Rail transit underground tunnel construction risk assessment and control method based on hierarchical progressive algorithm

Abstract

The invention relates to a rail transit underground tunnel construction risk assessment and control method based on a hierarchical progressive algorithm, and the method comprises the steps: determining related risk factors through the data of a construction project, carrying out the priority ranking of the risk factors, determining risk problems one by one, and further determining necessary risk factors according to the risk problems, and then different risk factors are integrated into one group, finally similar part combinations are screened out, the remaining risk problems are evaluated respectively, and the risk evaluation of the whole construction project is obtained through integration. According to the method, the risk in the construction process of the rail transit underground tunnel can be systematically identified, evaluated and controlled through a layered progressive algorithm, so that the construction safety and efficiency are improved. According to the method, comprehensiveness and deepness of risk assessment are ensured, repeated calculation of similar problems is avoided, the calculation amount is reduced, and the assessment efficiency is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of construction risk assessment, and in particular to a method for assessing and controlling construction risks of underground tunnels in rail transit based on a hierarchical progressive algorithm. Background Art

[0002] With the acceleration of urbanization, rail transit underground tunnel projects, as an important part of urban transportation construction, are becoming increasingly complex and risky. The construction of rail transit underground tunnels involves multiple fields such as geology, engineering, technology, and management. Various risk issues that may be encountered during the construction process, such as uncertainty in geological conditions, challenges in construction technology, and loopholes in safety management, may have a significant impact on the progress, cost, and safety of the project.

[0003] Traditional risk assessment methods often rely on empirical judgment or simple qualitative analysis, which makes it difficult to comprehensively and accurately assess the various risks in the construction of underground rail transit tunnels. In addition, these methods often lack systematicity and structure, and are difficult to adapt to complex and changing construction environments and risk factors.

[0004] Therefore, it is necessary to provide a risk assessment and control method for rail transit underground tunnel construction based on a hierarchical progressive algorithm to solve the above technical problems. Summary of the invention

[0005] The present invention overcomes the deficiencies of the prior art and provides a method for risk assessment and control of underground tunnel construction in rail transit based on a hierarchical progressive algorithm.

[0006] To achieve the above object, the technical solution adopted by the present invention is: a method for risk assessment and control of underground tunnel construction in rail transit based on a hierarchical progressive algorithm, comprising the following steps:

[0007] Acquire relevant data of the construction project and construct a hierarchical evaluation structure, wherein the hierarchical evaluation structure includes: a scheme layer, a criterion layer and a target layer;

[0008] The scheme-level assessment: based on the relevant data of the construction project, identify several risk factors, prioritize the several risk factors, and use them as core factors to determine risk issues one by one; each risk issue is associated with several risk factors, including a core factor and other risk factors;

[0009] The criterion-level evaluation: performing similarity analysis on the risk issues obtained from the solution-level evaluation, filtering out the risk issues with similarities exceeding a threshold, retaining the risk issues with the highest priority, and evaluating them separately;

[0010] The target layer assessment: integrating several assessment results obtained from the criterion layer assessment to obtain the risk assessment of the entire construction project;

[0011] Based on the target layer assessment results, formulate construction risk control strategies and emergency plans.

[0012] In a preferred embodiment of the present invention, it further includes: constructing a risk question library, including the following steps:

[0013] Collect historical tunnel construction accident cases and accident analysis reports;

[0014] Based on the collected data, summarize the common factors that cause accidents and form a list of risk factors;

[0015] Classify each item in the risk factor list and identify specific risk issues, each risk issue being associated with at least one risk factor;

[0016] Use project management or database tools to build a structured risk issue library, which includes: descriptions of several risk issues, related risk factors, construction impacts and recommended control measures.

[0017] In a preferred embodiment of the present invention, the identification of risk factors in the solution-level evaluation includes:

[0018] Analyze the relevant data of the construction project to obtain project characteristics and tunnel construction conditions;

[0019] The project characteristics and tunnel construction conditions are matched with the risk factors in the risk problem library to find out the risk factors that are consistent with or similar to the current construction project conditions.

[0020] In a preferred embodiment of the present invention, in the scheme-level evaluation, the identified risk factors are prioritized, including:

[0021] Retrieve the frequency of occurrence and possible impact of these identified risk factors from the risk factor library, and conduct a severity assessment of the possible impact;

[0022] Draw a risk matrix based on the frequency and severity assessment of risk factors;

[0023] Based on the risk matrix drawn, determine the priority of each risk factor.

