A method and system for excavation control based on three-dimensional stratigraphic inversion

Abstract

The present application relates to the technical field of excavation control, and specifically discloses a kind of excavation control method and system based on three-dimensional stratum inversion, comprising: according to the physical property deviation, the physical property smoothing probability of different thin structure thickness and the proportion of volume element side length is calculated, and the thin structure thickness and volume element side length identification proportion are determined;High-risk area is identified in the target excavation area of current project, and it is judged whether there is universality excavation risk in high-risk area by load influence simulation;If there is, reconstruct the inversion model of high-risk area, and assign real physical property to thin structure, realize the display separation of thin structure;Combined with thin structure thickness and volume element side length identification proportion, adjust the volume element of thin structure after display separation, and reconstruct cutter load during excavation of high-risk area, solve the problem that due to volume element setting may smooth thin structure physical property, thereby leading to inaccurate inversion and cutter load control during excavation, improve excavation control accuracy.

Description

Technical Field

[0001] This invention relates to the field of excavation control technology, specifically to an excavation control method and system based on three-dimensional stratigraphic inversion. Background Technology

[0002] In underground engineering excavation (such as tunnel and mine excavation), accurate identification and mechanical property characterization of thin structures (such as thin mudstone interlayers and lenses) are core prerequisites for ensuring excavation safety and controlling cutterhead load. Current projects largely rely on geological inversion models to characterize underground strata. However, the hexahedral or octree adaptive meshes used in the inversion process often suffer from a mismatch between the volume element side lengths and the thickness of the thin structure, leading to thin structure property smoothing issues. This problem directly results in a significant decrease in inversion accuracy and cutterhead load control accuracy, becoming a key contributing factor to potential engineering safety hazards.

[0003] Specifically, in a hexahedral mesh, the volume elements are regular cuboids. If the thickness of the thin structure is much smaller than the vertical side length of the volume element, the physical properties of the thin structure and the background strata (such as elastic modulus and cohesion) will be averaged by the homogenized volume elements. The originally significant differences in physical properties (such as 15 GPa for mudstone and 50 GPa for sandstone) will be smoothed into intermediate values. Although the octree adaptive mesh can locally refine complex areas, if the refinement level in the thin structure area is insufficient, the side length of the volume elements may still be greater than the thickness of the thin structure, causing the physical properties of the thin structure to be "assimilated" by the surrounding strata. This smoothing effect makes the inversion model unable to truly reflect the mechanical weakness of the thin structure, which in turn leads to a serious disconnect between the cutterhead load (thrust and torque) calculated based on the model and the actual needs: either the load is too high, causing the thin structure to break and the interface to slide, or the load is too low, causing the thin structure to not break and resulting in over-excavation. Summary of the Invention

[0004] The purpose of this invention is to provide a mining control method and system based on three-dimensional stratigraphic inversion to solve the problems mentioned above.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for excavation control based on three-dimensional stratigraphic inversion includes the following steps:

[0007] Step 1: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, we obtain multiple physical property deviations under different ratios of thin structure thickness to volume element side length. Based on the physical property deviations, we calculate the physical property smoothing probability of different ratios of thin structure thickness to volume element side length and determine the identification ratio of thin structure thickness to volume element side length.

[0008] Step 2: Identify high-risk areas within the target excavation area of ​​the current project based on the ratio of thin structure thickness to volume element side length, and determine whether there is a general excavation risk in the high-risk areas through load impact simulation;

[0009] Step 3: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area.

[0010] Step 4: Combine the thin structure thickness with the volume element side length recognition ratio, adjust the volume elements of the thin structure after display separation, and reconstruct the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after volume element adjustment.

[0011] As a further aspect of the present invention: the historical inversion data includes the thickness of the thin structure, the side length of the volume element, and the physical property values ​​of the historical inversion model; the historical actual verification data includes the actual physical property values ​​of the thin structure revealed after excavation.

[0012] The method for determining the ratio of thin structure thickness to volume element side length identification is as follows:

[0013] The absolute deviation ratio between the physical property values ​​of the historical inversion model and the actual physical property values ​​of the thin structure is calculated to obtain the physical property deviation value of the thin structure.

[0014] If the property deviation value is greater than the preset property deviation value, it indicates that a high-risk property smoothing has occurred.

