A method for predicting interfacial shear stress of polystyrene foam block interlock

Abstract

The present application belongs to the technical field of road construction material performance prediction, and provides a polystyrene foam block interlocking interface shear stress prediction method, which comprises the following steps: step one, determining the influence factors of shear stress prediction index as independent variables; step two, constructing a shear stress peak value estimation model and calculating the shear stress peak value; step three, establishing a polystyrene foam block shear stress prediction model; and step four, model testing and application. The method can calculate the shear stress value range of the polystyrene foam block, which can be used to predict the shear stress value of the polystyrene foam block and judge whether the shear stress value of the polystyrene foam block under the coupling of multiple factors meets the construction standard, effectively avoids engineering problems caused by the fact that the interface shear stress does not meet the standard, and significantly improves the structural reliability and durability of the polystyrene foam block application section.

Description

Technical Field

[0001] This invention belongs to the field of road construction material performance prediction technology, specifically relating to a method for predicting shear stress at the interlocking interface of polystyrene foam blocks. Background Technology

[0002] In road and bridge construction, traditional sand, gravel, and concrete materials suffer from drawbacks such as high weight, low construction efficiency, and high resource consumption. Polystyrene foam (EPS), with its core advantages of being lightweight, low-consumption, and highly efficient, has become an ideal alternative to traditional materials and is widely used in key engineering components such as roadbed filling, slope protection, and bridge bearings. The shear stress at the interlocking interface of EPS blocks directly determines the anti-slip capability, overall stability, and long-term durability of the engineering structure. Therefore, accurate prediction of its shear stress is a core aspect of engineering design selection, construction quality control, and safety risk assessment.

[0003] However, existing methods for predicting shear stress at EPS interlocking interfaces have many key technical flaws, leading to a serious disconnect between the prediction results and actual engineering needs, as detailed below: 1. Failure to consider the core regulatory role of material density: Existing methods default to a general calculation model for EPS of a single density, ignoring the essential differences in key properties such as porosity, cell wall thickness, hardness, and compressive strength between EPS of different densities (e.g., EPS19, EPS29). Low-density EPS has high porosity and a loose structure, while high-density EPS has a dense structure and superior mechanical properties. This difference directly leads to significant differences in shear stress bearing capacity. The "one-size-fits-all" calculation mode of existing methods results in a deviation of more than 30% between predicted values ​​and actual shear stress, easily leading to problems such as incorrect selection of construction parameters, insufficient structural shear reserve, or excessive material waste.

[0004] 2. Coupling effects of unquantified interlocking structure design parameters: Existing projects commonly use "boob-groove" interlocking structures, which form a "friction-bond" composite interface through mechanical interlocking, replacing the traditional pure friction planar splicing and significantly improving shear resistance. However, existing prediction methods only consider a single structural parameter (such as focusing only on the number of interlocks or only on the shape), without systematically quantifying the synergistic effect of the interlocking structure's shape (different contact area and stress transmission methods) and number (differences in the number of interlocking points) on shear stress. This fails to provide scientific support for the optimal selection of interlocking structures and makes it difficult to meet the stringent shear stability requirements of engineering scenarios such as bridge bearings and high slopes.

[0005] 3. Incomplete Coverage of Complex Stress Conditions: In practical engineering, EPS blocks must withstand the coupled effects of vertical stress (overhead load) and horizontal strain (structural deformation). Vertical stress directly regulates the interfacial shear stress through the "normal pressure-friction" relationship, and the effect of this effect is controlled by the degree of interlocking of the structure. Horizontal strain is directly related to the amount of interfacial deformation; when the deformation exceeds a critical value, it will cause a sharp drop in shear stress. Existing methods only consider a single stress factor and do not reveal the synergistic influence of multiple stress conditions, resulting in prediction results that cannot adapt to complex engineering conditions and cannot provide a reliable basis for long-term structural stability assessment.

[0006] 4. Insufficient model reliability and engineering adaptability: Existing prediction methods mostly use simple linear fitting models, which do not consider the nonlinear characteristics of multi-factor coupling, resulting in low goodness of fit (R² is mostly below 0.8); moreover, no dedicated prediction models have been established for typical density EPS, and there is a lack of graded quantification of shear stress range, making it impossible to intuitively determine whether EPS material is suitable for the shear resistance requirements of specific projects, and making it difficult to guide the optimization of construction schemes.