[0024] In a preferred embodiment of the present invention, in the scheme-level evaluation, the risk issues are determined by, specifically, sorting the risk factors according to their priorities and matching a risk issue for each risk factor from a risk factor library in turn.

[0025] In a preferred embodiment of the present invention, in the criterion layer evaluation, risk issues are evaluated separately, including:

[0026] According to the risk factors associated with the risk problem, the specific performance of these risk factors in the tunnel construction project is determined, and their performance is quantified and unified to obtain the performance score;

[0027] Conduct quantitative analysis on risk factors and calculate the impact weight of each risk factor on the risk assessment;

[0028] Calculate the risk level of each risk issue based on the performance score and impact weight of the risk factor Where n is the number of risk factors associated with a particular risk problem, A i is the performance score of the ith risk factor, w i is the impact weight of the ith risk factor.

[0029] In a preferred embodiment of the present invention, the influence weight of the risk factor is calculated using the hierarchical analysis method, including:

[0030] Construct a hierarchical model, including the target layer, problem layer and factor layer, where the target layer is defined as minimizing risk, the problem layer includes specific risk problems, and the factor layer includes risk factors related to these risk problems; let the target layer be G, and the problem layer be C1, C2, …, C n , the factor layers are A1, A2, …, A m ;

[0031] For each risk issue in the issue layer, construct a pairwise comparison matrix P,

[0032]

[0033] Among them, P ij Indicates risk factor F i Relative to risk factor F j the relative importance of k is the number of risk factors associated with a particular risk problem;

[0034] Calculate the eigenvector w of the pairwise comparison matrix P, which represents the weight of each risk factor relative to a specific risk problem; the weight vector w is obtained by normalizing each column of P and averaging; let w = (w1, w2, ..., w k ) T ,but

[0035]

[0036] Among them, w i Risk factor F i The weighting relative to a specific risk issue.

[0037] In a preferred embodiment of the present invention, in the target layer assessment, the assessment results of multiple risk issues are integrated, including:

[0038] Assess the severity of the impact or consequences that may be caused by the occurrence of the risk problem and obtain the risk loss;

[0039] Based on the risk level and risk loss of each risk issue, the construction risk assessment is calculated:

[0040]

[0041] Among them, Ri is the risk level of the i-th risk issue, and Qi is the risk loss of the i-th risk issue.

[0042] In a preferred embodiment of the present invention, the calculation of risk loss includes:

[0043] Determine a quantitative indicator for each type of consequence. Casualties are quantified as the estimated number of casualties B, cost increase is quantified as the estimated additional cost C, and construction delay is quantified as the estimated additional days D.

[0044] The severity of each type of consequence is assigned an equivalent value, which is determined based on historical data or expert experience, specifically:

[0045] Casualties: The equivalent value of each casualty is set to w B ;

[0046] Cost increase: The equivalent value of the additional cost per unit is set to w C ;

[0047] Construction delay: The equivalent value of each unit of extra days is set to w D ;

[0048] Calculate the risk loss Q caused by the occurrence of this risk problem = (B×w B )+(C×w C )+(D×w D ).

[0049] In a preferred embodiment of the present invention, it also includes: the hierarchical assessment structure combines real-time monitoring data and construction project-related changes to update the identification and ranking of risk factors, thereby updating the risk assessment.

[0050] The present invention solves the defects existing in the background technology and has the following beneficial effects:

[0051] (1) The present invention provides a method for risk assessment and control of underground tunnel construction for rail transit based on a hierarchical progressive algorithm. The method determines the risk factors involved through various data of the construction project, prioritizes the risk factors, and determines the risk issues one by one. The necessary risk factors are further determined based on the risk issues, and then different risk factors are integrated into a group. Finally, similar partial combinations are screened out, and the remaining risk issues are evaluated separately and integrated to obtain a risk assessment of the entire construction project. The method ensures the comprehensiveness and depth of the risk assessment, avoids repeated calculations of similar problems, reduces the amount of calculation, and improves the evaluation efficiency.

[0052] (2) In the present invention, the solution layer is the bottom layer of the hierarchical evaluation structure and is also the basic layer. The solution layer first identifies all possible risk factors involved in this construction project based on the collected construction project-related data, and then prioritizes these risk factors. According to the order of risk factors, a risk problem is determined with the risk factor as the core. After that, other risk factors necessary for the assessment are determined based on this risk problem. Therefore, each risk problem is associated with a core risk factor and other risk factors. Other risk factors may also be the core risk factors of other risk problems. By matching relevant risk factors in the risk problem library, omissions in manual judgment and screening can be avoided, which is more comprehensive.

