Method for optimizing structure of excavation and filling junction area of asphalt concrete panel

Abstract

The invention discloses a method for optimizing the structure of an excavation and filling junction area of an asphalt concrete panel. The method comprises the following steps: 1, determining the safety performance index of the asphalt concrete panel at the bottom of a reservoir; 2, selecting panel structure parameters of the excavation and filling junction area of the asphalt concrete panel; 3, obtaining a safety performance index response value; 4, fitting a response surface regression prediction model corresponding to the safety performance index response value; 5, acquiring an optimal region of the panel structure parameter combination of the excavation and filling junction part; 6, obtaining the selectable area range of the thickening thickness and the thickening range of the panel trapezoid body under different excavation gradients under the condition of meeting the safety performance index; 7, establishing an optimized mathematical model for the optimization design of the excavation and filling junction part; and 8, solving the optimal shape parameters of the excavation and filling junction part. According to the method, the safety performance index is determined, the thickening and volume increasing of the trapezoid body of the panel is taken as a target function, the safety and economical efficiency of the dam body are comprehensively considered, and important technical support is provided for construction of the asphalt concrete panel at the bottom of the pumped storage power station.

Description

Technical Field

[0001] The invention belongs to the technical field of asphalt concrete dam structure optimization design, and in particular relates to a method for optimizing the structure of an asphalt concrete panel excavation and filling interface area. Background Art

[0002] The upper reservoir basin project of a pumped storage power station is different from conventional reservoir dams or fill projects. It is mainly composed of the main dam, auxiliary dam, reservoir bank mountains and reservoir bottom. When the natural water head of the upper reservoir is low, it is necessary to build a high fill basin to increase the power generation head. The upper reservoir is usually built on the top of a mountain with a steep depression. In order to meet the storage capacity requirements, the upper reservoir basin is mostly built in a combination of excavation and filling, with large fill height and filling volume. The special geological and topographical conditions and functional requirements determine that the reservoir basin project of the pumped storage power station must be built according to local conditions and the situation. The project often has a very complex structural type, especially for the high fill basin, the excavation and filling interface is intricate and the ring reservoir shape is diverse. To this end, under the premise of ensuring the safety of the dam body, it is of great engineering significance to optimize the asphalt concrete panel at the junction of excavation and filling and effectively improve the stress and deformation at the junction of excavation and filling. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a method for optimizing the excavation and filling interface area of ​​an asphalt concrete panel in response to the deficiencies in the above-mentioned prior art. The method takes tensile strain, shear stress and maximum settlement as safety performance indicators, and thickening and increasing the volume of the trapezoidal body of the panel as the objective function. The method comprehensively considers the safety and economy of the dam body, provides important technical support for the construction of asphalt concrete panels at the bottom of a pumped-storage power station, and facilitates its popularization and use.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for optimizing the structure of the cut-and-fill interface of an asphalt concrete panel, characterized in that the method comprises the following steps:

[0005] Step 1: Determine the safety performance index of the reservoir bottom asphalt concrete panel: Establish a finite element numerical model of the reservoir bottom asphalt concrete panel, analyze the stress and deformation results of the excavation and filling interface of the reservoir bottom asphalt concrete panel, and determine the safety performance index of the reservoir bottom asphalt concrete panel;

[0006] The safety performance indicators include tensile strain, shear stress and maximum settlement;

[0007] Step 2: Select the panel structure parameters of the asphalt concrete panel cut-fill interface area: establish a geometric model of the shape parameters of the asphalt concrete panel cut-fill interface area, and select the panel structure parameters of the asphalt concrete panel cut-fill interface area;

[0008] The panel structure parameters include body shape parameters and the excavation slope at the junction of cut and fill;

[0009] The body shape parameters include the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range;

[0010] Step 3: Obtain the response value of the safety performance index: Taking the panel structure parameters as the test parameters and the safety performance index as the response, the response surface method is used to design a variety of test schemes, and a three-dimensional finite element calculation model of the earth-rock dam for each test scheme is established to obtain the response value of the safety performance index;

[0011] Step 4: Fitting the response surface regression prediction model corresponding to the response value of the safety performance index: According to the three-dimensional finite element numerical calculation results of the earth-rock dam, respectively fit the response surface regression prediction model of the tensile strain, the response surface regression prediction model of the shear stress and the response surface regression prediction model of the maximum settlement;

[0012] Step 5, obtaining the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling: constructing a reasonable area of ​​each response surface regression prediction model, and performing an intersection operation to obtain the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling;

[0013] Step 6. Obtain the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions: within the optimal area of ​​the panel structural parameter combination at the junction of the excavation and filling of the reservoir bottom asphalt concrete panel, draw a value range diagram of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slope conditions to obtain the value range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under the specific excavation slope ratio; by changing the slope ratio of the excavation slope, the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions can be obtained;