[0007] In summary, existing methods fail to achieve multi-dimensional synergistic consideration of "material properties, structural design, and stress conditions," resulting in low accuracy in shear stress prediction and poor engineering adaptability. They cannot meet the dual requirements of structural safety and construction efficiency for road, bridge, and other engineering projects. There is an urgent need for a prediction method that can comprehensively consider the coupled influence of multiple factors and accurately quantify shear stress. Summary of the Invention

[0008] To address the aforementioned technical problems, this invention provides a method for predicting shear stress at the interlocking interface of polystyrene foam blocks, thereby resolving the issues in the prior art. The technical solution adopted by this invention is as follows: A method for predicting shear stress at the interlocking interface of polystyrene foam blocks includes: Step 1: Determine the influencing factors of the shear stress prediction index and use them as independent variables; Step 2: Construct a peak shear stress prediction model and calculate the peak shear stress; Step 3: Establish a cumulative probability prediction model for interfacial shear stress in polystyrene foam blocks; Step 4: Perform goodness-of-fit and likelihood ratio tests on the cumulative probability prediction model of interfacial shear stress. After passing the tests, use the cumulative probability prediction model of interfacial shear stress to predict the shear stress value of the interlocking interface of polystyrene foam blocks and determine whether it meets the construction standards.

[0009] Furthermore, in step one, the independent variables include the shape S of the interlocking structure, the number N of the interlocking structures, the horizontal strain H, the vertical stress σ, and the interfacial adhesion force. and interface friction angle .

[0010] Furthermore, the shape of the interlocking structure is triangular when S=1 and square when S=2; the number of interlocking structures N is 1 or 4; the horizontal strain H ranges from 1% to 5%; and the vertical stress σ ranges from 10 kPa to 40 kPa.

[0011] Furthermore, interfacial adhesion Interfacial friction angle The determination was made by collecting test data under multivariable coupling conditions using an indoor shear test system.

[0012] Furthermore, step two includes: constructing a peak shear stress prediction model using a linear fitting formula, and substituting different vertical stresses σ and interfacial adhesion forces. and interface friction angle The parameter values ​​were used to calculate the peak shear stress of the polystyrene foam block. ; The linear fitting formula is: , where A and B are dimensionless parameters.

[0013] Furthermore, in step three, the cumulative probability prediction model for interfacial shear stress is expressed as: in For constant terms, As the independent variable, is the regression coefficient.

[0014] Furthermore, in step three, for both EPS19 and EPS29 polystyrene foam blocks, cumulative probability prediction models for interfacial shear stress are established respectively, and the peak shear stress ranges of EPS19 and EPS29 are assigned graded values ​​respectively, where: The peak shear stress range of EPS19 is 8kPa-30kPa, and the graded values ​​are: y=1 corresponds to shear stress value P∈[8,17), y=2 corresponds to P∈[17,23), y=3 corresponds to P∈[23,27], and y=4 corresponds to P∈[27,30]. The peak shear stress range of EPS29 is 10kPa-50.5kPa, and the graded values ​​are as follows: y=1 corresponds to shear stress value P∈[10,20), y=2 corresponds to P∈[20,30), y=3 corresponds to P∈[30,40), and y=4 corresponds to P∈[40,50.5].

[0015] 8. The method for predicting shear stress at the interlocking interface of polystyrene foam blocks according to claim 1, characterized in that: in step four, the goodness-of-fit test adopts Pearson's test and bias test, and the test standard is P value > 0.05; the significance standard of the likelihood ratio test is P value < 0.001.

[0016] The present invention has the following beneficial effects: (1) This invention can simultaneously consider factors such as the material's own density, the shape and number of interlocking structures, and stress. Through multivariate coupling analysis, it can achieve efficient and accurate prediction of the shear stress of polystyrene foam blocks (EPS) under different engineering environments, solving the problems of large prediction deviation and poor engineering adaptability of traditional methods under complex working conditions. It provides a scientific basis for the construction of polystyrene foam block (EPS) materials in road, bridge and other building engineering projects, and ensures structural stability and construction safety.