[0053] (3) In the present invention, the criterion layer is performed after the solution layer is completed. The solution layer evaluates a number of risk issues and multiple risk factors associated with each risk issue. The criterion layer evaluates these risk issues and performs similarity analysis to evaluate the similarity between every two risk issues. In addition, a similarity threshold is set in the criterion layer. The threshold is set according to the accuracy requirements and computing power. Preferably, if there are two risk issues with a similarity of more than 90%, one of them will be screened out. The screening standard is based on the priority of the core risk factor when the risk issue is determined. Risk issues with high priority are retained. Through the above steps, it is possible to avoid the high overlap of multiple risk issues obtained by the solution layer evaluation, which in turn leads to a waste of computing power and speeds up the evaluation efficiency.

[0054] (4) In the present invention, dynamic risk factors are introduced in the risk factor identification and priority sorting. According to the real-time changes of these dynamic risk factors, the identified risk factors are dynamically introduced and removed, and the priority sorting of the risk factors also changes in real time, and then the risk issues also change dynamically. The present invention realizes dynamic assessment of the construction risks of underground tunnels of rail transit based on the risk factors fed back by facts and the dynamic changes of priority sorting. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work.

[0056] Figure 1 It is a flow chart of the risk assessment and control method for underground tunnel construction of rail transit based on a hierarchical progressive algorithm of the present invention. DETAILED DESCRIPTION

[0057] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0058] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein. Therefore, the protection scope of the present invention is not limited to the specific embodiments disclosed below.

[0059] Application Overview

[0060] The risk assessment methods for underground tunnel construction mainly include: empirical scoring method and dynamic weight assessment method.

[0061] In the experience scoring method, simple ones mainly rely on experience judgment or simple qualitative analysis. If a more accurate and authoritative evaluation is required, the participation of various experts in scoring is required. However, this method relies too much on the subjective judgment of experts and may have personal bias. If the dynamic changes of construction risks are also included in the evaluation, each evaluation will take a long time and be difficult to implement.

[0062] Although the existing assessment method that combines the dynamic weight assessment method with the prospect-regret theory can complete the basic tasks of risk assessment and provide results to a certain extent, this method cannot accurately capture some new problems that arise during construction. These randomly occurring risks do not appear in the initial assessment model, resulting in unpredictable deviations in the assessment results and poor accuracy and efficiency of risk assessment.

[0063] In response to the above-mentioned technical problems, the concept of this application is to propose a risk assessment and control method for rail transit underground tunnel construction based on a hierarchical progressive algorithm. It determines the risk factors involved through various data of the construction project, prioritizes the risk factors, and determines the risk issues one by one. It further determines the necessary risk factors based on the risk issues, and then integrates the different risk factors into a group. Finally, similar partial combinations are screened out, and the remaining risk issues are evaluated separately and integrated to obtain a risk assessment of the entire construction project. This method ensures the comprehensiveness and in-depth nature of the risk assessment, avoids repeated calculations of similar problems, reduces the amount of calculations, and improves the evaluation efficiency.

[0064] Exemplary Methods

[0065] like Figure 1 As shown, the present invention provides a method for risk assessment and control of underground tunnel construction in rail transit based on a hierarchical progressive algorithm, comprising the following steps:

[0066] S1. Obtain relevant data of the construction project and build a hierarchical evaluation structure, which includes: plan layer, criterion layer and target layer;

[0067] S2. Scheme-level assessment: Based on the relevant data of the construction project, several risk factors are divided, and the risk factors are prioritized, and the risk issues are determined one by one with them as the core factors;

[0068] Each risk issue is associated with several risk factors, including: a core factor and other risk factors;

[0069] S3, Criteria-level evaluation: Perform similarity analysis on several risk issues obtained from the solution-level evaluation, filter out risk issues with similarity exceeding the threshold, retain the risk issues with the highest priority, and evaluate them separately;

[0070] S4, Target level assessment: Integrate several assessment results obtained from the criterion level assessment to obtain the risk assessment of the entire construction project;

[0071] S5. Based on the target layer assessment results, formulate construction risk control strategies and emergency plans.