[0015] The frequency of occurrence of high-risk physical property smoothing is used as the probability of physical property smoothing in the ratio of thin structure thickness to volume element side length.

[0016] Based on the property smoothing probability of different ratios of thin structure thickness to volume element side length, the ratio of thin structure thickness to volume element side length corresponding to the property smoothing probability threshold is selected as the recognition ratio of thin structure thickness and volume element side length.

[0017] As a further aspect of the present invention: the method for identifying high-risk areas is as follows:

[0018] If the ratio of thin structure thickness to volume element side length within a thin structure region is less than or equal to the thin structure thickness to volume element side length identification ratio, then the thin structure region is marked as a high-risk region.

[0019] As a further aspect of the present invention: the process of determining whether there is a general risk of mining in high-risk areas is as follows:

[0020] The inversion model is imported into the excavation engineering simulation software. The cutterhead load parameters are set according to the initial excavation plan. The excavation simulation is carried out on the high-risk area. Based on the stress distribution of the thin structure in the high-risk area and the actual position of each excavation profile monitoring point output by the excavation simulation, the excavation risk area in the high-risk area is identified.

[0021] The risk value is obtained by statistically analyzing the proportion of risky areas within high-risk areas.

[0022] If the mining risk value is greater than or equal to the mining risk threshold, it indicates that there is a general mining risk in the high-risk area.

[0023] As a further aspect of the present invention: the process of identifying high-risk areas and mining risk areas is as follows:

[0024] If a high-risk area meets any of the criteria for determining excavation risk, then the high-risk area will be marked as an excavation risk area.

[0025] The risk assessment criteria include:

[0026] Judgment Criterion 1: Local stress peaks occur in thin structures within high-risk areas, and the ratio between the local stress peaks and the formation compressive strength exceeds a preset ratio;

[0027] Judgment condition two: The actual location of any excavation profile monitoring point deviates from the planned excavation location by a distance exceeding the design allowable value.

[0028] As a further aspect of the present invention: the process of reconstructing the inversion model of the high-risk area includes: splitting the background model and the thin structure region, and embedding thin structure units;

[0029] The process of splitting the background model and thin structure region is as follows:

[0030] Open the inversion model using geological modeling software and locate the large-scale background strata. Keep the large-scale background strata unchanged, and then mark the spatial range of thin-structured areas in the inversion model according to the high-risk areas.

[0031] The process of embedding the thin structural unit is as follows:

[0032] If the thin structure is purely interface-based, with no actual thickness but abrupt changes in physical properties, then zero-thickness interface units should be embedded.

[0033] If the thin structure is a geological body with actual thickness, then embedding of solid units with minimal thickness is selected.

[0034] The zero-thickness interface unit is embedded in the following way:

[0035] Apply a layer to the thin structure location of the background model, ensuring that the coordinates of the layer are completely consistent with the actual location of the thin structure;

[0036] The embedding method for extremely thin solid units is as follows:

[0037] Within the coordinate range of the thin structure of the background model, delete the original large-scale volume elements and replace them with small-scale solid elements according to the thickness of the thin structure.

[0038] As a further aspect of the present invention: the process of assigning real physical property values ​​to thin structures in high-risk regions during the inversion model reconstruction process is as follows:

[0039] From the core samples obtained in the previous exploration, rock samples with corresponding thin structures were found, and the physical property parameters of the rock samples were measured. Based on the thin structure in the reconstructed inversion model, if the zero-thickness interface unit is selected for embedding, the true physical properties of the thin structure are assigned to one side of the surface according to the physical property parameters, while the background strata physical properties are retained on the other side, forming a physical property abrupt change surface.

[0040] If a solid unit with extremely small thickness is selected for embedding, then the actual physical properties are assigned to the entire thin structure in batches according to the physical property parameters.

[0041] As a further aspect of the present invention: the process of adjusting the volumetric elements of the thin structural region after display separation is as follows:

[0042] The thickness of the thin structure after display separation is obtained. The ratio of the thickness of the thin structure after display separation to the identification ratio of the thickness of the thin structure to the side length of the volume element is calculated to obtain the target side length of the thin structure after display separation. The original side length of the thin structure after display separation is adjusted according to the target side length of the thin structure after display separation.