[0017] (2) The prediction accuracy is greatly improved: This invention breaks through the limitations of traditional single-factor analysis, constructs a multi-dimensional coupled prediction system of material density, interlocking structure and stress conditions, establishes special models for EPS19 and EPS29 respectively, and the model fit R²≥0.9, and the deviation between the predicted value and the actual value is controlled within 5%, which solves the core pain point of large prediction deviation in existing methods.

[0018] (3) Significantly enhanced engineering adaptability: The coupling effect of design parameters such as the shape and number of interlocking structures has been quantified, and the shear stress range of EPS with different densities has been clarified. It can directly provide engineering with full-process guidance for material selection, structural optimization and parameter adjustment, and adapt to the shear resistance requirements of different engineering scenarios such as roads, bridges and high slopes.

[0019] (4) Outstanding risk control capabilities: The model can predict in advance whether the shear stress of the EPS interlock interface meets the design standards, effectively avoiding safety risks such as structural slippage and instability caused by insufficient shear resistance, reducing construction rework rate, and according to engineering practice verification, it can reduce related costs by 15%-25%.

[0020] (5) The model is highly reliable and practical: It adopts a cumulative probability model to reveal the nonlinear relationship of multi-factor coupling, and ensures the scientific nature of the model through dual verification by goodness-of-fit test and likelihood ratio test; the model calculation process is simple and can be directly embedded into engineering design software to realize rapid prediction and graded evaluation of shear stress, significantly improving design and construction efficiency; it is applicable to prediction or optimization of roads, railways, bridges and other related industries, testing or analyzing materials by measuring the chemical or physical properties of materials, and electronic digital data processing industries. Attached Figure Description

[0021] Figure 1 This is a flowchart of the method. Detailed Implementation

[0022] The following will be described in conjunction with embodiments of the present invention. Figure 1The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Unless otherwise specified, the technical means used in the embodiments are conventional means well known to those skilled in the art.

[0023] This invention proposes a method for predicting the shear stress at the interlocking interface of polystyrene foam blocks, enabling efficient and accurate prediction of shear stress at the EPS interlocking interface under different engineering scenarios. This provides a scientific basis for engineering design selection, interlocking structure optimization, construction quality control, and safety risk assessment, ultimately improving the stability of engineering structures, reducing construction costs, and shortening the construction period. It is applicable to prediction or optimization in road, railway, and bridge applications, as well as industries such as testing or analyzing materials by measuring their chemical or physical properties and electronic digital data processing. The specific steps include: Step 1: Determine the influencing factors of the shear stress prediction index and use them as independent variables: The independent variables include the shape S of the interlocking structure, the number N of the interlocking structures, the horizontal strain H, the vertical stress σ, and the interfacial adhesion force. and interface friction angle ; Step 2: Construct a peak shear stress prediction model and calculate the peak shear stress: A peak shear stress prediction model is constructed using a linear fitting formula, substituting different vertical stresses σ and interfacial adhesion forces. and interface friction angle The parameter values ​​were used to calculate the peak shear stress of the polystyrene foam block. The linear fitting formula is: , where A and B are dimensionless parameters; Step 3: Establish a shear stress prediction model for polystyrene foam blocks: Treat shear stress prediction as a multi-classification problem, and establish cumulative probability prediction models for interfacial shear stress for polystyrene foam blocks of two typical densities, EPS19 and EPS29; assign graded values ​​to the peak shear stress ranges of EPS19 and EPS29 respectively. The functional form of the cumulative probability prediction model is: in For constant terms, As the independent variable, These are the regression coefficients; Step Four: Model Validation and Application: The goodness-of-fit and likelihood ratio tests are performed on the cumulative shear stress prediction models for the EPS19 and EPS29 interfaces established in Step Three. After passing the tests, the model is used to predict the shear stress values ​​at the interlocking interfaces of polystyrene foam blocks and to determine whether they meet construction standards. Specifically, the cumulative shear stress prediction models for the EPS19 and EPS29 interfaces established in Step Three undergo a dual test: Goodness-of-fit test: Pearson test and Deviance test were used, requiring a p-value > 0.05 (significance level α = 0.05) to ensure that there is no significant difference between the theoretical predictions of the model and the actual experimental values; Likelihood ratio test: Compare the basic model containing only constant terms with the final model containing all independent variables, and require a significance test P < 0.001 to ensure that the independent variables have a significant explanatory power for shear stress; After passing the inspection, the model is applied to the actual project: input the EPS density type, interlocking structure design parameters (S, N) and stress conditions (H, σ) of the target project, and output the predicted shear stress value and its strength grade through the model to determine whether it meets the shear resistance standard of the engineering design, and guide the selection of materials, optimization of interlocking structures and adjustment of construction parameters.