[0072] Project construction related data include: engineering design and tunnel construction conditions, etc. Specifically: engineering design refers to the tunnel starting point, tunnel end point, alignment, cross-sectional diameter, length and construction technology scheme, etc., which are related to tunnel design, while tunnel construction conditions are meteorological conditions, topography, stratum lithology, geological structure, hydrological conditions and tunnel surrounding rock level, etc., as well as more detailed exploration data, etc. This application first uses a hierarchical progressive algorithm to construct a hierarchical evaluation structure based on the above-mentioned project construction related data, including: scheme layer, criterion layer and target layer. Among them, the scheme layer is the determination of risk factors and risk issues, the criterion layer is the screening and evaluation of risk issues, and the target layer is the integrated criterion layer evaluation structure. This application divides the risk assessment of the entire construction project into scheme layer, criterion layer and target layer, and then conducts a progressive analysis layer by layer to obtain the risk assessment of the entire construction project. This application starts from the most fundamental factors that cause construction risks, analyzes and evaluates layer by layer, and constructs a systematic risk assessment framework to ensure that all types of risks that may occur during the entire construction cycle are fully considered, enhancing the comprehensiveness of risk assessment.

[0073] Below, each step will be described in detail.

[0074] In step S1, relevant data of the construction project is obtained, and a hierarchical evaluation structure is constructed. The hierarchical evaluation structure includes: a scheme layer, a criterion layer, and a target layer.

[0075] That is to say, first obtain relevant data of the construction project through design documents, technical specifications, engineering drawings, geological exploration, environmental assessment and historical construction reports, etc. Then, based on the collected data, identify all possible risk factors to build the solution layer, which is the bottom layer of the hierarchical assessment structure. The criterion layer is built and evaluated based on the evaluation results of the solution layer, and the target layer is the integration of the evaluation results of the criterion layer. The analysis and evaluation layer by layer ensures the systematic and comprehensive risk assessment.

[0076] Risk issues generally refer to the problems that may be encountered during the construction of underground rail transit tunnels, which may lead to casualties, increased costs and delays in construction. Further, risk issues include:

[0077] Geological risk: The uncertainty of geological conditions is one of the most unpredictable factors in tunnel construction. For example, encountering complex fault zones during tunnel construction will make it difficult for the shield machine to excavate, which will not only require multiple shutdowns, increase costs, but also seriously delay the construction period.

[0078] Safety risks: including but not limited to the safety of construction workers, equipment damage and environmental damage. According to incomplete statistics, casualties caused by safety accidents such as landslides, water seepage and explosions occur frequently during tunnel construction at home and abroad.

[0079] Technology implementation risk: involves the reliability of new technology application, equipment performance stability and feasibility of construction plan. With the widespread application of advanced construction technologies such as shield method and TBM (full-section rock tunnel boring machine), the lack of technical adaptability and innovation ability has become a key factor restricting the progress and quality of the project.

[0080] In step S1, the risk question library is also constructed, including the following steps:

[0081] S11. Obtain domestic and foreign tunnel construction accident cases through literature research, and analyze the frequency, type and cause of accidents in combination with accident analysis reports.

[0082] S12. Based on the analysis results of step S11, common factors that may cause accidents are summarized to form a risk factor list, such as the degree of rock fragmentation in the fault fracture zone, the degree of rock fissure development, the degree of equipment aging, and other risk factors, as well as a series of specific factors that may cause construction risks.

[0083] S13. Classify the items in the risk factor list and identify specific risk issues. Each risk issue is associated with at least one risk factor. Each risk issue needs to be described in detail with its background, potential impact and possible triggering conditions to provide a clear direction for subsequent risk assessment and control.

[0084] S14. Use project management software or database tools to build a structured risk database, which includes: risk factors, frequency of occurrence of risk factors, resulting risk issues, possible impacts and recommended control measures.

[0085] The present invention constructs a systematic risk problem library to optimize the risk assessment process and make it more structured. The solution breaks down the overall risk assessment framework of the construction project into multiple sub-items, namely risk problems, which can accurately identify and manage each risk node, while ensuring a comprehensive review of all types of risks that may emerge during the entire construction process. Through in-depth analysis of risk problems and their associated risk factors, the present invention can guide the formulation of more accurate and effective risk control measures and emergency response plans, thereby significantly reducing the probability of risk occurrence and its potential impact.

[0086] Furthermore, risk problems are divided into normal problems and random problems.

[0087] Among them, normal problems are risk problems that may occur in all tunnel construction projects. Normal problems are related to basic activities and management during the construction process and do not depend on specific geological conditions or project-specific factors. Normal problems include: equipment failure, operational errors and safety management loopholes. Normal problems are risk problems that must be selected in risk assessment.