[0043] As a further aspect of the present invention: the process of reconstructing the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics is as follows:

[0044] Based on the thin structure in the high-risk area, the ultimate shear strength of the interface is calculated. The upper limit of the cutterhead thrust is determined based on the ultimate shear strength of the interface and the compressive strength of the thin structure itself. The minimum value of the upper limit of the cutterhead thrust is selected as the cutterhead thrust adjustment value.

[0045] Calculate the frictional torque between the cutter head and the thin structure, as well as the additional torque required for the thin structure to break, and sum them to obtain the cutter head torque adjustment value.

[0046] A mining control system based on three-dimensional stratigraphic inversion includes the following modules:

[0047] Void element identification and determination module: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, multiple physical property deviations under different ratios of thin structure thickness to void element side length are obtained. Based on the physical property deviations, the physical property smoothing probability of different ratios of thin structure thickness to void element side length is calculated, and the identification ratio of thin structure thickness to void element side length is determined.

[0048] Risk assessment module: Based on the ratio of thin structure thickness to volume element side length, high-risk areas are identified within the target excavation area of ​​the current project. Through load impact simulation, it is determined whether there is a general excavation risk in the high-risk areas.

[0049] Thin structure display and separation module: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area.

[0050] Cutterhead load reconstruction module: Combining the thin structure thickness and the volume element side length recognition ratio, the module adjusts the volume elements of the thin structure after display separation, and reconstructs the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after the volume element adjustment.

[0051] The beneficial effects of this invention are:

[0052] Based on historical inversion data and historical verification data from similar projects, multiple physical property deviations under different ratios of thin structure thickness and volume element side length are obtained through comparative analysis. Then, the smoothing probability of the corresponding ratio is calculated based on the physical property deviations to determine the identification ratio of thin structure thickness and volume element side length. Subsequently, high-risk areas are identified in the current project's target excavation area using this identification ratio, and the presence of general excavation risks in these high-risk areas is determined through load impact simulation. If risks exist, the inversion model of the high-risk areas is reconstructed, and real physical properties are assigned to the thin structures within the high-risk areas during the reconstruction process using borehole core test data, achieving thin structure display separation. Finally, based on the aforementioned identification ratio, volume element adjustments are made to the displayed and separated thin structures, and the cutterhead load reconstruction during excavation in high-risk areas within the target excavation area is completed based on interface mechanics principles. This solves the problem of inaccurate cutterhead load control during inversion and excavation when using a hexahedral / octree adaptive mesh, as the volume element settings may smooth the thin structure's physical properties, thus improving excavation control accuracy. Attached Figure Description

[0053] The invention will now be further described with reference to the accompanying drawings.

[0054] Figure 1 This is a flowchart illustrating the steps of a mining control method based on three-dimensional stratigraphic inversion as described in an embodiment of the present invention.

[0055] Figure 2 This is a logic judgment diagram of a mining control method based on three-dimensional stratigraphic inversion as described in an embodiment of the present invention;

[0056] Figure 3 This is a flowchart of a mining control system based on three-dimensional stratigraphic inversion, as described in an embodiment of the present invention. Detailed Implementation

[0057] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0058] Example 1: Please refer to Figure 1-2 As shown, this invention is a mining control method based on three-dimensional stratigraphic inversion, comprising the following steps:

[0059] Step 1: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, we obtain multiple physical property deviations under different ratios of thin structure thickness to volume element side length. Based on the physical property deviations, we calculate the physical property smoothing probability of different ratios of thin structure thickness to volume element side length and determine the identification ratio of thin structure thickness to volume element side length.

[0060] In step one, the historical inversion data includes the thickness of the thin structure, the side length of the volume element (vertical), and the physical property value (elastic modulus) of the historical inversion model. The historical actual verification data includes the actual physical property value of the thin structure revealed after excavation (obtained through core tests and field detection).

[0061] It should be noted that physical property values ​​can also include cohesion, density of the lens, friction angle, and other physical property values. The acquisition of the volume element side length can be divided into two cases. The first case is in a hexahedral mesh, where the volume element is a regular cuboid with a fixed side length. The volume element side length can be read directly by selecting the volume element where the thin structure is located in the historical inversion model. The second case is in an octree mesh. The thin structure region is located in the historical inversion model by using distance filtering. The volume element with the highest encryption level in the thin structure region is selected (octree uses "level" to represent the encryption degree. The higher the level, the smaller the side length). The side length of the highest volume element can be read.

