Search

CN-121997633-A - Method for analyzing vulnerability of rigid pavement under wheel load effect by considering foundation performance degradation

CN121997633ACN 121997633 ACN121997633 ACN 121997633ACN-121997633-A

Abstract

A method for analyzing vulnerability of a rigid pavement under the action of wheel load considering the degradation of foundation performance. The method comprises the steps of establishing an airport rigid pavement simplified analysis model, determining a maximum tensile strain value range of a critical pavement bottom corresponding to each damage level, introducing a foundation support rigidity degradation coefficient, calculating the maximum tensile strain of the pavement bottom actually generated, constructing a vulnerability function in the form of a standard normal distribution cumulative function, calculating the comprehensive failure probability and the like. According to the method, the airport rigid pavement vulnerability analysis framework considering the degradation of the foundation performance is established by introducing the degradation coefficient of the foundation support rigidity and combining the reliability theory, so that the quantitative calculation of the pavement failure probability under different degradation degrees is realized. The space variability of the foundation support rigidity and the structural performance degradation rule can be comprehensively reflected, and the analysis result is closer to the actual operation condition. The calculation process is simple and efficient, the precision is high, the applicability is strong, and scientific, reliable and technical support can be provided for structural safety evaluation, operation maintenance and life prediction of the airport rigid pavement.

Inventors

  • CHEN YU
  • Li Ninglu
  • WU JIALIANG
  • HUANG XIN
  • LI CHANGHUI
  • WU KUN
  • QI LIN

Assignees

  • 中国民航大学

Dates

Publication Date
20260508
Application Date
20251224

Claims (7)

