A tunnel construction whole-process numerical simulation method based on non-contact measurement

Abstract

The present application relates to the technical fields of numerical simulation, in particular to a tunnel construction whole process numerical simulation method based on non-contact measurement, comprising: S1, obtaining the tunnel structure corresponding to the shape and size of the tunnel, the construction conditions corresponding to the construction method and construction steps of the tunnel, and dividing the tunnel into multiple sample areas according to the tunnel structure and construction conditions; S2, obtaining the settlement of the measuring points in each sample area, setting the tunnel center as the starting point, and obtaining the settlement distribution map according to the distance between the measuring points and the tunnel center; S3, obtaining the vertical displacement of the tunnel bottom, the normal displacement of the two sides of the tunnel and the settlement area generated during the tunnel construction under the corresponding construction step according to the settlement distribution map, and calculating the maximum settlement factor and the correction factor; S4, identifying the maximum settlement point and the maximum change point in the tunnel, and using the finite element model to simulate the maximum change point as the basis; the construction efficiency and quality are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of numerical simulation, in particular to a tunnel construction whole-process numerical simulation method based on non-contact measurement. BACKGROUND

[0002] The numerical simulation technology of tunnel construction process is a method of simulating and predicting the tunnel construction process by computer. This method can simulate the stress, displacement, deformation and other parameters in the tunnel excavation process, so as to evaluate the safety and stability in the construction process. Numerical simulation technology mainly includes finite element method, boundary element method, discrete element method, etc., among which the finite element method is the most widely used method. The finite element method divides the tunnel and the surrounding soil into a finite number of small elements, and describes the mechanical behavior of each element through mathematical equations. By solving these equations, the stress, displacement, deformation and other parameters in the excavation process can be obtained. Numerical simulation technology needs to consider many factors, such as the mechanical parameters of soil and rock, construction sequence, construction method, etc., in order to more accurately simulate the actual situation.

[0003] For example, Chinese patent publication No. CN116680964A discloses a tunnel through active fault water and mud inrush disaster numerical simulation method and device, wherein the method comprises: obtaining the geometric parameters of the tunnel, constructing a three-dimensional numerical model of the tunnel through the active fault by a preset finite difference numerical simulation method and a preset particle discrete element numerical simulation method, and applying boundary conditions to set the initial stress state. The numerical simulation result of the tunnel through the active fault water and mud inrush disaster is obtained by simulating the tunnel through the active fault water and mud inrush disaster. The embodiment of the present application can establish a three-dimensional numerical model of the tunnel through the active fault, and obtain the whole process of the tunnel through the active fault water and mud inrush disaster under the action of different intensity, different frequency and different direction seismic waves by simulating the mechanical behavior of the tunnel surrounding rock and fluid-structure coupling.

[0004] The prior art simulates the tunnel disaster by analyzing the corresponding fault and flow, but when the tunnel construction conditions and tunnel structure change, it is also necessary to verify the correlation between the settlement and the set tunnel conditions and other elements, and to simulate and evaluate the situation generated by the whole to identify the risks that can be generated by the current construction. SUMMARY

[0005] In order to solve the above technical problems, the technical scheme adopted by the present application is: a tunnel construction whole-process numerical simulation method based on non-contact measurement, comprising: S1, obtaining the shape, size of the tunnel corresponding to the tunnel structure, the construction method and the construction step corresponding to the construction condition, and dividing the tunnel into multiple sample areas according to the tunnel structure and the construction condition.

[0006] S2, obtain the settlement amount of the measuring points in each sample area, set the tunnel center as the starting point, and obtain the settlement distribution map according to the distance of the measuring points from the tunnel center.

[0007] S3, according to the settlement distribution map, obtain the vertical displacement of the tunnel bottom, the normal displacement of the two sides of the tunnel and the settlement area generated during the tunnel construction under the corresponding construction step, calculate the maximum settlement factor and the correction factor.

[0008] S4, identify the maximum settlement point and the maximum change point in the tunnel, use the finite element model based on the maximum change point as the basis for simulation, and output the simulation factor related to settlement based on the simulation result.

[0009] S5, combine the simulation factor, the correction factor and the maximum settlement factor to form the final prediction model, and couple the prediction model according to the measuring points used during calculation to obtain the simulation evaluation result of the tunnel construction.

[0010] The beneficial effects of the present application are that the present application can more accurately simulate the settlement during the tunnel construction process by combining the non-contact measurement technology and the finite element model, thereby improving the simulation accuracy; through the simulation evaluation result of the tunnel construction by the prediction model, the construction personnel can more accurately understand the potential risks during the tunnel construction process and take corresponding measures for prevention and control; the present scheme can also provide simulation results under different construction methods for construction personnel, thereby helping to select the optimal construction method and improving the construction efficiency and quality. BRIEF DESCRIPTION OF DRAWINGS

[0011] The present application will be further described below in combination with the drawings and examples.

