Duct piece bearing safety early warning method and system in large-diameter shield synchronous pushing and splicing mode and storage medium

Abstract

The invention discloses a duct piece bearing safety early warning method and system in a large-diameter shield synchronous pushing and splicing mode and a storage medium. The method comprises the following steps that S1, a construction three-dimensional grid model is constructed; s2, analyzing and obtaining water and soil stress and shield tail bounce borne by the duct piece; s3, finite element simulation is conducted according to the construction three-dimensional grid model, the water and soil stress and the shield tail bounce, and ultimate deformation of the duct piece is obtained; and S4, judging whether the ultimate deformation of the duct piece is greater than a safety threshold, and if so, outputting early warning information. According to the method, the finite element simulation technology is utilized, the limit deformation data of the duct piece in the synchronous pushing and splicing mode can be obtained and compared with the safety threshold value, and when the limit deformation exceeds the safety threshold value, the system automatically outputs early warning information to provide timely feedback for constructors so as to take corresponding prevention measures.

Description

Technical Field

[0001] The present invention relates to the technical field of shield tunnel segment construction, and in particular to a segment load safety early warning method, system and storage medium in a large-diameter shield synchronous pushing and splicing mode. Background Art

[0002] Conventional shield construction adopts an alternating push-and-splice mode, which forces the different systems of the shield machine to start and stop frequently, seriously affecting the efficiency of tunnel construction. Synchronous push-and-splice is a very promising method to solve this problem. Synchronous push-and-splice means that while the shield machine is advancing forward, a part of the cylinder is retracted to complete the splicing of the segments, thereby achieving shield advancement and segment assembly at the same time. Since the distance between the cylinders is smaller than that in the conventional mode during synchronous push-and-splice, the relative position of the shield tail structure and the segment is significantly different from that of conventional assembly, which makes the stress condition of the segment uncertain, resulting in the segment being deformed or even damaged due to insufficient support. Summary of the invention

[0003] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a segment load safety early warning method in a large-diameter shield synchronous pushing and splicing mode.

[0004] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A segment load safety warning method in a large-diameter shield synchronous pushing and assembling mode comprises the following steps: S1, constructing a three-dimensional construction grid model; S2, analyzing and obtaining the water-soil stress and the shield tail rebound force on the segment; S3, performing finite element simulation according to the three-dimensional construction grid model, the water-soil stress and the shield tail rebound force to obtain the ultimate deformation of the segment; S5, judging whether the ultimate deformation of the segment is greater than a safety threshold: if so, outputting a warning message.

[0005] Further, step S2 includes: Get the stress of the soil layer in the vertical direction: ; The soil at depth The unit weight, is the Poisson's ratio of the soil, h is the depth of the soil layer, is the vertical stress of the soil layer, is the lateral pressure coefficient; The water and soil stress on the segment in polar coordinates is obtained as: ; is the tunnel radius, is the radial normal stress, is the hoop normal stress, is the radial shear stress, is the tangent shear stress; R is the distance from the soil layer to the center of the tunnel, is the polar coordinate angle of the soil layer.

[0006] Further, step S2 further includes: according to the grease pressure on the pipe segment ,right , , Make corrections to obtain the soil stress on the corrected segment: .

[0007] Further, step S2 includes: Obtain the vertical component of the shield tail rebound force of the segment : = ; in Indicates that the angle is The interval is divided into The first intervals, It is the rebound force provided by the shield tail brush per unit arc length; is the starting angle of the shield tail brush arrangement, The coverage angle of the shield tail brush arrangement range.

[0008] Furthermore, step S3 includes: simulating the change of force and ultimate deformation of the pipe segments during the synchronous pushing and assembling process by time stepping.

[0009] Furthermore, the simulation of the change of the force and the ultimate deformation of the pipe segments during the synchronous pushing and assembling process by time stepping specifically includes: In the first time step, the cylinder thrust is applied to all the segment support shoe surfaces to simulate the force when a ring of segments is installed and obtain the ultimate deformation of the segment; In the second time step, the thrust of the three adjacent cylinders is removed to simulate the stress conditions when installing the next ring of segments and obtain the ultimate deformation of the segments.

[0010] Furthermore, step S1 specifically includes: constructing a construction three-dimensional grid model according to the basic three-dimensional model, the oil cylinder distance, the segment splicing characteristics and the shield tail brush support situation.

[0011] Furthermore, the oil cylinder distance d satisfies: .

