Method for evaluating seaworthiness performance of rigid overlay composite pavement structure in cold region

Abstract

The invention discloses a method for evaluating the seaworthiness performance of a rigid overlay composite pavement structure in a cold region. The method comprises the following steps: collecting soil matrix moisture content; the thickness of an original pavement panel is corrected; calculating a soil matrix reaction modulus; determining a standard model; correcting the aircraft load; calculating the vertical deformation of the pavement slab; detecting the actual deformation amount; calculating a pavement fatigue coefficient; judging a fatigue failure state; calculating shear deformation; calculating an interlayer combination coefficient; and outputting a pavement fatigue coefficient, an interlayer combination coefficient and a cold region airport runway airworthiness performance report of the cold region airport. According to the method, the characteristics of the airport in the cold region and the characteristics of the composite pavement can be considered, and the airworthiness of the runway is represented by the deformation in a mode of combining theoretical calculation and actual detection. In addition, the method can also provide a cold region airport runway seaworthiness performance report for related personnel, which not only helps to improve the safety and service ability of the cold region airport, but also can provide data support for pavement design and maintenance.

Description

Technical Field

[0001] The invention belongs to the technical field of airport engineering, and in particular relates to an airworthiness performance evaluation method for a rigid overlaid composite pavement structure in cold regions. Background Art

[0002] As global climate change intensifies, the construction and maintenance of airports in cold regions face more and more challenges. The unique climate conditions in cold regions, such as low temperature, snowfall, and icing, will directly affect the structural performance and airworthiness safety of the pavement. Therefore, it is particularly important to study the pavement structure suitable for cold regions, especially the airworthiness performance evaluation method of the rigid overlay composite pavement structure.

[0003] Rigid overlay composite pavement structure refers to the addition of a rigid overlay layer on the original pavement panel on the basis of the traditional pavement to enhance the pavement's bearing capacity and durability. This structure can not only effectively resist the negative impact of extreme climate in cold regions, but also improve the pavement's service life and maintenance efficiency. However, pavement structures in cold regions may suffer from cracks, peeling and other defects under the influence of multiple factors such as aircraft wheel loads, temperature changes, and melting ice and snow, resulting in reduced airworthiness. Therefore, it is particularly important to establish a scientific and reasonable airworthiness performance evaluation method. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide a method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions.

[0005] In order to achieve the above-mentioned object, the method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions provided by the present invention comprises the following steps performed in sequence:

[0006] 1) Phase S1 of collecting soil moisture content of cold region airports: In this phase, multiple sensors buried in the soil foundation below the runway of cold region airports are used to collect soil moisture content at different locations of the runway of cold region airports, and the average soil moisture content ω is calculated from all soil moisture contents;

[0007] 2) S2 stage of correcting the thickness of the original road panel by considering the damage of the original road panel: In this stage, the corrected thickness of the original road panel can be determined by the actual thickness of the original road panel and the reduction coefficient of the thickness of the old concrete slab. The formula is:

[0008] h2=Ch2'(1)

[0009] Where: h2' is the actual thickness of the original pavement panel, C is the reduction coefficient of the thickness of the old concrete slab, which is determined according to Table 9.0.2 in the "Civil Airport Concrete Pavement Design Code".

[0010] 3) S3 stage of calculating the soil base reaction modulus considering the temperature change: In this stage, the soil base rebound modulus E is calculated based on the average value ω of the soil base moisture content obtained in step 1), and the formula is:

[0011] E=aω b (2)

[0012] Among them: a, b are the correlation coefficients of soil base rebound modulus and soil base moisture content. In cold regions, a is 246.38 and b is -0.7171.

[0013] Then, based on the soil base rebound modulus E, the soil base reaction modulus k is calculated using the following formula:

[0014]

[0015] Where: H is the total thickness of the rigid overlay composite pavement, H = h1 + h2, h1 is the thickness of the rigid overlay layer, E * is the modulus of resilience of the rigid overlay layer, which is obtained according to the heavy hammer test (HWD).

