Large-scale urban bridge and tunnel network evaluation method based on quantitative total risk loss

Abstract

The invention discloses a large-scale urban bridge and tunnel network evaluation method based on quantitative total risk loss, and the method comprises the steps: 1, carrying out the crawling of an open-source geographic platform, obtaining the topological data of a road network, and building a bridge and tunnel network model; 2, simplifying edges and nodes of the bridge and tunnel network model according to road grades and intersection conditions; 3, converting the traffic speed data to obtain daily average traffic volume data; 4, performing conversion on the single structure score data in the detection report to obtain a single structure failure probability; 5, defining spatial inhomogeneous Markov chain simulation structure state evolution; 6, defining a direct and indirect total loss quantification formula considering structural failure, casualties, traffic closed detour and additional carbon emission; and 7, carrying out quantitative evaluation on the long-term annual total risk loss of the large-scale bridge and tunnel network of a certain city. The method overcomes the defect that the current bridge and tunnel network evaluation method only concerns the safety loss and lacks consideration on the function loss, and is suitable for efficient management and maintenance of the large-scale bridge and tunnel network.

Description

Technical Field

[0001] The present invention relates to a bridge-tunnel network evaluation method, and in particular to a large-scale urban bridge-tunnel network evaluation method based on quantified total risk loss. Background Art

[0002] As the lifeline of urban transportation networks, bridges and tunnels boast the prominent function of connecting different areas over short distances, playing an irreplaceable role in meeting people's needs for convenient and efficient travel. At the same time, due to their structural characteristics, bridge and tunnel structures are also vulnerable links in the transportation network. They are more susceptible to damage and aging over long periods of service, making them more susceptible to extreme accidents. These can cause damage to individual structures, numerous casualties, reduced network functionality, and urban environmental pollution, with significant negative impacts on safety and functionality. Therefore, ensuring their safe and smooth operation is a prerequisite for the safe operation of urban transportation networks and regional economic development.

[0003] Ensuring the proper functioning of bridge and tunnel structures requires financial investment. Faced with the gradual degradation of bridge and tunnel structures, scientifically planning funding allocation based on the condition and functionality of each bridge and tunnel is crucial. Currently, a common approach worldwide is to maintain individual structures through scoring and rating. This localized approach completely ignores the topological characteristics of individual structures within the transportation network, resulting in a significant waste of manpower, material, and financial resources.

[0004] Individual bridge and tunnel structures are distributed across transportation networks and carry varying amounts of traffic. Consequently, they possess varying degrees of importance within the network. Quantifying this importance through appropriate measurement methods has been a research hotspot in recent years. Currently, research primarily considers the impact of individual structure failures on network safety, deriving importance indicators through vulnerability analysis. While these approaches provide in-depth analysis of safety losses, they still fail to consider functional losses. Therefore, we propose an urban bridge and tunnel network assessment method that fully considers the total risk of safety and functional losses. This method provides intuitive and more reasonable quantitative estimates compared to traditional assessment methods, enabling urban transportation management and maintenance departments to conduct more scientific and targeted maintenance. Summary of the Invention

[0005] To address the current problem of urban bridge and tunnel network status assessments failing to fully consider safety and functional losses, this paper provides a large-scale urban bridge and tunnel network assessment method based on quantified total risk loss. This method addresses the shortcoming of current bridge and tunnel network assessment methods, which focus solely on safety losses while failing to consider functional losses. It provides an intuitive and reasonable quantitative estimate of the total risk loss of bridge and tunnel networks, making it suitable for the efficient management and maintenance of large-scale bridge and tunnel networks.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] A large-scale urban bridge and tunnel network assessment method based on quantified total risk loss includes the following steps:

[0008] Step 1: Crawling the open source geographic platform to obtain road network topology data and build a bridge-tunnel network model;

[0009] Step 2: Simplify the edges and nodes of the bridge-tunnel network model according to road grades and intersection conditions;