[0024] The shape S of the interlocking structure in step one is a triangle with S=1 or a square with S=2; the number N of the interlocking structures is 1 or 4; the horizontal strain H ranges from 1% to 5%; and the vertical stress σ ranges from 10 kPa to 40 kPa.

[0025] interfacial adhesion in step one Interfacial friction angle The determination was made by collecting test data under multivariable coupling conditions using an indoor shear test system.

[0026] In step two, the dimensionless parameter A has a value range of 0.89-1.14, and the dimensionless parameter B has a value range of -1.45-0.6.

[0027] In step three, the peak shear stress range of EPS19 is [8kPa, 30kPa], and the graded values ​​are as follows: y=1 corresponds to the shear stress value P∈[8,17), y=2 corresponds to P∈[17,23), y=3 corresponds to P∈[23,27], and y=4 corresponds to P∈[27,30]. The peak shear stress range of EPS29 is [10kPa, 50.5kPa], and the graded values ​​are as follows: y=1 corresponds to the shear stress value P∈[10,20), y=2 corresponds to P∈[20,30), y=3 corresponds to P∈[30,40], and y=4 corresponds to P∈[40,50.5].

[0028] The establishment of the polystyrene foam block shear stress prediction model in step three is based on treating shear stress prediction as a multi-classification problem. The cumulative probability prediction models of EPS19 and EPS29 interface shear stress are established separately, and the peak ranges of EPS19 and EPS29 shear stress are assigned hierarchical values.

[0029] In step four, the goodness-of-fit test employs Pearson's test and bias test, with a p-value > 0.05 as the criterion. The significance criterion for the likelihood ratio test is p < 0.001. The cumulative probability prediction model for the EPS19 and EPS29 interface shear stress in step four can be used to predict the shear stress value of polystyrene foam blocks (EPS) and determine whether the shear stress value of polystyrene foam blocks (EPS) under multi-factor coupling meets construction standards.

[0030] Specific embodiments of the present invention are as follows: Based on the shear test results of two types of polystyrene foam (EPS) specimens, the determination of the peak shear stress of polystyrene foam (EPS) is analyzed as a specific case.

[0031] Reference Figure 1 Step 1: Determine the influencing factors of the shear stress prediction index and use them as independent variables: The independent variables include the shape S of the interlocking structure, the number N of the interlocking structures, the horizontal strain H, the vertical stress σ, and the interfacial adhesion force. and interface friction angle ; The shape S of the independent variable interlocking structure, where S=1 represents a triangle and S=2 represents a square, representing two different contact areas and stress transfer methods; the number N of the interlocking structure is 1 or 4 to characterize the influence of the number of interlocking units on shear stress; the horizontal strain H is 1%, 2%, 3%, 4%, and 5%, covering the deformation conditions that EPS blocks may face in actual engineering; vertical stress... The values ​​are 10 kPa, 20 kPa, 30 kPa, and 40 kPa, corresponding to the overburden load range that geotextile foam blocks can withstand in engineering scenarios such as roadbeds and slopes; at the same time, the interfacial adhesion strength is selected. Interfacial friction angle As an indicator of interface contact characteristics; Step 2: Construct a peak shear stress prediction model and calculate the peak shear stress; The peak shear stress of polystyrene foam (EPS) was calculated using a model for predicting the peak shear stress of EPS under different vertical stresses, interfacial adhesion forces, and interfacial friction angles. In this example, a formula for predicting the peak shear stress of polystyrene foam (EPS) is established using shear test results under different vertical stress, interfacial adhesion, and friction angle conditions.

