A risk assessment method for tunnel civil construction facilities during operation under long-term rainfall conditions

Abstract

The present invention relates to the technical field of safety assessment of tunnel earth construction facilities, and specifically to a risk assessment method for tunnel earth construction facilities in operation period under long-term rainfall conditions. The assessment method uses the safety risk level of tunnel earth construction facilities under long-term rainfall conditions as an assessment standard, wherein the safety risk level is based on a comprehensive evaluation of annual precipitation intensity, the degree of influence of precipitation on tunnel earth construction facilities, and the sensitivity of tunnel earth construction facilities to water loss. The annual precipitation intensity is the annual precipitation in the tunnel site area. Compared with the prior art, the beneficial effect of the present invention is that the method aims to comprehensively consider the characteristics of atmospheric precipitation, geological rock formations, and tunnel earth construction facilities, thereby realizing the assessment of the safety and reliability risks of tunnel earth construction facilities under the action of groundwater from the perspective of the entire life cycle.

Description

Technical Field

[0001] The present invention relates to the technical field of safety assessment of tunnel earth construction facilities, and in particular to a risk assessment method for tunnel earth construction facilities during operation under long-term rainfall conditions. Background Art

[0002] In the process of safety risk assessment of tunnel engineering facilities, rainfall is an important factor affecting the safety and reliability of tunnel earthwork facilities. Tunnel earthwork facilities are under the influence of rainfall infiltration for a long time, and their safety and reliability are reduced, especially in areas with developed geological structures and poor conditions of tunnel earthwork facilities. The existing safety risk assessment methods for tunnel earthwork facilities are mostly focused on the changing laws of tunnel surrounding rock stability under extreme weather conditions; while there are few studies on the influence of long-term rainfall infiltration on tunnels throughout their life cycle, and it is difficult to implement a safe and reliable risk assessment method for tunnel earthwork facilities under multi-dimensional groundwater effects.

[0003] Long-term rainfall climate conditions are different from extreme weather disasters. Extreme weather disasters are extremely heavy rainfall in a short period of time. Under long-term rainfall conditions, tunnel earth construction facilities are not faced with short-term strong support. It is necessary to combine all aspects of tunnel earth construction facilities to meet the requirements of long rainfall to improve the safety of tunnel earth construction facilities. However, existing construction technologies often only involve tunnel protection under extreme rainfall weather conditions, and fail to make comprehensive judgments on all aspects of the tunnel to adapt the tunnel to long rainfall conditions and meet safety requirements.

[0004] Therefore, developing a risk assessment method for tunnel civil construction facilities in the operation period under long-term rainfall conditions not only has urgent research value, but also has good economic benefits and industrial application potential, which is the driving force and basis for the completion of the present invention. Summary of the invention

[0005] In order to overcome the above-mentioned defects of the prior art, the inventors conducted in-depth research and completed the present invention after paying a lot of creative work.

[0006] Specifically, the technical problem to be solved by the present invention is to provide a risk assessment method for tunnel earth construction facilities during operation under long-term rainfall conditions, so as to solve the problem that the existing technology lacks analysis on the safety of tunnel earth construction facilities under long rainfall conditions.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A risk assessment method for tunnel earth construction facilities in operation period under long-term rainfall conditions, wherein the assessment method uses the safety risk level of tunnel earth construction facilities under long-term rainfall conditions as an assessment standard, wherein the safety risk level is based on a comprehensive evaluation of annual precipitation intensity, the degree of influence of precipitation on tunnel earth construction facilities, and the sensitivity of tunnel earth construction facilities to water loss, wherein the annual precipitation intensity is the annual precipitation in the tunnel site area, and the degree of influence of precipitation on tunnel earth construction facilities and the sensitivity of tunnel earth construction facilities to water loss are assessed as follows:

[0009] (1) Analyze the relationship between the stratum permeability characteristics and the tunnel alignment, and based on this relationship, combine the karst development status of the stratum and the development of geological structures to obtain the tunnel stratum environment type;

[0010] (2) Obtain the degree of influence of precipitation on tunnel earth construction facilities based on the tunnel stratum environment type and annual precipitation intensity;

[0011] (3) Screen the risk factors that affect the sensitivity of tunnel water damage and establish risk factor judgment criteria;

[0012] (4) Obtain the water loss type of tunnel earthwork construction, determine the relationship between tunnel earthwork construction and risk factors based on the water loss type, comprehensively analyze the water loss sensitivity risk factors of each tunnel earthwork construction, and obtain the water loss sensitivity level of the tunnel earthwork construction;

[0013] (5) Obtain the safety risk level of tunnel civil construction facilities based on the impact of precipitation on tunnel civil construction facilities and the water damage sensitivity level of civil construction facilities;

[0014] (6) Develop a treatment plan based on the safety risk level of the tunnel civil engineering facilities and the type of water damage in the tunnel civil engineering facilities.