[0016] 4) Determine the S4 stage of the standard aircraft model; the aircraft model with the maximum aircraft load that the runway of the cold region airport can withstand is determined as the standard aircraft model;

[0017] 5) S5 stage to correct the aircraft load considering the temperature change: In this stage, the aircraft load of the standard aircraft is corrected using the air density. The calculation formula of the aircraft load P of the corrected standard aircraft is:

[0018]

[0019] Where: ρ is the air density above the cold region airport, ρ0 is the air density at 20°C, which is 1.205 kg / m 3 , P0 is the aircraft load of the standard aircraft model, determined according to the "Civil Airport Cement Concrete Pavement Design Specification";

[0020] 6) S6 stage for calculating the vertical deformation of the pavement panel under the standard aircraft load: In this stage, the rigid overlay layer in the rigid overlay composite pavement is regarded as the upper beam, and the original pavement panel is regarded as the lower beam. The composite beam model is constructed by the Euler-Bernoulli beam model and the Winkle foundation model to obtain the deformation control equation shown in formula (5). Then, the deformation control equation is solved to obtain formulas (6) and (7). Finally, the corrected original pavement panel thickness h2 obtained in step 2), the soil foundation reaction modulus k obtained in step 3), and the corrected standard aircraft load P obtained in step 5) are substituted into formulas (6) and (7) to obtain the vertical deformation y of the rigid overlay composite pavement under the standard aircraft load;

[0021]

[0022] Wherein, h1 is the thickness of the rigid overlay layer; h2 is the thickness of the original road panel; E1 is the elastic modulus of the rigid overlay layer; E2 is the elastic modulus of the original road panel; I1 is the moment of inertia of the rigid overlay layer, I2 is the moment of inertia of the original road panel, and I i =bh i 3 / 12, b is the width of the original road panel; A1 is the cross-sectional area of ​​the rigid overlay layer, A2 is the cross-sectional area of ​​the original road panel, A i =bh i ; s is the tangential deformation of the pavement panel under aircraft load; k u is the interlaminar shear stiffness, which can be obtained through shear test;

[0023] Solving equation (5) yields:

[0024] y=C1e λx +C2e -λx +e αx (C3cosβx+C4 sinβx)+e -αx (C5 cosβx+C6 sinβx) (6)

[0025] s=B1e λx +B2e -λx +e αx (B3 cosβx+B4 sinβx)+e -αx (B5 cosβx+B6 sinβx) (7)

[0026] Where x is the distance from any point on the road panel to the center point of the road panel;

[0027]

[0028] Re(θ2) is the real part of the complex number θ2, and Im(θ2) is the imaginary part of the complex number θ2; λ, θ1, θ2, Q, P, A, B, and C are characters defined to simplify the results and have no practical meaning; i is an imaginary unit; e is a natural constant; C1, C2, C3, C4, C5, C6, B1, B2, B3, B4, B5, and B6 are unknown coefficients, which can be determined by substituting the following boundary conditions into equations (6) and (7):

[0029] The center point of the road panel is x = 0, and we have:

[0030] s(0)=0,y'(0)=0

[0031] The edge of the road panel is x = l, x = -l, and we have:

[0032] y(l)=0,y(-l)=0

[0033] y”(l)=0,y”(-l)=0

[0034] 7) S7 stage of detecting the actual deformation of the runway of the cold region airport: In this stage, sensors are arranged on the rigid overlay composite pavement to obtain the actual vertical deformation y of the rigid overlay composite pavement under aircraft load. i ' and the actual tangential deformation of the rigid overlay composite pavement s i ';

[0035] 8) The pavement fatigue coefficient of the cold region airport is calculated in the S8 stage. In this stage, the vertical deformation y of the rigid overlay composite pavement under the standard aircraft load obtained in step 6) and the actual vertical deformation y of the rigid overlay composite pavement under the aircraft load obtained in step 7) are calculated. i ', the pavement fatigue coefficient γ of the cold region airport is calculated using the following formula:

[0036]

[0037] Where: N ei The number of actions allowed for the rigid overlay composite pavement is determined by the fatigue equation shown below;

[0038]

[0039] Where: σ is the maximum stress at the edge of the rigid overlaid composite pavement obtained by simulation, and f is the design bending tensile strength of the rigid overlaid composite pavement;