[0032] In the formula This represents the peak shear stress of polystyrene foam (EPS) blocks. Indicates vertical stress. Indicates interfacial adhesion. The angle of friction at the interface is represented by A and B, which are dimensionless parameters.

[0033] The peak shear stress data of polystyrene foam blocks (EPS) under different densities, interlocking structure shapes, and interlocking structure numbers obtained from the experiment are shown in Tables 1 and 2 below.

[0034] Table 1. Peak shear stress (kPa) of interlocking polystyrene foam blocks (EPS19)

[0035] Table 2 Peak shear stress (kPa) of interlocking polystyrene foam blocks (EPS29)

[0036] Table 3 shows the parameter values ​​in the regression equation for the peak shear stress of polystyrene foam (EPS) blocks under different vertical stresses, interfacial adhesion forces, and friction angles.

[0037] Table 3. Parameter values ​​of the regression equation for shear stress of polystyrene foam (EPS) blocks under different working conditions.

[0038] Due to variations in the prediction models for polystyrene foam (EPS) blocks with different densities, interlocking structure shapes, and numbers of interlocking structures, R... 2 The values ​​are all greater than 0.9, indicating that the regression equation has a high degree of fit.

[0039] Using the established formula for predicting peak shear stress, the peak shear stress of polystyrene foam (EPS) blocks under different vertical stresses, interfacial adhesion forces, and friction angles was predicted. The prediction results are shown in Tables 4 and 5.

[0040] Table 4. Prediction of Peak Shear Stress in Interlocking Polystyrene Foam Blocks (EPS19)

[0041] Table 5. Prediction of Peak Shear Stress of Interlocking Polystyrene Foam Blocks (EPS29)

[0042] The actual values ​​of shear stress in polystyrene foam (EPS) blocks under different vertical stresses, interfacial adhesion forces, and friction angles are close to the predicted values, further proving the accuracy of the estimated equations.

[0043] Step 3: Establish a shear stress prediction model for polystyrene foam blocks: Treat shear stress prediction as a multi-classification problem, and establish cumulative probability prediction models for interfacial shear stress for polystyrene foam blocks of two typical densities, EPS19 and EPS29; assign graded values ​​to the peak shear stress ranges of EPS19 and EPS29 respectively. In this example, the shear stress of two different density materials, EPS19 and EPS29, was selected from the experiment and assigned to graded values. The shear stress distribution range of EPS19 is [8kPa, 30kPa], and the shear stress distribution range of EPS29 is [10kPa, 50.5kPa].

[0044] To derive a predictive model for the shear stress of polystyrene foam (EPS) blocks of different densities, this example utilizes a cumulative probability model. Cumulative probability analysis uses nonlinear functions to handle the relationship between multiple independent and dependent variables, transforming this relationship into a probability output. This type of model can better preserve the categorical and ordinal information of the dependent variable. The establishment of the EPS shear stress prediction model considers the shear stress range as a multi-classification problem, and separate predictive models for the interfacial shear stress of EPS19 and EPS29 materials with different densities are established.

[0045] The cumulative probability model in this example has the following functional form: In the formula For constant terms, As the independent variable, is the regression coefficient.

[0046] In this example, the predicted peak values ​​of the interface shear stress of EPS19 and EPS29 are grouped separately. For the cumulative probability model of EPS19, the data is divided into 4 levels and assigned corresponding values ​​y=1, y=2, y=3, and y=4, where 1 represents the shear stress value P∈[8,17); 2 represents the shear stress value P∈[17,23); 3 represents the shear stress value P∈[23,27); and 4 represents the shear stress value P∈[27,30]. For the cumulative probability model of EPS29, the data is divided into 4 levels: 1 represents the shear stress value P∈[10,20); 2 represents the shear stress value P∈[20,30); 3 represents the shear stress value P∈[30,40); and 4 represents the shear stress value P∈[40,50.5]. The weight coefficient of each characteristic index is calculated, and a preliminary prediction model for the shear stress of polystyrene foam (EPS) is constructed.

[0047] The cumulative probability fitting equation for the shear stress of polystyrene foam (EPS) obtained in this example is as follows: Prediction model for EPS19 interfacial shear stress: Prediction model for EPS29 interfacial shear stress values: A cumulative probability goodness-of-fit test was performed, and the results are shown in Figure 6 below.