[0014] Step 7: Establishing an optimized mathematical model for the optimal design of the cut-and-fill interface of the asphalt concrete panel: Taking the increase in volume of the trapezoidal thickening of the panel as the objective function, and taking the safety performance index and the panel structure parameters as the constraints, establishing an optimized mathematical model for the optimal design of the cut-and-fill interface of the asphalt concrete panel;

[0015] Step 8. Determine the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir: Comprehensively consider the safety and economy of the asphalt concrete panel at the bottom of the reservoir, take the increase in volume by thickening the trapezoidal body of the panel as the objective function, construct the objective function and the shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir and the display expression of the excavation slope, and use the nonlinear programming method to solve the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir.

[0016] The above-mentioned asphalt concrete panel cut-and-fill interface structural optimization method is characterized in that: in step 1, the allowable tensile strain of the safety performance index is obtained by tensile loading the asphalt concrete sample and measuring its deformation under different tensile forces until the asphalt concrete sample breaks, and the stress-strain curve of the asphalt concrete sample can be obtained from the test data, thereby determining the strain values ​​of the elastic stage, yield stage and fracture stage, and then determining the allowable tensile strain of the asphalt concrete panel;

[0017] The allowable shear stress of the safety performance index is nonlinear, and its value is related to the cohesion generated by asphalt and the internal friction resistance generated by aggregate, that is, Among them, τ is the shear stress, C is the cohesion of asphalt concrete, σ is the normal total stress on the sliding surface, is the internal friction angle;

[0018] The maximum allowable settlement of the safety performance index is obtained by obtaining the relationship between the maximum settlement and the backfill depth through the data recorded in the literature related to the settlement of the reservoir bottom panel of the existing pumped storage power station, and obtaining the maximum allowable settlement.

[0019] The above-mentioned asphalt concrete panel cut-and-fill interface structure optimization method is characterized in that: in step three, the response surface analysis software Design-Expert is used to design multiple test schemes using the response surface method, and a three-dimensional finite element calculation model of the earth-rock dam is established for each test scheme.

[0020] The above-mentioned asphalt concrete panel cut-and-fill interface structural optimization method is characterized in that: in step 4, by comparing the data of model significance detection, lack-of-fit item detection, and correlation test, a suitable tensile strain response surface regression prediction model, a shear stress response surface regression prediction model, and a maximum settlement response surface regression prediction model are fitted;

[0021] After obtaining the corresponding response surface regression prediction model, the normal probability distribution diagram of the residual, the distribution diagram of the residual and the predicted value, and the distribution diagram of the predicted value and the actual value of each response surface regression prediction model were analyzed through diagnosis; the variance analysis was performed on the fitted response surface regression prediction model, and the response surface regression prediction model was considered qualified when the accompanying probability value of the model regression coefficient statistic was less than 0.05 and the model determination coefficient and the corrected determination coefficient were both greater than 0.8.

[0022] The above-mentioned asphalt concrete panel cut-and-fill interface structural optimization method is characterized by: in step five, the data processing software Mathematic is used to construct a reasonable area for each response surface regression prediction model, and an intersection operation is performed to obtain the optimal area of ​​the panel structural parameter combination at the cut-and-fill interface of the reservoir bottom asphalt concrete panel.

[0023] The above-mentioned asphalt concrete panel cut-fill interface structure optimization method is characterized in that: in step 7, the minimum volume increase of the panel trapezoidal body thickening is taken as the objective function, and its constraint condition is Where b is the thickness of the panel trapezoidal body, b min b is the minimum value of the thickening thickness of the panel trapezoid, max is the maximum value of the panel trapezoidal body thickening thickness, l is the panel trapezoidal body thickening range, l min is the minimum value of the panel trapezoidal body thickening range, l max is the maximum value of the panel trapezoidal body thickening range, i is the slope ratio of the excavation slope at the junction of cut and fill, i min is the minimum slope ratio of the excavation slope at the junction of cut and fill, i max is the maximum slope ratio of the excavation slope at the junction of cut and fill, ε max is the maximum tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, [ε t ] is the allowable tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, τ max is the maximum shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, [τ t ] is the allowable shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, u max is the maximum settlement at the junction of the asphalt concrete panel at the bottom of the reservoir, [u t ] is the maximum allowable settlement at the junction of the excavation and filling of the asphalt concrete panel at the bottom of the reservoir.

