Method for determining the design life of asphalt pavement on highways

Abstract

This invention relates to a method for determining the design life of asphalt pavement for highways. Currently, there are only general principles for determining the design life of highways, lacking specific methods. This method initially estimates the design life, calculates the pavement structure thickness; calculates the social benefit evaluation value and environmental carrying capacity evaluation value; estimates the life-cycle cost; determines the technical benefits; establishes a standard decision matrix for the social benefit evaluation value, environmental carrying capacity evaluation value, life-cycle cost, and technical benefits for each design life, and ranks them to determine the optimal design life. This method is the first to propose using social benefits, environmental carrying capacity, life-cycle cost, and technical benefits as analytical indicators for the design life of asphalt pavement for highways. By establishing an indicator judgment matrix, a decision matrix, and a proximity ranking, the design life of asphalt pavement for highways is determined, filling a methodological gap in current standards and providing a methodological and technical approach for the design, construction, maintenance, and operation management of highways.

Description

Technical Field

[0001] This invention relates to the field of road engineering technology, specifically to a method for determining the design life of asphalt pavement for highways. Background Technology

[0002] With the rapid development of my country's economy and highway transportation, the problems of high asphalt pavement resource consumption and high operation and maintenance costs during highway construction have become increasingly prominent. This has led to increasingly stringent requirements for the lifespan of highway asphalt pavements, making long-life asphalt pavements the main direction of highway asphalt pavement development. Although my country's asphalt pavement design specifications stipulate that the design life of highway asphalt pavements should not be less than 15 years, the specifications lack specific methods and procedures for determining the design life. This results in the actual engineering practice where the design life of Chinese highway asphalt pavements is consistently set at 15 years, with no cases exceeding or falling below 15 years. In contrast, the design life of foreign highway asphalt pavements is generally 20 to 50 years. For example, the design life of French highways is 20 or 30 years, that of American highways is 30 to 50 years, and that of Japanese highways is 40 years. However, foreign countries also only have general requirements for determining the design life of highways, lacking specific methods.

[0003] Therefore, it is necessary to propose a quantitative calculation method that comprehensively considers multiple factors to determine the design life of asphalt pavement for highways. Summary of the Invention

[0004] The purpose of this invention is to provide a method for determining the design life of asphalt pavement on highways, so as to at least solve the problem that there is currently no specific method and process for determining the design life of asphalt pavement on highways.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for determining the design life of asphalt pavement for highways is provided, the method comprising:

[0007] Several design lifes are initially proposed, and the pavement structure thickness corresponding to each design life is calculated.

[0008] Select social benefit evaluation indicators and calculate the social benefit evaluation value;

[0009] Select environmental carrying capacity evaluation indicators and calculate the environmental carrying capacity evaluation value;

[0010] Based on the pavement structure thickness corresponding to each design life, estimate the total life cycle cost corresponding to each design life.

[0011] Calculate the area of ​​benefit between the pavement service performance curve and the minimum acceptable level of pavement performance for each design life, and determine the technical benefits for each design life.

[0012] Establish a standard decision matrix for the social benefit evaluation value, environmental carrying capacity evaluation value, life cycle cost and technical benefits for each design life, and rank them to determine the optimal design life.

[0013] Furthermore, the selected social benefit evaluation indicators include:

[0014] Establish a social benefit evaluation index system:

[0015] The system includes four categories of evaluation indicators: impact on social and regional development, impact on inter-regional connections, impact on technological progress, and impact on the transportation environment.

[0016] Determine the individual evaluation indicators for each category of evaluation indicators, and use them as indicators for evaluating social benefits:

[0017] The impact on social and regional development includes four individual evaluation indicators: impact on employment of residents in the project area, degree of social stability in the project area, degree of improvement in the spiritual life of residents in the project area, and degree of improvement in the material life of residents in the project area. The impact on inter-regional connectivity includes three individual evaluation indicators: exchange between project areas, development of foreign trade in the project area, and urban-rural integration in the project area. The impact on technological progress includes three individual evaluation indicators: impact on the level of project consulting work, impact on the level of project construction, and impact on the level of project decision-making and management. The impact on the transportation environment includes two individual evaluation indicators: changes in transportation in the project area and the degree of impact on the convenience of transportation in the project area.

[0018] Furthermore, the calculation of the social benefit evaluation value includes:

[0019] Determine the weights of social benefit evaluation indicators:

[0020] By establishing a judgment matrix for social benefit evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing the eigenvector and performing matrix consistency checks, the weights of the social benefit evaluation indicators are determined.

[0021] Construct a membership matrix for social benefit evaluation indicators:

[0022] Based on the social benefit evaluation indicators, establish a set of factors and comments for different evaluation indicators, calculate the membership degree, and determine the membership matrix of social benefit evaluation indicators.