[0010] Step 3: Convert the traffic speed data to obtain the average daily traffic volume data;

[0011] Step 4: Convert the monomer structure score data in the test report to obtain the monomer structure failure probability;

[0012] Step 5: Define a spatial non-homogeneous Markov chain to simulate the evolution of the structural state;

[0013] Step 6: Define a quantitative formula for the total direct and indirect losses that takes into account structural failure, casualties, traffic closures and detours, and additional carbon emissions;

[0014] Step 7: Conduct a quantitative assessment of the long-term annual total risk loss of a city's large-scale bridge and tunnel network.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. By defining a quantitative formula for the total direct and indirect losses that takes into account structural failure, casualties, traffic closures and detours, and additional carbon emissions, this method addresses the shortcoming of current bridge-tunnel network evaluation methods that only focus on safety losses but fail to consider functional losses. It achieves an intuitive and reasonable quantitative estimation of the total risk loss of bridge-tunnel networks, which is suitable for the efficient management and maintenance of large-scale bridge-tunnel networks.

[0017] 2. By conducting a long-term risk loss assessment on a large-scale bridge and tunnel network in a certain city, which includes 681 bridges and tunnels, 462 nodes, and 812 edges, it is proved that the present invention can provide an intuitive and reasonable quantitative estimate of the total risk loss of a long-term service bridge and tunnel network, and can provide support for the efficient management and maintenance of large-scale bridge and tunnel networks. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a flow chart of a large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to the present invention;

[0019] Figure 2 To simplify the topological structure diagram of the bridge-tunnel network model;

[0020] Figure 3 This is the evolution diagram of the bridge grade ratio within the Third Ring Road of Wuhan City;

[0021] Figure 4This is a bar chart of the number of bridge grades within the Third Ring Road of Wuhan City;

[0022] Figure 5 This is the evolution diagram of the bridge grade ratio outside the Third Ring Road in Wuhan;

[0023] Figure 6 This is a bar chart of the number of bridge grades outside the Third Ring Road in Wuhan;

[0024] Figure 7 This is a graph of the total loss values ​​of the top ten monomer structures without considering the failure probability;

[0025] Figure 8 The top ten single structures are located in the bridge-tunnel network without considering the probability of failure;

[0026] Figure 9 This is a diagram showing the direct losses of the top ten monomer structures without considering the probability of failure;

[0027] Figure 10 This is a diagram showing the indirect losses of the top ten monomer structures without considering the probability of failure;

[0028] Figure 11 This figure shows the evolution of the total annual risk loss value of Wuhan’s bridge and tunnel network considering the failure probability. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described below with reference to the accompanying drawings, but is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention that does not depart from the spirit and scope of the technical solution of the present invention should be included in the scope of protection of the present invention.

[0030] The present invention provides a large-scale urban bridge and tunnel network assessment method based on quantified total risk loss, such as Figure 1 As shown, the method includes the following steps:

[0031] Step 1: Crawling the open source geographic platform to obtain road network topology data and build a bridge-tunnel network model.

[0032] In this step, the road network topology data includes road type, direction, length, number of lanes, and name, type, longitude and latitude of bridge and tunnel units.

[0033] In this step, the bridge-tunnel network model is a network model with intersections as nodes, roads as undirected edges, and bridge-tunnel monomers as edge failure elements.

[0034] Step 2: Simplify the edges and nodes of the bridge-tunnel network model according to road grades and intersection conditions.

[0035] In this step, the method for simplifying edges is as follows: (1) deleting roads that have no significant impact on the network topology performance, including but not limited to internal sections of regional communities and forest trails, and retaining only expressways, trunk roads, main roads, secondary roads, and tertiary roads; (2) not simplifying expressways, trunk roads, and main roads, and deleting secondary roads and tertiary roads when there are no bridges or tunnels on the edges, and retaining them when there are bridges and tunnels on the edges.

[0036] In this step, the method for simplifying nodes is: if the number of nodes is sparse and clustered within a relatively close range (1 km), the nodes are condensed.