[0024] The above-mentioned asphalt concrete panel cut-and-fill interface structure optimization method is characterized in that: in step eight, the process of solving the optimal shape parameters of the cut-and-fill interface of the reservoir bottom asphalt concrete panel includes the following steps:

[0025] Step 801: Taking the increase in volume by thickening the panel trapezoid as the objective function, construct a volume display expression Among them, V is the volume increased by thickening the trapezoidal body of the panel, and L is the length of the excavation line;

[0026] Step 802, selecting the slope ratio of the excavation slope and the excavation line length at the actual cut-fill interface, and simplifying the volume display expression;

[0027] Step 803, according to step 6, the thickness and range of the thickening of the panel trapezoidal body under the excavation slope condition are obtained, so that the slope ratio of the excavation slope at the actual junction of cut and fill and the excavation line length of the panel trapezoidal body thickness and range of the thickening range can be obtained, and the coordinate points in the slice area are substituted into the simplified volume display expression to obtain the range of variation of the thickening volume of the panel trapezoidal body under the premise of meeting the safety requirements, and then the minimum value of the thickening volume of the panel trapezoidal body can be obtained.

[0028] Compared with the prior art, the present invention has the following advantages:

[0029] 1. The present invention can optimize the geometric dimensions of the interface between the panel and the cut-fill area, effectively improve the stress and strain conditions at the interface between the cut-fill area, and is easy to promote and use.

[0030] 2. The present invention integrates the response surface method into the numerical simulation calculation of three-dimensional finite element, which significantly reduces the amount of calculation while ensuring the calculation accuracy, and can fit the results at a high progress. A regression prediction model of the relevant safety performance indicators of the model is established, which not only clearly expresses the relationship between the safety performance indicators and the structural parameters of each optimized panel, but also can make a specific analysis of the influence of a single safety performance indicator on other safety performance indicators. The reasonable range of the constructed safety performance indicators can intuitively indicate the range of values ​​of the panel structural parameters that meet the panel safety conditions, as well as the volume increase of the panel trapezoidal thickening area as the objective function. Under the premise of meeting the safety of the panel structure and taking into account the engineering economy that the project needs to consider, the use of asphalt is reduced, and a reference is provided for the structural optimization of the asphalt concrete panel excavation and filling junction area.

[0031] In summary, the present invention determines the safety performance index of the optimized design of the panel at the junction of cut and fill, selects the panel structural parameters of the panel at the junction of cut and fill, adopts the response surface method to design the test plan, obtains the response value of the safety performance index, establishes a safety performance index response surface regression prediction model, obtains the optimal area of ​​the combination of panel structural parameters at the junction of cut and fill, obtains the value range of the optional area of ​​the panel structural parameters, establishes a mathematical model for the optimized design of the panel at the junction of cut and fill, solves the optimal body parameters of the trapezoidal thickening of the panel at the junction of cut and fill, takes tensile strain, shear stress, and maximum settlement as safety performance indicators, takes the increase in volume of the trapezoidal thickening of the panel as the objective function, comprehensively considers the safety and economy of the dam body, provides important technical support for the construction of asphalt concrete panels at the bottom of the pumped storage power station reservoir, and is convenient for popularization and use.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a diagram illustrating the thickened portion of the trapezoidal body of the panel of the present invention and related design parameters;

[0034] Figure 2 A three-dimensional finite element model of a pumped storage power station of the present invention;

[0035] Figure 3 It is the cloud diagram of tensile strain calculation of the panel of the present invention;

[0036] Figure 4 This is a cloud diagram showing the shear stress calculation of the panel of the present invention;

[0037] Figure 5 It is the cloud map of panel settlement calculation of the present invention;

[0038] Figure 6 This is the optimal interval effect diagram of the shear stress of the present invention;

[0039] Figure 7 This is the optimal area effect diagram of the present invention;

[0040] Figure 8 The value range of other design parameters when the excavation slope of the present invention is 1:2.0;

[0041] Fig. 9 The figure is a flowchart of the method of the present invention. DETAILED DESCRIPTION

[0042] like Figures 1 to 9 As shown, the method for optimizing the structure of the cut-and-fill interface area of ​​the asphalt concrete panel of the present invention comprises the following steps:

[0043] Step 1: Determine the safety performance index of the reservoir bottom asphalt concrete panel: Establish a finite element numerical model of the reservoir bottom asphalt concrete panel, analyze the stress and deformation results of the excavation and filling interface of the reservoir bottom asphalt concrete panel, and determine the safety performance index of the reservoir bottom asphalt concrete panel;

[0044] The safety performance indicators include tensile strain, shear stress and maximum settlement;

[0045] In this embodiment, in step 1, the allowable tensile strain of the safety performance index is obtained by tensile loading the asphalt concrete sample and measuring its deformation under different tensile forces until the asphalt concrete sample breaks. The stress-strain curve of the asphalt concrete sample can be obtained from the test data, thereby determining the strain values ​​of the elastic stage, yield stage and fracture stage, and then determining the allowable tensile strain of the asphalt concrete panel;

[0046] The allowable shear stress of the safety performance index is nonlinear, and its value is related to the cohesion generated by asphalt and the internal friction resistance generated by aggregate, that is, Among them, τ is the shear stress, C is the cohesion of asphalt concrete, σ is the normal total stress on the sliding surface, is the internal friction angle;

[0047] The maximum allowable settlement of the safety performance index is obtained by obtaining the relationship between the maximum settlement and the backfill depth through the data recorded in the literature related to the settlement of the reservoir bottom panel of the existing pumped storage power station, and obtaining the maximum allowable settlement.