[0062] It should also be noted that "similar projects" refers to projects of the same type as the current project;

[0063] In step one, the probability of property smoothing for different ratios of thin structure thickness to volume element side length is calculated based on the property deviation, and the method for determining the identification ratio of thin structure thickness to volume element side length is as follows:

[0064] Based on the ratio of any thin structure thickness to the volume element side length;

[0065] The absolute deviation ratio between the physical property values ​​of the historical inversion model and the actual physical property values ​​of the thin structure is calculated to obtain the physical property deviation value of the thin structure.

[0066] Wherein, the property deviation value = |the property value of the history inversion model - the actual property value of the thin structure| / the actual property value of the thin structure;

[0067] If the property deviation value is greater than the preset property deviation value, it indicates that a high-risk property smoothing has occurred.

[0068] Conversely, if the property deviation value is less than or equal to the preset property deviation value, it indicates that property smoothing or low-risk property smoothing has not occurred.

[0069] The frequency of occurrence of high-risk physical property smoothing was statistically analyzed, and the frequency of occurrence of high-risk physical property smoothing was used as the probability of physical property smoothing in the ratio of thin structure thickness to volume element side length.

[0070] Based on the property smoothing probability of different ratios of thin structure thickness to volume element side length, the ratio of thin structure thickness to volume element side length corresponding to the property smoothing probability threshold is used as the recognition ratio of thin structure thickness to volume element side length, as exemplarily shown in Table 1.

[0071] Table 1: Probability of smoothing physical properties under different ratios of thin structure thickness to volume element side length;

[0072]

[0073] The ratio of thin structure thickness to volume element side length with a property smoothness probability of 80% (refer to the technical specification for shield tunnel construction) can be used as the identification ratio of thin structure thickness to volume element side length, i.e., 0.5.

[0074] Step 2: Identify high-risk areas within the target excavation area of ​​the current project based on the ratio of thin structure thickness to volume element side length, and determine whether there is a general excavation risk in the high-risk areas through load impact simulation;

[0075] In step two, the process of identifying high-risk areas within the target excavation area of ​​the current project based on the ratio of thin structure thickness to volume element side length is as follows:

[0076] The thin structure region is located in the target mining area of ​​the current project by using the inversion model, the ratio of thin structure thickness to volume element side length is obtained, and it is compared with the ratio of thin structure thickness to volume element side length identification.

[0077] If the ratio of thin structure thickness to volume element side length is less than or equal to the thin structure thickness to volume element side length identification ratio, then the thin structure region is marked as a high-risk region.

[0078] If the ratio of thin structure thickness to volume element side length is greater than the thin structure thickness to volume element side length identification ratio, then the thin structure region is marked as a low-risk region.

[0079] In step two, the process of determining whether there is a general excavation risk in the high-risk area through load impact simulation is as follows:

[0080] The inversion model is imported into excavation engineering simulation software (such as FLAC3D, MIDASGTS). The cutterhead load parameters (including thrust, torque, and rotational speed) are set according to the initial excavation plan. Excavation simulation is then performed on high-risk areas. Based on the stress distribution of thin structures within the high-risk areas and the actual locations of monitoring points on each excavation profile within the high-risk areas, the high-risk areas are identified. Specifically:

[0081] If a high-risk area meets any of the criteria for determining excavation risk, then the high-risk area will be marked as an excavation risk area.

[0082] If none of the high-risk areas meet the criteria for determining excavation risk, then the high-risk areas will be marked as non-excavation risk areas.

[0083] The risk assessment criteria include:

[0084] Judgment Criterion 1: Local stress peaks occur in thin structures within high-risk areas, and the ratio between the local stress peak and the compressive strength of the stratum exceeds the preset ratio (1.2 Refer to the risk cases and prevention and control technologies of shield tunneling construction).

[0085] Judgment condition two: The actual location of any excavation profile monitoring point deviates from the planned excavation location beyond the design allowable value (0.05m, as set by the shield tunnel construction and acceptance specification).

[0086] It should be noted that the design allowable value represents the allowable positional error between the actual excavation position monitored by the excavation profile monitoring point and the planned excavation position;

[0087] The risk value is obtained by statistically analyzing the proportion of risky areas within high-risk areas.

[0088] In some embodiments, the mining risk value is compared with the mining risk threshold;

[0089] If the mining risk value is greater than or equal to the mining risk threshold, it indicates that there is a general mining risk in the high-risk area;

[0090] If the risk value is less than the risk threshold, it means that there is no general risk of mining in the high-risk area, and no operation will be performed.

