the construction safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on the structures shown in these drawings without creative efforts.

[0046] Figure 1 Schematic diagram of the tunnel rectification scheme in the prior art;

[0047] Figure 2 Flow chart in an embodiment of the present invention;

[0048] Figure 3 Schematic diagram of the structure after the completion of step S2 in an embodiment of the present invention;

[0049] Figure 4 Schematic diagram of the structure after the completion of step S5 in an embodiment of the present invention;

[0050] Figure 5 Schematic diagram of equivalent the over-excavated side lining of the existing tunnel to a horizontal cantilever beam in an embodiment of the present invention;

[0051] Figure 6Schematic diagram of equivalenting the first support component to a secondary statically indeterminate structure in an embodiment of the present invention;

[0052] Figure 7 Axial force schematic diagram of the first rod and the second rod in an embodiment of the present invention.

[0053] The realization of the purpose, functional characteristics and advantages of the present invention will be further described with reference to the embodiments and the accompanying drawings.

[0054] Explanation of the reference numerals in the drawings:

[0055] 10. Temporary steel support on the over-excavated side; 20. Existing tunnel; 210. Current road surface; 220. Lining on the over-excavated side; 230. Lining on the under-excavated side; 30. Newly built tunnel; 310. Remaining box structure; 311. Second arch foot box; 312. Second arch wall box; 320. Inverted arch secondary lining; 40. First support component; 410. First arch foot box; 420. First arch wall box; 430. First temporary steel support; 440. First rod; 450. Second rod; 50. Second support component. Detailed implementation manners

[0056] 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.

[0057] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the protection scope of the present invention.

[0058] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0059] In addition, the descriptions involving "right part", "middle part", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, the features defined with "right part", "middle part" may explicitly or implicitly include at least one such feature. In addition, the technical solutions between the various embodiments can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement it. When the combination of the technical solutions appears to be contradictory or unable to be implemented, it should be considered that such a combination of the technical solutions does not exist and is not within the protection scope required by the present invention.

[0060] Please refer to the attached Figures 1 to 7 , a tunnel deviation correction method in an embodiment provided by the present invention includes the following steps:

[0061] S1. Obtain the deviation correction section range of the existing tunnel 20, and assemble the first support assembly 40 on the inner side of the over-excavated side lining 220 within the deviation correction section range; wherein, the first support assembly 40 includes a first arch footing box body 410, a first arch wall box body 420, and a first temporary steel support 430. The first arch footing box body 410 is fixedly connected to the existing road surface 210 of the existing tunnel 20. The first arch wall box body 420 is connected to the top of the first arch footing box body 410. One end of the first temporary steel support 430 is lapped on the existing road surface 210, and the other end is connected to the inner wall of the first arch wall box body 420;

[0062] S2. Install the second support assembly 50 on the outer side of the first arch wall box body 420; wherein, one end of the second support assembly 50 is connected to the outer wall of the first arch wall box body 420, and the other end is connected to the over-excavated side lining 220;

[0063] S3. Demolish the under-excavated side lining 230 of the existing tunnel 20, then excavate the surrounding rock on the under-excavated side to the arch wall design contour line of the new tunnel 30. After clearing the slag, assemble the remaining box body structure 310, and then demolish the first temporary steel support 430 and the second support assembly 50; wherein, the first arch footing box body 410, the first arch wall box body 420, and the remaining box body structure 310 jointly enclose to form the arch wall lining structure of the new tunnel 30;

[0064] It should be noted that the demolition of the under-excavated side lining 230 should follow the principle of from top to bottom. The longitudinal length of each demolition should not be greater than 5m. During construction, static blasting or a combination of manual and mechanical demolition can be used, and explosive blasting and open blasting construction are not allowed.

[0065] Furthermore, bolt through holes (not shown in the figure) can be reserved in the remaining box body structure 310, and systematic bolts are driven into the under-excavated side through the reserved bolt through holes to enhance the stability and safety of the overall structure.

[0066] S4. Demolish the existing road surface and the bottom invert of the existing tunnel 20 to the invert design contour line of the new tunnel 30, and excavate the lower surrounding rock on the under-excavated side to the invert design contour line;

[0067] S5. Construct the secondary invert lining 320 of the new tunnel 30 according to the invert design contour line. After the secondary invert lining 320 reaches the strength, construct the remaining conventional structures, such as the invert backfill layer, the central water channel, the transverse water pipe, and other conventional structures.