[0048] Step 2: Select the panel structure parameters of the asphalt concrete panel cut-fill interface area: establish a geometric model of the shape parameters of the asphalt concrete panel cut-fill interface area, and select the panel structure parameters of the asphalt concrete panel cut-fill interface area;

[0049] The panel structure parameters include body shape parameters and the excavation slope at the junction of cut and fill;

[0050] The body shape parameters include the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range;

[0051] It should be noted that the panel at the junction of cut and fill is taken as the object, and according to the optimized structural form, the geometric model of the trapezoidal thickened part of the panel is constructed using AutoCAD software. According to the specific engineering example, the structural parameters of the trapezoidal thickened part of the panel are selected and the selected parameters of the built project are referred to to determine the value range of the panel structural parameters, as shown in Table 1.

[0052] Table 1

[0053] Panel structure parameters Numeric Panel trapezoid thickening thickness b 0.2～1.0 Panel trapezoidal body thickening range l 6～14 Slope ratio of trapezoidal body i 1:1～1:3

[0054] Step 3: Obtain the response value of the safety performance index: Taking the panel structure parameters as the test parameters and the safety performance index as the response, the response surface method is used to design a variety of test schemes, and a three-dimensional finite element calculation model of the earth-rock dam for each test scheme is established to obtain the response value of the safety performance index;

[0055] In this embodiment, in step 3, the response surface analysis software Design-Expert is used to design multiple test schemes using the response surface method, and a three-dimensional finite element calculation model of the earth-rock dam is established for each test scheme.

[0056] It should be noted that, based on the panel structure parameters as the test parameters, the experimental design adopts a 3-factor 5-level design, and the distribution is represented by -α, -1, 0, 1, α (α = 1.682). The factor levels are shown in Table 2.

[0057] Table 2

[0058] level b l i -1.682 0.2 6 1:1 -1 0.4 8 1:1.5 0 0.6 10 1:2 1 0.8 12 1:2.5 1.682 1.0 14 1:3

[0059] According to the 5-level design idea, the most widely used central composite method design test scheme in the response surface method is selected. In the response surface analysis software Design-Expert, after setting the optimization parameters of "Numeric factors" and "Categoric factors", the panel structure parameters, factor levels and the number of center points are set, and finally the name and number of responses are designed, the optimization design test scheme can be generated as shown in Table 3.

[0060] Table 3

[0061]

[0062]

[0063] Through the analysis of the three-dimensional finite element calculation model of the earth-rock dam, the tensile stress of the panels of different test schemes can be directly obtained through the stress cloud diagram of E, Max.Principal in the finite element software result visualization, such as Figure 3 shown.

[0064] During the normal water storage period of the pumped storage power station, three-dimensional shear stress appears at the junction of the excavation and filling of the reservoir bottom panel, namely, the shear stress along the river, the shear stress along the dam axis, and the vertical shear stress. The shear stress along the river is less than the allowable shear stress as one of the performance indicators for measuring safety. Through the analysis of the three-dimensional finite element calculation model of the earth-rock dam, the tensile stress of the reservoir bottom panel in different test schemes can be directly obtained through the stress cloud diagram of S12 in the visualization of the finite element software results, such as Figure 4 shown.

[0065] Through the analysis of the three-dimensional finite element calculation model of the earth-rock dam, the settlement of the bottom slab of the reservoir under different test schemes can be directly obtained through the deformation cloud diagram of U and U3 in the visualization of the finite element software results, such as Figure 5 shown.

[0066] Step 4: Fitting the response surface regression prediction model corresponding to the response value of the safety performance index: According to the three-dimensional finite element numerical calculation results of the earth-rock dam, respectively fit the response surface regression prediction model of the tensile strain, the response surface regression prediction model of the shear stress and the response surface regression prediction model of the maximum settlement;

[0067] In this embodiment, in step 4, by comparing the data of model significance test, lack-of-fit item test, and correlation test, a suitable response surface regression prediction model of tensile strain, a response surface regression prediction model of shear stress, and a response surface regression prediction model of maximum settlement are fitted;

[0068] After obtaining the corresponding response surface regression prediction model, the normal probability distribution diagram of the residual, the distribution diagram of the residual and the predicted value, and the distribution diagram of the predicted value and the actual value of each response surface regression prediction model were analyzed through diagnosis; the variance analysis was performed on the fitted response surface regression prediction model, and the response surface regression prediction model was considered qualified when the accompanying probability value of the model regression coefficient statistic was less than 0.05 and the model determination coefficient and the corrected determination coefficient were both greater than 0.8.

