Construction method of asymmetric ground surface settlement prediction model, and prediction method and system

Abstract

The invention discloses a construction method of an asymmetric ground surface settlement prediction model and a prediction method and system. Comprising the following steps: firstly, establishing a bias tunnel convergence mode by defining bias parameters so as to quantify the bias degree, establishing a conversion relation between an overall coordinate system and a local coordinate system, and analyzing the influence of a horizontal stratum and an inclined stratum; then, on the basis of the defined bias voltage parameters and the coordinate conversion relation, in combination with numerical integration and coordinate conversion, an initial section of the bias voltage tunnel and a settlement integral model corresponding to the built section are built; and finally, fusing the initial section and the settlement volume integral model corresponding to the built section into an asymmetric ground surface settlement prediction model of the unsymmetrical pressure tunnel by using an equivalent superposition principle. Through the asymmetric ground surface settlement prediction model, the settlement change from the initial section to the built section of the bias tunnel can be analyzed step by step, the asymmetric law of the ground surface settlement of the bias tunnel can be accurately predicted and analyzed, and the design, construction and management of the bias shallow-buried excavation subway station are effectively guided.

Description

Technical Field

[0001] The present invention relates to the technical field of digital processing methods specifically applicable to specific applications, and particularly relates to a method for constructing an asymmetric ground settlement prediction model, a prediction method, and a system. Background Art

[0002] With the expansion of the subway transportation network in China, tunnel design inevitably takes into account the influence of complex topographic and geological condition differences and environmental differences. Especially in terrains such as mountains, hills, river valleys, and areas close to building complexes, rivers, or with formation differences, which has led to the wide distribution of shallow-buried tunnels with uneven pressure in mined subway stations. In the construction of uneven-pressure tunnels, the asymmetry of ground settlement is particularly significant, and issues such as the control of surrounding rock stability and the safety of the support structure system have always been research hotspots in the engineering field.

[0003] Currently, researchers have proposed various ground settlement prediction methods based on different theories. For example, empirical formula method, semi-empirical and semi-theoretical method, theoretical analytical method, numerical simulation method, artificial neural network prediction method, stochastic medium theory method, etc. However, the above studies all assume that the tunnel convergence mode is symmetric convergence, and the resulting ground settlement also shows symmetry. In actual engineering, most tunnels are uneven-pressure tunnels, and their ground settlement often shows asymmetry. Furthermore, the current existing research on the ground settlement of uneven-pressure tunnels mainly focuses on aspects such as construction optimization, surrounding rock stability analysis, and construction monitoring of uneven-pressure tunnels, and mostly relies on specific projects, lacking a theoretical basis for quantitative analysis, so as to obtain the ground settlement situation that conforms to actual engineering. Summary of the Invention

[0004] Aiming at the deficiencies of the existing technology, the present invention proposes a method for constructing an asymmetric ground settlement prediction model, a prediction method, and a system, which solves the technical difficulties of predicting the asymmetric ground settlement of uneven-pressure tunnels. The specific technical solutions are as follows:

[0005] In the first aspect, a method for constructing an asymmetric ground settlement prediction model is provided. In the first realizable manner of the first aspect, it includes:

[0006] Define the uneven-pressure parameter of the uneven-pressure tunnel, and establish the coordinate transformation relationship between the overall coordinate system and the local coordinate system after the uneven-pressure tunnel is ellipticized;

[0007] Based on the tunnel uneven-pressure parameter and the coordinate transformation relationship, construct the settlement integral model corresponding to the initial cross-section of the uneven-pressure tunnel, and the settlement integral model corresponding to the completed cross-section of the uneven-pressure tunnel;

[0008] Fuse the settlement integral model corresponding to the initial cross-section and the settlement integral model corresponding to the completed cross-section to construct an asymmetric ground settlement prediction model for the uneven-pressure tunnel.

[0009] Combined with the first implementation manner of the first aspect, in the second implementation manner of the first aspect, the bias parameters include: bias angle, ground loss rate, tunnel ovalization bias parameter, and / or overall settlement parameter;

[0010] Among them, the bias angle is the included angle between the long axis of the tunnel ellipse and the horizontal direction;

[0011] The specific calculation formula of the ground loss rate is as follows:

[0012]

[0013] The tunnel ovalization bias parameter includes:

[0014]

[0015] The specific calculation formula of the overall settlement parameter is as follows:

[0016]

[0017] Among them, V l is the ground loss rate, v1 is the equivalent radial uniform shrinkage value of the cross-section radius caused by ground loss, R is the tunnel excavation radius, v2 and v3 are the cross-section convergence values corresponding to the short-axis direction and the long-axis direction caused by tunnel ovalization respectively, and v4 is the cross-section shrinkage value in the tunnel bias settlement direction.