[0037] Step 3: Convert the traffic speed data to obtain the average daily traffic volume data.

[0038] In this step, the average daily traffic volume data is obtained by converting the speed data of each representative moment into flow data based on the BPR formula, and then multiplying it by the length of the time window and accumulating it. The specific formula is:

[0039]

[0040] Where V k,i is the actual speed of road k at time i; V k,f and C k are the free speed and capacity of road k, respectively, and are defined as follows with reference to the latest "Urban Road Engineering Design Code": 100 km / h and 2300 pcu / h for expressways, 80 km / h and 2100 pcu / h for trunk roads, 50 km / h and 1700 pcu / h for main roads, 40 km / h and 1650 pcu / h for secondary roads, and 30 km / h and 1600 pcu / h for tertiary roads; α and β are the control parameters of the BPR formula, respectively. The standard BPR formula takes values ​​of 0.15 and 4.0, respectively. This invention follows the standard formula value method; CDI k,i is the congestion index of road k at time i; T k,i and T k,f The actual travel time and the travel time under free driving are respectively; Q k,i is the flow rate of road k at time i; T iis the length of the time window representing time i, 1 hour for the morning peak period (7:00-9:00) and the evening peak period (17:00-19:00), 3 hours for the late night period (23:00-5:00), and 2 hours for the rest of the time periods; n is the number of time moments, and according to the length of the divided time windows, there are 13 time moments, namely 2:00, 5:00, 7:00, 8:00, 9:00, 11:00, 13:00, 15:00, 17:00, 18:00, 19:00, 21:00, and 23:00, that is, n = 13; N k is the number of lanes on road k; ADT k is the average daily traffic volume of road k.

[0041] Step 4: Convert the monomer structure scoring data in the test report to obtain the monomer structure failure probability.

[0042] In this step, the calculation of the failure probability of a single structure is based on the latest "Urban Bridge Maintenance Technical Standard" and AASHTO standards. The specific formula is:

[0043]

[0044] P f,a =Φ(-β a )

[0045] Where, β a is the reliability index of the monomer structure a; BCI a The test report score of monomer structure a; P f,a is the failure probability of monomer structure a; Φ(·) is the standard normal distribution function.

[0046] Step 5: Define a spatial non-homogeneous Markov chain to simulate the evolution of structural states.

[0047] In this step, the spatial nonhomogeneous Markov chain is defined based on the local traffic regulations for trucks. If local regulations exist, the nonhomogeneous Markov chain is defined based on the restricted area. If no regulations exist, the nonhomogeneous Markov chain degenerates into a homogeneous Markov chain.

[0048] In this step, the transition probability matrix of the Markov chain only considers the degradation of adjacent ratings, and does not consider cross-level degradation and rating increases due to maintenance. It is specifically expressed as:

[0049]

[0050] Where, T p is the transition probability matrix; p ij is the probability that a monomer structure with status rating i will be rated j in the next year, 0≤p ij ≤1, Since cross-grade degradation and rating upgrades are not considered, All unknown probabilities are fitted based on the failure probabilities converted from the scoring data in the test report.

[0051] Step 6: Define a quantitative formula for the total direct and indirect losses that takes into account structural failure, casualties, traffic closures and detours, and additional carbon emissions.

[0052] In this step, the direct and indirect total losses of structural failure, casualties, traffic closure and detour, and additional carbon emissions are considered to quantify the structural repair costs, structural failure carbon emission costs, casualty compensation costs, detour time costs, detour length costs, and detour carbon emission costs. The specific formula is:

[0053]