[0069] In this embodiment, the response surface regression prediction model of shear stress Response Surface Regression Model for Prediction of Tensile Strain Response surface regression prediction model for maximum sedimentation

[0070]

[0071] Step 5, obtaining the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling: constructing a reasonable area of ​​each response surface regression prediction model, and performing an intersection operation to obtain the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling;

[0072] In this embodiment, in step five, the data processing software Mathematic is used to construct a reasonable area of ​​each response surface regression prediction model, and an intersection operation is performed to obtain the optimal area of ​​the panel structural parameter combination at the junction of the excavation and filling of the reservoir bottom asphalt concrete panel.

[0073] It should be noted that the highly reliable and significant regression prediction model established in step 4 uses the "Region Plot 3D" command in the data processing software Mathematic to construct a reasonable three-dimensional space region for each safety performance indicator;

[0074] After obtaining a reasonable area of ​​safety performance indicators by inputting the command three-dimensional region map “Region Plot 3D”, first obtain an implicit area that meets the three safety performance indicators by inputting the command implicit region “Implicit Region”, and then input the command three-dimensional region map “Region Plot3D” to obtain a three-dimensional optimal area of ​​the structural parameter combination at the junction of the panel cut and fill that meets all performance indicators.

[0075] Taking the reasonable shear stress area as an example, Figure 6 As shown, enter the command in Mathematic:

[0076] Y1=Region Plot 3D[3321.46-745.63*i-119.29*l+523.67*b-21.30*i*l+1772.46*i*b-24.2 4*l*b+2413.65*i^2+1.03*l^2+510.81*b^2<=0.05{i,1,3},{l,6,14},{b,0 .2,1.0}, PlotStyle->Directive[RGBColor[1,1,0.21],Opacity[0.3]],Ticks->{{1,1.5,2,2.5,3},{6,8,10,12,14},{0.2,0.4,0.6,0.8,1.0}},Plot Range Padding->None,Mesh->None,Axes Label->{Style["i",21],Style["l",21],Style["b",21]},TicksStyle->Directive["Times New Roman",17],Boundary Style->None] to get the following result: Figure 6 The three-dimensional space shear stress area is shown.

[0077] By inputting the implicit region "Implicit Region", three implicit regions satisfying different safety performance indicators are obtained: W1=Implicit Region[{3321.46-745.63*i-119.29*l+523.67*b-21.30*i*l+1772.46*i*b-24.24*l*b+2413.65*i^2+1.03*l^2+510.81*b^2<=500, 2014.90-1741.78*i-23.27*l-1014.35*b+3.63i*l-120.38i*b+7.46l*b+1071.16*i^2 +0.13*l^2+869.57*b^2<=550, 1.2345+1.6895*i-0.0346*l+0.2020*b+0.0050i*l-0.0500i*b+0.0020l*b-0.6530*i^2+0.0002*l^2-0.4055*b^2<=500, 1<=i<=3, 6<=l<=14, 0.2<=b<=1.0},{i,l,b}] obtains an implicit region that meets the three safety performance indicators.

[0078] W2=Region Plot 3D[W1,Box Ratios->{1,1,1},Plot Theme->"Dark Mesh",Color Function->"Neon Colors",Axes->True,Axes

[0079] Label->{Style["i",18],Style["l",18],Style["b",18]},Plot

[0080] Range->{{1,3},{6,14},{0.2,1.0}},Boxed->True,Boundary

[0081] Style->Directive[Red,Thick],Plot

[0082] Points->14, Ticks->{{1,1.5,2,2.5,3},{6,8,10,12,14},{0.2,0.4,0.6,0.8,1.0}}, Ticks Style->Directive["Times New Roman",13]] to get an optimal area that meets all performance indicators, such as Figure 7 shown.