[0012] Figure 1 It is a flowchart of a tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0013] Figure 2 It is a flowchart of step S1 of a tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0014] Figure 3 It is a flowchart of step S2 of a tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0015] Figure 4 It is a flowchart of step S23 of a tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0016] Figure 5 It is a flowchart of step S3 of a tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0017] Figure 6 is a flowchart of step S31 of the tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0018] Figure 7 is a flowchart of step S32 of the tunnel construction whole-process numerical simulation method based on non-contact measurement.

[0019] Figure 8 is a flowchart of step S4 of the tunnel construction whole-process numerical simulation method based on non-contact measurement. DETAILED DESCRIPTION

[0020] Embodiments of the present application are described in detail below. The embodiments described below are exemplary only, and are not to be understood as limiting the present application. In the embodiments, unless specific techniques or conditions are mentioned, techniques or conditions described in the literature in the field or according to product manuals are used.

[0021] Reference Figure 1 A tunnel construction whole-process numerical simulation method based on non-contact measurement, comprising: S1, acquiring a tunnel structure corresponding to a shape and size of the tunnel, a construction condition corresponding to a construction method and construction steps of the tunnel, and dividing the tunnel into a plurality of sample regions according to the tunnel structure and the construction condition.

[0022] S2, acquiring a settlement amount of a measuring point in each sample region, setting a tunnel center as a starting point, and obtaining a settlement distribution map according to a distance of the measuring point from the tunnel center.

[0023] S3, acquiring a vertical displacement of a tunnel bottom, a normal displacement of both sides of the tunnel, and a settlement area generated during tunnel construction according to the settlement distribution map under a corresponding construction step, and calculating a maximum settlement factor and a correction factor.

[0024] S4, identifying a maximum settlement point and a maximum change point in the tunnel, using a finite element model to simulate the maximum change point as a basis, and outputting a simulation factor related to settlement based on a simulation result.

[0025] S5, combining the simulation factor, the correction factor, and the maximum settlement factor to form a final prediction model, coupling the prediction model according to a measuring point used during calculation, and obtaining a simulation evaluation result of tunnel construction.

[0026] The shape and size of the tunnel can be represented as shown below: shape: circular, rectangular, horseshoe-shaped, etc.; size: diameter, width, height, etc.

[0027] The tunnel structure is represented as a support method and a lining type, the lining type including shotcrete, prefabricated segments, etc., the support method including anchor rods, steel arches, etc., a drainage system: drainage ditches, drainage pipes, etc. At this time, different tunnel structures used can result in different preliminary stresses and stress changes of the overall tunnel, ultimately resulting in different settlements and corresponding displacement conditions.

[0028] The construction condition represents the current tunnel construction method, geological conditions, hydrological conditions, etc. corresponding to the construction step; the construction method is, for example, drill and blast method, shield method, TBM method, etc.; the construction step is used to clearly define the steps and order of the tunnel construction at this time, to determine the corresponding conditions of the tunnel in the whole construction process, such as excavation, consolidation, protection, final stage, etc., to verify the changes such as settlement and displacement of the overall tunnel; the construction condition can represent the boundary condition for the current simulation verification, and using this boundary simulation condition can identify the characteristics of the tunnel after selecting the excavation part, the boundary condition and the related geological condition of the part, so as to obtain a finite difference solution more similar to the current actual situation.

[0029] The divided sample area is divided into multiple sample areas of equal size according to the required number under each construction condition, and the sample area set under different construction steps is adjusted.

[0030] The simulation method used can be FLAC3D, UDEC, 3DEC, PFC, Abaqus, etc. in tunnel construction simulation; when using the simulation software, the boundary conditions and initial conditions of the model are set according to the actual situation of the tunnel, the boundary conditions usually include fixed boundary, free boundary and stress boundary of the model, etc.; the initial conditions include the initial stress state, temperature, etc. of the rock-soil mass.