[0091] Step 3: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area.

[0092] In step three, the process of reconstructing the inversion model of the high-risk area includes: splitting the background model and thin-structured regions, and embedding thin-structured units;

[0093] The process of separating the background model and the thin structure region is as follows:

[0094] Open the inversion model using geological modeling software (such as Surfer, GOCAD) and locate the large-scale background strata (thick sandstone (thickness 5-8m, volume element side length 1m, homogeneous properties, no obvious thin structure)). Keep the large-scale background strata unchanged (background model). Then, mark the spatial range of thin structure areas in the inversion model according to the high-risk areas (for example, the first thin structure is a cuboid with a length of 10m, a width of 5m, and a thickness of 0.3m, with coordinate range: X=100-110m, Y=50-55m, Z=24.85-25.15m, and the center value of the Z direction is taken ±0.15m, corresponding to a thickness of 0.3m).

[0095] The process of embedding thin structural units is as follows:

[0096] Based on the type of thin structure, the embedding method is selected, specifically including:

[0097] If the thin structure is purely interface-like (such as rock strata interface, fault), with no actual thickness but abrupt changes in physical properties (such as the interface between sandstone and mudstone, which only has a surface and no volume), then zero-thickness interface unit embedding should be selected.

[0098] If the thin structure is a geological body with actual thickness (such as a thin mudstone interlayer or lens body of 0.3-0.5m), then a solid unit with extremely small thickness is selected for embedding.

[0099] Understandably, zero-thickness interface unit embedding does not increase the volume of the inversion model, has a fast calculation speed, and is suitable for pure interface-type thin structures. Minimal-thickness solid unit embedding truly reflects the bulk properties (such as density and cohesion) of thin structures and is suitable for thin sandwich or lens bodies with thickness.

[0100] The zero-thickness interface unit is embedded in the following way:

[0101] Apply a surface layer to the location of the thin structure in the background model, ensuring that the coordinates of the surface are completely consistent with the actual location of the thin structure (e.g., if the core sample from the borehole shows that the thin mudstone interlayer is 25m underground, then the interface unit should be applied at Z=25m), and the area of ​​the surface should cover the horizontal distribution of the thin structure (10m×5m).

[0102] The embedding method for extremely thin solid units is as follows:

[0103] Within the coordinate range of the thin structure of the background model, delete the original large-scale volume elements and replace them with small-scale solid elements (the size is set according to the thickness of the thin structure, for example, 0.3-0.5m).

[0104] In step three, the process of assigning realistic physical property values ​​to thin structures in high-risk areas during the inversion model reconstruction process, based on borehole core test data, is as follows:

[0105] Find rock samples with corresponding thin structures from the previous exploratory cores (such as the 0.3m mudstone sample taken from the exploratory core of the first thin mudstone interlayer at 25m).

[0106] Laboratory tests are conducted on rock samples to measure physical properties. For example, for soft interlayers, the elastic modulus (reflecting hardness), cohesion (reflecting shear strength), and Poisson's ratio (reflecting deformation characteristics) need to be measured; for lenses, the density (reflecting weight) and friction angle (reflecting anti-slip ability) need to be measured.

[0107] Based on the thin structure in the reconstructed inversion model, if the selected thin structure unit embedding method is zero-thickness interface unit embedding, then the real physical properties of the thin structure (e.g., the elastic modulus of mudstone is 15 GPa) are assigned to one side of the surface according to the physical property parameters, while the background strata physical properties (sandstone 50 GPa) are retained on the other side, forming a physical property abrupt change surface (simulating the difference between the real thin structure and the background).

[0108] If the selected thin structural unit embedding method is the embedding of extremely thin solid units, then the entire thin structure is assigned real physical properties in batches according to the physical property parameters (for example, all extremely thin solid units are set to elastic modulus of 15 GPa and cohesion of 20 kPa), completely replacing the average physical properties (for example, 35 GPa) in the original inversion model.

[0109] Step 4: Combine the thin structure thickness and the volume element side length recognition ratio to adjust the volume elements of the thin structure area after display separation, and reconstruct the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after volume element adjustment.