[0048] Table 6 Goodness-of-fit test table

[0049] In this study, the p-values ​​for both the Pearson statistic and the Deviance statistic in the table are greater than 0.05. With a significance level of α = 0.05, this result satisfies the core logic of statistical testing: when the p-value is greater than the significance level, it indicates that there is no statistically significant difference between the theoretical predictions of the model and the actual experimental observations.

[0050] Cumulative probability likelihood ratio and significance tests were performed, and the likelihood ratios of the final model using all covariates and the model using only constant terms were compared. The test results are shown in Table 7.

[0051] Table 7. Likelihood Ratio Test Table for Prediction Model

[0052] As shown in the table above, the intercept values ​​of the -2 log-likelihood are all greater than the final values; at the same time, the significance of both final models is less than 0.05, indicating that the independent variables have significant explanatory power for the dependent variable in the model, that is, the model fit is relatively high.

[0053] The above test results fully verify the reliability and applicability of the cumulative probability model from a statistical perspective, proving that the model can accurately characterize the variation law of shear stress in polystyrene foam (EPS) under the coupling effect of multiple factors, and effectively avoid the problems existing in traditional prediction methods.

[0054] Step 4: Model Validation and Application: Perform goodness-of-fit and likelihood ratio tests on the cumulative probability prediction model of EPS19 and EPS29 interface shear stress established in Step 3. After passing the tests, use the model to predict the shear stress value of the interlocking interface of polystyrene foam blocks and determine whether it meets the construction standards.

[0055] The following verifies the prediction equation for the shear stress value at the EPS19 interface: A set of data is randomly selected from the original data, namely X1=1, X2=1, X3=4, X4=3. Substituting this data into the EPS19 interface shear stress prediction formula, we obtain: It can be seen that y=3 has the highest probability, that is, the possible range of the shear stress value of polystyrene foam block (EPS) is in the third level, where the third level represents the shear stress value P∈[23,27). The predicted value of the shear stress of polystyrene foam block (EPS) is 25.4kPa, so the above prediction equation meets the requirements.

[0056] The following verifies the prediction equation for the shear stress value at the EPS29 interface: A set of data is randomly selected from the original data, namely X1=2, X2=2, X3=2, X4=3. Substituting this data into the EPS29 interface shear stress prediction formula, we can obtain: As can be seen, y=3 has the highest probability, that is, the shear stress value of polystyrene foam (EPS) is at the third level, where the third level represents the shear stress value P∈[30,40). The predicted value of the shear stress of polystyrene foam (EPS) is 36.2kPa, so the above prediction equation meets the requirements.

[0057] By conducting random tests on the EPS19 and EPS29 models respectively, their predicted values ​​both meet the actual range, further proving the accuracy of the polystyrene foam block (EPS) shear stress prediction model. This model can be further applied to practical engineering projects to efficiently evaluate the structural stability and safety of polystyrene foam block (EPS) materials during construction.

[0058] In summary, this invention first collects shear stress data of polystyrene foam (EPS) blocks under multivariate coupled conditions using an indoor shear test system. The influencing factors include EPS density grade, interlocking structure shape, number of interlocking structures, horizontal strain amplitude, and vertical stress level. Through fitting analysis of interfacial adhesion and internal friction angle, the peak shear stress under each test condition is calculated, and a peak shear stress prediction model is constructed to achieve preliminary prediction of peak shear stress under different conditions. The predicted peak values ​​are then graded and quantified. Finally, based on a cumulative probability model, an interfacial strength prediction model for two typical EPS fillers, EPS19 and EPS29, is constructed. This overcomes the limitations of traditional single-factor analysis methods, comprehensively and systematically considering core influencing factors such as material density, interlocking structure design, and stress conditions, thus constructing a multi-dimensional coupled EPS shear stress prediction model. Among them, the material density covers common types such as EPS19 and EPS29; the interlocking structure design is refined to key parameters such as shape and number; the stress conditions include vertical stress and horizontal strain, realizing comprehensive coverage of actual engineering stress scenarios, solving the problem of predictive bias caused by incomplete consideration of factors in existing technologies, and greatly improving the comprehensiveness and reliability of the model. This invention establishes cumulative probability models for predicting shear stress under EPS19 and EPS29 conditions, respectively. These models can more accurately predict peak shear stress under different density conditions and efficiently assess the structural stability and safety of polystyrene foam (EPS) materials during construction based on the model predictions. This proactively avoids construction risks caused by low-strength areas, optimizes construction parameter selection, reduces rework costs due to prediction errors, and significantly improves construction efficiency and project quality. It provides scientific and efficient technical support for the application of EPS materials in road, bridge, and other building construction projects.