[0040] 9) Stage S9 for judging the fatigue damage state of the rigid overlaid composite pavement; in this stage, the fatigue damage state of the rigid overlaid composite pavement is determined by comparing the pavement fatigue coefficient γ of the cold region airport obtained in step 8) with 1, and the formula is as follows:

[0041]

[0042] 10) Calculate the shear deformation of the rigid overlay composite pavement in step S10; in this stage, use formula (7) in step 6) to calculate the interlayer shear stiffness k of the standard model u When s0 is 0, the shear deformation of the rigid overlaid composite pavement is s0;

[0043] 11) The interlayer bonding coefficient of the rigid overlaid composite pavement is calculated in step S11. In this stage, the shear deformation s0 of the rigid overlaid composite pavement obtained in step 10) and the actual tangential deformation s of the rigid overlaid composite pavement obtained in step 7) are calculated. i ', calculate the interlayer bonding coefficient μ of the rigid overlay composite pavement, the formula is:

[0044]

[0045] 12) Output the pavement fatigue coefficient γ, interlayer bonding coefficient μ and runway airworthiness performance report of cold region airports according to user instructions.

[0046] In step 1), the sensor is a MP406 water content sensor.

[0047] The cold region rigid overlay composite pavement structure airworthiness evaluation method provided by the present invention has the following advantages: it can take into account the characteristics of cold region airports and the characteristics of composite pavement, and characterize the airworthiness of the runway by the deformation through a combination of theoretical calculation and actual detection. In addition, the method can also provide relevant personnel with a cold region airport runway airworthiness performance report, which not only helps to improve the safety and service capabilities of cold region airports, but also can provide data support for pavement design and maintenance. DETAILED DESCRIPTION

[0048] Figure 1 A flow chart of the method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions provided by the present invention. The present invention is described in detail below with reference to the accompanying drawings

[0049] like Figure 1 As shown, the method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions provided by the present invention comprises the following steps performed in sequence:

[0050] 1) S1 stage of collecting soil moisture content of cold region airports: In this stage, multiple MP406 moisture sensors buried in the soil foundation below the runway of cold region airports are used to collect soil moisture content at different positions of the runway of cold region airports, and the average soil moisture content ω is calculated from all soil moisture contents;

[0051] 2) S2 stage of correcting the thickness of the original road panel by considering the damage of the original road panel: Before laying the rigid overlay on the original road panel, the structure of the original road panel has been damaged. Therefore, in this stage, the corrected thickness of the original road panel can be determined by the actual thickness of the original road panel and the reduction coefficient of the old concrete slab thickness. The formula is:

[0052] h2=Ch2'(1)

[0053] Where: h2' is the actual thickness of the original pavement panel, C is the reduction coefficient of the thickness of the old concrete slab, which is determined according to Table 9.0.2 in the "Civil Airport Concrete Pavement Design Code".

[0054] 3) S3 stage of calculating the soil foundation reaction modulus considering the temperature change: The ground temperature of the cold-region airport foundation is constantly changing due to the influence of the cold-region temperature. Therefore, the soil foundation will change from freezing to melting to freezing again. The moisture content of the soil foundation will change in different seasons, and then the strength will change. In this stage, the soil foundation rebound modulus E is calculated based on the average value of the soil foundation moisture content ω obtained in step 1), and the formula is:

[0055] E=aω b (2)

[0056] Among them: a, b are the correlation coefficients of soil base rebound modulus and soil base moisture content. In cold regions, a is 246.38 and b is -0.7171.

[0057] Then, based on the soil base rebound modulus E, the soil base reaction modulus k is calculated using the following formula:

[0058]

[0059] Where: H is the total thickness of the rigid overlay composite pavement, H = h1 + h2, h1 is the thickness of the rigid overlay layer, E * is the modulus of resilience of the rigid overlay layer, which is obtained according to the heavy hammer test (HWD).