[0018] Combined with the first implementation manner of the first aspect, in the third implementation manner of the first aspect, the settlement amount integral model corresponding to the initial cross-section is constructed as:

[0019]

[0020] Inclined formation;

[0021] Horizontal formation;

[0022] Among them, z is the buried depth of the excavation unit, β is the main influence angle of the formation, (η, ξ) is the coordinate of any point in the overall coordinate system after tunnel ovalization, a is the horizontal distance between the excavation unit and the intersection position, x is the horizontal distance coordinate of the settlement point with the surface position corresponding to the excavation unit as the origin, θ is the slope of the inclined formation, and b, c, and d are the upper and lower limits of the double integral of the settlement amount integral model corresponding to the initial cross-section respectively.

[0023] Combined with the first implementation manner of the first aspect, in the fourth implementation manner of the first aspect, the settlement amount integral model corresponding to the completed cross-section is constructed as:

[0024]

[0025] x′ = x + v4cosα;

[0026] ΔH = H, horizontal formation;

[0027] ΔH = H + (a - x)tanθ, inclined formation;

[0028] Wherein, (η′, ξ′) are the coordinates of any point on the tunnel after ellipse transformation in the local coordinate system, ɑ is the bias angle, H is the buried depth of the tunnel center relative to the ground surface, and f′, e′, h′, g′ are the upper and lower limits of the double integral of the settlement integral model.

[0029] Combined with the first implementation manner of the first aspect, in the fifth implementation manner of the first aspect, constructing the settlement integral model includes:

[0030] Determine the integration region and the upper and lower limits of the integral corresponding to the settlement integral model according to the tunnel excavation structure parameters and the bias parameters.

[0031] Combined with the fifth implementation manner of the first aspect, in the sixth implementation manner of the first aspect, the specific calculation formulas for the upper and lower limits of the double integral of the settlement integral model corresponding to the initial section are as follows:

[0032]

[0033] Combined with the fifth implementation manner of the first aspect, in the seventh implementation manner of the first aspect, the specific calculation formulas for the upper and lower limits of the double integral of the settlement integral model corresponding to the completed section are as follows:

[0034]

[0035] In the second aspect, a method for predicting asymmetric ground settlement is provided, including:

[0036] Adopt the construction method described in any one of the first to seventh implementation manners of the first aspect to establish an asymmetric ground settlement prediction model for a bias tunnel;

[0037] Obtain the on-site test values corresponding to the various bias parameters of the bias tunnel to be predicted, and predict the ground settlement amount of the bias tunnel through the asymmetric ground settlement prediction model.

[0038] In the third aspect, an asymmetric ground settlement prediction system is provided, including:

[0039] A model construction module configured to adopt the construction method described in any one of the first to seventh implementation manners of the first aspect to establish an asymmetric ground settlement prediction model for a bias tunnel;

[0040] The settlement prediction module is configured to obtain the on-site test values corresponding to the bias parameters of the bias tunnel to be predicted, and predict the ground settlement amount of the bias tunnel through the asymmetric ground settlement prediction model.

[0041] Advantageous effects: By adopting the construction method, prediction method and system of the asymmetric ground settlement prediction model of the present invention, the bias degree of the tunnel can be quantified by introducing bias parameters, and based on the defined bias parameters, using the principle of equivalent superposition, combining numerical integration and coordinate transformation, an asymmetric ground settlement prediction model is constructed. This asymmetric ground settlement prediction model can gradually analyze the settlement changes from the initial section to the completed section of the bias tunnel, simplifies the calculation complexity, and ensures the unity and accuracy of the calculation methods for different strata. It can accurately predict and analyze the asymmetric law of the ground settlement of the bias tunnel, and effectively guide the design, construction and management of the bias shallow-buried mined subway station. Description of the Drawings

[0042] In order to more clearly illustrate the specific embodiments of the present invention, the drawings required for use in the specific embodiments will be briefly introduced below. In all the drawings, the components or parts are not necessarily drawn to actual scale.

[0043] Figure 1 It is a flowchart of the construction method of the asymmetric ground settlement prediction model provided by an embodiment of the present invention;

[0044] Figure 2 It is a flowchart of the asymmetric ground settlement prediction method provided by an embodiment of the present invention;

[0045] Figure 3 It is a system block diagram of the asymmetric ground settlement prediction system provided by an embodiment of the present invention;

[0046] Figure 4 It is a schematic diagram of the overall coordinate system;

[0047] Figure 5 It is a schematic diagram of the local coordinate system. Specific Embodiments

[0048] The embodiments of the technical solutions of the present invention will be described in detail below with reference to the drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention, so they are only examples and cannot be used to limit the protection scope of the present invention.