[0015] In the present invention, as an improvement, obtaining the tunnel stratum environment type includes:

[0016] Obtain the water permeability characteristics of the stratum where the tunnel line is located, wherein the stratum is divided into a permeable layer, an impermeable layer and a water-bearing interlayer based on the water permeability characteristics;

[0017] The basis for judging the type of stratum environment is obtained based on the water permeability characteristics of the stratum where the tunnel line is located. The basis for judging includes the development of geological structures and the karst development state of the stratum. The specific basis for judging is as follows:

[0018] When the tunnel line is located in the aquiclude, the stratum environment is classified according to the development of geological structures;

[0019] When the tunnel line is located in the permeable layer and the water-bearing interlayer, the formation environment is classified according to the karst development state of the formation and the development of the geological structure;

[0020] Comprehensively analyze the development of different geological structures and the karst development status of the strata to obtain the tunnel stratum environment type.

[0021] In the present invention, as an improvement, the tunnel line is located in the aquiclude, and the stratum environment types are classified according to the development of geological structures as follows:

[0022] The geological structure is developed as syncline or other, and the stratigraphic environment type is general;

[0023] The geological structure is developed into a fault fracture zone, and the stratigraphic environment type is poor;

[0024] The geological structure is developed into a fault fracture zone plus anticline, and the stratigraphic environment type is poor.

[0025] In the present invention, as an improvement, the karst development state of the formation includes weak development, medium development and strong development;

[0026] The tunnel line is located in the permeable layer. According to the karst development state of the stratum and the development of geological structure, the stratum environment types are classified as follows:

[0027] Under the condition of weak karst development in the local formation, the other, fault fracture zone and syncline in the geological structure development correspond to the formation environment types of general, poor and poor respectively;

[0028] When the stratum karst is moderately developed, the other, fault fracture zone or syncline, and fault fracture zone plus syncline in the geological structure development correspond to the stratum environment types of poor, poor, and poor, respectively;

[0029] When the stratum karst is strongly developed, the geological structure development is other, fault fracture zone or syncline, and the corresponding stratum environment types are poor and extremely poor respectively;

[0030] The tunnel line is located in the water-bearing interlayer. According to the karst development state of the strata and the development of geological structures, the stratum environment types are classified as follows:

[0031] Under the condition of weak karst development in the local formation, the other, fault fracture zone or syncline, and fault fracture zone plus syncline in the geological structure development correspond to the formation environment types of general, poor, and poor respectively;

[0032] When the karst in the local formation is moderately developed or strongly developed, the geological structure development is other, fault fracture zone or syncline, fault fracture zone plus syncline, and the corresponding stratigraphic environment types are poor, poor, and extremely poor, respectively.

[0033] In the present invention, as an improvement, the impact degree of precipitation on tunnel earth construction facilities is based on the four-level classification of tunnel stratum environment types combined with the annual precipitation intensity classification of the tunnel site area, wherein the annual precipitation intensity of the tunnel site area includes four intensities: extremely strong, relatively strong, medium and relatively weak. The stratum environment type is used as the first judgment basis, and the annual precipitation intensity of the tunnel site area is used as the second judgment basis. The two are combined to obtain the impact degree of precipitation on tunnel earth construction facilities, and the impact degree specifically includes four levels: extremely serious, relatively heavy, medium and light.

[0034] In the present invention, as an improvement, the risk factors affecting the sensitivity of tunnel water damage are screened including:

[0035] Analyze the characteristics of water damage in highway tunnels during operation and obtain the types of water damage in tunnel earthwork facilities;

[0036] Select water damage sensitivity risk factors and classify the conditions of water damage sensitivity risk factors;

[0037] Based on the water loss types of tunnel civil construction facilities, the classification status of various water loss sensitivity factors is comprehensively considered to obtain the water loss sensitivity level of each water loss type;

[0038] The types of water loss in tunnel civil construction facilities include lining structure, lining joints, pavement structure and maintenance passage.