[0060] 4) Determine the S4 stage of the standard aircraft model; the aircraft model with the maximum aircraft load that the runway of the cold region airport can withstand is determined as the standard aircraft model;

[0061] 5) S5 stage of correcting aircraft loads considering temperature changes: The load effect of aircraft on the pavement is related to the lift of the aircraft, and one of the main factors affecting lift is air density. Considering that temperature changes in cold areas will cause changes in air density and thus affect the load effect of aircraft on the pavement, in this stage, the aircraft load of standard aircraft is corrected using air density. The calculation formula for the corrected aircraft load P of standard aircraft is:

[0062]

[0063] Where: ρ is the air density above the cold region airport, ρ0 is the air density at 20°C, which is 1.205 kg / m 3 , P0 is the aircraft load of the standard aircraft model, determined according to the "Civil Airport Cement Concrete Pavement Design Specification";

[0064] 6) S6 stage for calculating the vertical deformation of the pavement panel under the load of standard aircraft: The deformation of the pavement under the aircraft load is an important basis for evaluating the airworthiness of the pavement. The Euler-Bernoulli beam model is one of the classical mechanical models that describe the bending of elastic beams. It has been widely used in engineering and can be used to calculate the force and deformation characteristics of beams. Therefore, in this stage, the rigid overlay layer in the rigid overlay composite pavement is regarded as the upper beam, and the original pavement panel is regarded as the lower beam. The composite beam model is constructed by the Euler-Bernoulli beam model and the Winkle foundation model to obtain the deformation control equation shown in formula (5). Then, the deformation control equation is solved to obtain formulas (6) and (7). Finally, the modified original pavement panel thickness h2 obtained in step 2), the soil foundation reaction modulus k obtained in step 3), and the modified standard aircraft load P obtained in step 5) are substituted into formulas (6) and (7) to obtain the vertical deformation y of the rigid overlay composite pavement under the load of standard aircraft.

[0065]

[0066] Wherein, h1 is the thickness of the rigid overlay layer; h2 is the thickness of the original road panel; E1 is the elastic modulus of the rigid overlay layer; E2 is the elastic modulus of the original road panel; I1 is the moment of inertia of the rigid overlay layer, I2 is the moment of inertia of the original road panel, and I i =bh i 3 / 12, b is the width of the original road panel; A1 is the cross-sectional area of ​​the rigid overlay layer, A2 is the cross-sectional area of ​​the original road panel, A i =bh i ; s is the tangential deformation of the pavement panel under aircraft load; k u is the interlaminar shear stiffness, which can be obtained through shear test;

[0067] Solving equation (5) yields:

[0068] y=C1e λx +C2e -λx +e αx (C3 cosβx+C4 sinβx)+e -αx (C5 cosβx+C6 sinβx) (6)

[0069] s=B1e λx +B2e -λx +e αx (B3 cosβx+B4 sinβx)+e -αx (B5 cosβx+B6 sinβx) (7)

[0070] Where x is the distance from any point on the road panel to the center point of the road panel;

[0071]

[0072] Re(θ2) is the real part of the complex number θ2, Im(θ2) is the imaginary part of the complex number θ2; λ, θ1, θ2, Q, P, A, B, C are characters defined to simplify the results and have no practical meaning; i is the imaginary unit; e is a natural constant;

[0073] C1, C2, C3, C4, C5, C6, B1, B2, B3, B4, B5, B6 are unknown coefficients, which can be determined by substituting the following boundary conditions into equations (6) and (7):

[0074] The center point of the road panel is x = 0, and we have:

[0075] s(0)=0,y'(0)=0

[0076] The edge of the road panel is x = l, x = -l, and we have:

[0077] y(l)=0,y(-l)=0

[0078] y”(l)=0,y”(-l)=0

[0079] 7) S7 stage of detecting the actual deformation of the runway of the cold region airport: In this stage, sensors are arranged on the rigid overlay composite pavement to obtain the actual vertical deformation y of the rigid overlay composite pavement under aircraft load. i ' and the actual tangential deformation of the rigid overlay composite pavement s i ';

[0080] 8) The pavement fatigue coefficient of the cold region airport is calculated in the S8 stage. In this stage, the vertical deformation y of the rigid overlay composite pavement under the standard aircraft load obtained in step 6) and the actual vertical deformation y of the rigid overlay composite pavement under the aircraft load obtained in step 7) are calculated. i ', the pavement fatigue coefficient γ of the cold region airport is calculated using the following formula:

[0081]

[0082] Where: N ei The number of actions allowed for the rigid overlay composite pavement is determined by the fatigue equation shown below;

[0083]