[0083] Step 6. Obtain the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions: within the optimal area of ​​the panel structural parameter combination at the junction of the excavation and filling of the reservoir bottom asphalt concrete panel, draw a value range diagram of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slope conditions to obtain the value range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under the specific excavation slope ratio; by changing the slope ratio of the excavation slope, the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions can be obtained;

[0084] It should be noted that, to draw the value range diagram of the panel trapezoidal body thickening thickness and the panel thickening range under different excavation slope conditions, enter the command drawing area "Region Plot", and substitute the specific value of the required excavation slope into the equation to obtain the value range of the panel trapezoidal body thickening thickness and the panel thickening range under the specific excavation slope ratio; change the slope ratio of the excavation slope, enter the same command drawing area "Region Plot", and you can get the optional regional range of the panel trapezoidal body thickening thickness and range under different excavation slopes under the premise of meeting all safety performance indicators;

[0085] Take the excavation slope of 1:2.0 as an example:

[0086] A 20 =Region Plot

[0087] [{3321.46-745.63*2-119.29*l+523.67*b-21.30*2*l+1772.46*2*b-24.24*l*b+2413.65*2^2+1.03 *l^2+510.81*b^2<=0.05&&2014.90-1741.78*2-23.27*l-1014.35*b+3.63*2*l-120.38*2*b+7.46*l *b+1071.16*2^2+0.13*l^2+869.57*b^2<=550&&1.2345+1.6895*2-0.0346*l+0.2020*b+0.0050*2*l -0.0500*2*b+0.0020*l*b-0.6530*2^2+0.0002*l^2-0.4055b^2<=500},{l,6,14},{b,0.2,1.0},Plot Legends->"Expressions",Color Function->"Neon Colors",Plot Theme->{"Detailed"},PlotStyle->Directive[Opacity

[500] ],PlotRangePadding->None,AxesStyle->Thick] obtain the range of the panel trapezoid thickening thickness and the panel thickening range under the condition of excavation slope of 1:2, such as Figure 8 shown.

[0088] Step 7: Establishing an optimized mathematical model for the optimal design of the cut-and-fill interface of the asphalt concrete panel: Taking the increase in volume of the trapezoidal thickening of the panel as the objective function, and taking the safety performance index and the panel structure parameters as the constraints, establishing an optimized mathematical model for the optimal design of the cut-and-fill interface of the asphalt concrete panel;

[0089] In this embodiment, in step 7, the objective function is to minimize the volume increase caused by thickening the panel trapezoidal body, and its constraint condition is: Where b is the thickness of the panel trapezoidal body, b min b is the minimum value of the thickening thickness of the panel trapezoid, max is the maximum value of the panel trapezoidal body thickening thickness, l is the panel trapezoidal body thickening range, l min is the minimum value of the panel trapezoidal body thickening range, l max is the maximum value of the panel trapezoidal body thickening range, i is the slope ratio of the excavation slope at the junction of cut and fill, imin is the minimum slope ratio of the excavation slope at the junction of cut and fill, i max is the maximum slope ratio of the excavation slope at the junction of cut and fill, ε max is the maximum tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, [ε t ] is the allowable tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, τ max is the maximum shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, [τ t ] is the allowable shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, u max is the maximum settlement at the junction of the asphalt concrete panel at the bottom of the reservoir, [u t ] is the maximum allowable settlement at the junction of the excavation and filling of the asphalt concrete panel at the bottom of the reservoir.

[0090] Step 8. Determine the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir: Comprehensively consider the safety and economy of the asphalt concrete panel at the bottom of the reservoir, take the increase in volume by thickening the trapezoidal body of the panel as the objective function, construct the objective function and the shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir and the display expression of the excavation slope, and use the nonlinear programming method to solve the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir.

[0091] In this embodiment, in step eight, the process of solving the optimal shape parameters of the excavation and filling interface of the reservoir bottom asphalt concrete panel includes the following steps:

[0092] Step 801: Taking the increase in volume by thickening the panel trapezoid as the objective function, construct a volume display expression Among them, V is the volume increased by thickening the trapezoidal body of the panel, and L is the length of the excavation line;

[0093] Step 802, selecting the slope ratio of the excavation slope and the excavation line length at the actual cut-fill interface, and simplifying the volume display expression;

[0094] In this embodiment, the constants in the formula and the optimized engineering example i=1:2 are substituted into the volume display expression It can be simplified to: V = 931.81bl-1863.62b 2 .

[0095] Step 803, according to step 6, the thickness and range of the thickening of the panel trapezoidal body under the excavation slope condition are obtained, so that the slope ratio of the excavation slope at the actual junction of cut and fill and the excavation line length of the panel trapezoidal body thickness and range of the thickening range can be obtained, and the coordinate points in the slice area are substituted into the simplified volume display expression to obtain the range of variation of the thickening volume of the panel trapezoidal body under the premise of meeting the safety requirements, and then the minimum value of the thickening volume of the panel trapezoidal body can be obtained.