[0023] Establish a comprehensive social benefit evaluation model and calculate the social benefit evaluation value:

[0024] The comprehensive model for social benefit evaluation is determined by using the weights of social benefit evaluation indicators and the membership matrix, and the social benefit evaluation value is calculated.

[0025] Furthermore, the selected environmental carrying capacity evaluation indicators include:

[0026] Establish an environmental carrying capacity evaluation index system:

[0027] The system includes three categories of evaluation indicators: social environmental impact, ecological environmental impact, and natural environmental impact.

[0028] Determine the individual evaluation indicators for the classification evaluation indicators, and use them as environmental carrying capacity evaluation indicators:

[0029] The social environmental impact includes four individual evaluation indicators: providing convenient transportation environment, impact of route obstruction, land area occupied by highway construction, and length of impact on facilities along the route; the ecological environment impact includes four individual evaluation indicators: length of passage through nature reserves, length of impact on landscape environment, vegetation cover change rate, and species change; the natural environment impact includes five individual evaluation indicators: number of new geological disasters, soil erosion modulus, air pollution index, surface water pollution index, and noise pollution index.

[0030] Furthermore, the computational environment carrying capacity evaluation value includes:

[0031] Determine the weights of environmental carrying capacity evaluation indicators:

[0032] By establishing a judgment matrix for environmental carrying capacity evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing the eigenvector and performing matrix consistency checks, the weights of the environmental carrying capacity evaluation indicators are determined.

[0033] Quantitative environmental carrying capacity evaluation indicators:

[0034] By investigating the potential consequences of environmental carrying capacity evaluation indicators, the quantitative values ​​of environmental carrying capacity evaluation indicators are obtained through statistical calculation.

[0035] Establish a comprehensive model for environmental carrying capacity assessment and calculate the social benefit evaluation value:

[0036] The comprehensive environmental carrying capacity evaluation model is determined by using the weights and quantitative values ​​of the environmental carrying capacity evaluation indicators, and the social benefit evaluation value is calculated.

[0037] Furthermore, the estimated life-cycle cost for each design year, based on the pavement structure thickness corresponding to each design year, includes:

[0038] Calculate the initial construction cost, pavement maintenance cost, pavement major and medium repair cost and residual value of highway asphalt pavement throughout its entire life cycle, and estimate the total life cycle cost of asphalt pavement for each design year; among which, pavement maintenance cost includes routine maintenance cost and preventive maintenance cost.

[0039] Furthermore, the calculation of the benefit area between the pavement service performance curve and the minimum acceptable level of pavement performance for each design life, and the determination of the technical benefits for each design life, include:

[0040] Plot the performance curves of highway asphalt pavement during daily maintenance, preventive maintenance, and major and medium repairs throughout its entire life cycle.

[0041] The area of ​​benefit between the pavement performance curve and the minimum acceptable level of pavement performance is calculated to characterize the technical benefits.

[0042] Furthermore, the establishment of a standard decision matrix for social benefit evaluation values, environmental carrying capacity evaluation values, life-cycle costs, and technical benefits for each design life, and the ranking to determine the optimal design life, includes:

[0043] Establish a judgment matrix for social benefit evaluation value, environmental carrying capacity evaluation value, life cycle cost and technical benefit for each design period, and transform it into a standardized matrix;

[0044] Calculate the largest eigenvalue and eigenvector of the judgment matrix, and perform normalization and matrix consistency checks on the eigenvectors to determine the weights of the evaluation indicators.

[0045] A normalized matrix is ​​constructed by using a weighted standardization matrix and evaluation index weights;

[0046] Calculate the positive and negative ideal solutions based on the normalized matrix;

[0047] Calculate the distance between different design lifespans and positive and negative ideal solutions;

[0048] Calculate the relative similarity of different design lifespans, sort the relative similarities by size, and determine the design life with the largest relative similarity as the optimal design life.

[0049] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0050] The method of this invention comprehensively considers social, environmental, economic, and technological factors, and for the first time proposes to use social benefits, environmental carrying capacity, life-cycle costs, and technical benefits as analytical indicators for the design life of asphalt pavement on highways. By establishing an indicator judgment matrix, a decision matrix, and a proximity ranking, the design life of asphalt pavement on highways is determined, filling a gap in the current standards. It provides a method and technical path for the design, construction, maintenance, and operation management of highways, and can take into account multiple factors such as social impact, environmental impact, technology, and economy, significantly improving the design and construction quality of asphalt pavement on highways. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other embodiments can be obtained from these drawings without creative effort.

[0052] Figure 1 This is a flowchart of the method of the present invention.