[0084] Where: σ is the maximum stress at the edge of the rigid overlaid composite pavement obtained by simulation, and f is the design bending tensile strength of the rigid overlaid composite pavement;

[0085] 9) Stage S9 for judging the fatigue damage state of the rigid overlaid composite pavement; in this stage, the fatigue damage state of the rigid overlaid composite pavement is determined by comparing the pavement fatigue coefficient γ of the cold region airport obtained in step 8) with 1, and the formula is as follows:

[0086]

[0087] 10) Calculate the shear deformation of the rigid overlay composite pavement in step S10; in this stage, use formula (7) in step 6) to calculate the interlayer shear stiffness k of the standard model u When s0 is 0, the shear deformation of the rigid overlaid composite pavement is s0;

[0088] 11) The interlayer bonding coefficient of the rigid overlaid composite pavement is calculated in step S11. In this stage, the shear deformation s0 of the rigid overlaid composite pavement obtained in step 10) and the actual tangential deformation s of the rigid overlaid composite pavement obtained in step 7) are calculated. i ', calculate the interlayer bonding coefficient μ of the rigid overlay composite pavement, the formula is:

[0089]

[0090] The larger the interlayer bonding coefficient μ of the rigid overlaid composite pavement, the better the interlayer bonding state of the rigid overlaid composite pavement. Conversely, it means that the interlayer bonding state of the rigid overlaid composite pavement is poor. When the interlayer bonding coefficient μ approaches 0, it indicates interlayer failure.

[0091] 12) Output the pavement fatigue coefficient γ, interlayer bonding coefficient μ and runway airworthiness performance report of cold region airports according to user instructions.