[0031] The construction simulation function of the software is used to simulate the construction process of the tunnel, which includes the simulation of excavation, support, lining and other steps. During the simulation process, the changes of the displacement, stress and other parameters of the tunnel can be monitored in real time. At this time, multiple regions are divided as sample regions, and multiple measurement points are set in each sample region to ensure that the entire region is covered. The data recorded by the measurement points are integrated, and the three-dimensional coordinates and settlement of each measurement point are recorded. The unit of the settlement is millimeter, which represents the depth of subsidence. Recording the settlement can show the settlement of the entire tunnel relative to the initial position on the bottom surface. At the same time, the change of the tunnel center when the tunnel subsides is more obvious, so the maximum settlement factor, correction factor and other values are set at the initial judgment position of the tunnel center. At the same time, whether there is a part with a settlement difference and whether there is a part with a relatively large displacement in the current tunnel need to be considered, and these contents are integrated to obtain a corresponding simulation factor. Finally, the prediction of the settlement of the entire tunnel is completed to simulate the change of the corresponding region during the construction process.

[0032] In an embodiment of the present application, step S1 obtains the shape, size, corresponding tunnel structure of the tunnel, construction method and construction step corresponding to the construction condition of the tunnel, and divides the tunnel into multiple sample regions according to the tunnel structure and construction condition.

[0033] When obtaining the settlement distribution, the settlement sensitive region is predicted according to the predicted excavation depth of the tunnel, the geological condition, the underground water level and other factors, and on this basis, the sample region and the measurement point are set to adjust the arrangement of observing the settlement distribution.

[0034] Therefore, in step S1, the setting of the sample region needs to be adjusted to identify the sensitive region and set the corresponding sample region.

[0035] As shown in Figure 2 Step S1 further includes the following implementation modes: S11, setting a first sample region based on the tunnel structure, and dividing the tunnel into different sample regions according to different lining types, support methods and the like in the tunnel structure.

[0036] S12, setting a second sample region based on the construction condition, and dividing the tunnel into different sample regions according to different construction methods, geological conditions, hydrological conditions and the like in the construction condition.

[0037] S13, taking the set first sample region and second sample region as the output sample region.

[0038] At this time, the tunnel is divided according to different tunnel structures and construction conditions to identify the region prone to settlement and stress change. At the same time, the influence of the set tunnel structure and construction condition on the tunnel construction can be evaluated when they are different.

[0039] Simultaneously, these obtained sample areas can be overlaid and analyzed according to the tunnel structure and construction conditions to identify areas with high comprehensive risks, as well as the buffer conditions around these areas. At this time, these risks and buffers will be realized through settlement and corresponding stress analysis to complete the control of settlement analysis.

[0040] In one embodiment of the present invention, step S2 obtains the settlement amount of each measurement point within the sample area, sets the tunnel center as the starting point, and obtains a settlement distribution map based on the distance of the measurement point from the tunnel center.

[0041] At this point, the settlement distribution will first be calculated by measuring the distance from each measurement point to the tunnel centerline; the settlement of each measurement point will be correlated with its distance to the tunnel centerline to form a settlement distribution table.

[0042] Use tools such as Excel and MATLAB to generate a settlement distribution map. This settlement distribution map will show the overall distribution of settlement, and will also include the three-dimensional coordinates of the measurement points to show the changes in different areas, as well as the distribution of settlement in different settlement areas when the distance between the measurement point and the tunnel centerline is the same, so as to quantify the distribution of settlement.

[0043] For example, each measurement point in the settlement distribution map can be represented as (x, y, z, d1, d2); where x, y, z represent the three-dimensional coordinates of the measurement point, d1 represents the settlement amount, and d2 represents the distance of the measurement point from the center of the tunnel; in order to quantify the distribution of the settlement amount, it is also necessary to determine the sample area where each measurement point is located in order to identify the relative relationship between the measurement points.

[0044] The main objective at this stage is to analyze stress changes primarily driven by settlement, and to simulate the environment surrounding the tunnel construction team and how it is affected by that environment.

[0045] When generating a settlement distribution map, it is necessary to collect settlement data from different sample areas according to the generated sample area, identify the trend of settlement change, and convert these identified parts into a settlement distribution map. The settlement can be simulated using elasticity models, plasticity models, etc., and the amount of settlement that will occur at this time can be predicted based on these simulations.

[0046] Therefore, as Figure 3 As shown, the implementation of step S2 includes the following: S21, based on the settlement of the measurement point, obtain the envelope ratio of the measurement point. At this time, the envelope ratio represents the ratio of the settlement value measured at the measurement point to the benchmark value. The benchmark value represents the maximum settlement value of the tunnel, which is obtained from the tunnel construction specifications.

[0047] S22, combine the envelope proportion of the measurement points to generate a first envelope curve located on the left side of the tunnel center line and a second envelope curve located on the right side of the tunnel center line, introduce the first envelope curve and the second envelope curve into the distance of the measurement points from the tunnel center, and calculate the fluctuation range corresponding to the settlement amount.

[0048] S23, mark the measurement points according to the fluctuation range of the settlement amount, and form a settlement distribution map by the marked measurement points.