[0039] In the present invention, as an improvement, water damage sensitivity risk factors include tunnel service life, lining structure diseases and defects, tunnel drainage, tunnel structure reinforcement, lining joint waterproofing structure condition, pavement structure condition and tunnel maintenance channel crack damage condition.

[0040] In the present invention, as an improvement, the classification status of various water damage sensitivity factors is comprehensively considered, and the water damage sensitivity level of each water damage type is obtained, including:

[0041] The water damage sensitivity level of the lining structure is obtained by combining the reinforcement condition of the lining structure, the disease and defect condition of the tunnel lining structure and the service life of the tunnel when the tunnel drainage state is obtained;

[0042] The lining joint water damage sensitivity level is obtained by the lining joint waterproof structure condition and the tunnel service time under the tunnel drainage condition;

[0043] The water damage sensitivity level of the pavement structure is obtained by combining the pavement structure condition with the tunnel service time when the tunnel drainage state is obtained;

[0044] The water damage sensitivity levels include weak vulnerability, medium vulnerability and strong vulnerability.

[0045] In the present invention, as an improvement, the grading conditions of tunnel service time include less than 10 years, 10-20 years and more than 20 years;

[0046] Tunnel drainage status includes unobstructed and blocked;

[0047] The reinforcement conditions of tunnel lining structures include plain concrete structure and reinforced concrete structure;

[0048] The diseases and defects of tunnel lining structure are divided into two conditions: at least one of the three defects of cracks, insufficient thickness and back voids exists, and none of the three defects exists.

[0049] In the present invention, as an improvement, the safety risk levels of tunnel civil construction facilities are as follows:

[0050]

[0051] Among them, the safety risks of tunnel civil construction facilities are divided into four levels: low risk, medium risk, high risk and extremely high risk.

[0052] Compared with the prior art, the present invention has the following beneficial effects:

[0053] (1) This method aims to comprehensively consider the characteristics of atmospheric precipitation, geological rock formations, and tunnel soil construction facilities, and thus evaluate the safety and reliability risks of tunnel soil construction facilities under the influence of groundwater from a full life cycle perspective.

[0054] (2) The present invention obtains the degree of influence of precipitation on the tunnel from the type of stratum environment where the tunnel line is located, and obtains the risk level of the tunnel earth construction facilities in combination with the water loss characteristics of the tunnel itself, thereby deriving the impact of the tunnel earth construction facilities under long rainfall conditions, providing a basis for strengthening or monitoring the structure of the tunnel earth construction facilities, and ensuring the safety of tunnel operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0056] Figure 1 Schematic diagram of the evaluation method of the present invention. DETAILED DESCRIPTION

[0057] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0058] A risk assessment method for tunnel earthwork facilities in operation under long-term rainfall conditions. This method comprehensively analyzes annual precipitation intensity, stratum environment type, and tunnel earthwork facilities water loss sensitivity, and specifically includes the following steps:

[0059] (1) Identification of the type of environment in which atmospheric precipitation infiltrates into the strata;

[0060] (2) Determination of sensitivity of tunnel earthwork to water damage;

[0061] (3) Obtain the risk level of tunnel earthwork facilities by combining the type of stratum environment and the sensitivity of tunnel earthwork facilities to water damage;

[0062] (4) Develop a treatment plan based on the risk level of tunnel earth construction facilities and the sensitivity of tunnel earth construction facilities to water damage to ensure the safety of tunnel earth construction facilities.

[0063] Among them, the identification of the type of atmospheric precipitation infiltration into the stratum environment is based on the annual precipitation intensity and the degree of influence of precipitation on the tunnel earthwork facilities. The annual precipitation intensity is the annual precipitation in the tunnel site area, including four intensity levels: extremely strong, relatively strong, medium and relatively weak, as follows:

[0064] When the total annual precipitation is greater than 800 mm, the annual precipitation intensity in the tunnel site is extremely strong;

[0065] When the total annual precipitation is between 600-800 mm and the single maximum precipitation is greater than 75 mm, the annual precipitation intensity in the tunnel site area is classified as extremely strong; otherwise, the annual precipitation intensity in the tunnel site area is classified as relatively strong.