Claims

1. A method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions, characterized by: The method comprises the following steps performed in sequence: 1) Phase S1 of collecting soil moisture content of cold region airports: In this phase, multiple sensors buried in the soil foundation below the runway of cold region airports are used to collect soil moisture content at different locations of the runway of cold region airports, and the average soil moisture content ω is calculated from all soil moisture contents; 2) S2 stage of correcting the thickness of the original road panel by considering the damage of the original road panel: In this stage, the corrected thickness of the original road panel can be determined by the actual thickness of the original road panel and the reduction coefficient of the thickness of the old concrete slab. The formula is: h2=Ch2'(1) Where: h2' is the actual thickness of the original pavement panel, C is the reduction factor of the thickness of the old concrete slab, which is determined according to Table 9.0.2 of the "Civil Airport Concrete Pavement Design Code"; 3) S3 stage of calculating the soil base reaction modulus considering the temperature change: In this stage, the soil base rebound modulus E is calculated based on the average value ω of the soil base moisture content obtained in step 1), and the formula is: E=aω b (2) Among them: a, b are the correlation coefficients of soil base rebound modulus and soil base moisture content. In cold regions, a is 246.38 and b is -0.7171. Then, based on the soil base rebound modulus E, the soil base reaction modulus k is calculated using the following formula: Where: H is the total thickness of the rigid overlay composite pavement, H = h1 + h2, h1 is the thickness of the rigid overlay layer, E * is the modulus of resilience of the rigid overlay layer, which is obtained according to the heavy hammer test; 4) Determine the S4 stage of the standard aircraft model; the aircraft model with the maximum aircraft load that the runway of the cold region airport can withstand is determined as the standard aircraft model; 5) S5 stage to correct the aircraft load considering the temperature change: In this stage, the aircraft load of the standard aircraft is corrected using the air density. The calculation formula of the aircraft load P of the corrected standard aircraft is: Where: ρ is the air density above the cold region airport, ρ0 is the air density at 20°C, which is 1.205 kg / m 3 , P0 is the aircraft load of the standard aircraft model, determined according to the "Civil Airport Cement Concrete Pavement Design Specification"; 6) S6 stage for calculating the vertical deformation of the pavement panel under the standard aircraft load: In this stage, the rigid overlay layer in the rigid overlay composite pavement is regarded as the upper beam, and the original pavement panel is regarded as the lower beam. The composite beam model is constructed by the Euler-Bernoulli beam model and the Winkle foundation model to obtain the deformation control equation shown in formula (5). Then, the deformation control equation is solved to obtain formulas (6) and (7). Finally, the corrected original pavement panel thickness h2 obtained in step 2), the soil foundation reaction modulus k obtained in step 3), and the corrected standard aircraft load P obtained in step 5) are substituted into formulas (6) and (7) to obtain the vertical deformation y of the rigid overlay composite pavement under the standard aircraft load; Wherein, h1 is the thickness of the rigid overlay layer; h2 is the thickness of the original road panel; E1 is the elastic modulus of the rigid overlay layer; E2 is the elastic modulus of the original road panel; I1 is the moment of inertia of the rigid overlay layer, I2 is the moment of inertia of the original road panel, and I i =bh i 3 / 12, b is the width of the original road panel; A1 is the cross-sectional area of ​​the rigid overlay layer, A2 is the cross-sectional area of ​​the original road panel, A i =bh i ; s is the tangential deformation of the pavement panel under aircraft load; k u is the interlaminar shear stiffness, which can be obtained through shear test; Solving equation (5) yields: y=C1e λx +C2e -λx +e αx (C3cosβx+C4sinβx)+e -αx (C5cosβx+C6sinβx) (6) s=B1e λx +B2e -λx +e αx (B3cosβx+B4sinβx)+e -αx (B5cosβx+B6sinβx) (7) Where x is the distance from any point on the road panel to the center point of the road panel; Re(θ2) is the real part of the complex number θ2, and Im(θ2) is the imaginary part of the complex number θ2; λ, θ1, θ2, Q, P, A, B, and C are characters defined to simplify the results and have no practical meaning; i is an imaginary unit; e is a natural constant; C1, C2, C3, C4, C5, C6, B1, B2, B3, B4, B5, and B6 are unknown coefficients, which can be determined by substituting the following boundary conditions into equations (6) and (7): The center point of the road panel is x = 0, and we have: s(0)=0,y'(0)=0 The edge of the road panel is x = l, x = -l, and we have: y(l)=0,y(-l)=0 y”(l)=0,y”(-l)=0 7) S7 stage of detecting the actual deformation of the runway of the cold region airport: In this stage, sensors are arranged on the rigid overlay composite pavement to obtain the actual vertical deformation y of the rigid overlay composite pavement under aircraft load. i ' and the actual tangential deformation of the rigid overlay composite pavement s i '; 8) The pavement fatigue coefficient of the cold region airport is calculated in the S8 stage. In this stage, the vertical deformation y of the rigid overlay composite pavement under the standard aircraft load obtained in step 6) and the actual vertical deformation y of the rigid overlay composite pavement under the aircraft load obtained in step 7) are calculated. i ', the pavement fatigue coefficient γ of the cold region airport is calculated using the following formula: Where: N ei The number of actions allowed for the rigid overlay composite pavement is determined by the fatigue equation shown below; Where: σ is the maximum stress at the edge of the rigid overlaid composite pavement obtained by simulation, and f is the design bending tensile strength of the rigid overlaid composite pavement; 9) Stage S9 for judging the fatigue damage state of the rigid overlaid composite pavement; in this stage, the fatigue damage state of the rigid overlaid composite pavement is determined by comparing the pavement fatigue coefficient γ of the cold region airport obtained in step 8) with 1, and the formula is as follows: 10) Calculate the shear deformation of the rigid overlay composite pavement in step S10; in this stage, use formula (7) in step 6) to calculate the interlayer shear stiffness k of the standard model u When s0 is 0, the shear deformation of the rigid overlaid composite pavement is s0; 11) The interlayer bonding coefficient of the rigid overlaid composite pavement is calculated in step S11. In this stage, the shear deformation s0 of the rigid overlaid composite pavement obtained in step 10) and the actual tangential deformation s of the rigid overlaid composite pavement obtained in step 7) are calculated. i ', calculate the interlayer bonding coefficient μ of the rigid overlay composite pavement, the formula is: 12) Output the pavement fatigue coefficient γ, interlayer bonding coefficient μ and runway airworthiness performance report of cold region airports according to user instructions.

2. The method for evaluating the airworthiness performance of a rigid overlaid composite pavement structure in cold regions according to claim 1 is characterized by: In step 1), the sensor is a MP406 water content sensor.

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