[0088] Random problems are risk problems related to uncertain factors such as project-specific geological conditions, construction methods, and weather. Such as risk problems caused by uncertain factors such as geological conditions, peripheral displacement, vault settlement, internal displacement of surrounding rock, surrounding rock pressure, surface subsidence, groundwater, etc. Random problems are risk problems that are selectively selected based on the actual project construction situation.

[0089] In the present invention, risk issues are divided into normal issues and random issues, ensuring the comprehensiveness of risk assessment. Normal issues are selected as issues in risk assessment due to their universality, which helps to prioritize the allocation of resources and attention. Random issues are selectively evaluated according to the specific circumstances of the project, allowing the project team to flexibly adjust resource allocation according to actual conditions, ensuring that key risks are effectively managed.

[0090] In step S2, the scheme level is evaluated: based on the relevant data of the construction project, a number of risk factors are divided, the risk factors are prioritized, and the risk issues are determined one by one with them as the core factors; each risk issue is associated with a number of risk factors, including: a core factor and other risk factors.

[0091] In other words, the program layer is the bottom layer of the hierarchical assessment structure and also the basic layer. The program layer first identifies all possible risk factors involved in this construction project based on the collected data related to the construction project, and then prioritizes these risk factors. According to the order of risk factors, a risk problem is determined with the risk factor as the core. After that, other risk factors necessary for the assessment are determined based on this risk problem. Therefore, each risk problem is associated with a core risk factor and other risk factors, and other risk factors may also be the core risk factors of other risk problems.

[0092] In step S2, the identification of risk factors includes:

[0093] S21. Analyze the relevant data of the construction project to obtain the project characteristics and tunnel construction conditions. The project characteristics include: the starting and ending points of the tunnel, the alignment, the cross-section diameter, the length, the construction technology plan, etc.; the tunnel construction conditions include: meteorological conditions, topography, lithology, geological structure, hydrological conditions and tunnel surrounding rock level, etc.

[0094] S22. Match the project characteristics with the tunnel construction conditions and the risk factors in the risk problem database to find out the risk factors that are consistent with or similar to the current construction project conditions.

[0095] By matching relevant risk factors in the risk question library, we can avoid omissions in manual judgment and screening and be more comprehensive.

[0096] Further, the identified risk factors are prioritized, including:

[0097] S23. The frequency of occurrence and possible impact of the identified risk factors are retrieved from the risk factor library, and the severity of the possible impact is assessed. The possible impacts caused by these risk factors include three situations, namely casualties, cost increase and construction delay. The degree of severity is uniformly measured in terms of minor, moderate, severe and catastrophic.

[0098] S24. Draw a risk matrix based on the frequency of occurrence and severity assessment of risk factors; represent the frequency of occurrence and severity assessment in a two-dimensional matrix, in which the horizontal axis represents the frequency of occurrence and the vertical axis represents the severity assessment; divide the matrix into several areas based on the division of frequency of occurrence and severity assessment, and each area represents a different level of importance.

[0099] S25. Determine the priority of each risk factor based on the drawn risk matrix; specifically, in the risk matrix, the risk factors located in the upper right corner of the risk matrix (i.e., high frequency of occurrence and high severity assessment) have a higher priority, while the risk factors located in the lower left corner of the risk matrix (i.e., low frequency of occurrence and low severity assessment) have a lower priority, and the multiple risk factors divided are prioritized.

[0100] In step S2, the risk problem is determined by, in particular, sorting the risk factors according to their priorities and matching a risk problem from the risk factor library for each risk factor in turn. In this risk problem, the risk factor plays a leading role.

[0101] Furthermore, several necessary risk factors are associated with the risk problem. Specifically, several risk factors related to the risk problem are matched in the risk problem library to form a group.

[0102] That is to say, after determining the risk problem, in order to evaluate the risk problem, it is necessary to determine the necessary risk factors that can affect the risk problem. These risk factors must include the risk factor used to determine the risk problem (i.e. the core factor).

[0103] In construction projects, some risk factors are variable, such as dynamic risk factors such as meteorological conditions, technical implementation, and settlement caused by construction. If only the exploration or detection data before construction is used to evaluate the risk of the entire construction project, it is difficult to fully control and track construction risks. In the present invention, dynamic risk factors are introduced in risk factor identification and priority sorting. According to the real-time changes of these dynamic risk factors, the identified risk factors are dynamically introduced and removed, and the priority sorting of risk factors also changes in real time, and then the risk issues also change dynamically. The present invention realizes the dynamic evaluation of the construction risk of underground tunnels of rail transit based on the dynamic changes of risk factors and priority sorting based on factual feedback.