[0053] Figure 2 It is a performance curve of highway asphalt pavement during daily maintenance, preventive maintenance and major and medium repairs throughout its entire life cycle. Detailed Implementation

[0054] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0055] It should be noted that similar labels and letters indicate similar items; therefore, once an item is defined in one embodiment, it does not need to be further defined and explained in subsequent embodiments. Furthermore, the term "comprising" and any variations thereof are intended to cover a non-exclusive inclusion, such as including a series of indicators, factors, or steps, not necessarily limited to a clearly listed list of all indicators, factors, or steps, but may include other indicators, factors, or steps used to implement the method that are not clearly listed.

[0056] Example 1:

[0057] This embodiment provides a method for determining the design life of asphalt pavement for highways. The steps can be executed in a computer system, such as a set of computer-executable instructions. Although the logical order is shown in the flowchart, in some cases, the steps can be executed in a different order. Figure 1 The methods include:

[0058] S1: Initially propose several design lifespans and calculate the pavement structure thickness corresponding to each design life, including:

[0059] Select the pavement structure type and initially determine the design life of the asphalt pavement. The design life can generally be 12 years, 15 years, 18 years, 20 years, 25 years, or 30 years. The thickness of the asphalt pavement structure is calculated and determined according to the asphalt pavement design specifications based on the traffic volume prediction results.

[0060] S2: Select social benefit evaluation indicators and calculate social benefit evaluation values, including:

[0061] S201: Establish a social benefit evaluation index system:

[0062] The social benefit evaluation indicators are selected and determined according to the social benefit evaluation indicator system table based on the impact of the expressway on the regional economy, social environment and natural resources during the construction and operation period. The number of social benefit evaluation indicators can be one or more.

[0063] The system includes four categories of evaluation indicators: impact on social and regional development, impact on inter-regional connections, impact on technological progress, and impact on the transportation environment.

[0064] S202: Determine the individual evaluation indicators for the classification evaluation indicators, as social benefit evaluation indicators:

[0065] The social and regional development impact includes four individual evaluation indicators: impact on residents' employment, social stability, improvement in residents' spiritual well-being, and improvement in residents' material well-being. The inter-regional connectivity impact includes three individual evaluation indicators: inter-regional exchange, development of foreign trade, and urban-rural integration. The technological progress impact includes three individual evaluation indicators: impact on the level of project consulting work, project construction, and project decision-making and management. The transportation environment impact includes two individual evaluation indicators: changes in transportation within the project area and the degree of improvement in transportation convenience. The specific social benefit evaluation indicator system is as follows:

[0066] Social benefit evaluation index system table

[0067]

[0068] S203: Calculate the social benefit evaluation value, including:

[0069] S20301: Determine the weights of social benefit evaluation indicators:

[0070] By establishing a judgment matrix for social benefit evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing the eigenvector and performing matrix consistency checks, the weights W of the social benefit evaluation indicators are determined.

[0071] S20302: Constructing the membership matrix of social benefit evaluation indicators:

[0072] Based on the social benefit evaluation indicators, establish a set of factors and comments for different evaluation indicators, calculate the membership degree, and determine the membership matrix of social benefit evaluation indicators.

[0073] The evaluation indicators and comment sets can be surveyed from highway maintenance managers, experts in the field, users, and other stakeholders through questionnaires, emails, online surveys, and on-site discussions. The specific social benefit evaluation indicator factors and comment set survey form is as follows:

[0074]

[0075] The membership degree of different evaluation indicators is calculated as follows:

[0076]

[0077] in:

[0078] r ij Indicator u i The membership degree of the j-th level comment;

[0079] v ij Indicator u i The number of people who received a rating of level j;

[0080] u i This represents a single evaluation indicator in the social benefits section of the table above;

[0081] The membership matrix R is obtained based on the membership degree calculation results.

[0082] S20303: Establish a comprehensive model for social benefit evaluation and calculate the social benefit evaluation value.

[0083] The comprehensive model for social benefit evaluation is determined by using the weights W of the social benefit evaluation indicators and the membership matrix R, and the social benefit evaluation value B is calculated.

[0084]

[0085] S3: Select environmental carrying capacity evaluation indicators and calculate environmental carrying capacity evaluation values, including:

[0086] S301: Establish an environmental carrying capacity evaluation index system:

[0087] Based on the impact of highway pavement construction and operation on the social, ecological and natural environment, environmental carrying capacity evaluation indicators are selected and determined through the environmental carrying capacity evaluation index system table. The number of evaluation indicators can be one or more.

[0088] The system includes three categories of evaluation indicators: social environmental impact, ecological environmental impact, and natural environmental impact.