[0049] The first envelope curve and the second envelope curve selected in step S22 are used to determine whether the settlement amounts on both sides of the tunnel fluctuate at opposite positions when the both sides are compared based on the tunnel center line, and the fluctuation range of the settlement amounts on both sides, the fluctuation range representing the numerical range in which the settlement amount can fluctuate at this time, that is, the maximum value and the minimum value of the settlement amount at the corresponding position are obtained to obtain the fluctuation range at this time.

[0050] Since the fluctuation range can show the change trend of the settlement amount with the distance from the tunnel center line, the part with a significant fluctuation range is marked to generate a settlement distribution map. When marking the measurement points, it is also necessary to determine the settlement amount in different fluctuation range intervals, generate multiple images according to each fluctuation range, and superimpose these images to form the final output settlement distribution map.

[0051] In an embodiment of the present application, when obtaining the settlement distribution map, it is necessary to analyze the change area of the settlement amount, and select the required settlement distribution map according to the change area of the settlement amount, such as combining the settlement amount of the measurement points in the rising area into a settlement distribution map, combining the settlement amount in the falling area into a settlement distribution map, or selecting the settlement amount with a very small range fluctuation to combine into a settlement distribution map.

[0052] Therefore, as shown in Figure 4 , step S23 can further include the following implementation manners.

[0053] S231, based on the fluctuation range of the settlement amount, trend analysis is performed on the settlement amount of the measurement points to obtain the symmetrical positions of the first envelope curve and the second envelope curve.

[0054] S232, according to the symmetrical positions of the first envelope curve and the second envelope curve, determine the fluctuation trend amount of the settlement amount with the distance from the tunnel center line.

[0055] S233, based on the fluctuation trend amount of the settlement amount, generate multiple initial settlement maps corresponding to the fluctuation trend amount, superimpose the initial settlement maps according to the positions and settlement amounts of the measurement points, and generate the output settlement distribution map.

[0056] At this time, according to the fluctuation range based on the settlement amount, a plurality of initial settlement graphs corresponding to the fluctuation range are generated, and the initial settlement graphs are superimposed according to the position and settlement amount of the measurement point to generate an output settlement distribution graph. The superimposition is weighted and averaged according to the corresponding measurement point position and settlement amount to determine the final superimposed measurement point position and settlement amount value of the measurement point to reflect the overall settlement amount change.

[0057] The fluctuation value at this time represents the ratio of the settlement amount to the average settlement amount; the symmetric position is the position of the first envelope curve and the second envelope curve relative to the tunnel center line, which is usually achieved by calculating the average or median of the settlement amount of the two curves at each distance, and selecting the point corresponding to the average or median settlement amount at each distance as the symmetric position at this time. For each symmetric position at each distance, the fluctuation trend amount is achieved by calculating the difference between the fluctuation amount of each measurement point and the fluctuation amount of the symmetric position, and a plurality of initial settlement graphs are generated according to the fluctuation trend amount at this time. Finally, a settlement distribution graph that can contain a position with obvious settlement trend change is superimposed.

[0058] In an embodiment of the present application, step S3 obtains the vertical displacement of the tunnel bottom, the normal displacement of the two sides of the tunnel and the settlement area generated during tunnel construction according to the settlement distribution graph, and calculates the maximum settlement factor and the correction factor.

[0059] As shown in Figure 5 , step S3 includes the following implementation manners.

[0060] S31, according to the construction conditions and the tunnel structure, the obtained settlement distribution graph is divided to determine the condition difference graph corresponding to the settlement distribution graph at this time.

[0061] At this time, the settlement distribution map is obtained, and the obtained settlement distribution map is divided according to the construction conditions and the tunnel structure to determine the condition difference map corresponding to the settlement distribution map at this time. The condition difference map is used to perform finite difference solving on the settlement distribution map according to the construction conditions and the tunnel structure, so as to obtain the settlement amount solution under the current construction conditions and the tunnel structure. This solving process aims to determine the stress change of the model due to the change of the settlement amount in the construction process. For example, using the finite difference method, the tunnel and the surrounding strata are discretized into a series of nodes and elements, the positions and densities of the nodes should be determined according to the size of the tunnel, the geological conditions and the expected settlement distribution; for each node, a displacement vector is defined to record the settlement amount of the node; according to the basic principles of elasticity, difference equations are established to describe the settlement and stress change of the tunnel and the surrounding strata. These equations will consider the displacement of the nodes, the elastic properties of the materials and the boundary conditions (such as the fixed constraints of the ground surface, the excavation face of the tunnel, etc.); the difference equations can be solved by iteration, and the displacement vector of each node is updated in each iteration until the convergence condition is reached; in the solving process of the difference equations, the boundary conditions need to be handled specially. For example, at the ground surface, a fixed displacement boundary condition can be set; at the excavation face of the tunnel, the stress release and displacement change caused by excavation need to be considered; the difference equations are solved to obtain the settlement amount of each node; according to the settlement amount data, the stress distribution of the tunnel and the surrounding strata is calculated; this can be achieved by substituting the settlement amount into the stress-strain relationship of elasticity; analyze the solving results to evaluate whether the settlement distribution and stress change of the tunnel meet the safety standards, compare the calculation results with the field monitoring data to verify the accuracy and reliability of the model; through these calculation methods, the comparison between the current simulation calculation results and the field monitoring data is reflected.