[0049] As Figure 1 shown in the flowchart of the construction method of the asymmetric ground settlement prediction model, the construction method includes:

[0050] Step 1: Define the bias parameters of the bias tunnel, and establish the coordinate transformation relationship between the overall coordinate system and the local coordinate system after the bias tunnel is ellipticized;

[0051] Step 2: Based on the tunnel bias parameters and the coordinate transformation relationship, construct the settlement integral model corresponding to the initial section of the bias tunnel and the settlement integral model corresponding to the completed section of the bias tunnel;

[0052] Step 3: Integrate the settlement integral model corresponding to the initial section and the settlement integral model corresponding to the completed section to construct an asymmetric ground settlement prediction model for the bias tunnel.

[0053] Specifically, first, establish the convergence mode of the bias tunnel by defining the bias parameters to quantify the degree of bias, and establish the transformation relationship between the global and local coordinate systems to analyze the influence of the horizontal and inclined strata. Then, based on the defined bias parameters and the coordinate transformation relationship, combined with numerical integration and coordinate transformation, establish the settlement integral models corresponding to the initial section and the completed section of the bias tunnel respectively. Finally, use the principle of equivalent superposition to fuse the settlement integral models corresponding to the initial section and the completed section in a superposed form into an asymmetric ground settlement prediction model for the bias tunnel.

[0054] The asymmetric ground settlement prediction model constructed in this way can gradually analyze the settlement changes from the initial section to the completed section of the bias tunnel, simplify the calculation complexity, and ensure the unity and accuracy of the calculation methods for different strata. It can accurately predict and analyze the asymmetric law of the ground settlement of the bias tunnel, and effectively guide the design, construction and management of the shallow-buried and mined subway station with bias.

[0055] In this embodiment, optionally, in Step 1, the settlement of the bias tunnel can be composed of three parts: ground loss, tunnel ovalization and overall bias settlement. The defined bias parameters can include: bias angle, ground loss rate, tunnel ovalization bias parameter and overall settlement parameter;

[0056] Among them, the bias angle is the angle between the major axis of the tunnel ellipse and the horizontal direction;

[0057] The specific calculation formula for the ground loss rate is as follows:

[0058]

[0059] The tunnel ovalization bias parameter includes:

[0060]

[0061] The specific calculation formula for the overall settlement parameter is as follows:

[0062]

[0063] Among them, V lis the formation loss rate, v1 is the equivalent radial uniform shrinkage value of the cross-section radius caused by formation loss, R is the tunnel excavation radius, v2 and v3 are the cross-section convergence values corresponding to the minor axis direction and major axis direction caused by tunnel ovalization respectively, and v4 is the cross-section shrinkage value in the direction of tunnel bias settlement.

[0064] If during the excavation of a bias tunnel, under the same conditions of soil layer properties, excavation method, and tunnel cross-section size, this actual project can be regarded as a plane strain problem for research. The established global coordinate system XOZ is established as Figure 4 shown. Then, with the centroid of the bias tunnel as the origin, the major axis as the horizontal axis, and the minor axis as the vertical axis, the established local coordinate system V′O′T′ is as Figure 5 shown.

[0065] The coordinate transformation relationship between the global coordinate system and the local coordinate system is:

[0066]

[0067] According to the random medium theory, after the cross-section unit A with coordinates (η, ξ) underground completely collapses, the calculation model of the settlement amount at the ground x away from the center of this unit can be determined as:

[0068]

[0069] Among them, W Ω (x) is the ground settlement amount caused by the initial cross-section of the bias tunnel excavation, is the ground settlement amount caused by the cross-section shrinkage after the completion of the bias tunnel.

[0070] In this embodiment, optionally, the settlement amount integral model corresponding to the initial cross-section constructed by double integral is:

[0071]

[0072] Inclined formation;

[0073] Horizontal formation;

[0074] Among them, z is the buried depth of the excavation unit, β is the main influence angle of the formation, (η, ξ) is the coordinate of any point in the global coordinate system after tunnel ovalization, and a is the horizontal distance between the excavation unit and the intersection position, as Figure 4As shown in the figure, taking the position corresponding to the excavation unit as the coordinate origin, the horizontal coordinate value at the intersection of the inclined ground surface and the horizontal ground surface, that is, the x value at the top of the inclined formation. x is the horizontal distance coordinate of the settlement point with the ground surface position corresponding to the excavation unit as the origin, θ is the slope of the inclined formation, and b, c, and d are the upper and lower limits of the double integral of the settlement amount integral model corresponding to the initial section. The area where x ≥ a is the horizontal formation, and the area where x < a is the inclined formation.