[0089] S302: Determine individual evaluation indicators for the classification evaluation indicators, as environmental carrying capacity evaluation indicators:

[0090] The social environmental impact includes four individual evaluation indicators: providing convenient transportation environment, impact of route obstruction, land area occupied by highway construction, and length of impact on roadside facilities. The ecological environmental impact includes four individual evaluation indicators: length of passage through nature reserves, length of impact on landscape environment, vegetation cover change rate, and species change. The natural environmental impact includes five individual evaluation indicators: number of new geological disasters, soil erosion modulus, air pollution index, surface water pollution index, and noise pollution index. The specific environmental carrying capacity evaluation indicator system is shown in the table below:

[0091]

[0092]

[0093] S303: Calculate the environmental carrying capacity evaluation value, including:

[0094] S30301: Determine the weights of environmental carrying capacity evaluation indicators:

[0095] By establishing a judgment matrix for environmental carrying capacity evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing and verifying the matrix consistency of the eigenvectors, the weights w of the environmental carrying capacity evaluation indicators are determined.

[0096] S30302: Quantitative Environmental Carrying Capacity Evaluation Indicators

[0097] By investigating the potential consequences of environmental carrying capacity evaluation indicators, the quantitative value R1 of the environmental carrying capacity evaluation indicators was obtained through statistical calculation.

[0098] The quantification of environmental carrying capacity evaluation indicators can be achieved through methods such as questionnaires, emails, online surveys, and on-site discussions. Surveys can be conducted among highway maintenance managers, experts in the field, users, and other stakeholders to investigate the potential consequences of these indicators. The survey results can then be statistically calculated to determine the quantification. The specific scoring results for the environmental carrying capacity evaluation indicators are as follows:

[0099]

[0100] Different evaluation indicators m a The evaluation was conducted by a number of experts, of whom a number of experts were deemed to have a significant impact. 11 The number of people affected is a. 12 The number of people less affected is a 13 a 11 +a 12 +a 13 =a, calculate different evaluation indicators m a R1 is the quotient of the number of people with the highest evaluation result and the total number of people.

[0101] S30303: Establish a comprehensive model for environmental carrying capacity assessment and calculate the social benefit evaluation value.

[0102] The comprehensive environmental carrying capacity evaluation model is determined by the weight w of the environmental carrying capacity evaluation index and the quantitative value R1 of the environmental carrying capacity evaluation index, and the social benefit evaluation value I is calculated.

[0103] I=wR1=[r1, r2,..., r m ]×[w1, w2, ..., w m (3)

[0104] S4: Based on the pavement structure thickness corresponding to each design life, estimate the total life-cycle cost for each design life, including:

[0105] Calculate the initial construction cost, pavement maintenance cost, pavement major and medium repair cost and residual value of highway asphalt pavement throughout its entire life cycle, and estimate the total life cycle cost of asphalt pavement for each design year; among which, pavement maintenance cost includes routine maintenance cost and preventive maintenance cost.

[0106] The initial construction cost of highway asphalt pavement can be calculated based on the pavement structure plan and the quota standard within the project area. The daily maintenance cost can be calculated and determined according to formula (4). The cost of preventive maintenance and major and medium repairs can be calculated and determined based on the maintenance plan implemented within the design life to keep the performance of asphalt pavement at the minimum acceptable level, combined with the quota standard within the project area. The pavement residual value is calculated and determined according to formula (5).

[0107] MC i= a + b × (100 - PCI) i )×AADT i (4)

[0109] in:

[0110] MC i —Routine maintenance cost in year i (RMB / ㎡ / year);

[0111] PCI i —Road condition index for year i;

[0112] AADT i —Average daily traffic volume in year i;

[0113] a, b — parameters. These two parameters are obtained by linear regression of the historical traffic volume of highways and their corresponding PCI (Technical Condition Index).

[0114]

[0115] in:

[0116] SV—Road Residual Value;

[0117] L a —The number of years from the year of the last maintenance to the end of the life cycle (or the end of the analysis period) of the maintenance measure;

[0118] L e —The expected service life of this maintenance measure, in years;

[0119] C r —The cost of this maintenance measure.

[0120] The total life cycle cost is calculated and determined using the following formula.

[0121]

[0122] in:

[0123] PWC xi,n ——Solution x i The present value of total costs over the analysis period n years;

[0124] IC xi ——Solution x i Initial construction costs;

[0125] MC xi,t ——Solution x i Routine maintenance costs in year t;

[0126] YC xi,t ——Solution x iPreventive maintenance costs in year t;

[0127] ZC xi,t ——Solution x i The cost of intermediate repairs in year t;

[0128] pwf i,t —The present value factor of the discount rate in year t, pwf i,t = 1 / (1+i) t ;

[0129] SV – Road surface residual value.