[0096] When the present invention is used, the safety performance index of the optimized design of the panel at the junction of cut and fill is determined, the panel structural parameters of the panel at the junction of cut and fill are selected, the response surface method is used to design the test plan, the response value of the safety performance index is obtained, and a safety performance index response surface regression prediction model is established to obtain the optimal area of ​​the panel structural parameter combination at the cut and fill junction, the value range of the panel structural parameter optional area is obtained, and a mathematical model for the optimized design of the panel at the junction of cut and fill is established, and the optimal body parameters of the thickened trapezoidal body of the panel at the junction of cut and fill are solved. The tensile strain, shear stress, and maximum settlement are used as safety performance indicators, and the increased volume of the thickened trapezoidal body of the panel is used as the objective function. The safety and economy of the dam body are comprehensively considered, and important technical support is provided for the construction of the asphalt concrete panel at the bottom of the pumped storage power station. The response surface method is integrated and applied In the numerical simulation calculation of three-dimensional finite element, the calculation amount is significantly reduced while ensuring the calculation accuracy, and the results can be fitted at a high progress. A regression prediction model of the relevant safety performance indicators of the model is established. It not only clearly expresses the relationship between the safety performance indicators and the structural parameters of each optimized panel, but also can make a specific analysis of the influence of a single safety performance indicator on other safety performance indicators. The reasonable interval of the constructed safety performance indicators can intuitively indicate the range of panel structural parameters that meet the panel safety conditions, as well as the volume increase of the panel trapezoidal thickening area as the objective function. Under the premise of meeting the safety of the panel structure and taking into account the engineering economy that the project needs to consider, the use of asphalt is reduced, and a reference is provided for the structural optimization of the asphalt concrete panel excavation and filling junction area.

[0097] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent structural change made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for optimizing the structure of the cut-and-fill interface of an asphalt concrete panel, characterized in that: The method comprises the following steps: Step 1: Determine the safety performance index of the reservoir bottom asphalt concrete panel: Establish a finite element numerical model of the reservoir bottom asphalt concrete panel, analyze the stress and deformation results of the excavation and filling interface of the reservoir bottom asphalt concrete panel, and determine the safety performance index of the reservoir bottom asphalt concrete panel; The safety performance indicators include tensile strain, shear stress and maximum settlement; Step 2: Selecting the panel structural parameters of the asphalt concrete panel cut-fill interface area: Establishing a geometric model of the shape parameters of the asphalt concrete panel cut-fill interface area, and selecting the panel structural parameters of the asphalt concrete panel cut-fill interface area; The panel structure parameters include body shape parameters and the excavation slope at the junction of cut and fill; The body shape parameters include the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range; Step 3: Obtain the response value of the safety performance index: Taking the panel structure parameters as the test parameters and the safety performance index as the response, the response surface method is used to design a variety of test schemes, and a three-dimensional finite element calculation model of the earth-rock dam for each test scheme is established to obtain the response value of the safety performance index; Step 4: Fitting the response surface regression prediction model corresponding to the response value of the safety performance index: According to the three-dimensional finite element numerical calculation results of the earth-rock dam, respectively fit the response surface regression prediction model of the tensile strain, the response surface regression prediction model of the shear stress and the response surface regression prediction model of the maximum settlement; Step 5, obtaining the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling: constructing a reasonable area of ​​each response surface regression prediction model, and performing an intersection operation to obtain the optimal area of ​​the panel structural parameter combination at the interface of the reservoir bottom asphalt concrete panel excavation and filling; Step 6. Obtain the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions: within the optimal area of ​​the panel structural parameter combination at the junction of the excavation and filling of the reservoir bottom asphalt concrete panel, draw a value range diagram of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slope conditions to obtain the value range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under the specific excavation slope ratio; by changing the slope ratio of the excavation slope, the optional regional range of the panel trapezoidal body thickening thickness and the panel trapezoidal body thickening range under different excavation slopes that meet the safety performance index conditions can be obtained; Step 7: Establishing an optimization mathematical model for the optimization design of the excavation and filling interface of the asphalt concrete panel: Taking the increase in volume of the trapezoidal thickening of the panel as the objective function, and taking the safety performance index and the panel structure parameters as the constraints, establishing an optimization mathematical model for the optimization design of the excavation and filling interface of the asphalt concrete panel; Step 8. Determine the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir: Comprehensively consider the safety and economy of the asphalt concrete panel at the bottom of the reservoir, take the increase in volume by thickening the trapezoidal body of the panel as the objective function, construct the objective function and the shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir and the display expression of the excavation slope, and use the nonlinear programming method to solve the optimal shape parameters of the excavation-fill interface of the asphalt concrete panel at the bottom of the reservoir.