[0066] When the total annual precipitation is between 400-600 mm and the single maximum precipitation is greater than 50 mm, the annual precipitation intensity in the tunnel site area is classified as extremely strong; otherwise, the annual precipitation intensity in the tunnel site area is classified as relatively strong.

[0067] When the total annual precipitation is less than 400 mm and the maximum single precipitation is greater than 25 mm, the annual precipitation intensity in the tunnel site is classified as medium; otherwise, the annual precipitation intensity in the tunnel site is classified as weak.

[0068] The impact of precipitation on tunnel soil construction facilities and the water loss sensitivity assessment method of tunnel soil construction facilities are as follows:

[0069] (1) Analyze the relationship between the stratum permeability characteristics and the tunnel alignment, and based on this relationship, combine the karst development status of the stratum and the development of geological structures to obtain the tunnel stratum environment type;

[0070] (2) Obtain the degree of influence of precipitation on tunnel earth construction facilities based on the tunnel stratum environment type and annual precipitation intensity;

[0071] (3) Screen the risk factors that affect the sensitivity of tunnel water damage and establish risk factor judgment criteria;

[0072] (4) Obtain the water loss type of tunnel earthwork construction, determine the relationship between tunnel earthwork construction and risk factors based on the water loss type, comprehensively analyze the water loss sensitivity risk factors of each tunnel earthwork construction, and obtain the water loss sensitivity level of the tunnel earthwork construction;

[0073] (5) The safety risk level of tunnel civil construction facilities is obtained based on the impact of precipitation on tunnel civil construction facilities and the water damage sensitivity level of civil construction facilities.

[0074] Based on the permeability characteristics, the strata are divided into impermeable layers, permeable layers and water-bearing interlayers. When the tunnel line is located in the water-bearing interlayer, the impact on the tunnel is greatest under heavy rainfall conditions. Therefore, it is necessary to analyze the stratum environment type based on the relationship between the tunnel line and the permeability characteristics of the strata.

[0075] When the stratum where the tunnel line is located is an impermeable layer, rainfall cannot directly act on the tunnel, and the impact of rainfall on the tunnel is small. It is only necessary to classify the stratum environment according to the development of geological structure;

[0076] When the tunnel line is located in the permeable layer and the water-bearing interlayer, under heavy rainfall conditions, the karst development state of the stratum will affect the tunnel soil construction facilities. The stratum environment needs to be classified according to the karst development state of the stratum and combined with the development of geological structures.

[0077] When the tunnel line is located in the stratum aquiclude, the stratum environment type is classified according to the development of geological structure as follows:

[0078] Geological structure development Syncline / Other Fault zone Fault fracture zone + syncline Tunnel ground environment type generally Poor Difference

[0079] When the tunnel line is located in the stratum aquiclude, the impact of heavy rainfall on the tunnel structure is relatively weak. Therefore, the stratum environment type is classified according to geological defects.

[0080] The karst development status of the strata includes weak development, medium development and strong development. The tunnel line is located in the permeable layer. According to the karst development status of the strata and the development of geological structures, the stratum environment types are classified as follows:

[0081]

[0082] When the tunnel line is located in a permeable layer, the ground seepage caused by heavy rainfall will not accumulate in the tunnel structure, and the impact on the tunnel structure is limited. Based on this influence relationship, the karst development status and geological structure development conditions are obtained to determine the tunnel stratum environment type.

[0083] The tunnel line is located in the water-bearing interlayer. According to the karst development state of the strata and the development of geological structures, the stratum environment types are classified as follows:

[0084]

[0085] When the tunnel line is located in the aquiferous interlayer, the stratum seepage brought by heavy rainfall will enter the stratum and gather at the tunnel structure. Therefore, it has a greater impact on the tunnel structure. Based on this influence relationship, the stratum environment type is obtained in combination with the karst development state of the stratum and the geological structure development.

[0086] The influence of precipitation on tunnel construction facilities is obtained based on the type of stratum environment and annual precipitation intensity as follows:

[0087]

[0088]

[0089] It can be seen from the above table that the impact of precipitation on tunnel earth construction facilities includes four levels: mild, moderate, severe and extremely severe.