[0054] Where, They are the repair costs, structural carbon emission costs, casualty compensation costs, detour time costs, detour length costs and detour carbon emission costs caused by the failure of single structure a, among which, and For direct losses, and is the indirect loss; K1 is the unit area structural cost, which is 1294$ / m according to AASHTO standard. 2 ;W a and L a are the plane width and length of the single structure a, in meters; K2 and K3 are the market carbon price and carbon emissions per unit area, respectively, which are 97.49 yuan / t and 33600 g / m according to the carbon market transaction price in my country as of the end of last year and the AASHTO standard. 2 ; V a,average is the average speed of the road where the single structure a is located at the representative moment; D car and D human where is the compensation for vehicle damage and personal injury, respectively. The former is set at RMB 150,000, and the latter is calculated based on the per capita disposable income of urban residents in the previous year in the local area according to the Supreme Court document and is calculated based on 20 years (one year is reduced for each additional year of age for those over 60 years old, and 5 years are taken for those over 75 years old); O is the average number of passengers per vehicle, which is 1.56 according to the AASHTO standard; R1 and R2 are the proportion of the population under / over 60 years old in the local census results; TV car and TV truck The time values ​​of small cars and trucks are 7.05$ / h and 20.56$ / h respectively according to AASHTO standards; C car and C truckThe driving costs per kilometer for small cars and trucks are 0.08$ / km and 0.375$ / km respectively according to AASHTO standards; CE car and CE truck are the carbon emissions per kilometer for small cars and trucks, which are 161g / km and 276g / km respectively according to the AASHTO standard; T a is the percentage of trucks in the total traffic volume on the road where the single structure a is located; D a d a and S a are the detour distance, detour days and detour speed caused by the failure of single structure a.

[0055] Step 7: Conduct a quantitative assessment of the long-term annual total risk loss of a city's large-scale bridge and tunnel network.

[0056] In this step, the formula for calculating the predicted value of the monomer structure score in the next t years is:

[0057]

[0058] Where, is the predicted score value of monomer structure a in the next t years, v a is the current state vector of structural monomer a. The state vector is a one-hot vector related to the current score and rating. If the current monomer score is 91 points (corresponding to level 1), the state vector is expressed as [91.00.00.00.00.0]; if the current monomer score is 75 points (corresponding to level 3), the state vector is expressed as [0.00.075.00.00.0].

[0059] In this step, the calculation formula for the annual total risk loss value of the bridge-tunnel network is:

[0060]

[0061] R a =P f,a ×TL a

[0062]

[0063] Where, TL a is the loss quantification value of the single structure a without considering the failure probability; R a is the quantitative value of risk loss considering the failure probability of the single structure a; R network is the quantitative value of the total risk of the entire bridge-tunnel network; N is the number of individual structures in the bridge-tunnel network.

[0064] Example:

[0065] Step 1: Crawling the open source geographic platform OpenStreetMap to obtain Wuhan road network topology data, including road type, direction, length, number of lanes, and bridge and tunnel name, type, latitude and longitude data. A network model is then established with intersections as nodes, roads as undirected edges, and bridges and tunnels as edge failure elements.

[0066] Step 2: Simplify the edges and nodes of the network model according to the road grade and intersection conditions. The simplified topological structure of the Wuhan bridge and tunnel network is as follows: Figure 2 shown.

[0067] Step 3: Convert the speed data at each representative moment into flow data based on the BPR formula, then multiply it by the time window length and add it up to obtain the daily average traffic volume data. The specific formula is:

[0068]

[0069] Where V k,i is the actual speed of road k at time i; V k,f and C k are the free speed and capacity of road k, respectively, and are defined as follows with reference to the latest "Urban Road Engineering Design Code": 100 km / h and 2300 pcu / h for expressways, 80 km / h and 2100 pcu / h for trunk roads, 50 km / h and 1700 pcu / h for main roads, 40 km / h and 1650 pcu / h for secondary roads, and 30 km / h and 1600 pcu / h for tertiary roads; α and β are the control parameters of the BPR formula, respectively. The standard BPR formula takes values ​​of 0.15 and 4.0, respectively. This invention follows the standard formula value method; CDI k,i is the congestion index of road k at time i; T k,i and T k,f The actual travel time and the travel time under free driving are respectively; Q k,i is the flow rate of road k at time i; T i is the length of the time window representing time i, 1 hour for the morning peak period (7:00-9:00) and the evening peak period (17:00-19:00), 3 hours for the late night period (23:00-5:00), and 2 hours for the rest of the time periods; n is the number of time moments, and according to the length of the divided time windows, there are 13 time moments, namely 2:00, 5:00, 7:00, 8:00, 9:00, 11:00, 13:00, 15:00, 17:00, 18:00, 19:00, 21:00, and 23:00, that is, n = 13; N k is the number of lanes on road k; ADT k is the average daily traffic volume of road k.