2. The method for optimizing the cut-and-fill interface structure of an asphalt concrete panel according to claim 1, characterized in that: In step 1, the allowable tensile strain of the safety performance index is obtained by tensile loading the asphalt concrete sample and measuring its deformation under different tensile forces until the asphalt concrete sample breaks. The stress-strain curve of the asphalt concrete sample can be obtained from the test data, thereby determining the strain values ​​of the elastic stage, yield stage and fracture stage, and then determining the allowable tensile strain of the asphalt concrete panel; The allowable shear stress of the safety performance index is nonlinear, and its value is related to the cohesion generated by asphalt and the internal friction resistance generated by aggregate, that is, Among them, τ is the shear stress, C is the cohesion of asphalt concrete, σ is the normal total stress on the sliding surface, is the internal friction angle; The maximum allowable settlement of the safety performance index is obtained by obtaining the relationship between the maximum settlement and the backfill depth through the data recorded in the literature related to the settlement of the reservoir bottom panel of the existing pumped storage power station, and obtaining the maximum allowable settlement.

3. The method for optimizing the cut-and-fill interface structure of an asphalt concrete panel according to claim 1, characterized in that: In step three, the response surface analysis software Design-Expert was used to design multiple test schemes using the response surface method, and a three-dimensional finite element calculation model of the earth-rock dam was established for each test scheme.

4. The method for optimizing the cut-and-fill interface structure of an asphalt concrete panel according to claim 1, characterized in that: In step 4, by comparing the data of model significance test, lack-of-fit item test and correlation test, suitable response surface regression prediction models of tensile strain, shear stress and maximum settlement are fitted; After obtaining the corresponding response surface regression prediction model, the normal probability distribution diagram of the residual, the distribution diagram of the residual and the predicted value, and the distribution diagram of the predicted value and the actual value of each response surface regression prediction model were analyzed through diagnosis; the variance analysis was performed on the fitted response surface regression prediction model, and the response surface regression prediction model was considered qualified when the accompanying probability value of the model regression coefficient statistic was less than 0.05 and the model determination coefficient and the corrected determination coefficient were both greater than 0.

8.

5. The method for optimizing the cut-and-fill interface structure of an asphalt concrete panel according to claim 1, characterized in that: In step five, the data processing software Mathematic is used to construct the reasonable area of ​​each response surface regression prediction model, and the intersection operation is performed to obtain the optimal area of ​​the panel structure parameter combination at the junction of the excavation and filling of the reservoir bottom asphalt concrete panel.

6. The method for optimizing the cut-and-fill interface structure of an asphalt concrete panel according to claim 1, characterized in that: In step 7, the objective function is to minimize the volume increase of the panel trapezoidal body by thickening, and its constraints are: Where b is the thickness of the panel trapezoidal body, b min b is the minimum value of the thickening thickness of the panel trapezoid, max is the maximum value of the panel trapezoidal body thickening thickness, l is the panel trapezoidal body thickening range, l min is the minimum value of the panel trapezoidal body thickening range, l max is the maximum value of the panel trapezoidal body thickening range, i is the slope ratio of the excavation slope at the junction of cut and fill, i min is the minimum slope ratio of the excavation slope at the junction of cut and fill, i max is the maximum slope ratio of the excavation slope at the junction of cut and fill, ε max is the maximum tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, [ε t ] is the allowable tensile strain at the junction of the asphalt concrete panel at the bottom of the reservoir, τ max is the maximum shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, [τ t ] is the allowable shear stress at the junction of the asphalt concrete panel at the bottom of the reservoir, u max is the maximum settlement at the junction of the asphalt concrete panel at the bottom of the reservoir, [u t ] is the maximum allowable settlement at the junction of the excavation and filling of the asphalt concrete panel at the bottom of the reservoir.

7. The method for optimizing the structure of the cut-and-fill interface of the asphalt concrete panel according to claim 6, characterized in that: In step eight, the process of solving the optimal shape parameters of the excavation and filling interface of the reservoir bottom asphalt concrete panel includes the following steps: Step 801: Taking the increase in volume by thickening the panel trapezoid as the objective function, construct a volume display expression Among them, V is the volume increased by thickening the trapezoidal body of the panel, and L is the length of the excavation line; Step 802, selecting the slope ratio of the excavation slope and the excavation line length at the actual cut-fill interface, and simplifying the volume display expression; Step 803, according to step 6, the thickness and range of the thickening of the panel trapezoidal body under the excavation slope condition are obtained, so that the slope ratio of the excavation slope at the actual junction of cut and fill and the excavation line length of the panel trapezoidal body thickness and range of the thickening range can be obtained, and the coordinate points in the slice area are substituted into the simplified volume display expression to obtain the range of variation of the thickening volume of the panel trapezoidal body under the premise of meeting the safety requirements, and then the minimum value of the thickening volume of the panel trapezoidal body can be obtained.

Images