[0012] The present invention also proposes a tunnel segment load-bearing safety warning system suitable for a shield synchronous pushing and assembling mode, comprising: a three-dimensional model building module, used to build a three-dimensional construction grid model; a force analysis module, used to analyze and obtain the water and soil stress and the shield tail rebound force on the segment; a finite element simulation module, used to perform finite element simulation based on the construction three-dimensional grid model, water and soil stress and the shield tail rebound force to obtain the ultimate deformation of the segment; a judgment module, used to judge whether the ultimate deformation of the segment is greater than a safety threshold, and if the ultimate deformation is greater than the safety threshold, output a warning message.

[0013] The present invention further provides a storage medium, wherein a computer program is stored in the storage medium, and when the computer program is executed by a processor, the steps of the method are implemented.

[0014] The present invention has the following beneficial effects: By constructing a three-dimensional construction grid model and combining the analysis of water-soil stress and shield tail rebound force, the stress condition of the segment during the synchronous pushing and assembling process of the shield can be accurately simulated, and the possible insufficient support force of the segment can be discovered in time to prevent the segment from deformation or damage, thereby ensuring construction safety. Using finite element simulation technology, this method can obtain the ultimate deformation data of the segment in the synchronous pushing and assembling mode and compare it with the safety threshold. When the ultimate deformation exceeds the safety threshold, the system will automatically output a warning message to provide timely feedback to the construction personnel so that they can take corresponding preventive measures.

[0015] In addition to the above-described purposes, features and advantages, the present invention has other purposes, features and advantages. The present invention will be further described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings constituting a part of this application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings: Figure 1 It is a schematic diagram of the overall process of the present invention; Figure 2 It is a cross-sectional view of the synchronous push-pull construction model provided by the present invention; Figure 3 A schematic diagram of the shield tail structure when the oil cylinder distance provided by the present invention is 2400 mm; Figure 4 A schematic diagram of the shield tail structure when the oil cylinder distance provided by the present invention is 2800 mm; Figure 5 A schematic diagram of the shield tail structure when the oil cylinder distance provided by the present invention is 3200 mm; Figure 6 The relationship between the vertical support component of the shield tail rebound force and the layout angle of the shield tail brush; Figure 7 Provide a schematic diagram of the vertical upward force component for the shield tail brush; Figure 8 The analysis diagram of the cylinder thrust force on the pipe segment at the first time step provided by the present invention; Fig. 9 The analysis diagram of the cylinder thrust force on the pipe segment at the second time step provided by the present invention; Fig.10 This is a deformation cloud diagram of the pipe segment provided by the present invention.

[0017] Legend: Shield body 1, segment 2, segment support shoe surface 3, shield tail supporting structure 4. DETAILED DESCRIPTION

[0018] 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.

[0019] 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.

[0020] 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.

[0021] In addition, the descriptions of "first", "second", etc. in the present invention are only used 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 "first" and "second" 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.

[0022] Please refer to Figure 1 An embodiment of the present invention provides a segment load safety warning method in a large-diameter shield synchronous pushing and assembly mode, including steps S1, S2, S3 and S4.

[0023] S1, constructing a three-dimensional grid model for construction; specifically, step S1 includes: constructing a three-dimensional grid model for construction according to the basic three-dimensional model, the distance between oil cylinders, the splicing characteristics of the pipe segments and the support conditions of the shield tail brush. Figure 2 , the main structures of the construction process include the shield body 1, the segment 2 and the shield tail support structure 4. The shield tail support structure 4 includes a shield tail brush. The segment 2 is divided into multiple sections and has a number of segment support shoe surfaces for the cylinder to contact and push. The cylinder is located at the front end of the shield machine and is used to support the side of the segment when assembling the segment. It relies on friction to temporarily fix the segment, and then the segment can be installed. The cylinder distance represents the distance from the segment to the front end of the shield machine. This distance affects the relative position of the segment and the effect of synchronous pushing. The segment splicing features are: simplified to a four-ring segment, of which the last two rings are simplified into a whole, such as Figure 2 As shown, the first two rings of segments are spliced ​​with staggered seams.

[0024] S2, analyze and obtain the water and soil stress and shield tail rebound force on the segment.

[0025] S3, finite element simulation is performed based on the construction three-dimensional grid model, water and soil stress and shield tail rebound force to obtain the ultimate deformation of the segment. It can be understood that a finite element model is constructed based on the construction three-dimensional grid model, water and soil stress and shield tail rebound force, material properties, and contact conditions, and then a finite element simulation is performed using the finite element model to obtain the stress condition and ultimate deformation of the segment.