  1. 1. The method for analyzing the vulnerability of the rigid pavement under the action of the wheel load considering the degradation of the foundation performance is characterized by comprising the following steps of: S1, establishing an airport rigid pavement simplified analysis model, wherein the model simplifies a three-dimensional pavement structure into a longitudinal two-dimensional section, a base layer and soil foundation in a limited depth range are equivalent to a series of mutually independent spring units, a pavement panel adopts a concrete plastic damage constitutive model, and pavement panel parameters, aircraft wheel-mounted parameters and wheel-mounted sliding paths are set; S2, dividing the damage level of the road surface plate into four types of slight damage, medium damage, serious damage and complete damage by taking the maximum tensile strain epsilon t of the bottom of the critical road surface plate as a damage index, and determining the value range of the maximum tensile strain epsilon t of the bottom of the critical road surface plate corresponding to each damage level, thereby quantifying the damage level; s3, introducing a foundation support rigidity degradation coefficient eta to represent the degree of degradation of the foundation support rigidity, and setting the foundation support rigidity to be uniform degradation or nonuniform degradation; s4, considering the uniform degradation and the non-uniform degradation of the foundation support rigidity, and calculating the actually generated maximum tensile strain of the bottom of the pavement based on the airport rigid pavement simplified analysis model established in the step S1 and the foundation support rigidity degradation coefficient eta introduced in the step S3; S5, defining the vulnerability of the rigid pavement under the action of the aircraft wheel load as the failure probability that the pavement reaches a specific failure state under the action of the aircraft wheel load under the condition of degradation of the supporting rigidity of the foundation, and constructing a vulnerability function in the form of a standard normal distribution cumulative function based on the maximum tensile strain epsilon t of the bottom of the critical pavement obtained in the step S2 and the maximum tensile strain epsilon ten of the bottom of the actually-generated pavement obtained in the step S4, wherein the vulnerability function is expressed as the failure probability that the response requirement of the pavement reaches the designated failure level j; S6, introducing a main landing gear track distribution model of the aircraft, assuming that tracks transversely follow standard normal distribution on a track panel, dispersing the cross section of the track panel into a plurality of equal-width strips, calculating the track distribution probability of each strip, and then calculating the comprehensive failure probability P f by adopting a probability weighting method by combining the foundation support rigidity degradation coefficient eta with the mean mu j and the standard deviation sigma j calculated in the step S5.
  2. 2. The method for analyzing vulnerability of rigid pavement under action of wheel load considering degradation of foundation performance according to claim 1, wherein in step S1, the method for establishing an airport rigid pavement simplified analysis model which simplifies a three-dimensional pavement structure into a longitudinal two-dimensional section, wherein a foundation layer and soil foundation within a limited depth range are equivalent to a series of mutually independent spring units, the pavement adopts a concrete plastic damage constitutive model, and concrete plastic damage constitutive model is set as follows: s1.1, establishing an airport rigid pavement simplified analysis model by utilizing finite element software ABAQUS, wherein the model analyzes a three-dimensional pavement structure by taking a unit width section along a transverse direction and approximately taking the unit width section as a longitudinal two-dimensional section, and enables a foundation layer and a soil foundation in a limited depth range to be wholly equivalent into a series of mutually independent spring units; S1.2, adopting a cement concrete pavement slab with the length of 5m multiplied by 5m as a pavement slab, and selecting a concrete plastic damage constitutive model built in finite element software ABAQUS; S1.3, taking the equivalent single-wheel load of the main landing gear of the aircraft as an aircraft wheel load value, wherein the wheel load sliding path comprises three typical paths of a longitudinal central line of a road surface plate, a transverse 1/4 position of the road surface plate and a longitudinal seam of the road surface plate.
  3. 3. The method for analyzing vulnerability of rigid pavement under the action of wheel load considering degradation of foundation performance according to claim 1, wherein in step S2, the range of the maximum tensile strain epsilon t of the bottom of the critical pavement corresponding to each damage level is as follows: The maximum tensile strain epsilon t of the bottom of the corresponding critical pavement is respectively in the value ranges of 0.00008-epsilon t ＜0.0001、0.0001≤ε t ＜0.00016、0.00016≤ε t <0.0003 and epsilon t -0.0003.
  4. 4. The method for analyzing vulnerability of rigid pavement under wheel load effect considering degradation of foundation performance according to claim 1, wherein in step S3, the formula of the degradation coefficient eta of foundation support rigidity is as follows: Wherein, K j and K 0 are respectively the base layer top surface reaction modulus with and without deterioration of foundation performance, the unit is MN/m 3 , 150MN/m 3 is taken according to the design Specification of cement concrete pavement of civil airports (MH/T5004-2010) by the base layer top surface reaction modulus K 0 with no deterioration of foundation performance, and the value range of the base layer top surface reaction modulus K j with deterioration of foundation performance is 30-150 MN/m 3 .