[0104] In step S3, the criterion layer evaluation: a similarity analysis is performed on a number of risk issues obtained from the solution layer evaluation, risk issues with similarities exceeding a threshold are screened out, and risk issues with the highest priority are retained and evaluated separately.

[0105] That is to say, the criteria layer is carried out after the solution layer is completed. The solution layer evaluates several risk issues and multiple risk factors associated with each risk issue. The criteria layer evaluates these risk issues and conducts similarity analysis to evaluate the similarity between every two risk issues. In addition, a similarity threshold is set in the criteria layer. The threshold is set according to the accuracy requirements and computing power. For two risk issues with a similarity of more than 90%, one of them must be screened out. The screening standard is based on the priority of the core risk factor when the risk issue is determined. The risk issues with high priority are retained, and the remaining multiple risk issues are screened out and evaluated separately.

[0106] In step S3, similarity analysis is performed on several risk issues obtained from the scheme level assessment, including:

[0107] S31. Assign a code to each risk factor identified at the scheme level. The code is a combination of numbers and letters, preferably three digits; the code may be X00, X01, X02, ..., X99, etc.

[0108] S32. Give each risk issue an equal priority based on the priority of the risk factor when determining the risk issue.

[0109] S33. Each risk issue and its associated risk factors are represented by a coding combination: priority-risk factor code; for example, 1-X01X02X18X22.

[0110] S34. Perform similarity matching on the coding combination of each risk issue, i.e., risk factor coding matching. Among multiple risk issues with a matching degree higher than 90%, retain the risk issue with the highest priority and screen out the remaining risk issues.

[0111] Through the above steps, it is possible to avoid the high overlap of multiple risk issues derived from the solution-level assessment, which would lead to a waste of computing power, and speed up the assessment efficiency.

[0112] In step S3, the risk issues are evaluated separately, including the following steps:

[0113] S35. Based on several risk factors associated with risk issues, determine the specific manifestations of these risk factors in tunnel construction projects, quantify and unify their manifestations, and obtain performance scores.

[0114] S36. Quantitatively analyze the risk factors and calculate the impact weight of each risk factor in the risk problem assessment; specifically, use the analytic hierarchy process to calculate the impact weight of the risk factors, including:

[0115] Construct a hierarchical model, including the goal layer, problem layer and factor layer, where the goal layer is defined as minimizing risk, the problem layer includes specific risk problems, and the factor layer includes risk factors related to these risk problems. Let the goal layer be G, the problem layer be C1, C2, …, C n , the factor layers are A1, A2, …, A m .

[0116] For each risk issue in the issue layer, construct a pairwise comparison matrix P,

[0117]

[0118] Among them, P ij Indicates risk factor F i Relative to risk factor F j the relative importance of k is the number of risk factors associated with a particular risk problem.

[0119] Calculate the eigenvector w of the pairwise comparison matrix P, which represents the weight of each risk factor relative to a specific risk problem. The weight vector w is obtained by normalizing each column of P and averaging it. Let w = (w1, w2, ..., w k ) T ,but where w i Risk factor F i The weighting relative to a specific risk issue.

[0120] Furthermore, it is necessary to calculate the consistency ratio CR of the pairwise comparison matrix P to test the consistency of the matrix. Among them, CI is the consistency index, λ max is the maximum eigenvalue of the pairwise comparison matrix P, k is the number of risk factors. RI is the random consistency index, whose value depends on the order k of the matrix and can be found in the standard table.

[0121] If CR < 0.1, the pairwise comparison matrix P is considered to have satisfactory consistency, otherwise the pairwise comparison matrix P needs to be readjusted.

[0122] S37. Calculate the risk level of each risk issue based on the performance score and impact weight of the risk factor; specifically, the total risk value of the risk issue Where n is the number of risk factors associated with a particular risk problem, A iis the performance score of the ith risk factor, w i is the impact weight of the ith risk factor. The total risk value R of the risk problem can be used to represent the risk level of the risk problem.

[0123] In one embodiment, the level of the risk problem is determined according to the total risk value R and with reference to a predefined risk level standard.

[0124] Through the above steps, the risk level of each risk issue can be systematically calculated, and effective risk control strategies and emergency plans can be formulated accordingly.

[0125] In step S4, target layer evaluation: integrating several evaluation results obtained from the criterion layer evaluation to obtain the risk assessment of the entire construction project.