[0068] Specifically, the deviation correction section range can be measured and determined in advance. The first support assembly 40 is installed inside the over-excavated side lining 220 of the existing tunnel 20 to form an inner temporary support, ensuring the structural stability during construction. The first support assembly 40 is connected to the over-excavated side lining 220 through the second support assembly 50 to form a support system in the form of internal and external coordination. Then, the original secondary lining on the under-excavated 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, they jointly enclose the new arch-wall lining structure to complete the replacement of the main lining structure. Then, the existing road surface and invert are removed, and the lower surrounding rock is excavated to the design contour to ensure the construction space for the invert. The invert secondary lining 320 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 the load from the temporary system to the permanent structure.

[0069] As a preferred example, please refer to the appendix 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 preferably can adopt the standard box form, which can effectively reduce the construction difficulty and project cost.

[0070] Preferably, it can be carried out in longitudinal segmental form according to the deviation correction section range of the tunnel. The construction sequence of each segment is carried out according to steps S1 to S5 until the normal tunnel section is constructed to complete the deviation correction of the deviation correction section range.

[0071] In the solution of the present application, by retaining a part of the existing lining on the over-excavated side and expanding and reconstructing the under-excavated side, the accurate adjustment of the tunnel axis is realized, and the problem of the 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, and the first arch-foot box 410 and the first arch-wall box 420 adopting a temporary and permanent combined support system (which can be used as a temporary support structure during construction and can also be used as the permanent lining structure of the new tunnel 30), the stability of the over-excavated side lining 220 during construction can be effectively improved, and it has strong usability, and different deviation correction schemes do not need to be formulated according to the size of the tunnel axis deviation.

[0072] Secondly, compared with the composite lining form adopted by the tunnel lining in 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 precast box structures, which can reduce the on-site casting time and improve the construction efficiency. In addition, the expansion of the under-excavated side will undoubtedly cause secondary disturbance to the surrounding rock. The box structure of the present application adopts rigid support, which can effectively reduce the disturbance of the surrounding rock and improve the construction safety.

[0073] 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 extending direction of the corrugated steel plate is consistent with the extending direction of the new tunnel 30, and the top of the corrugated steel plate is fixedly connected to the first arch wall box body 420.

[0074] Specifically, the extending direction of the corrugated steel plate is consistent with the extending direction of the new tunnel 30, which can significantly improve its longitudinal bending stiffness and form a continuous longitudinal support system. Both the corrugated steel plate and the I-beam are prefabricated components, which can be quickly assembled to shorten the construction period.

[0075] Preferably, as Figure 3 shown, a splicing groove (not shown in the figure) is arranged on the inner side of the first arch wall box body 420, and a bevel is arranged on the upper edge of the splicing groove for easy splicing and used for connecting to the top of the corrugated steel plate. The corrugated steel plate is used as the first temporary steel support 430, one end is lapped on the existing road surface 210, and the other end is lapped in the splicing groove. Further, a channel steel is arranged at the upper end of the corrugated steel plate as a connecting flange and is connected to the first arch wall box body 420 through bolts.

[0076] Further, connecting rods can also be arranged between the first arch foot box body 410 and the corrugated steel plate, and between the first arch wall box body 420 and the corrugated steel plate to enhance the stability of the overall structure.

[0077] Further, a connection port (not shown in the figure) can also be arranged on the upper edge of the outer side of the first arch wall box body 420, with a longitudinal spacing of 40 cm, for connecting the I-beam, that is, one end of the I-beam is connected at the connection port, and the other end is connected to the over-excavated side lining 220.

[0078] Further, an opening 200 80 cm can be arranged at the bottom end of the corrugated steel plate, with an interval of 5 m, as an escape passage exit, so that it has both the functions of escape and rescue to ensure construction safety.

[0079] Further, the existing road surface 210 can also be grooved, and the arch foot end of the first arch foot box body 410 can be connected in the groove. Specifically, those skilled in the art can choose according to actual needs.

[0080] As a preferred embodiment, the model of the corrugated steel plate is obtained through the following steps:

[0081] S11, when it is determined that the lining structure of the existing tunnel 20 is in a stable state, determine the lower limit value of the support force that the first support assembly 40 needs to provide to the second support assembly 50;

[0082] 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;

[0083] S13, determining the model of the corrugated steel plate according to the theoretical axial force.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] As a preferred implementation, the step S11 specifically includes the following steps:

[0088] 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;

[0089] 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;

[0090] 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;

[0091] 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:

[0092] Using formula Calculate the vertical uniform pressure q of the surrounding rock above the overcut side lining 220; where: is the bulk density of 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.