[0026] S4, judging whether the limit deformation of the pipe segment is greater than the safety threshold: if so, outputting warning information to remind the construction personnel that the pipe segment support needs to be optimized. If not, it means that the support of the pipe segment is within the safety range.

[0027] The embodiment of the present invention provides a safety warning method for the bearing capacity of pipe segments in a synchronous pushing and splicing mode of a large-diameter shield. By constructing a three-dimensional construction grid model and combining the analysis of water-soil stress and the rebound force of the shield tail, the method can accurately simulate the stress conditions of the pipe segments during the synchronous pushing and splicing of the shield, timely discover the possible insufficient supporting force of the pipe segments, prevent the pipe segments from being deformed or damaged, and thus ensure construction safety. By using finite element simulation technology, the method can obtain the ultimate deformation data of the pipe segments in the synchronous pushing and splicing mode and compare it with the safety threshold. When the ultimate deformation exceeds the safety threshold, the system will automatically output warning information to provide timely feedback to the construction personnel so that corresponding preventive measures can be taken. Through the accurate evaluation of the bearing capacity of the pipe segments, the method helps to optimize the design and construction plan of the shield machine, especially when the relative position of the shield tail structure and the pipe segments is significantly different from the conventional assembly, it can provide more accurate technical guidance for the construction.

[0028] In some embodiments of the present invention, step S2 comprises: Get the stress of the soil layer in the vertical direction: ; The soil at depth The unit weight, is the Poisson's ratio of the soil, h is the depth of the soil layer, is the vertical stress of the soil layer, is the lateral pressure coefficient; The water and soil stress on the segment in polar coordinates is obtained as: ; is the tunnel radius, is the radial normal stress, is the hoop normal stress, is the radial shear stress, is the tangent shear stress, and The direction of the force is vertical, and are forces with different directions but equal magnitude. R is the distance from the soil layer to the center of the tunnel, is the polar coordinate angle of the soil layer. R in polar coordinates is the radial distance, is the angle between the line connecting the position of the soil layer and the center of the circle and the x-axis. These two parameters can determine a polar coordinate position. The polar coordinate position represents the distance R from the center of the tunnel and the direction angle is The soil microelement is obtained by this method.

[0029] Step S2 also includes: according to the grease pressure on the pipe segment ,right , , Make corrections.

[0030] Specifically, the water-soil stress caused by grease pressure is , , : .

[0031] right , , Make corrections to obtain the corrected water and soil stresses on the segment , , : .

[0032] From the above, the corrected water-soil stress on the segment can be obtained: .

[0033] By considering the grease pressure to simulate more realistic soil stress, more accurate soil stress and segment stress conditions can be obtained, providing more accurate basic data for subsequent calculations and early warnings.

[0034] In some embodiments of the present invention, step S2 comprises: Obtain the vertical component of the shield tail rebound force of the segment : = ; Reference Figure 6 and Figure 7 ,in Indicates that the angle is The interval is divided into The first intervals, The angle is The total number of subintervals into which the interval is divided, is the subinterval number, The coverage angle of the shield tail brush arrangement range. It is the rebound force provided by the shield tail brush per unit arc length; is the starting angle of the brush arrangement at the tail of the shield. Thus, the vertical component of the rebound force of the tail of the shield is obtained, that is, the force that plays a supporting role, providing an accurate data basis for simulating the force of the real segment.

[0035] In some embodiments of the present invention, step S3, finite element simulation includes: simulating the changes in stress and extreme deformation of the pipe segments during the synchronous pushing and assembly process through time steps, that is, simulating stress and deformation in various states during the construction process, so that the entire construction process can be simulated and predicted, thereby achieving full-process safety analysis and early warning.

[0036] In a further embodiment of the present invention, the step-by-step simulation of the change in force and the limit deformation of the pipe segments during the synchronous pushing and assembling process specifically includes: Reference Figure 8 ,In the first time step, the cylinder thrust is applied to all the segment support shoe surfaces 3 to simulate the force when a ring of segments is installed and obtain the ultimate deformation of the segment.

[0037] Reference Fig. 9 When installing the bottom segment, it is necessary to remove the thrust of the three cylinders first. Therefore, in the second time step, the thrust of the three adjacent cylinders is removed to simulate the stress conditions when installing the next ring of segments and obtain the ultimate deformation of the segment.