[0126] In step S4, the assessment results of multiple risk issues are integrated, including the following steps:

[0127] S41. Evaluate the severity of the impact or consequences that may be caused by the occurrence of risk problems and obtain risk losses. The risk loss assessment uses the consequence equivalent estimation method to quantify and unify the severity of the consequences such as casualties, cost increases, and construction delays in risk problem events, including:

[0128] S411. Determine a quantitative indicator for each type of consequence, such as casualties can be quantified as the expected number of casualties B, cost increase can be quantified as the expected additional cost C, and construction delay can be quantified as the expected additional days D;

[0129] S412. Assign an equivalent value to the severity of each type of consequence, which is determined based on historical data or expert experience, such as:

[0130] Casualties: The equivalent value of each casualty can be set to w B ;

[0131] Cost increase: The equivalent value of the additional cost per unit can be set to w C ;

[0132] Construction delay: The equivalent value of each unit of extra days can be set to w D ;

[0133] S413. Calculate the risk loss Q caused by the occurrence of the risk problem = (B × w B )+(C×w C )+(D×w D ).

[0134] S42. Calculate the construction risk assessment based on the risk level and risk loss of each risk issue Among them, Ri is the risk level of the ith risk issue, and Qi is the risk loss of the ith risk issue.

[0135] Furthermore, according to the value of the construction risk assessment S and referring to the predefined risk level standard, the construction risk assessment level is determined, such as being divided into five levels, as shown in Table 1:

[0136] Table 1. Risk level classification

[0137] Risk Level Level Range Acceptance criteria Level 1 0≤S<20h Ignoreable Level 2 20h≤S<40h Permissible Level 3 40h≤S<60h Acceptable Level 4 60h≤S<80h Unacceptable Level 5 80h≤S<100h Refuse to accept

[0138] The h in Table 2 is the grade range parameter, which is set according to the value of the construction risk assessment S.

[0139] Through the above steps, the present application proposes a risk assessment and control method for rail transit underground tunnel construction based on a hierarchical progressive algorithm, which determines the risk factors involved through various data of the construction project, prioritizes the risk factors, and determines the risk issues one by one, and further determines the necessary risk factors based on the risk issues, and then integrates the different risk factors into a group, and finally screens out similar partial combinations, and separately evaluates and integrates the remaining risk issues to obtain a risk assessment for the entire construction project. This method ensures the comprehensiveness and depth of the risk assessment, avoids repeated calculations of similar problems, reduces the amount of calculations, and improves the evaluation efficiency.

[0140] In step S5, the risk control method is specifically as follows: pay attention to the construction risk level calculated in step S4 that reaches level 2 or above, identify the current risk problem, the risk level and risk loss of the risk problem from the risk problem library, and sort the risk problems according to the priority of each risk problem determined in step S2, and identify the key risk factors that have the greatest impact on the project or the highest probability of occurrence. Then, for each key risk factor, query the corresponding control measures in the risk problem library, summarize, design and implement targeted risk control strategies, and further formulate emergency plans.

[0141] In one embodiment, after construction, changes occur in geology, meteorology, technical implementation, engineering design, etc. Based on the relevant data of the construction project after the changes, several risk factors are re-identified, and based on the re-identified risk factors, evaluations are performed in sequence at the solution level, criterion level, and target level.

[0142] Furthermore, the hierarchical assessment structure combines real-time monitoring data, such as settlement monitoring data, to update the risk assessment by identifying and ranking risk factors. This approach can capture the dynamic changes of risks during the construction process and provide real-time decision support.

[0143] Safety risks, geological environment, and changes in technical implementation during the construction process lead to increases and changes in technical problems and risk factors. The present invention reflects these changes in risk problems or risk factors, and realizes dynamic risk assessment of the entire project construction. It can provide managers with real-time decision support and help the project team respond to sudden risk events during the construction process in a timely manner.

[0144] The above is based on the ideal embodiment of the present invention. Through the above description, relevant personnel can make various changes and modifications without departing from the technical concept of the present invention. The technical scope of the present invention is not limited to the content in the specification, and the technical scope must be determined according to the scope of the claims.

Claims

1. A risk assessment and control method for underground tunnel construction of rail transit based on a hierarchical progressive algorithm, characterized in that: The following steps are involved: Acquire relevant data of the construction project and construct a hierarchical evaluation structure, wherein the hierarchical evaluation structure includes: a scheme layer, a criterion layer and a target layer; The scheme-level assessment: based on the relevant data of the construction project, identify several risk factors, prioritize the several risk factors, and use them as core factors to determine risk issues one by one; each risk issue is associated with several risk factors, including a core factor and other risk factors; The criterion-level evaluation: performing similarity analysis on the risk issues obtained from the solution-level evaluation, filtering out the risk issues with similarities exceeding a threshold, retaining the risk issues with the highest priority, and evaluating them separately; The target layer assessment: integrating several assessment results obtained from the criterion layer assessment to obtain the risk assessment of the entire construction project; Based on the target layer assessment results, formulate construction risk control strategies and emergency plans.

2. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 1 is characterized in that: Also includes: Building a risk question library includes the following steps: Collect historical tunnel construction accident cases and accident analysis reports; Based on the collected data, summarize the common factors that cause accidents and form a list of risk factors; Classify each item in the risk factor list and identify specific risk issues, each risk issue being associated with at least one risk factor; Use project management or database tools to build a structured risk issue library, which includes: descriptions of several risk issues, related risk factors, construction impacts and recommended control measures.

3. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 2 is characterized by: In the scheme-level assessment, the identification of risk factors includes: Analyze the relevant data of the construction project to obtain project characteristics and tunnel construction conditions; The project characteristics and tunnel construction conditions are matched with the risk factors in the risk problem library to find out the risk factors that are consistent with or similar to the current construction project conditions.

4. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 2 is characterized in that: In the scenario-level assessment, the identified risk factors are prioritized, including: Retrieve the frequency of occurrence and possible impact of these identified risk factors from the risk factor library, and conduct a severity assessment of the possible impact; Draw a risk matrix based on the frequency and severity assessment of risk factors; Based on the risk matrix drawn, determine the priority of each risk factor.

5. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 2 is characterized by: In the scheme-level evaluation, the risk issues are determined by, specifically, sorting the risk factors according to their priorities and matching a risk issue from the risk factor library for each risk factor in turn.

6. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 1 is characterized by: In the criteria level assessment, risk issues are assessed separately, including: According to the risk factors associated with the risk problem, the specific performance of these risk factors in the tunnel construction project is determined, and their performance is quantified and unified to obtain the performance score; Conduct quantitative analysis on risk factors and calculate the impact weight of each risk factor on the risk assessment; Calculate the risk level of each risk issue based on the performance score and impact weight of the risk factor Where n is the number of risk factors associated with a particular risk problem, A i is the performance score of the ith risk factor, w i is the impact weight of the ith risk factor.

7. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 6 is characterized by: The impact weights of risk factors are calculated using the analytic hierarchy process, including: Construct a hierarchical model, including the target layer, problem layer and factor layer, where the target layer is defined as minimizing risk, the problem layer includes specific risk problems, and the factor layer includes risk factors related to these risk problems; let the target layer be G, and the problem layer be C1, C2, …, C n , the factor layers are A1, A2, …, A m ; For each risk issue in the issue layer, construct a pairwise comparison matrix P, Among them, P ij Indicates risk factor F i Relative to risk factor F j the relative importance of k is the number of risk factors associated with a particular risk problem; Calculate the eigenvector w of the pairwise comparison matrix P, which represents the weight of each risk factor relative to a specific risk problem; the weight vector w is obtained by normalizing each column of P and averaging; let w = (w1, w2, ..., w k ) T ,but Among them, w i Risk factor F i The weighting relative to a specific risk issue.

8. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 6 is characterized by: In the target layer assessment, the assessment results of multiple risk issues are integrated, including: Assess the severity of the impact or consequences that may be caused by the occurrence of the risk problem and obtain the risk loss; Based on the risk level and risk loss of each risk issue, the construction risk assessment is calculated: Among them, Ri is the risk level of the i-th risk issue, and Qi is the risk loss of the i-th risk issue.

9. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 8, characterized in that: The calculation of the risk loss includes: Determine a quantitative indicator for each type of consequence. Casualties are quantified as the estimated number of casualties B, cost increase is quantified as the estimated additional cost C, and construction delay is quantified as the estimated additional days D. The severity of each type of consequence is assigned an equivalent value, which is determined based on historical data or expert experience, specifically: Casualties: The equivalent value of each casualty is set to w B ; Cost increase: The equivalent value of the additional cost per unit is set to w C ; Construction delay: The equivalent value of each unit of extra days is set to w D ; Calculate the risk loss Q caused by the occurrence of this risk problem = (B×w B )+(C×w C )+(D×w D ).

10. The method for risk assessment and control of underground tunnel construction for rail transit based on hierarchical progressive algorithm according to claim 1, characterized in that: Also includes: The hierarchical assessment structure updates the risk assessment by combining real-time monitoring data and construction project related changes to update the identification and ranking of risk factors.

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