[0062] Therefore, as shown in Figure 6 the implementation process of step S31 can be as follows.

[0063] S311, based on the settlement distribution map, determine the difference area for finite difference solving; this area should cover the parts with significant settlement change, complex construction conditions or special tunnel structure.

[0064] S312, divide the difference area into multiple difference grids based on the tunnel structure and construction conditions; within the determined difference area, divide the difference grids according to certain rules; the division of the grids should consider the complexity of the construction conditions and the tunnel structure, as well as the accuracy requirements of the solving. Usually, square or rectangular grids are used for division to ensure that the same form of difference equation is obtained on each grid node.

[0065] S313, extract the difference grid solving precision and calculation conditions, set the difference format corresponding to the difference grid; common difference formats include upwind format, Lax-Wendroff format, Maccormack format, etc.; when selecting the difference format, the wave propagation direction, numerical stability and calculation efficiency should be considered.

[0066] S314, according to the difference format and the settlement distribution map, construct the difference equation set, each equation in the equation set corresponds to a difference equation on the difference grid node; by solving the difference equation set, the numerical solution of the settlement can be obtained;

[0067] S315, the difference equation set is graphically displayed to generate a conditional difference graph; the position of each grid node, the coefficient of the difference equation and the boundary condition of the solution and other information should be clearly marked in the conditional difference graph.

[0068] When the conditional difference graph is obtained, the key areas and abnormal values of settlement and stress change are identified to determine whether the settlement and stress at this time are within the acceptable range, which quantifies the analysis of the conditional difference graph and verifies the maximum settlement factor corresponding to the settlement and stress change under different conditions.

[0069] S32, the conditional difference graph is solved by finite difference to obtain the solution result of the conditional difference, which includes the position of the grid node after solving the difference equation, the settlement obtained by solving, and the boundary condition, to identify the value of the settlement and the value of the maximum settlement factor in the conditional difference graph under different conditions.

[0070] As shown in Figure 7 , the implementation process of step S32 can include the following ways.

[0071] S321, discretize the tunnel and the surrounding bottom layer to generate a plurality of target nodes, the position and density of the target nodes should be determined according to the size of the tunnel, the geological conditions and the distribution of the fluctuation trend quantity in the settlement distribution map; each target node corresponds to a unit.

[0072] S322, set the displacement vector corresponding to the target node, iterate the displacement vector until the convergence condition is reached, and output the displacement vector that meets the convergence condition as the target displacement vector; the displacement vector represents the vertical displacement of the tunnel bottom and the normal displacement of the tunnel sides.

[0073] S323, based on the target displacement vector, obtain the displacement boundary condition of the target displacement vector;

[0074] S324, based on the displacement boundary condition, determine the settlement and stress distribution of the tunnel and the surrounding strata, and output as the solution result of the conditional difference.

[0075] At this time, the displacement of the target node, the elastic properties of the material, and the corresponding boundary conditions are considered, and the difference equation is set, which can be expressed as shown below.

[0076] Ku = F; where Ku = F can represent the current required difference equation, K is the stiffness matrix, which represents the elastic properties of the material, and u is the displacement vector; F is the external force vector, which represents the external load and boundary conditions.

[0077] The stiffness matrix is determined by the elastic modulus and Poisson's ratio of the material, and can be represented as shown below.

[0078] K = ∫ V B T DBdV; where K represents the stiffness matrix, which is used to represent the stiffness relationship between the target nodes; ∫ V represents integration over the integration domain V, V represents the volume of the element corresponding to the target node, B represents the strain-displacement matrix, which converts the displacement of the target node into the strain of the element, B T represents the transpose of the strain-displacement matrix, D represents the elastic matrix, which represents the elastic properties of the material; dV represents the volume element.

[0079] The external force vector is mainly affected by the external force and the corresponding material, as shown below.