[0130] S5: Calculate the benefit area between the pavement service performance curve and the minimum acceptable level of pavement performance for each design life, and determine the technical benefits for each design life, including:

[0131] S501: Draw performance curves for highway asphalt pavements during daily maintenance, preventive maintenance, and major and medium repairs throughout their entire life cycle, such as... Figure 2 As shown.

[0132] S502: Calculate the area of ​​benefit between the pavement performance curve and the minimum acceptable level of pavement performance, used to characterize technical benefits.

[0133] S e =S1+S2 (7)

[0135] in:

[0136] S e —Area of ​​technical benefits;

[0137] S1—The area of ​​the upper sloping part of the performance curve when no road maintenance measures are implemented;

[0138] S2—The area of ​​the upper sloping portion of the performance curve after implementing a certain maintenance measure;

[0139] f1(t) — Performance curve function of unmaintained pavement;

[0140] f2(t) — Road surface performance curve function after implementing a certain maintenance measure;

[0141] A – The highest acceptable level for road surface;

[0142] t1 — The time for implementing maintenance;

[0143] t2 — The time it takes for the performance index to rise to the minimum acceptable level after a certain maintenance measure is implemented.

[0144] S6: Establish a standard decision matrix for the social benefit evaluation value, environmental carrying capacity evaluation value, life-cycle cost, and technical benefits for each design life, and rank them to determine the optimal design life, including:

[0145] S601: Establish a judgment matrix X for social benefit evaluation values, environmental carrying capacity evaluation values, life-cycle costs, and technical benefits for each design period, where (x ij ) m×4 Transformed into a standardized matrix R2, which is (t ij ) m×4 ;

[0146]

[0147] in:

[0148] Element x ij Let represent the j-th evaluation index value of the i-th scheme, where i = 1, ..., m; j = 1, ..., 4.

[0149]

[0150]

[0151] S602: Calculate the maximum eigenvalue and eigenvector of the judgment matrix, and perform normalization processing and matrix consistency check on the eigenvector to determine the evaluation index weight W1;

[0152] S603: Construct a normalized matrix C using the weighted normalization matrix R2 and the evaluation index weights W1;

[0153] C = W × R

[0154]

[0155] in:

[0156] c ij =w j ×r ij i=1,2,…,m; j=1,2,3,4.

[0157] S604: Calculate the positive ideal solution X based on the normalized matrix. + and negative ideal solution X - ;

[0158]

[0159]

[0160] S605: Calculate the distance between different design lifespans and positive and negative ideal solutions;

[0161]

[0162]

[0163] S606: Calculate the relative similarity C between different design years. i For relative proximity C i Sort by size, C i The larger the value, the better the solution; relative similarity C i The design life at the maximum value is determined as the optimal design life.

[0164]

[0165] Example 2:

[0166] This embodiment uses the asphalt pavement project of Highway A as an example to specifically describe this method:

[0167] (1) Initially determine the design life of asphalt pavement and calculate and determine the pavement structure.

[0168] Based on the commonly used asphalt pavement structure types in the area where Expressway A is located, and considering the advantages and disadvantages of different types of asphalt pavement structures and their regional adaptability, it was determined that the asphalt pavement of Expressway A would adopt a semi-rigid base asphalt pavement. The initial design life is proposed for six schemes: 8 years, 10 years, 12 years, 15 years, 18 years, and 20 years. The pavement structure thickness corresponding to the six schemes is calculated based on the traffic volume.

[0169] Specifically:

[0170]

[0171] (2) Social benefit evaluation

[0172] ① Select social benefit evaluation indicators

[0173] Based on the impact of Expressway A on the regional economy, social environment, and natural resources during its construction and operation, the social benefit evaluation indicators for Expressway A are selected and determined according to the social benefit evaluation indicator system table, as shown in the table below:

[0174]

[0175] ② Determine the weights of social benefit evaluation indicators

[0176] Establish a judgment matrix for different evaluation indicators of the social benefits of Expressway A, calculate the maximum eigenvalue and eigenvector of the judgment matrix, and obtain the weights of the social benefit evaluation indicators after normalizing the eigenvectors. Perform matrix consistency test to obtain the weights of the social benefit evaluation indicators for different schemes.

[0177]

[0178]

[0179] ③ Construct a membership matrix of social benefit evaluation indicators

[0180] Based on the established factors and comment sets of different evaluation indicators, surveys were conducted among highway maintenance managers, experts in the field, users and users through questionnaires, emails, online surveys, and on-site discussions. After statistical analysis of the survey results, the membership matrix of social benefit evaluation indicators was determined according to the above formula (1).

[0181]

[0182] ④ Calculate the social benefit evaluation value

[0183] Calculate the social benefit evaluation values ​​of different schemes according to the above formula (2).