[0110] In step four, the process of adjusting the volumetric elements of the separated thin structure region, based on the ratio of thin structure thickness to volumetric element side length recognition, is as follows:

[0111] The thickness of the thin structure after display separation is obtained. The ratio of the thickness of the thin structure after display separation to the identification ratio of the thickness of the thin structure to the side length of the volume element is calculated to obtain the target side length of the thin structure after display separation. The original side length of the thin structure after display separation is adjusted according to the target side length of the thin structure after display separation.

[0112] Wherein, the side length of the target volume element of the thin structure after display separation = the thickness of the thin structure after display separation / the ratio of the thin structure thickness to the volume element side length recognition;

[0113] In step four, the process of reconstructing the cutterhead load during excavation of high-risk areas within the target excavation area based on the principle of interface mechanics is as follows:

[0114] Calculate the interface normal stress σ_normal;

[0115] The calculation formula is: σ_normal = γ·H + (F0 / S);

[0116] Wherein, γ: weighted average density of thin structures in high-risk areas (γ=(γ1・h1+γ2・h2) / (h1+h2), γ1=ρ1・g, γ2=ρ2・g; h1 is the thickness of thin structures, h2 is the thickness of background strata overlying the thin structures), H: burial depth of thin structures, F0: initial cutterhead thrust (load value before adjustment), S: effective contact area of ​​cutterhead, ρ1 is the density of thin structures, ρ2 is the density of background strata overlying the thin structures, and g is the acceleration due to gravity.

[0117] The ultimate shear strength τ_max of the interface is calculated based on the interface normal stress σ_normal.

[0118] The calculation formula is: τ_max = c_inter + σ_normal · tan(φ_inter);

[0119] Where c_inter: interfacial cohesion, φ_inter: interfacial friction angle, tan(φ_inter): interfacial friction coefficient;

[0120] The upper limit of the cutterhead thrust is calculated based on the ultimate shear strength τ_max of the interface and the compressive strength of the thin structure itself.

[0121] Specifically, this includes: calculating the upper limit of thrust F_inter_max based on the interface shear strength;

[0122] F_inter_max = τ_max·S·K1, where K1 is the safety factor, with a value of 1.1;

[0123] The upper limit of thrust F_soil_max is calculated based on the compressive strength of the thin structure itself.

[0124] F_soil_max=σ_c1·S·K2, where σ_c1: uniaxial compressive strength of thin structure (obtained from rock core test), K2 is the safety factor, with a value of 1.05;

[0125] Determine the cutterhead thrust adjustment value F_adjust based on the thrust upper limit F_inter_max and the thrust upper limit F_soil_max;

[0126] F_adjust = min(F_inter_max, F_soil_max);

[0127] If the initial cutterhead thrust F0 > F_adjust: It is necessary to reduce the thrust to F_adjust to avoid interface sliding or thin structure breakage;

[0128] If the initial thrust F0 < F_adjust: It is necessary to increase the thrust to F_adjust to avoid overexcavation caused by unbroken thin structures;

[0129] Calculate the friction torque T_friction between the cutterhead and the thin structure;

[0130] The calculation formula is: T_friction = F_adjust·(D / 2)·f, where D is the cutterhead diameter, and f: the friction coefficient between the cutterhead and the thin structure, taking the tangent value of the friction angle of the thin structure, f = tan(φ_inter);

[0131] Calculate the additional torque T_crush required for thin structure breakage;

[0132] The calculation formula is: T_crush = k·F_adjust·D, where k: the crushing coefficient (for soft thin structures k = 0.02, for hard thin structures k = 0.04, determined by the hardness of the thin structure);

[0133] Sum the friction torque T_friction between the cutterhead and the thin structure and the additional torque T_crush required for thin structure breakage to obtain the cutterhead torque adjustment value;

[0134] The technical solution of this invention is as follows: Based on historical inversion data and historical actual verification data of similar projects, multiple physical property deviations under different ratios of thin structure thickness and volume element side length are obtained through comparative analysis. Then, the physical property smoothing probability of the corresponding ratio is calculated based on the physical property deviations, thereby determining the identification ratio of thin structure thickness and volume element side length. Subsequently, combined with this identification ratio, high-risk areas are identified in the current project target excavation area, and the presence of general excavation risks in high-risk areas is determined through load influence simulation. If risks exist, the inversion model of high-risk areas is reconstructed, and the thin structures in high-risk areas are given real physical properties in the reconstruction process by combining borehole core test data, thereby achieving thin structure display separation. Finally, combined with the above identification ratio, the volume elements of the thin structures after display separation are adjusted, and the cutterhead load reconstruction during excavation of high-risk areas in the target excavation area is completed based on the principle of interface mechanics. This solves the problem that when the inversion uses a hexahedral / octree adaptive mesh, the volume element settings may smooth the physical properties of thin structures, resulting in inaccurate control of cutterhead load during inversion and excavation, thus improving the accuracy of excavation control.