[0038] Reference Figures 3 to 5 In a specific embodiment of the present invention, the oil cylinder distance d satisfies: , the cylinder distance within this range is within the controllable and safe selection range. Fig.10 , usually it is necessary to perform finite element simulation on different lengths of oil cylinder distances to verify their safety. In this example, since the two bottom segments are subjected to the greatest force, the deformation cloud map of the two bottom segments is taken as the result output, see Fig.10 .

[0039] The present invention also proposes a tunnel segment load-bearing safety warning system suitable for a shield synchronous pushing and assembling mode, comprising: a three-dimensional model construction module, used to construct a three-dimensional construction grid model; a force analysis module, used to analyze and obtain the water and soil stresses and the shield tail rebound force on the segment; a finite element simulation module, used to perform finite element simulation based on the construction three-dimensional grid model, water and soil stresses and the shield tail rebound force to obtain the ultimate deformation of the segment; a judgment module, used to judge whether the ultimate deformation of the segment is greater than a safety threshold, and if the ultimate deformation is greater than the safety threshold, output a warning message.

[0040] The present invention further provides a storage medium, wherein a computer program is stored in the storage medium, and when the computer program is executed by a processor, the steps of the method are implemented.

[0041] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for early warning of segment load safety in a large-diameter shield synchronous push-to-assemble mode, characterized in that: The steps include: S1, constructing a three-dimensional grid model for construction; S2, analyze and obtain the water and soil stress and shield tail rebound force on the segment; S3, finite element simulation is performed based on the construction three-dimensional grid model, water and soil stress and shield tail rebound force to obtain the ultimate deformation of the segment; S4, determine whether the ultimate deformation of the segment is greater than the safety threshold: If so, a warning message is output.

2. The segment bearing safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 1 is characterized in that: Step S2 includes: Get the stress of the soil layer in the vertical direction: ； The soil at depth The unit weight, is the Poisson's ratio of the soil, h is the depth of the soil layer, is the vertical stress of the soil layer, is the lateral pressure coefficient; The water and soil stress on the segment in polar coordinates is obtained as: ； is the tunnel radius, is the radial normal stress, is the hoop normal stress, is the radial shear stress, is the tangent shear stress; R is the distance from the soil layer to the center of the tunnel, is the polar coordinate angle of the soil layer.

3. The segment load safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 2 is characterized in that: Step S2 also includes: according to the grease pressure on the pipe segment ,right , , Make corrections to obtain the corrected water and soil stresses on the segment: 。 4. The segment bearing safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 1 or 2 is characterized in that: Step S2 includes: Obtain the vertical component of the shield tail rebound force of the segment : = ； in Indicates that the angle is The interval is divided into The first intervals, It is the rebound force provided by the shield tail brush per unit arc length; is the starting angle of the shield tail brush arrangement, The coverage angle of the shield tail brush arrangement range.

5. The segment load safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 1 is characterized in that: Step S3 includes: Through time stepping, the changes in stress and ultimate deformation of the segments during the synchronous pushing and assembly process are simulated.

6. The segment load safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 5 is characterized in that: The simulation of the change of the force and the ultimate deformation of the pipe segments during the synchronous pushing and assembling process by time stepping specifically includes: In the first time step, the cylinder thrust is applied to all the segment support shoe surfaces to simulate the force when a ring of segments is installed and obtain the ultimate deformation of the segment; In the second time step, the thrust of the three adjacent cylinders is removed to simulate the stress conditions when installing the next ring of segments and obtain the ultimate deformation of the segments.

7. The method for early warning of segment load safety in synchronous pushing and assembling mode of a large-diameter shield machine according to claim 1 is characterized in that: Step S1 specifically includes: constructing a construction three-dimensional grid model according to the basic three-dimensional model, the oil cylinder distance, the segment splicing characteristics and the shield tail brush support situation.

8. The segment bearing safety early warning method in the synchronous pushing and assembling mode of a large-diameter shield according to claim 1 is characterized in that: The cylinder distance d satisfies: .

9. A tunnel segment bearing safety warning system suitable for use in a shield synchronous pushing and assembling mode, characterized in that: include: 3D model building module, used to build a 3D grid model for construction; Force analysis module, used to analyze and obtain the water and soil stress on the segment and the rebound force of the shield tail; Finite element simulation module, used to perform finite element simulation based on the construction 3D grid model, water and soil stress and shield tail rebound force to obtain the ultimate deformation of the segment; The judgment module is used to judge whether the ultimate deformation of the pipe segment is greater than the safety threshold. If the ultimate deformation is greater than the safety threshold, an early warning message is output.

10. A storage medium storing a computer program, wherein: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.

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