[0090] After obtaining the impact of precipitation on tunnel earthwork facilities, it is necessary to determine the water damage sensitivity of tunnel earthwork facilities. First, screen the risk factors that affect tunnel water damage sensitivity, including:

[0091] Analyze the characteristics of water damage in highway tunnels during operation. By analyzing the characteristics of water damage in highways during previous operation periods, it is found that most of the water damage in highway tunnels during operation occurs at the connections and cracks of the tunnel structure. Therefore, it is necessary to judge the structural integrity and joint structure conditions to obtain the type of water damage in the tunnel earthwork construction.

[0092] Select the sensitive risk factors that affect tunnel water loss, and classify the conditions of water loss sensitive risk factors according to the different degrees of influence under different conditions of risk factors;

[0093] Based on the water loss types of tunnel civil construction facilities, the classification status of various water loss sensitivity factors is comprehensively considered to obtain the water loss sensitivity level of each water loss type;

[0094] Tunnel earth construction water loss is mainly divided into four categories: lining structure leakage and damage, lining joints water gushing, pavement water gushing and maintenance road water gushing. Therefore, tunnel earth construction water loss types include lining structure, lining joints, pavement structure and maintenance passage.

[0095] Water damage sensitivity risk factors include tunnel service life, lining structure diseases and defects, tunnel drainage, tunnel structure reinforcement, lining joint waterproofing structure condition, pavement structure condition and crack damage condition of tunnel maintenance channel.

[0096] In terms of tunnel service time, tunnels with less than 10 years are marked as G, tunnels with 10-20 years are marked as H, and tunnels with more than 20 years are marked as K.

[0097] Among the tunnel lining structural defects and defects, if there are any of the following three conditions, namely cracks, insufficient thickness, and back voids, it is marked as W; if there is no condition of any of the three conditions, it is marked as V;

[0098] Tunnel drainage patency status includes unobstructed and blocked;

[0099] The reinforcement conditions of tunnel lining structures include plain concrete structures and reinforced concrete structures;

[0100] The waterproof structural conditions of tunnel lining joints include structural integrity and structural failure;

[0101] The deterioration of the tunnel cable trench includes intactness and damage;

[0102] The tunnel pavement structural conditions include intact and raised cracked.

[0103] Taking into account the classification of various water damage sensitivity factors, the water damage sensitivity level of each water damage type is obtained, including:

[0104] Classification of water damage sensitivity levels of lining structures:

[0105]

[0106] Classification of water damage sensitivity levels of lining joints:

[0107]

[0108] Classification of water damage sensitivity levels of pavement structures:

[0109]

[0110] Classification of water damage sensitivity levels of maintenance channels:

[0111]

[0112] When a tunnel has the above water damage types and has different water damage sensitivity levels, the most serious water damage sensitivity level shall be used as the water damage sensitivity level of the tunnel civil construction facilities, and corresponding treatment measures shall be formulated for this water damage type.

[0113] After obtaining the water damage sensitivity level of tunnel earthwork facilities, the safety risk level of tunnel earthwork facilities is obtained by combining the impact of precipitation on tunnel earthwork facilities, as shown in the following table:

[0114]

[0115] Among them, the safety risks of tunnel civil construction facilities are divided into four levels: low risk, medium risk, high risk and extremely high risk. Treatment measures are formulated based on the above civil construction facility risk levels and the most serious water damage types.

[0116] Embodiment 1:

[0117] A tunnel completed and put into operation in 2021 was designed and constructed using the New Austrian Tunneling Method. The tunnel site is an erosional low mountain and hilly landform area. The bedrock is directly exposed at the top of the foundation in most areas, and interlayer joints and fissures are developed. No large-scale karst development phenomenon or large caves were found during the survey, and only local dissolution grooves and small dissolution holes were found. The tunnel site is a sedimentary rock fissure water-bearing area, and the stable groundwater level is lower than the design elevation of the tunnel. According to statistics, the annual precipitation in the tunnel site was 644 mm last year, and the rainfall reached 701 mm on a certain day in summer due to extreme weather.

[0118] (1) Obtaining the type of stratum environment where the tunnel line is located

[0119] Through geological survey, it is known that the tunnel line is located in the water-bearing interlayer. The stratigraphic environment type is classified according to the karst development state of the stratigraphic layer and the development of the geological structure. The stratigraphic karst is weakly developed and there is a fault fracture zone. By comparison, it can be seen that the stratigraphic environment type is poor.