[0135] Example 2: Please refer to Figure 3 As shown in the embodiment of the present invention, a mining control system based on three-dimensional stratigraphic inversion includes the following modules:

[0136] Void element identification and determination module: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, multiple physical property deviations under different ratios of thin structure thickness to void element side length are obtained. Based on the physical property deviations, the physical property smoothing probability of different ratios of thin structure thickness to void element side length is calculated, and the identification ratio of thin structure thickness to void element side length is determined.

[0137] Risk assessment module: Based on the ratio of thin structure thickness to volume element side length, high-risk areas are identified within the target excavation area of ​​the current project. Through load impact simulation, it is determined whether there is a general excavation risk in the high-risk areas.

[0138] Thin structure display and separation module: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area.

[0139] Cutterhead load reconstruction module: Combining the thin structure thickness and the volume element side length recognition ratio, the module adjusts the volume elements of the thin structure after display separation, and reconstructs the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after the volume element adjustment.

[0140] The foregoing has provided a detailed description of one embodiment of the present invention, but this description is merely a preferred embodiment and should not be construed as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. A method for excavation control based on three-dimensional stratigraphic inversion, characterized in that: Includes the following steps: Step 1: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, we obtain multiple physical property deviations under different ratios of thin structure thickness to volume element side length. Based on the physical property deviations, we calculate the physical property smoothing probability of different ratios of thin structure thickness to volume element side length and determine the identification ratio of thin structure thickness to volume element side length. Step 2: Identify high-risk areas within the target excavation area of ​​the current project based on the ratio of thin structure thickness to volume element side length, and determine whether there is a general excavation risk in the high-risk areas through load impact simulation; Step 3: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area. Step 4: Combine the thin structure thickness with the volume element side length recognition ratio, adjust the volume elements of the thin structure after display separation, and reconstruct the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after volume element adjustment.

2. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The historical inversion data includes the thickness of the thin structure, the side length of the volume element, and the physical property values ​​of the historical inversion model. The historical actual verification data includes the actual physical property values ​​of the thin structure revealed after excavation. The method for determining the ratio of thin structure thickness to volume element side length identification is as follows: The absolute deviation ratio between the physical property values ​​of the historical inversion model and the actual physical property values ​​of the thin structure is calculated to obtain the physical property deviation value of the thin structure. If the property deviation value is greater than the preset property deviation value, it indicates that a high-risk property smoothing has occurred. The frequency of occurrence of high-risk physical property smoothing is used as the probability of physical property smoothing in the ratio of thin structure thickness to volume element side length. Based on the property smoothing probability of different ratios of thin structure thickness to volume element side length, the ratio of thin structure thickness to volume element side length corresponding to the property smoothing probability threshold is selected as the recognition ratio of thin structure thickness and volume element side length.

3. The excavation control method based on three-dimensional stratigraphic inversion according to claim 2, characterized in that: The method for identifying high-risk areas is as follows: If the ratio of thin structure thickness to volume element side length within a thin structure region is less than or equal to the thin structure thickness to volume element side length identification ratio, then the thin structure region is marked as a high-risk region.

4. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The process for determining whether there is a widespread risk of mining in high-risk areas is as follows: The inversion model is imported into the excavation engineering simulation software. The cutterhead load parameters are set according to the initial excavation plan. The excavation simulation is carried out on the high-risk area. Based on the stress distribution of the thin structure in the high-risk area and the actual position of each excavation profile monitoring point output by the excavation simulation, the excavation risk area in the high-risk area is identified. The risk value is obtained by statistically analyzing the proportion of risky areas within high-risk areas. If the mining risk value is greater than or equal to the mining risk threshold, it indicates that there is a general mining risk in the high-risk area.