[0080] where F is the external force vector, ∫ V represents integration over the integration domain, N represents the shape function matrix, which is used to interpolate the node displacement to any point within the element; N T represents the transpose of the shape function matrix, ρ represents the density of the material, g represents the acceleration of gravity, dV represents the volume element, represents integration over the boundary , A represents the boundary of the element; t represents the external force on the boundary, which represents the surface force acting on the boundary; dA represents the area element.

[0081] The strain-displacement matrix B corresponding to the stiffness matrix K at this time is used to convert the displacement vector of the target node into the strain of the element, which depends on the shape of the element divided from the tunnel at this time and the displacement field, which can be represented as, for example.

[0082] where x, y represent the coordinates of the target node, N1, N2 represent the values of the shape function matrix.

[0083] For example N i represents the value of the shape function at the i-th node within the element corresponding to the target node, ξ i , η iThe coordinates of the i-th node in the unit corresponding to the target node; At this time, the simple explanation is the conversion method on the plane, when it becomes three-dimensional, the coordinate z is introduced to complete the corresponding strain-displacement transformation.

[0084] At this time, the coordinates in the strain-displacement matrix can be the product of the shape function of the target node, the coordinates of the target node, and the coordinates of the nodes in the unit corresponding to the target node, so as to adjust the node value in the unit and realize the conversion of the displacement vector of the target node to the unit strain.

[0085] The elastic matrix D can be in the following form.

[0086] Where E represents the elastic modulus, and v represents the Poisson's ratio. This matrix converts strain to stress.

[0087] The stress and strain, and the displacement related content can be solved by the above set matrix, to obtain the settlement amount to be identified and the corresponding stress at this time.

[0088] In step S322, the displacement vector is calculated each time until the displacement increment calculated by the displacement vector is less than the convergence threshold, and it is considered that the current displacement vector meets the requirements and is output as the target displacement vector.

[0089] In step S323, the initial value of the displacement boundary condition is set to 0, and the displacement change amount of the tunnel in the construction process is set as the displacement boundary condition.

[0090] In step S324, the stress and settlement around the calculated displacement boundary condition are obtained, and the solving result at this time is output to process the settlement distribution and stress change of the tunnel.

[0091] In step S32, the displacement value is calculated by solving the change value of the displacement vector, and according to the direction of the displacement of the tunnel, the displacement value solved at this time can be directly calculated to identify the current displacement condition. At the same time, the stress condition converted at this time is also solved to assist in identifying the settlement amount to be output, so as to prevent unreasonable parts of stress conversion.

[0092] S33, according to the solving result, the maximum settlement factor of the settlement amount is obtained.

[0093] The maximum settlement factor is represented as the ratio of the settlement corresponding to the maximum fluctuation trend in the settlement distribution diagram to the settlement in the solving result, to reflect the settlement under the corresponding displacement boundary condition and corresponding condition. If the maximum settlement factor is close to 1, it indicates that the settlement trend set previously is similar to the solving analysis at this time, and the overall prediction is relatively accurate. If it is obviously greater than 1, it indicates that the previous settlement trend is obviously underestimated, and the overall prediction underestimates the value of the settlement affected by the boundary condition and the like. If it is obviously less than 1, it indicates that the affected value is overestimated previously, or the overall predicted value is greatly different.

[0094] For the displacement and settlement area generated at this time, the displacement, settlement area and calculated settlement solution are combined to obtain the corresponding correction factor at this time. The correction factor is used to evaluate the stability of the tunnel and judge whether there is a safety hazard in the tunnel. According to the size and change trend of the correction factor, the parameter adjustment and optimization in the construction process are guided to ensure the safety and stability of the tunnel construction.

[0095] S34, combining the solving result with the displacement and settlement area to obtain a correction factor.

[0096] The correction factor here is represented as the comprehensive value of the settlement area, settlement, displacement vector and stress change amount in the solving result. The settlement area, settlement, displacement vector and stress change amount in the solving result are obtained, normalized, and the correction factor is calculated.

[0097] Wherein, λ j represents the correction factor of the jth element, ε j represents the stress change amount of the jth element, u j represents the displacement vector of the jth element, SA 1,j represents the settlement of the jth element, SA 2,j represents the settlement area of the jth element, and the displacement vector is normalized. The normalization of the displacement vector is in the form of normalization after the modulus value of the displacement vector is calculated, or the vector is directly normalized.

[0098] In an embodiment of the present application, step S4 identifies the maximum settlement point and the maximum change point in the tunnel, uses the finite element model to simulate the maximum change point as the basis, and outputs a simulation factor related to settlement based on the simulation result.

[0099] The simulation factor is used to simulate the most obvious point in the tunnel construction process and verify the change of the most obvious point in the overall construction, to clearly identify the parts that need to be paid attention to in the tunnel construction. In this step, the settlement amount obtained is mainly used to identify the changes.