[0184]

[0185] (3) Environmental carrying capacity assessment

[0186] ① Select environmental carrying capacity evaluation indicators

[0187] Based on the impact of the construction and operation of Expressway A on the social, ecological and natural environment, environmental carrying capacity evaluation indicators are selected and determined in conjunction with the environmental carrying capacity evaluation index system table.

[0188]

[0189] ② Determine the weights of environmental carrying capacity evaluation indicators

[0190] Since the environmental impacts of different asphalt pavement construction and operation schemes are mainly reflected in the ecological and natural environment, and have the same importance in the environmental carrying capacity evaluation, the weights of individual indicators in the environmental carrying capacity evaluation index of the design life of asphalt pavement of Expressway A are all taken as [0.25, 0.25, 0.25, 0.25].

[0191] ③ Quantitative environmental carrying capacity evaluation indicators

[0192] By investigating the potential consequences of environmental carrying capacity evaluation indicators, quantitative values ​​of these indicators are obtained through statistical calculation.

[0193]

[0194] ④ Calculate the environmental carrying capacity evaluation value

[0195] Calculate the environmental carrying capacity evaluation value of different schemes for Expressway A based on the above formula (3).

[0196]

[0197] (4) Life-cycle cost analysis

[0198] Based on the six different proposed plans for Expressway A, the initial construction costs, road maintenance costs (including routine maintenance costs and preventive maintenance costs), road major and medium repair costs, and residual value of the different plans are calculated and analyzed over a period of 25 years.

[0199] ① Initial construction costs

[0200] The initial construction cost of Expressway A includes the construction costs corresponding to each structural layer of the pavement, and is calculated and determined according to the quota standards of the region where Expressway A is located. Taking Scheme 1 as an example, the initial construction cost of Scheme 1 is shown in the table below.

[0201] Fee Categories Cost (RMB / square meter) Year of Implementation 4cmAC-13C 83 early years of construction 6cmAC-16C 100 early years of construction 12cmATB-25 165 early years of construction Adhesive layer (2 layers) 7 early years of construction Transdermal layer 6 early years of construction Sealing 18 early years of construction 15cm cement-stabilized crushed stone 105 early years of construction 18cm cement-stabilized crushed stone 126 early years of construction 18cm graded crushed stone 36 early years of construction total 646 early years of construction

[0202] ② Road maintenance costs (including routine maintenance costs and preventative maintenance costs) and road major and medium repair costs

[0203] Based on the degradation of pavement performance during the analysis period under different schemes, routine maintenance, preventive maintenance, and intermediate repairs are adopted to keep pavement performance above the minimum acceptable level. The cost of the implemented maintenance schemes can be calculated according to the quota standards of the area where Expressway A is located.

[0204] Taking Scheme 1 as an example, the road surface performance degradation curve of Scheme 1 during the phased period is as follows: Figure 2 As shown, in order to maintain the pavement performance of Scheme 1 at or above good during the analysis period, preventive maintenance is required in the 3rd year, and intermediate maintenance is required in the 9th and 18th years. Routine maintenance is carried out throughout the entire analysis period. Referring to the quota standards in the area where Expressway A is located, the different maintenance costs are shown in the table below.

[0205] category Cost (RMB / square meter) Year of Implementation Preventive maintenance 2.5 Year 3 Intermediate revision 240 Year 9, Year 18 Routine maintenance costs 149 Each year during the analysis period

[0206] ③ Residual value at the end of the period

[0207] Based on the performance degradation of the pavement and the maintenance measures adopted during the analysis period, the pavement residual value of different schemes is calculated using formula (5). Taking Scheme 1 as an example, since Scheme 1 will undergo a mid-term repair in the 18th year, and the expected service life after the mid-term repair is considered to be 5 years, the remaining service life at the end of the design period is 0 years, and the residual value at the end of the period is SV=0.

[0208] ④ Calculation of total life cycle cost

[0209] The total life cycle cost for different design years is calculated according to formula (6). The time value of money needs to be considered in the calculation process. The discount rate is 5%. The construction cost, maintenance cost and residual value at the end of the period are all discounted to the initial year of construction. The present value of the total life cycle cost of different schemes is shown in the table below.

[0210] plan Initial construction costs Maintenance costs residual value Total life cycle cost one 646 404.4 0 1050.4 two 667 403.5 0 1070.5 three 671 403.3 0 1074.3 Four 699 404.3 0 1103.3 five 727 406.2 0 1133.2 six 758 408.0 0 1166.0

[0211] (5) Technical Benefit Analysis

[0212] Based on formula (7), the benefit area between the pavement performance degradation curve and the minimum acceptable level of pavement performance after routine maintenance, preventive maintenance and intermediate repair of the asphalt pavement of Expressway A during the analysis period is calculated, and the technical benefits of different schemes are determined, as shown in the table below.