[0120] (2) Impact of precipitation on tunnel construction facilities

[0121] It is known that the total annual precipitation in the tunnel site is 644 mm, between 600-800 mm, and the maximum single precipitation is 87 mm, which is greater than 75 mm. The annual precipitation intensity is extremely strong. Judging from the geological environment type and annual precipitation intensity, it can be seen that long-term precipitation has a serious impact on the tunnel soil construction facilities.

[0122] (3) Water damage sensitivity level of tunnel earthwork facilities

[0123] Through the tunnel operation monitoring record form, the tunnel obtained information on the current technical condition of the tunnel as follows: there are cracks and water leakage in the tunnel lining, the inspection road cover is missing and has not been repaired in time, the weeds in the drainage facilities have not been cleared in time, and there are fallen objects on the road surface.

[0124] The tunnel has been in service for three years. Cracks and water leakage have appeared in the reinforced concrete lining. The drainage ditch was not cleaned up in time, resulting in blockage of tunnel drainage. No other defects were found. Therefore, the main types of water damage in the tunnel's civil engineering construction are water leakage and defect damage in the lining structure.

[0125] Based on the above conditions, it can be concluded that the tunnel earthwork facility has a medium vulnerability to water damage.

[0126] (4) Risk assessment of safety and reliability of tunnel civil construction facilities

[0127] The earthwork facilities of the tunnel are seriously affected by long-term precipitation, and the water damage sensitivity of the earthwork facilities of the tunnel is medium. According to the present invention, the safety and reliability risk of the earthwork facilities of the tunnel is determined to be high, and the water damage of the tunnel structure is relatively serious. It is necessary to take timely measures to repair the cracks in the tunnel lining, inspect the tunnel drainage pipes, and clean up the debris in the drainage ditch in time to ensure the smooth flow of the drainage channel, so as to avoid the impact of leakage water in the stratum on the tunnel.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for risk assessment of earthwork facilities in tunnels during operation under long-term rainfall conditions, characterized in that: The evaluation method uses the safety risk level of tunnel earth construction facilities under long-term rainfall conditions as the evaluation standard, wherein the safety risk level is based on a comprehensive evaluation of the annual precipitation intensity, the degree of influence of precipitation on tunnel earth construction facilities, and the sensitivity of tunnel earth construction facilities to water loss. The annual precipitation intensity is the annual precipitation in the tunnel site area. The degree of influence of precipitation on tunnel earth construction facilities and the sensitivity of tunnel earth construction facilities to water loss are evaluated as follows: (1) Analyze the relationship between the stratum permeability characteristics and the tunnel alignment, and based on this relationship, combine the karst development status of the stratum and the development of geological structures to obtain the tunnel stratum environment type; (2) Obtain the degree of influence of precipitation on tunnel earth construction facilities based on the tunnel stratum environment type and annual precipitation intensity; (3) Screen the risk factors that affect the sensitivity of tunnel water damage and establish risk factor judgment criteria; (4) Obtain the water loss type of tunnel earthwork construction, determine the relationship between tunnel earthwork construction and risk factors based on the water loss type, comprehensively analyze the water loss sensitivity risk factors of each tunnel earthwork construction, and obtain the water loss sensitivity level of the tunnel earthwork construction; (5) Obtain the safety risk level of tunnel civil construction facilities based on the impact of precipitation on tunnel civil construction facilities and the water damage sensitivity level of civil construction facilities; (6) Formulate a treatment plan based on the safety risk level of the tunnel civil construction facilities and the type of water damage in the tunnel civil construction facilities; Screening of risk factors affecting tunnel water damage susceptibility includes: Analyze the characteristics of water damage in highway tunnels during operation and obtain the types of water damage in tunnel earthwork facilities; Select water damage sensitivity risk factors and classify the conditions of water damage sensitivity risk factors; Based on the water loss types of tunnel civil construction facilities, the classification status of various water loss sensitivity factors is comprehensively considered to obtain the water loss sensitivity level of each water loss type; The types of water damage in tunnel civil construction include lining structure, lining joint, pavement structure and maintenance channel; Water damage sensitivity risk factors include tunnel service life, lining structure diseases and defects, tunnel drainage, tunnel structure reinforcement, lining joint waterproofing structure, pavement structure and crack damage of tunnel maintenance channel; Taking into account the classification of various water damage sensitivity factors, the water damage sensitivity level of each water damage type is obtained, including: The water damage sensitivity level of the lining structure is obtained by combining the reinforcement condition of the lining structure, the disease and defect condition of the tunnel lining structure and the service life of the tunnel when the tunnel drainage state is obtained; The lining joint water damage sensitivity level is obtained by the lining joint waterproof structure condition and the tunnel service time under the tunnel drainage condition; The water damage sensitivity level of the pavement structure is obtained by combining the pavement structure condition with the tunnel service time when the tunnel drainage state is obtained; The water damage sensitivity levels include weak vulnerability, medium vulnerability and strong vulnerability.

2. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 1 is characterized in that: The types of tunnel stratum environment are as follows: Obtain the water permeability characteristics of the stratum where the tunnel line is located, wherein the stratum is divided into a permeable layer, an impermeable layer and a water-bearing interlayer based on the water permeability characteristics; The basis for judging the type of stratum environment is obtained based on the water permeability characteristics of the stratum where the tunnel line is located. The basis for judging includes the development of geological structures and the karst development state of the stratum. The specific basis for judging is as follows: When the tunnel line is located in the aquiclude, the stratum environment is classified according to the development of geological structures; When the tunnel line is located in the permeable layer and the water-bearing interlayer, the formation environment is classified according to the karst development state of the formation and the development of the geological structure; Comprehensively analyze the development of different geological structures and the karst development status of the strata to obtain the tunnel stratum environment type.

3. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 2 is characterized in that: The tunnel line is located in the aquiclude, and the stratum environment types are classified according to the development of geological structures as follows: The geological structure is developed as syncline or other, and the stratigraphic environment type is general; The geological structure is developed into a fault fracture zone, and the stratigraphic environment type is poor; The geological structure is developed into a fault fracture zone plus anticline, and the stratigraphic environment type is poor.

4. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 2 is characterized in that: The karst development states of the formations include weak development, moderate development and strong development; The tunnel line is located in the permeable layer. According to the karst development state of the stratum and the development of geological structure, the stratum environment types are classified as follows: Under the condition of weak karst development in the local formation, the other, fault fracture zone and syncline in the geological structure development correspond to the formation environment types of general, poor and poor respectively; When the stratum karst is moderately developed, the other, fault fracture zone or syncline, and fault fracture zone plus syncline in the geological structure development correspond to the stratum environment types of poor, poor, and poor, respectively; When the stratum karst is strongly developed, the geological structure development is other, fault fracture zone or syncline, which correspond to the stratum environment types of poor and extremely poor respectively; The tunnel line is located in the water-bearing interlayer. According to the karst development state of the strata and the development of geological structures, the stratum environment types are classified as follows: Under the condition of weak karst development in the local formation, the other, fault fracture zone or syncline, and fault fracture zone plus syncline in the geological structure development correspond to the formation environment types of general, poor, and poor respectively; When the karst in the local formation is moderately developed or strongly developed, the geological structure development is other, fault fracture zone or syncline, fault fracture zone plus syncline, and the corresponding stratigraphic environment types are poor, poor, and extremely poor, respectively.

5. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 1 is characterized in that: The impact of precipitation on tunnel earth construction facilities is based on the four-level classification of tunnel stratum environment types and combined with the annual precipitation intensity of the tunnel site. The annual precipitation intensity of the tunnel site includes four intensities: extremely strong, relatively strong, medium and relatively weak. The stratum environment type is the first judgment basis, and the annual precipitation intensity of the tunnel site is the second judgment basis. The two are combined to determine the impact of precipitation on tunnel earth construction facilities. The specific impact levels include extremely serious, heavy, medium and light.

6. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 1 is characterized by: The service life of tunnels is classified into the following categories: less than 10 years, 10-20 years, and more than 20 years. Tunnel drainage status includes unobstructed and blocked; The reinforcement conditions of tunnel lining structures include plain concrete structure and reinforced concrete structure; The diseases and defects of tunnel lining structure are divided into two conditions: at least one of the three defects of cracks, insufficient thickness and back voids exists, and none of the three defects exists.

7. The risk assessment method for tunnel earthwork facilities in operation period under long-term rainfall conditions according to claim 1 is characterized in that: The safety risk levels of tunnel civil construction facilities are as follows: Among them, the safety risks of tunnel civil construction facilities are divided into four levels: low risk, medium risk, high risk and extremely high risk.

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