  5. 5. The method for analyzing the vulnerability of the rigid pavement under the action of the wheel load considering the degradation of the foundation performance according to claim 4, wherein in the step S4, the concrete method for calculating the actually generated maximum tensile strain of the pavement bottom based on the airport rigid pavement simplified analysis model established in the step S1 and the foundation support rigidity degradation coefficient eta introduced in the step S3 is as follows: S4.1, when the foundation support rigidity is uniformly degraded, selecting a plurality of base layer top surface reaction moduli K j with the degradation of foundation performance within the range of 30-150 MN/m 3 , calculating a corresponding group of foundation support rigidity degradation coefficients eta according to a formula (1) in the step S3, analyzing by using an airport rigidity pavement simplified analysis model established in the step S1, and respectively obtaining the actually generated pavement bottom maximum tensile strain epsilon ten under each foundation support rigidity degradation coefficient eta according to three wheel-mounted sliding paths set in the step S1.3; S4.2, when the foundation support rigidity is unevenly degenerated, selecting a plurality of base layer top surface reaction moduli K j with the foundation performance within the range of 30-150 MN/m 3 , and calculating a corresponding group of foundation support rigidity degenerating coefficients eta according to the formula (1) in the step S3; wherein sigma represents the standard deviation of a normal distribution function of the foundation support rigidity; And then randomly generating a group of foundation support stiffness values under each foundation support stiffness degradation coefficient eta based on the mean value mu and the variation coefficient CV, randomly distributing the generated foundation support stiffness values to each position of a spring unit under the pavement in the airport rigid pavement simplified analysis model established in the step S1, analyzing by utilizing the airport rigid pavement simplified analysis model, and respectively calculating actually-generated pavement bottom maximum tensile strain epsilon ten corresponding to the foundation support stiffness values under each foundation support stiffness degradation coefficient eta according to three wheel-mounted sliding paths set in the step S1.3.
  6. 6. The method for analyzing the vulnerability of the rigid pavement under the action of the wheel load considering the degradation of the foundation performance according to claim 5, wherein in the step S5, the specific method for constructing the vulnerability function in the form of the standard normal distribution cumulative function is as follows: the expression of the vulnerability function in the form of the standard normal distribution cumulative function is as follows: Wherein S d is response to the demand S d , and the actually generated maximum tensile strain epsilon ten of the bottom of the pavement panel obtained in the step S4 is taken; to respond to capability Taking the maximum tensile strain epsilon t of the critical pavement slab bottom obtained in the step S2, responding to the requirement S d and responding to the capability The ratio is used for quantifying the safety margin of the road panel under the action of airplane wheel load; Will respond to the requirements S d and response capabilities Is regarded as obeying the lognormal distribution, in the formula (3) And (3) performing unitary linear regression fitting to obtain a mean mu j and a standard deviation sigma j , wherein the expressions are as follows: μ j =a ln(η)+b (1); Wherein a and b are the slope and intercept in the unitary linear regression fit expression respectively, S r is the sum of squares of the residual errors of each calculation point in the unitary linear regression fit expression; Converting the damage probability P f of the road panel with the response requirement reaching the specified damage level j shown in the formula (3) into a cumulative distribution function form of standard normal distribution shown in the formula (6) based on the mean mu j and the standard deviation sigma j , and then obtaining a corresponding road panel vulnerability function expression under each damage level j based on the formula (6), wherein the damage probability represents the failure probability of the road panel under the degradation degree of the foundation performance; Where Φ is a cumulative distribution function of the standard normal distribution.
  7. 7. The method for analyzing the vulnerability of the rigid pavement under the action of the wheel load considering the degradation of the foundation performance according to claim 6, wherein in the step S6, the aircraft main landing gear track distribution model is introduced, the track is assumed to transversely follow the standard normal distribution on the pavement surface plate, the cross section of the pavement surface plate is divided into a plurality of equal-width strips, the wheel load distribution probability of each strip is calculated, and then the comprehensive failure probability P f is calculated by adopting a probability weighting method by combining the foundation support rigidity degradation coefficient eta with the average mu j and the standard deviation sigma j calculated in the step S5, wherein the concrete method comprises the following steps: S6.1, dispersing the cross section of the road panel into e strips with the same width, wherein the width of each strip is f meters, the value of the width of each strip is approximately consistent with the transverse dimension of the simplified wheel marks of the main landing gear of the aircraft, and the relationship between the dimension 5m x 5m of the road panel and the f set in the step S1.2 satisfies the following formula: e*f=5 (7); calculating the wheel load distribution probability of the strip i by using a standard normal distribution cumulative probability expression shown in the formula (8), wherein the wheel load distribution probability of the symmetrical strip is twice that of a single strip; Wherein a i and b i respectively represent a lower limit and an upper limit of a transverse coordinate of a strip i, mu is a mean value of transverse distribution of a wheel track, sigma is a standard deviation of transverse distribution of the wheel track, phi is a cumulative distribution function of standard normal distribution, and the expression is as follows: S6.2, calculating the average mu j and standard deviation sigma j of corresponding vulnerability functions according to the formula (4) and (5) in the step S5 based on the wheel load distribution probability of the strip i, calculating the comprehensive failure probability that the road surface plate reaches the damage level j under the action of the aircraft wheel load by adopting a probability weighting method, and for the foundation support rigidity degradation coefficient eta, calculating a formula of the comprehensive failure probability P f of the road surface plate with the damage level j as shown in the formula (10): Wherein phi is a cumulative distribution function of standard normal distribution, and p i is the wheel load distribution probability of the strip i.