[0100] The maximum settlement point is used to identify the point with the maximum settlement amount and find the point with the maximum settlement amount change value during the simulation of the model, so as to identify the point most easily affected; for example, the settlement rate and settlement amount under different tunnel structures and construction conditions are identified to quantify the simulation factor, and the simulation result at this time is output as the simulation factor.

[0101] The simulation manner is the same as the finite element solution manner in step S3, and the settlement rate and settlement amount of the settlement amount are identified according to the calculated displacement vector, so as shown in Figure 8 step S4 also includes the following implementation manners.

[0102] S41, obtaining the settlement rate and settlement amount of the maximum change point under different tunnel structures and construction conditions.

[0103] S42, calculating the simulation factor related to settlement based on the settlement rate and settlement amount.

[0104] Therefore, the simulation factor is represented as the settlement rate and settlement amount are obtained, and the maximum settlement area corresponding to the current settlement amount is obtained, the settlement rate, settlement amount and maximum settlement area are normalized, and the simulation factor is calculated.

[0105] wherein ψ represents the simulation factor, the maximum settlement area, SA1 represents the settlement amount, SA3 represents the settlement rate, and e represents the exponential constant; at this time, the settlement amount represents the settlement amount of the maximum change point, the settlement rate also represents the settlement rate of the maximum change point, and the maximum settlement area represents the maximum settlement area corresponding to the current maximum change point, so as to quantify the value of the simulation factor at this time and the change of the settlement amount under the corresponding simulation.

[0106] In an embodiment of the present application, step S5 combines the simulation factor, the correction factor and the maximum settlement factor to form a final prediction model, and the prediction model is coupled according to the measurement points used during calculation to obtain the simulation evaluation result of the tunnel construction.

[0107] Therefore, the coupling manner at this time is to identify the measurement points used during calculation of the simulation factor, the correction factor and the maximum settlement factor, and the positions of the measurement points, and to splice the measurement points directly involved in the calculation according to the relative positions to determine the simulation evaluation result of the settlement caused by the tunnel construction at the same position at this time, and to output the relative simulation evaluation result to obtain the evaluation of the tunnel construction.

[0108] For example, the simulation factor, the correction factor and the maximum settlement factor can be combined directly to obtain the combined simulation evaluation result, for example, the simulation evaluation result can be represented as

[0109] wherein L represents a simulation evaluation result, ψ represents a simulation factor, λ represents a correction factor, and δ max represents a maximum settlement factor, w1 represents a weight of the simulation factor, w2 represents a weight of the correction factor, and w3 represents a weight of the maximum settlement factor; the weights are set in order of the simulation factor, the correction factor, and the maximum settlement factor, and are 0.4, 0.3, and 0.3, respectively.

[0110] The final simulation evaluation result is used to represent the analysis result of the settlement amount and the current construction process after the simulation, and is used to simulate whether the current construction project meets the requirements, for example, when the simulation evaluation result is negative, it means that there is an error between the current simulation content and the expected requirements, and the construction content needs to be adjusted to reduce the possible risks in the construction, and the value at this time needs to be close to the set threshold value, for example, the set threshold value is 0.6, when close to this value, it means that the overall evaluation result meets the requirements, and the current construction can be observed to continuously adjust the simulation content to improve the safety of the construction.

[0111] Although the embodiments of the present application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the present application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the present application, which are still covered by the protection scope of the present application.

Claims

1. A method for numerical simulation of the whole process of tunnel construction based on non-contact measurement, characterized in that, The method comprises the following steps: S1, obtaining the tunnel structure corresponding to the shape and size of the tunnel, the construction condition corresponding to the construction method and construction steps of the tunnel, and dividing the tunnel into multiple sample areas according to the tunnel structure and the construction condition; S2, obtaining the settlement of each measurement point in each sample area, setting the tunnel center as the starting point, and obtaining the settlement distribution map according to the distance of the measurement point from the tunnel center; S3, obtaining the vertical displacement of the tunnel bottom, the normal displacement of the two sides of the tunnel and the settlement area generated during the tunnel construction according to the settlement distribution map under the corresponding construction step, and calculating the maximum settlement factor and the correction factor; S4, identifying the maximum settlement point and the maximum change point in the tunnel, using the finite element model to simulate the maximum change point as the basis, and outputting the simulation factor related to the settlement based on the simulation result; S5, combining the simulation factor, the correction factor and the maximum settlement factor to form the final prediction model, coupling the prediction model according to the measurement points used during calculation, and obtaining the simulation evaluation result of the tunnel construction; Step S3 comprises the following implementation manners: S31, dividing the obtained settlement distribution map according to the construction condition and the tunnel structure to determine the condition difference map corresponding to the settlement distribution map at this time; S32, performing finite difference solution on the condition difference map to obtain the solution result of the condition difference; S33, obtaining the maximum settlement factor of the settlement according to the solution result; S34, combining the solution result with the displacement and the settlement area to obtain the correction factor; The correction factor is represented as follows: the settlement area, the settlement, the displacement vector and the stress change amount in the solution result are normalized to calculate the correction factor: ； wherein, denotes a correction factor for the jth element, denotes a stress change amount for the jth element, denotes a displacement vector for the jth element, denotes a settlement amount for the jth element, denotes a settlement area for the jth element; The simulation evaluation result is represented as follows: the simulation factor, the correction factor and the maximum settlement factor are combined to obtain the combined simulation evaluation result: ； wherein, represents a simulation evaluation result, represents a simulation factor, represents a correction factor, represents a maximum settlement factor, represents a weight of a simulation factor, represents a weight of a correction factor, represents a weight of a maximum settlement factor.