[0070] Step 4. Refer to the latest "Urban Bridge Maintenance Technical Standards" and AASHTO standards, convert the scoring data in the inspection report to obtain the structural failure probability. The specific formula is:

[0071]

[0072] P f,a =Φ(-β a )

[0073] Where, β a is the reliability index of the monomer structure a, BCI a The test report score of monomer structure a, P f,a is the failure probability of monomer structure a, and Φ(·) is the standard normal distribution function.

[0074] Step 5. According to the "Notice on Further Optimizing the Management of Truck Traffic" (Wuhan Public Security Bureau Traffic Management Bureau

[2023] No. 64) issued in 2023, bridges and tunnels within the Third Ring Road restrict the passage of some large trucks. Therefore, a non-homogeneous Markov chain is defined inside and outside the Third Ring Road. At the same time, the transition probability matrix only considers adjacent rating degradation, ignoring cross-level degradation and rating increases due to maintenance. Specifically, it is expressed as:

[0075]

[0076] Where, T p is the transition probability matrix, p ij is the probability that a monomer structure with status rating i will be rated j in the next year, 0≤p ij ≤1, Since cross-grade degradation and rating upgrades are not considered, All unknown probabilities are fitted based on the failure probabilities converted from the scoring data in the test report.

[0077] Step 6. Define a quantitative formula for the total direct and indirect losses that takes into account structural failure, casualties, traffic closures and detours, and additional carbon emissions. Quantify the structural repair costs, carbon emission costs of structural failure, compensation costs for casualties, detour time costs, detour length costs, and detour carbon emission costs. The specific formula is:

[0078]

[0079] Where, They are the repair costs, structural carbon emission costs, casualty compensation costs, detour time costs, detour length costs and detour carbon emission costs caused by the failure of single structure a, among which, and For direct losses, and is the indirect loss; K1 is the unit area structural cost, which is 1294$ / m according to AASHTO standard. 2 ;W a and L a are the plane width and length of the single structure a, in meters; K2 and K3 are the market carbon price and carbon emissions per unit area, respectively, which are 97.49 yuan / t and 33600 g / m according to the carbon market transaction price in my country as of the end of last year and the AASHTO standard. 2 ; V a,average is the average speed of the road where the single structure a is located at the representative moment; D car and D human where 1 is the compensation for vehicle damage and 1 is the compensation for personal injury, respectively. The former is set at RMB 150,000, and the latter is calculated based on the per capita disposable income of urban residents in Wuhan in the previous year (RMB 64,346) according to the Supreme Court document and is calculated over a 20-year period (one year is reduced for each additional year of age over 60 years old, and 5 years are taken for those over 75 years old); O is the average number of passengers per vehicle, which is 1.56 according to the AASHTO standard; R1 and R2 are the proportion of the population under / over 60 years old in the local census results, which are 0.8277 and 0.1723 according to the latest Wuhan census results; TV car and TV truck The time values ​​of small cars and trucks are 7.05$ / h and 20.56$ / h respectively according to AASHTO standards; C car and C truck The driving costs per kilometer for small cars and trucks are 0.08$ / km and 0.375$ / km respectively according to AASHTO standards; CE car and CE truck are the carbon emissions per kilometer for small cars and trucks, which are 161g / km and 276g / km respectively according to the AASHTO standard; T a is the percentage of trucks in the total traffic volume on the road where the single structure a is located; D a d a and S a are the detour distance, detour days and detour speed caused by the failure of single structure a.