Description

Method for analyzing vulnerability of rigid pavement under wheel load effect by considering foundation performance degradation Technical Field The invention belongs to the technical field of airport engineering, and particularly relates to a method for analyzing vulnerability of a rigid pavement under the action of wheel load in consideration of foundation performance degradation. Background The cement concrete pavement has the characteristics of high strength, high durability and the like, and is currently becoming a main stream rigid pavement structure of civil airports in China. Because the road surface slab is influenced by the repeated action of airplane wheel load, the scouring of a base layer, the infiltration of rainwater and the like in service, the strength of the base layer and the soil base under the road surface slab is attenuated, so that the supporting rigidity of the foundation is reduced, and even the slab bottom is in a void state, thereby obviously increasing the cracking risk of the road surface slab and influencing the safety of the road surface and the service life. The existing airport pavement finite element simplification method generally assumes that a substrate of a plate bottom void area is not supported, ignores the residual supporting effect and the space non-uniform degradation characteristic of foundation rigidity, and is difficult to reflect the gradual change characteristic of foundation performance degradation in actual service, so that pavement damage probability evaluation deviation is larger. In addition, the existing rigid pavement vulnerability analysis method focuses on the functional vulnerability research of an airport pavement system under military strike and extreme weather, and lacks consideration of pavement foundation performance degradation and rigid pavement vulnerability analysis method under the daily airplane wheel load. Disclosure of Invention In order to solve the problems, the invention aims to provide a method for analyzing vulnerability of a rigid pavement under the action of wheel load in consideration of the degradation of foundation performance. In order to achieve the above object, the method for analyzing the vulnerability of the rigid pavement under the action of the wheel load considering the degradation of the foundation performance provided by the invention comprises the following steps sequentially carried out: S1, establishing an airport rigid pavement simplified analysis model, wherein the model simplifies a three-dimensional pavement structure into a longitudinal two-dimensional section, a base layer and soil foundation in a limited depth range are equivalent to a series of mutually independent spring units, a pavement panel adopts a concrete plastic damage constitutive model, and pavement panel parameters, aircraft wheel-mounted parameters and wheel-mounted sliding paths are set; S2, dividing the damage level of the road surface plate into four types of slight damage, medium damage, serious damage and complete damage by taking the maximum tensile strain epsilon i of the bottom of the critical road surface plate as a damage index, and determining the value range of the maximum tensile strain epsilon i of the bottom of the critical road surface plate corresponding to each damage level, thereby quantifying the damage level; s3, introducing a foundation support rigidity degradation coefficient eta to represent the degree of degradation of the foundation support rigidity, and setting the foundation support rigidity to be uniform degradation or nonuniform degradation; s4, considering the uniform degradation and the non-uniform degradation of the foundation support rigidity, and calculating the actually generated maximum tensile strain of the bottom of the pavement based on the airport rigid pavement simplified analysis model established in the step S1 and the foundation support rigidity degradation coefficient eta introduced in the step S3; S5, defining the vulnerability of the rigid pavement under the action of the aircraft wheel load as the failure probability that the pavement reaches a specific failure state under the action of the aircraft wheel load under the condition of degradation of the supporting rigidity of the foundation, and constructing a vulnerability function in the form of a standard normal distribution cumulative function based on the maximum tensile strain epsilon i of the bottom of the critical pavement obtained in the step S2 and the maximum tensile strain epsilon ten of the bottom of the actually-generated pavement obtained in the step S4, wherein the vulnerability function is expressed as the failure probability that the response requirement of the pavement reaches the designated failure level j; S6, introducing a main landing gear track distribution model of the aircraft, assuming that tracks transversely follow standard normal distribution on a track panel, dispersing the cross section of the track panel into a plura