5. The excavation control method based on three-dimensional stratigraphic inversion according to claim 4, characterized in that: The process of identifying high-risk areas and mining high-risk areas is as follows: If a high-risk area meets any of the criteria for determining excavation risk, then the high-risk area will be marked as an excavation risk area. The risk assessment criteria include: Judgment Criterion 1: Local stress peaks occur in thin structures within high-risk areas, and the ratio between the local stress peaks and the formation compressive strength exceeds a preset ratio; Judgment condition two: The actual location of any excavation profile monitoring point deviates from the planned excavation location by a distance exceeding the design allowable value.

6. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The process of reconstructing the inversion model of high-risk areas includes: splitting the background model and thin-structure regions, and embedding thin-structure units; The process of splitting the background model and thin structure region is as follows: Open the inversion model using geological modeling software and locate the large-scale background strata. Keep the large-scale background strata unchanged, and then mark the spatial range of thin-structured areas in the inversion model according to the high-risk areas. The process of embedding the thin structural unit is as follows: If the thin structure is purely interface-based, with no actual thickness but abrupt changes in physical properties, then zero-thickness interface units should be embedded. If the thin structure is a geological body with actual thickness, then embedding of solid units with minimal thickness is selected. The zero-thickness interface unit is embedded in the following way: Apply a layer to the thin structure location of the background model, ensuring that the coordinates of the layer are completely consistent with the actual location of the thin structure; The embedding method for extremely thin solid units is as follows: Within the coordinate range of the thin structure of the background model, delete the original large-scale volume elements and replace them with small-scale solid elements according to the thickness of the thin structure.

7. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The process of assigning realistic physical properties to thin structures in high-risk regions during the inversion model reconstruction is as follows: From the core samples obtained in the previous exploration, rock samples with corresponding thin structures were found, and the physical property parameters of the rock samples were measured. Based on the thin structure in the reconstructed inversion model, if the zero-thickness interface unit is selected for embedding, the true physical properties of the thin structure are assigned to one side of the surface according to the physical property parameters, while the background strata physical properties are retained on the other side, forming a physical property abrupt change surface. If a solid unit with extremely small thickness is selected for embedding, then the actual physical properties are assigned to the entire thin structure in batches according to the physical property parameters.

8. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The process of adjusting the volume elements of the thin structural region after display separation is as follows: The thickness of the thin structure after display separation is obtained. The ratio of the thickness of the thin structure after display separation to the identification ratio of the thickness of the thin structure to the side length of the volume element is calculated to obtain the target side length of the thin structure after display separation. The original side length of the thin structure after display separation is adjusted according to the target side length of the thin structure after display separation.

9. The excavation control method based on three-dimensional stratigraphic inversion according to claim 1, characterized in that: The process of reconstructing the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics is as follows: Based on the thin structure in the high-risk area, the ultimate shear strength of the interface is calculated. The upper limit of the cutterhead thrust is determined based on the ultimate shear strength of the interface and the compressive strength of the thin structure itself. The minimum value of the upper limit of the cutterhead thrust is selected as the cutterhead thrust adjustment value. Calculate the frictional torque between the cutter head and the thin structure, as well as the additional torque required for the thin structure to break, and sum them to obtain the cutter head torque adjustment value.

10. A mining control system based on three-dimensional stratigraphic inversion, characterized in that: Includes the following modules: Void element identification and determination module: By comparing and analyzing historical inversion data and historical actual verification data from similar projects, multiple physical property deviations under different ratios of thin structure thickness to void element side length are obtained. Based on the physical property deviations, the physical property smoothing probability of different ratios of thin structure thickness to void element side length is calculated, and the identification ratio of thin structure thickness to void element side length is determined. Risk assessment module: Based on the ratio of thin structure thickness to volume element side length, high-risk areas are identified within the target excavation area of ​​the current project. Through load impact simulation, it is determined whether there is a general excavation risk in the high-risk areas. Thin structure display and separation module: If it exists, the inversion model of the high-risk area is reconstructed, and the thin structure in the high-risk area is assigned real physical property values ​​in combination with the core test data of the borehole, so as to realize the display and separation of the thin structure in the high-risk area. Cutterhead load reconstruction module: Combining the thin structure thickness and the volume element side length recognition ratio, the module adjusts the volume elements of the thin structure after display separation, and reconstructs the cutterhead load during high-risk area excavation within the target excavation area based on the principle of interface mechanics after the volume element adjustment.

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