[0075] In this embodiment, optionally, the upper and lower limits of the double integral of the settlement amount integral model corresponding to the initial section can be set artificially. To reduce the influence of human factors, they can also be determined according to the actual working conditions at the construction site and the tunnel excavation radius. The specific calculation formula is as follows:

[0076]

[0077] In this embodiment, optionally, the constructed settlement amount integral model corresponding to the completed section is:

[0078]

[0079] ΔH = H, for the horizontal formation;

[0080] ΔH = H + (a - x)tanθ, for the inclined formation;

[0081] Among them, (η′, ξ′) is the coordinate of any point in the local coordinate system after the tunnel is ellipticized, α is the bias angle, H is the buried depth of the tunnel center relative to the ground surface, and f′, e′, h′, g′ are the upper and lower limits of the double integral of the settlement amount integral model.

[0082] When the cross-section shrinkage value in the direction of tunnel bias settlement is not equal to 0, bias settlement needs to be considered, then:

[0083]

[0084] Conversely, when the cross-section shrinkage value in the direction of tunnel bias settlement is equal to 0, bias settlement does not need to be considered, then:

[0085]

[0086] Among them, K is the settlement trough width parameter, and the specific calculation formula is as follows:

[0087] K = 1 - 0.02φ, where φ is the weighted average of the internal friction angles of the soil layers above the tunnel crown calculated according to the thickness;

[0088] k is the soil layer property parameter, and z is the buried depth of the soil layer above the tunnel.

[0089] In this embodiment, the upper and lower limits of the double integral of the settlement amount integral model corresponding to the completed cross-section can also be determined according to the tunnel excavation radius and the bias pressure parameters. The specific calculation formula is as follows:

[0090]

[0091] As Figure 2 shown in the flowchart of the asymmetric ground settlement prediction method, the prediction method includes:

[0092] Step S1: Adopt the above construction method to establish an asymmetric ground settlement prediction model for the bias pressure tunnel;

[0093] Step S2: Obtain the on-site test values of the bias pressure parameters corresponding to the bias pressure tunnel to be predicted, and predict the ground settlement amount of the bias pressure tunnel through the asymmetric ground settlement prediction model.

[0094] Specifically, first, the above construction method can be used to construct an asymmetric ground settlement prediction model for the bias pressure tunnel. Then, the bias pressure angle, formation loss rate, tunnel ovalization bias pressure parameter, and overall bias settlement parameter of the tunnel monitoring surface can be monitored in real time from the excavation site using corresponding data acquisition equipment, and the ground settlement amount of the bias pressure tunnel can be accurately predicted in real time through the constructed asymmetric ground settlement prediction model, capturing the asymmetric law of the ground settlement of the bias pressure tunnel to effectively guide the design, construction, and management of the shallow-buried and mined subway station with bias pressure.

[0095] In this embodiment, equipment such as a laser section scanner and a high-precision displacement sensor can be used to monitor the bias pressure angle of the tunnel monitoring surface. A ground settlement monitoring system and a ground penetrating radar are used to monitor the formation loss rate. A laser section scanner and a high-precision electronic level are used to monitor the tunnel ovalization bias pressure parameter. A high-precision settlement gauge and an optical fiber sensor are used to monitor the overall bias settlement parameter.

[0096] As Figure 3 shown in the system block diagram of the asymmetric ground settlement prediction system, the prediction system includes:

[0097] A model construction module configured to establish an asymmetric ground settlement prediction model for the bias pressure tunnel by adopting the above construction method;

[0098] A settlement prediction module configured to obtain the on-site test values of the bias pressure parameters corresponding to the bias pressure tunnel to be predicted, and predict the ground settlement amount of the bias pressure tunnel through the asymmetric ground settlement prediction model.

[0099] Specifically, the prediction system consists of a model construction module and a settlement prediction module. Among them, the model construction module can adopt the above construction method to construct an asymmetric ground settlement prediction model for a biased tunnel. The settlement prediction module can use corresponding data acquisition equipment at the excavation site to monitor the bias angle, formation loss rate, tunnel ovalization bias parameter, and overall bias settlement parameter of the tunnel monitoring surface in real time, and accurately predict the ground settlement amount of the biased tunnel in real time through the constructed asymmetric ground settlement prediction model, capturing the asymmetric law of the ground settlement of the biased tunnel, so as to effectively guide the design, construction, and management of the shallow-buried and mined subway station with bias pressure.