[0093] 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;

[0094] 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.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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:

[0099] 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;

[0100] S122, calculating the deadweight load of the first supporting assembly 40;

[0101] 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.

[0102] 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.

[0103] Furthermore, the step S13 specifically includes the following steps:

[0104] S131, firstly select a type of corrugated steel plate according to construction experience, and use it as the current type of corrugated steel plate;

[0105] 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;

[0106] S133. Determine the safety factor of the corrugated steel plate based on the calculated axial force and the theoretical axial force;

[0107] S134. Determine whether the safety factor is greater than a preset threshold;

[0108] S135. When the safety factor is greater than the preset threshold, determine that the current model of corrugated steel plate meets the design requirements, and use the current model of corrugated steel plate as the model of the corrugated steel plate;

[0109] S136. When the safety factor is less than or equal to the preset threshold, determine that the current model of corrugated steel plate does not meet the design requirements, reselect a model of corrugated steel plate, and use it as the current model of corrugated steel plate, then return to step S132.

[0110] Specifically, the first arch foot box body 410 and the first arch wall box body 420 can adopt conventional structural dimensions. Based on construction experience or similar engineering cases, initially select a model of corrugated steel plate as a candidate to narrow the selection range and improve efficiency. For example, the total height of the first arch foot box body 410 and the first arch wall box body 420 is h1, the longitudinal length is b1, and the thickness is t1. For the current model of corrugated steel plate, the wave height is h2, the thickness is t2, the single wavelength is L, and the longitudinal length is b2. Then the length coefficient of the current model of corrugated steel plate is K2 = 1 + 2 h2 / L, and the net cross-sectional area A = K2 t2 b2;

[0111] Use the formula to calculate the calculated axial force of the current model of corrugated steel plate , where is the allowable stress of the steel;

[0112] Use the formula to obtain the safety factor of the corrugated steel plate , where is the theoretical axial force.

[0113] When the safety factor is greater than the preset threshold, determine that the current model of corrugated steel plate meets the design requirements, and use the current model of corrugated steel plate as the model of the corrugated steel plate; among them, the preset threshold is preferably set to 1.5.

[0114] When the safety factor is less than or equal to the preset threshold, determine that the current model of corrugated steel plate does not meet the design requirements, reselect a model of corrugated steel plate, and use it as the current model of corrugated steel plate, then return to step S132. That is, it is necessary to reselect a larger model of steel plate to increase the safety factor and return to step S132 until the conditions are met.

[0115] This embodiment can avoid material and construction waste caused by over - design or potential safety hazards caused by under - design, while taking into account economy and safety. By verifying and selecting types based on experience, it reduces the arbitrariness of human judgment and improves the reliability of the design.

[0116] This application also provides a specific example to illustrate the process of selecting corrugated steel plates, which is as follows:

[0117] As Figure 6 and Figure 7 shown, the first arch - foot box body 410 and the first arch - wall box body 420 adopt conventional dimensions. Take h1 = 0.4m, longitudinal length b1 = 1.0m, thickness t1 = 0.01m, corrugated steel plate wave height 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 body 410 and the first arch - wall box body 420 = 6.0m, the width of the corrugated steel plate along the tunnel radial direction = 6.0m, the included angle θ1 between the first arch - foot box body 410 and the first arch - wall box body 420 and the existing ground = 60°, the included angle θ2 between the corrugated steel plate and the existing ground = 60°, the lining unit weight ρ = 7850kg / m³. Through the above - mentioned formula, the lower limit value of the supporting force F = 1535KN is obtained, the theoretical axial force is 1768.9KN, the corrugated steel plate is selected as Q235 steel, and the allowable stress of the steel = 190MPa. According to the above - mentioned formula, the safety factor = 1.88 is greater than the preset threshold value of 1.5. Therefore, the current corrugated steel plate can meet the requirements.

[0118] As a preferred embodiment, between step S2 and step S3, there is also a step: injecting foamed concrete into the inner side of the over - excavated side lining 220 through the first grouting hole reserved on the first arch - foot box body 410 and the second grouting hole reserved on the first arch - wall box body 420;

[0119] and / or between step S3 and S4, there is also a step: continuing to inject foamed concrete into the inner side of the over - excavated side lining 220 through the second grouting hole reserved on the first arch - wall box body 420 to fill the remaining cavity between the over - excavated side lining 220 and the first arch - wall box body 420.