[0080] Step 7: Conduct a long-term assessment of Wuhan's large-scale bridge-tunnel network, which consists of 681 individual bridges and tunnels, 462 nodes, and 812 edges. The formula for calculating the predicted individual structural score in the next year t is:

[0081]

[0082] Where, is the predicted score value of monomer structure a in the next t years, v a is the current state vector of structural monomer a. The state vector is a one-hot vector related to the current score and rating. If the current monomer score is 91 points (corresponding to level 1), the state vector is expressed as [91.00.00.00.00.0]; if the current monomer score is 75 points (corresponding to level 3), the state vector is expressed as [0.00.075.00.00.0]. Figure 3 、 Figure 4 The long-term evolution of the bridge and tunnel structures within the Third Ring Road is shown in Figures 1 and 2. It can be seen that the evolution rate within the Third Ring Road is relatively slow. After 30 years, the proportion of Grade 4-5 structures is less than 30%, and after 50 years, it has not yet reached 50%. Figure 5 、 Figure 6 They respectively represent the long-term evolution of the bridge and tunnel structures outside the Third Ring Road. It can be seen that the evolution rate within the Third Ring Road is relatively faster, and the proportion of level 4-5 has reached 56.9% after 50 years.

[0083] The calculation formula for the total annual risk loss value of the bridge-tunnel network is:

[0084]

[0085] R a =P f,a ×TL a

[0086]

[0087] Where, TL a is the loss quantification value of the single structure a without considering the failure probability, R a is the quantitative value of risk loss considering the failure probability of the single structure a, R network It is a quantitative value for the total risk of the entire bridge-tunnel network. Figure 7 、 Figure 8 They represent the total loss values ​​of the top ten single structures without considering the failure probability and their positions in the bridge-tunnel network. It can be seen that most of the top-ranked ones are Yangtze River bridges, because they not only have large structural spans, but also will bring about a huge detour distance in the event of failure. The rest are bridges leading to Wuhan Tianhe Airport because they bear a large amount of traffic. Figure 9 、 Figure 10 The figures represent the direct and indirect loss components of the top ten single structures, ignoring the probability of failure. It can be seen that carbon emissions account for a relatively low proportion of direct losses, with personnel and vehicle losses comparable to infrastructure losses. However, carbon emissions account for the vast majority of indirect losses, followed by detour time, and the smallest proportion is detour distance. Figure 11 It represents the evolution of the total annual risk loss value of Wuhan’s bridge and tunnel network during long-term service, taking into account the failure probability.

Claims

1. A large-scale urban bridge and tunnel network assessment method based on quantified total risk loss, characterized by The method comprises the following steps: Step 1: Crawling the open source geographic platform to obtain road network topology data and build a bridge-tunnel network model; Step 2: Simplify the edges and nodes of the bridge-tunnel network model according to road grades and intersection conditions; Step 3: Convert the traffic speed data to obtain the average daily traffic volume data; Step 4: Convert the monomer structure score data in the test report to obtain the monomer structure failure probability; Step 5: Define a spatial non-homogeneous Markov chain to simulate the evolution of the structural state; Step 6: Define a quantitative formula for the total direct and indirect losses that takes into account structural failure, casualties, traffic closures and detours, and additional carbon emissions; Step 7: Conduct a quantitative assessment of the long-term annual total risk loss of a city's large-scale bridge and tunnel network.

2. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 1, the road network topology data includes road type, direction, length, number of lanes, and name, type, longitude and latitude of bridge and tunnel units; the bridge and tunnel network model is a network model with intersections as nodes, roads as undirected edges, and bridge and tunnel units as edge failure elements.

3. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In the second step, the method for simplifying the edges is as follows: (1) deleting roads that have no obvious impact on the network topology performance, and only retaining expressways, trunk roads, main roads, secondary roads, and tertiary roads; (2) not simplifying expressways, trunk roads, and main roads, and deleting secondary roads and tertiary roads when there are no bridges or tunnels on the edges, and retaining them when there are bridges and tunnels on the edges; the method for simplifying the nodes is as follows: if the number of nodes in a relatively close range is sparse and clustered, the nodes are condensed.

4. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 3, the daily average traffic volume data is obtained by converting the speed data of each representative moment into flow data based on the BPR formula, and then multiplying it by the time window length and accumulating it. The specific formula is: Where V k,i is the actual speed of road k at time i; V k,f and C k are the free speed and capacity of road k respectively; α and β are the control parameters of BPR formula respectively; CDI k,i is the congestion index of road k at time i; T k,i and T k,f The actual travel time and the travel time under free driving are respectively; Q k,i is the flow rate of road k at time i; T i is the length of the time window representing time i; N k is the number of lanes on road k; n is the number of representative moments; ADT k is the average daily traffic volume of road k.

5. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 4, the calculation formula for the failure probability of the monomer structure is: P f,a =Φ(-β a ) Where, β a is the reliability index of the monomer structure a; BCI a The test report score of monomer structure a; P f,a is the failure probability of monomer structure a; Φ(·) is the standard normal distribution function.

6. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 5, the spatial nonhomogeneous Markov chain is defined according to the truck restriction regulations of the local traffic administration bureau. If there are relevant regulations, the nonhomogeneous Markov chain is defined according to the restricted area; if there are no relevant regulations, the nonhomogeneous Markov chain degenerates into a homogeneous Markov chain.

7. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 5, the transition probability matrix of the Markov chain only considers the degradation of adjacent ratings, and does not consider cross-level degradation and rating increases due to maintenance. It is specifically expressed as: Where, T p is the transition probability matrix; p ij is the probability that a monomer structure with status rating i will be rated j in the next year, 0≤p ij ≤1, All unknown probabilities are fitted based on the failure probabilities converted from the scoring data in the test report.

8. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 6, the quantification formula for the total direct and indirect losses, including structural failure, casualties, traffic closures and detours, and additional carbon emissions, is: Where, are the repair cost, structural carbon emission cost, casualty compensation cost, detour time cost, detour length cost and detour carbon emission cost caused by the failure of single structure a; K1 is the structural cost per unit area; W a and L a are the plane width and length of the single structure a respectively; K2 and K3 are the market carbon price and the carbon emission per unit area respectively; V a,average is the average speed of the road where the single structure a is located at the representative moment; D car and D human are the compensation amounts for vehicle damage and casualties respectively; O is the average number of passengers per vehicle; R1 and R2 are the proportion of the population aged 60 or above according to the local census results; TV car and TV truck are the time values ​​of a small car and a truck respectively; C car and C truck are the driving costs per kilometer for small cars and trucks respectively; CE car and CE truck are the carbon emissions per kilometer for small cars and trucks respectively; T a is the percentage of trucks in the total traffic volume on the road where the single structure a is located; D a d a and S a are the detour distance, detour days and detour speed caused by the failure of single structure a.

9. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 7, the formula for calculating the predicted value of the monomer structure score in the next t years is: Where, is the predicted score value of monomer structure a in the next t years; v a is the current state vector of the structural monomer a; T p is the transition probability matrix.

10. The large-scale urban bridge and tunnel network assessment method based on quantified total risk loss according to claim 1 is characterized in that In step 7, the calculation formula for the total annual risk loss value of the bridge and tunnel network is: Where, TL a is the quantified value of the loss of the single structure a without considering the failure probability; are the repair costs, structural carbon emission costs, casualty compensation costs, detour time costs, detour length costs and detour carbon emission costs caused by the failure of single structure a; R a P is the quantitative value of risk loss considering the failure probability of the single structure a; f,a is the failure probability of the single structure a; R network is the quantitative value of the total risk of the entire bridge-tunnel network; N is the number of individual structures in the bridge-tunnel network.

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