[0100] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be covered by the scope of the claims and the description of the present invention.

Claims

1. A method for constructing an asymmetric ground settlement prediction model, characterized in that, Including: Define the bias parameters of the bias tunnel and establish the coordinate transformation relationship between the overall coordinate system and the local coordinate system after the ellipse transformation of the bias tunnel; Based on the tunnel bias parameters and the coordinate transformation relationship, construct the settlement integral model corresponding to the initial cross-section of the bias tunnel and the settlement integral model corresponding to the completed cross-section of the bias tunnel; Fuse the settlement integral model corresponding to the initial cross-section and the settlement integral model corresponding to the completed cross-section to construct an asymmetric ground settlement prediction model for the bias tunnel.

2. The method for constructing an asymmetric ground settlement prediction model according to claim 1, wherein The bias parameters include: bias angle, ground loss rate, tunnel ellipse bias parameters, and / or overall subsidence parameters; Among them, the bias angle is the angle between the long axis of the tunnel ellipse and the horizontal direction; The specific calculation formula of the ground loss rate is as follows: The tunnel ellipse bias parameters include: The specific calculation formula of the overall subsidence parameter is as follows: Among them, V l is the ground loss rate, v1 is the equivalent radial uniform shrinkage value of the cross-sectional radius caused by ground loss, R is the tunnel excavation radius, v2 and v3 are the cross-sectional convergence values corresponding to the minor axis direction and the major axis direction caused by tunnel ovalization respectively, and v4 is the cross-sectional shrinkage value in the direction of tunnel bias settlement.

3. The method for constructing the asymmetric ground settlement prediction model according to claim 1, wherein The constructed settlement integral model corresponding to the initial cross-section is: Inclined formation; Horizontal strata; Among them, z is the buried depth of the excavation unit, β is the main influence angle of the stratum, (η, ξ) is the coordinate of any point in the overall coordinate system after the ellipse transformation of the tunnel, a is the horizontal distance between the excavation unit and the intersection position, x is the horizontal distance coordinate of the settlement point with the surface position corresponding to the excavation unit as the origin, θ is the slope of the inclined stratum, and b, c, d are the upper and lower limits of the double integral of the settlement integral model corresponding to the initial cross-section.

4. The method for constructing the asymmetric ground settlement prediction model according to claim 1, characterized in that, The constructed settlement integral model corresponding to the completed cross-section is: x′ = x + v4cosα; ΔH = H, for horizontal strata; ΔH = H + (a - x)tanθ, for inclined strata; Among them, (η′, ξ′) is the coordinate of any point in the local coordinate system after the ellipse transformation of the tunnel, α is the bias angle, H is the buried depth of the tunnel center relative to the surface, and f′, e′, h′, g′ are the upper and lower limits of the double integral of the settlement integral model.

5. The method for constructing an asymmetric ground settlement prediction model according to claim 1, characterized in that Constructing the settlement integral model includes: According to the tunnel excavation structure parameters and the bias parameters, determine the integration region and the upper and lower limits of the integration corresponding to the settlement integral model.

6. The method for constructing an asymmetric ground settlement prediction model according to claim 5, characterized in that, The specific calculation formula of the upper and lower limits of the double integral of the settlement integral model corresponding to the initial cross-section is as follows:

7. The method for constructing the asymmetric ground settlement prediction model according to claim 5, characterized in that, The specific calculation formula of the upper and lower limits of the double integral of the settlement integral model corresponding to the completed cross-section is as follows:

8. An asymmetric ground settlement prediction method, characterized in that, Including: Adopt the construction method described in any one of claims 1-7 to establish an asymmetric ground settlement prediction model for the bias tunnel; Obtain the on-site test values corresponding to the bias parameters of the bias tunnel to be predicted, and predict the ground settlement amount of the bias tunnel through the asymmetric ground settlement prediction model.

9. An asymmetric ground settlement prediction system, characterized in that, Including: A model construction module configured to adopt the construction method described in any one of claims 1-7 to establish an asymmetric ground settlement prediction model for the bias tunnel; A settlement prediction module configured to obtain the on-site test values corresponding to the bias parameters of the bias tunnel to be predicted, and predict the ground settlement amount of the bias tunnel through the asymmetric ground settlement prediction model.

Images