[0213] plan one two three Four five six Area of ​​Benefit 4386.56 4369.16 4367.10 4317.95 4254.09 4196.65

[0214] (6) Design life analysis

[0215] ① Establish a standard decision matrix

[0216] Establish a judgment matrix for evaluating the social benefits, environmental carrying capacity, life-cycle costs, and technical benefits of different options for Expressway A.

[0217]

[0218] The judgment matrix is ​​transformed into a standardized matrix using equations (8) and (9).

[0219]

[0220] ② Determine the weights of the evaluation indicators

[0221] Since the social benefits, environmental carrying capacity, life-cycle costs, and technical benefits of different schemes for Expressway A are equally important, the weights of the evaluation index for the design life of asphalt pavement on Expressway A are all set to [0.25, 0.25, 0.25, 0.25].

[0222] ③ Construct a weighted normalized matrix

[0223] The normalized matrix C is constructed by weighting, as shown below:

[0224]

[0225] ④ Determine the positive and negative ideal solutions for different evaluation indicators.

[0226] Based on the weighted normalization matrix, the positive ideal solution X is calculated using equations (10) and (11). + and negative ideal solution X - .

[0227] X + =[0.25 0 0 0] X - =[0 0 0 0]

[0228] ⑤ Calculate the distance between different solutions and the positive and negative ideal solutions.

[0229] Calculate the distances between different schemes of high-speed A and the positive and negative ideal solutions according to equations (12) and (13).

[0230]

[0231]

[0232] ⑥ Calculate the relative similarity of different schemes and rank them.

[0233] According to formula (14), the relative similarity of different schemes for Expressway A is calculated and sorted. It can be seen that the relative similarity of scheme four is the largest, that is, the optimal design life of the asphalt pavement of Expressway A is 15 years.

[0234] plan <![CDATA[C i ]]> Sort Option 1 0.4641 5 Option 2 0.4892 4 Option 3 0.5139 3 Option 4 0.5966 1 Option 5 0.5212 2 Option Six 0.2577 6

[0235] In this embodiment, the social benefits, environmental carrying capacity, life cycle cost and technical benefits of the A Expressway at different design lifespans were calculated, and a comprehensive evaluation was conducted to conclude that the optimal design life for the asphalt pavement of the A Expressway is 15 years.

[0236] Those skilled in the art will understand that all or part of the functions of the embodiments of the present invention can be implemented by hardware or by computer program. When all or part of the functions in the above embodiments are implemented by computer program, the program can be stored in a computer-readable storage medium, which may include: read-only memory, random access memory, disk, optical disk, hard disk, etc., and the program is executed by a computer to achieve the above functions. For example, the program can be stored in the memory of a device, and when the program in the memory is executed by the processor, all or part of the above functions can be achieved. In addition, when all or part of the functions in the above embodiments are implemented by computer program, the program can also be stored in a storage medium such as a server, another computer, disk, optical disk, flash drive, or portable hard drive, and can be downloaded or copied to the memory of a local device, or the system of the local device can be updated. When the program in the memory is executed by the processor, all or part of the functions in the above embodiments can be achieved.

[0237] The above examples illustrate the present invention only to aid in understanding it and are not intended to limit the scope of the invention. Those skilled in the art can make various simple deductions, modifications, or substitutions based on the principles of this invention.

Claims

1. A method for determining the design life of asphalt pavement for highways, characterized in that: The method includes: Several design lifes are initially proposed, and the pavement structure thickness corresponding to each design life is calculated. Select social benefit evaluation indicators and calculate the social benefit evaluation value; Select environmental carrying capacity evaluation indicators and calculate the environmental carrying capacity evaluation value; Based on the pavement structure thickness corresponding to each design life, estimate the total life cycle cost corresponding to each design life. Calculate the area of ​​benefit between the pavement service performance curve and the minimum acceptable level of pavement performance for each design life, and determine the technical benefits for each design life. Establish a standard decision matrix for social benefit evaluation value, environmental carrying capacity evaluation value, life cycle cost and technical benefit for each design life, and rank them to determine the optimal design life; The selected social benefit evaluation indicators include: Establish a social benefit evaluation index system: The system includes four categories of evaluation indicators: impact on social and regional development, impact on inter-regional connections, impact on technological progress, and impact on the transportation environment. Determine the individual evaluation indicators for each category of evaluation indicators, and use them as indicators for evaluating social benefits: The impact on social and regional development includes four individual evaluation indicators: impact on employment of residents in the project area, degree of social stability in the project area, degree of improvement in the spiritual life of residents in the project area, and degree of improvement in the material life of residents in the project area. The impact on inter-regional connectivity includes three individual evaluation indicators: exchange between project areas, development of foreign trade in the project area, and urban-rural integration in the project area. The impact on technological progress includes three individual evaluation indicators: impact on the level of project consulting work, impact on the level of project construction, and impact on the level of project decision-making and management. The impact on the transportation environment includes two individual evaluation indicators: changes in transportation in the project area and the degree of impact on the convenience of transportation in the project area. The selected environmental carrying capacity evaluation indicators include: Establish an environmental carrying capacity evaluation index system: The system includes three categories of evaluation indicators: social environmental impact, ecological environmental impact, and natural environmental impact. Determine the individual evaluation indicators for the classification evaluation indicators, and use them as environmental carrying capacity evaluation indicators: The social environmental impact includes four individual evaluation indicators: providing convenient transportation environment, impact of route obstruction, land area occupied by highway construction, and length of impact on facilities along the route; the ecological environment impact includes four individual evaluation indicators: length of passage through nature reserves, length of impact on landscape environment, vegetation cover change rate, and species change; the natural environment impact includes five individual evaluation indicators: number of new geological disasters, soil erosion modulus, air pollution index, surface water pollution index, and noise pollution index.