2. The method of claim 1, wherein the method is characterized by, Step S1 further comprises the following implementation manners: S11, setting a first sample area based on the tunnel structure, and dividing the tunnel into different sample areas according to different lining types, support methods and the like in the tunnel structure in the first sample area; S12, setting a second sample area based on the construction condition, and dividing the tunnel into different sample areas according to different construction methods, geological conditions, hydrological conditions and the like in the construction condition in the second sample area; S13, taking the set first sample area and second sample area as the output sample area.

3. The method of claim 1, wherein the method is characterized by, The implementation manner of step S2 comprises the following contents: S21, obtaining the envelope ratio of the measurement point based on the settlement of the measurement point; S22, combining the envelope ratio of the measurement point to generate a first envelope curve located on the left side of the tunnel center line and a second envelope curve located on the right side of the tunnel center line, introducing the first envelope curve and the second envelope curve into the distance of the measurement point from the tunnel center, and calculating the fluctuation range corresponding to the settlement; S23, marking the measurement points according to the fluctuation range of the settlement to form the settlement distribution map.

4. The method of claim 3, wherein the method is characterized by, Step S23 further comprises the following implementation manners: S231, performing trend analysis on the settlement of the measurement points based on the fluctuation range of the settlement to obtain the symmetric position of the first envelope curve and the second envelope curve; S232, determine the fluctuation trend of the settlement amount with the distance of the tunnel center line according to the symmetric position of the first envelope curve and the second envelope curve; S233, generate an initial settlement map corresponding to the fluctuation trend of the settlement amount based on the fluctuation trend of the settlement amount, and superimpose the initial settlement map according to the position and settlement amount of the measurement point to generate an output settlement distribution map.

5. The method of claim 1, wherein the method is characterized by, The implementation process of step S31 is as follows: S311, determine the difference area for finite difference solution based on the settlement distribution map; S312, divide the difference area into a plurality of difference grids based on the tunnel structure and construction conditions; S313, extract the difference grid solving precision and calculation conditions, and set the difference format corresponding to the difference grid; S314, construct a difference equation set according to the difference format and the settlement distribution map; S315, graphically display the difference equation set to generate a conditional difference map.

6. The method of claim 1, wherein the method is characterized by, The implementation process of step S32 includes the following modes: S321, discretize the tunnel and surrounding strata to generate a plurality of target nodes, the position and density of the target nodes should be determined according to the size of the tunnel, the geological conditions and the distribution of the fluctuation trend in the settlement distribution map; each target node corresponds to a unit; S322, set the displacement vector corresponding to the target node, and continuously iterate the displacement vector until the convergence condition is reached, and output the displacement vector that meets the convergence condition as the target displacement vector; S323, obtain the displacement boundary condition of the target displacement vector based on the target displacement vector; S324, determine the settlement amount and stress distribution of the tunnel and surrounding strata based on the displacement boundary condition, and output the result of the conditional difference solution.

7. The method of claim 1, wherein the method is characterized by, Step S4 further includes the following implementation modes: S41, obtain the settlement rate and settlement amount of the maximum change point under different tunnel structures and construction conditions; S42, calculate the simulation factor related to settlement based on the settlement rate and settlement amount; The simulation factor is represented as: obtain the settlement rate, settlement amount, and maximum settlement area corresponding to the current settlement amount, normalize the settlement rate, settlement amount, and maximum settlement area, and calculate the simulation factor; ； wherein, represents a simulation factor, represents a maximum settling area, represents a settling amount, represents a settling rate, represents an exponential constant.

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