[0059] This invention plays an important role in architectural design, material selection, and the assessment of the stability and safety of engineering projects, and can be applied to road transportation fields such as roads and bridges.

[0060] This invention considers the influence of material properties, interfacial interlocking, and stress conditions on the shear stress of polystyrene foam blocks (EPS). Using this method, the range of EPS shear stress values ​​can be calculated, which can be used to predict EPS shear stress values ​​and determine whether the shear stress values ​​of EPS under multi-factor coupling meet construction standards. This effectively avoids engineering problems caused by non-compliance of interfacial shear stress standards, significantly improving the structural reliability and durability of road sections using EPS.

[0061] The above embodiments are merely descriptions of preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Any modifications, alterations, alterations, or substitutions made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for predicting shear stress at the interlocking interface of polystyrene foam blocks, characterized in that, include: Step 1: Determine the influencing factors of the shear stress prediction index and use them as independent variables; Step 2: Construct a peak shear stress prediction model and calculate the peak shear stress; Step 3: Establish a cumulative probability prediction model for interfacial shear stress in polystyrene foam blocks; Step 4: Perform goodness-of-fit and likelihood ratio tests on the cumulative probability prediction model of interfacial shear stress. After passing the tests, use the cumulative probability prediction model of interfacial shear stress to predict the shear stress value of the interlocking interface of polystyrene foam blocks and determine whether it meets the construction standards.

2. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 1, characterized in that: In step one, the independent variables include the shape S of the interlocking structure, the number N of the interlocking structures, the horizontal strain H, the vertical stress σ, and the interfacial adhesion force. and interface friction angle .

3. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 2, characterized in that: When the shape of the interlocking structure is S=1, it is triangular; when S=2, it is square; the number of interlocking structures N is 1 or 4; the horizontal strain H ranges from 1% to 5%; the vertical stress σ ranges from 10 kPa to 40 kPa.

4. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 2, characterized in that: interfacial adhesion Interfacial friction angle The determination was made by collecting test data under multivariable coupling conditions using an indoor shear test system.

5. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 2, characterized in that: Step two includes: constructing a peak shear stress prediction model using a linear fitting formula, and substituting different vertical stresses σ and interfacial adhesion forces. and interface friction angle The parameter values ​​were used to calculate the peak shear stress of the polystyrene foam block. ; The linear fitting formula is: , where A and B are dimensionless parameters.

6. A method for predicting shear stress at the interlocking interface of a polystyrene foam block according to any one of claims 1-5, characterized in that: In step three, the cumulative probability prediction model for interfacial shear stress is expressed as follows: in For constant terms, As the independent variable, is the regression coefficient.

7. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 6, characterized in that: In step three, for both EPS19 and EPS29 polystyrene foam blocks, cumulative probability prediction models for interfacial shear stress are established, and the peak shear stress ranges of EPS19 and EPS29 are assigned graded values, where: The peak shear stress range of EPS19 is 8kPa-30kPa, and the graded values ​​are: y=1 corresponds to shear stress value P∈[8,17), y=2 corresponds to P∈[17,23), y=3 corresponds to P∈[23,27], and y=4 corresponds to P∈[27,30]. The peak shear stress range of EPS29 is 10kPa-50.5kPa, and the graded values ​​are as follows: y=1 corresponds to shear stress value P∈[10,20), y=2 corresponds to P∈[20,30), y=3 corresponds to P∈[30,40), and y=4 corresponds to P∈[40,50.5].

8. The method for predicting shear stress at the interlocking interface of a polystyrene foam block according to claim 1, characterized in that: In step four, the goodness-of-fit test uses the Pearson test and the bias test, with the test criterion being P > 0.05; the significance criterion for the likelihood ratio test is P < 0.001.

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