[0120] Backfilling the over - excavated side cavity with foamed concrete has the advantages of simple construction technology, low material cost, short construction period, and can evenly transfer the structural stress of the over - excavated side lining 220 to the first support assembly 40 and the second support assembly 50, having high practical value.

[0121] Furthermore, after step S5, the following steps are also included:

[0122] S6. Continuously pour concrete into the first springing box body 410, the first arch wall box body 420 and the remaining box body structures 310. After the concrete is filled, it can significantly enhance the bearing capacity of the box body for the surrounding rock pressure and construction loads, as well as the structural strength as a permanent lining structure in the later stage. The concrete grade and materials such as steel fibers can be adjusted according to the surrounding rock geological conditions.

[0123] The above are only the preferred embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural or equivalent process transformation made by using the content of the specification and drawings of the present invention, or directly or indirectly applied in other related technical fields, shall be similarly 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 box structure together enclose 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 rectification 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 rectification 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 rectification 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 rectification method according to claim 3, characterized in that, In step S12, determining the theoretical axial force on the corrugated steel plate according to the sum of self-weights and the lower limit value of the supporting force specifically includes the following steps: S121, equivalent the first support assembly to a secondary statically indeterminate structure; wherein, the first arch foot box body and the first arch wall box body are the first members, the corrugated steel plate is the second member, the end point where the first member is connected to the existing ground is point 1, the other end point is point 2, the second member is rigidly connected to the first member at point 2, the lower limit value of the supporting force perpendicular to the first member acts at point 2, and the other end point of the second member is point 3 and is hinged to the existing ground; S122, calculate the self-weight load of the first support assembly; S123, input the self-weight load, the lower limit value of the supporting force, and the secondary statically indeterminate structure into a 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 value of the supporting force.

6. The tunnel deviation rectification method according to claim 4, characterized in that, Step S13 specifically includes the following steps: S31, first initially select a type of corrugated steel plate according to construction experience and use it as the current type of corrugated steel plate; S32, obtain the allowable stress and net cross-sectional area of the steel of the current type of corrugated steel plate, and calculate the calculated axial force of the current type of corrugated steel plate according to the allowable stress and net cross-sectional area of the steel; S33, determine the safety factor of the corrugated steel plate according to the calculated axial force and the theoretical axial force; S34, determine whether the safety factor is greater than a preset threshold; S35, when the safety factor is greater than the preset threshold, determine that the current type of corrugated steel plate meets the design requirements and use the current type of corrugated steel plate as the type of the corrugated steel plate; S36, when the safety factor is less than or equal to the preset threshold, determine that the current type of corrugated steel plate does not meet the design requirements, re-select a type of corrugated steel plate and use it as the current type of corrugated steel plate, and then return to step S32.

7. The tunnel deviation rectification method according to claim 4, characterized in that The specific steps of step S115 include: using the formula to determine the lower limit value of the supporting force that the first supporting component needs to provide to the second supporting component at point C ; where is the total vertical uniformly distributed load, is the length from point A to point C, is the length from point C to point B.

8. The tunnel deviation rectification method according to claim 4, wherein, In step S113, calculating the vertical uniform pressure of the surrounding rock above the over-excavated side lining specifically includes the following steps: Use the formula to calculate the vertical uniform pressure q of the surrounding rock above the over-excavated side lining; where is the unit weight of the surrounding rock mass, is the chamber diameter of the existing tunnel, is the lateral pressure coefficient, is the internal friction angle of the surrounding rock, is the thickness of the overlying surrounding rock at the top of the existing tunnel.

9. The tunnel deviation rectification method according to claim 1, characterized in that, Between step S2 and step S3, there is also a step: injecting foamed concrete into the inner side of the over-excavated side lining through the first grouting hole reserved on the first arch foot box body and the second grouting hole reserved on the first arch wall box body; and / or between step S3 and S4, there is also a step: continuously injecting foamed concrete into the inner side of the over-excavated side lining through the second grouting hole reserved on the first arch wall box body to fill the remaining cavity between the over-excavated side lining and the first arch wall box body.

10. The tunnel deviation rectification method according to claim 9, characterized in that, After step S5, there are also the following steps: S6, continue to pour concrete into the first arch foot box body, the first arch wall box body, and the remaining box body structures.

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