2. The method according to claim 1, characterized in that: The calculation of the social benefit evaluation value includes: Determine the weights of social benefit evaluation indicators: By establishing a judgment matrix for social benefit evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing the eigenvector and performing matrix consistency checks, the weights of the social benefit evaluation indicators are determined. Construct a membership matrix for social benefit evaluation indicators: Based on the social benefit evaluation indicators, establish a set of factors and comments for different evaluation indicators, calculate the membership degree, and determine the membership matrix of social benefit evaluation indicators. Establish a comprehensive social benefit evaluation model and calculate the social benefit evaluation value: The comprehensive model for social benefit evaluation is determined by using the weights of social benefit evaluation indicators and the membership matrix, and the social benefit evaluation value is calculated.

3. The method according to claim 2, characterized in that: The computational environment carrying capacity evaluation value includes: Determine the weights of environmental carrying capacity evaluation indicators: By establishing a judgment matrix for environmental carrying capacity evaluation indicators, calculating the maximum eigenvalue and eigenvector of the judgment matrix, and then normalizing the eigenvector and performing matrix consistency checks, the weights of the environmental carrying capacity evaluation indicators are determined. Quantitative environmental carrying capacity evaluation indicators: By investigating the potential consequences of environmental carrying capacity evaluation indicators, the quantitative values ​​of environmental carrying capacity evaluation indicators are obtained through statistical calculation. Establish a comprehensive model for environmental carrying capacity assessment and calculate the environmental carrying capacity assessment value: The comprehensive environmental carrying capacity evaluation model is determined by the weights of the environmental carrying capacity evaluation indicators and the quantitative values ​​of the environmental carrying capacity evaluation indicators, and the environmental carrying capacity evaluation value is calculated.

4. The method according to claim 3, characterized in that: The estimated life-cycle cost for each design life, based on the pavement structure thickness corresponding to each design life, includes: Calculate the initial construction cost, pavement maintenance cost, pavement major and medium repair cost and residual value of highway asphalt pavement throughout its entire life cycle, and estimate the total life cycle cost of asphalt pavement for each design year; among which, pavement maintenance cost includes routine maintenance cost and preventive maintenance cost.

5. The method according to claim 4, characterized in that: The calculation of the benefit area between the pavement service performance curve and the minimum acceptable level of pavement performance for each design life, and the determination of the technical benefits for each design life, include: Plot the performance curves of highway asphalt pavement during daily maintenance, preventive maintenance, and major and medium repairs throughout its entire life cycle. The area of ​​benefit between the pavement performance curve and the minimum acceptable level of pavement performance is calculated to characterize the technical benefits.

6. The method according to claim 5, characterized in that: The establishment of a standard decision matrix for social benefit evaluation values, environmental carrying capacity evaluation values, life-cycle costs, and technical benefits at each design life, and the ranking to determine the optimal design life, includes: Establish a judgment matrix for social benefit evaluation value, environmental carrying capacity evaluation value, life cycle cost and technical benefit for each design period, and transform it into a standardized matrix; Calculate the largest eigenvalue and eigenvector of the judgment matrix, and perform normalization and matrix consistency checks on the eigenvectors to determine the weights of the evaluation indicators. A normalized matrix is ​​constructed by using a weighted standardization matrix and evaluation index weights; Calculate the positive and negative ideal solutions based on the normalized matrix; Calculate the distance between different design lifespans and positive and negative ideal solutions; Calculate the relative similarity of different design lifespans, sort the relative similarities by size, and determine the design life with the largest relative similarity as the optimal design life.

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