A tunnel construction risk grading evaluation system of risk level division

Abstract

This invention discloses a tunnel construction risk classification and evaluation system, belonging to the field of risk classification and evaluation technology. It addresses the problem of reduced accuracy in risk assessment of tunnel underpass construction under existing railway operating conditions. The system utilizes a support correction module to collect grouting support data, calculate the support reinforcement index, and correct geometric deviations of the support structure by combining pipe roof inclination angle. A surrounding rock assessment module acquires surrounding rock reflection signal data to evaluate the uniformity of surrounding rock reinforcement and generates a support risk level based on the corrected support reinforcement index, determining whether support densification is necessary. A railway analysis module retrieves train axle load and train formation length, calculates the train's longitudinal impact coefficient, and analyzes the track settlement response. A resonance identification module filters high-disturbance trains based on the track settlement response, identifies the disturbance superposition time, and detects wheel-rail vibration data, generating a resonance risk level for the train's impact on the tunnel underpass project. This achieves a dynamic risk classification and evaluation system coupling tunnel support status and train disturbance.

Description

Technical Field

[0001] This invention relates to the field of risk classification and evaluation technology, and more specifically, to a risk classification and evaluation system for tunnel construction. Background Technology

[0002] With the continuous expansion of the railway transportation network, the number of railway underpass tunnel construction projects is gradually increasing. When tunnel underpass construction is carried out under the existing railway operation status, due to the spatial coupling relationship between the construction area and the railway track structure, the tunnel excavation and support process may affect the stability of the overlying track structure, and the train operation load will also cause periodic disturbances to the tunnel support structure and the stability of the surrounding rock.

[0003] The existing technology has the following shortcomings:

[0004] Currently, existing technologies mostly rely on construction monitoring data or surrounding rock grade for single-dimensional risk assessment, which makes it difficult to accurately control the impact of tunnel grouting reinforcement effect and the geometric deviation of support structure on the stability of surrounding rock. This leads to uneven surrounding rock reinforcement and enhanced coupling response between train operation load disturbance and construction structure, making it difficult to identify and assess track settlement response and wheel-rail vibration superposition effects in a timely manner. As a result, the accuracy and real-time performance of tunnel underpass construction risk assessment under existing railway operation conditions are reduced. Therefore, a tunnel construction risk classification and evaluation system based on risk level is proposed.

[0005] The information disclosed in the background section is only intended to enhance the understanding of the background of this disclosure, and therefore may include information that does not constitute prior art known to those skilled in the art. Summary of the Invention

[0006] To overcome the aforementioned deficiencies in the prior art, embodiments of the present invention provide a tunnel construction risk classification and evaluation system for risk level division. This system addresses the problems mentioned in the background art by employing a collaborative risk assessment mechanism that utilizes support reinforcement index correction analysis, surrounding rock reflection signal uniformity assessment, train operation load impact calculation, and wheel-rail vibration resonance identification.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a tunnel construction risk classification and evaluation system, comprising a support correction module, a surrounding rock assessment module, a railway analysis module, and a resonance identification module, the functions of which are as follows:

[0008] When the support correction module performs tunnel underpass project under railway operation status, it collects grouting support data of the tunnel underpass project, calculates the support reinforcement index based on the grouting support data, detects the pipe roof inclination angle of the tunnel underpass project, corrects the support reinforcement index using the pipe roof inclination angle, and transmits the corrected support reinforcement index to the surrounding rock assessment module.

[0009] The surrounding rock assessment module scans the reinforced surrounding rock, detects the surrounding rock reflection signal data, assesses the uniformity of the surrounding rock reinforcement based on the surrounding rock reflection signal data, generates the support risk level by combining the corrected support reinforcement index, and determines whether to perform support densification treatment on the current construction area. The judgment result is then transmitted to the railway analysis module.

[0010] After performing the support densification process, the railway analysis module accesses the railway operation table to retrieve the axle load and train formation length of different trains passing through the current construction area. Based on the axle load, it calculates the longitudinal impact coefficient of each train passing through, analyzes the track settlement response in combination with the train formation length, and transmits the track settlement response to the resonance identification module.

[0011] The resonance identification module filters and marks passing trains based on the track settlement response, identifies the disturbance superposition time of the marked passing trains, detects the wheel-rail vibration data of the marked passing trains within the disturbance superposition time, and generates the resonance risk level of the marked passing trains for the tunnel underpass project.

[0012] In a preferred embodiment, in the support correction module, when performing tunnel underpass construction while the existing railway line remains operational, grouting support data for the tunnel underpass project is collected, including grouting pressure, grouting volume, and grouting duration.

[0013] Grouting pressure refers to the fluid pressure formed when grout is injected into the fractured structure of the surrounding rock through a grouting pump;

[0014] Grouting volume refers to the volume of grout injected into the surrounding rock during a single grouting operation cycle;

[0015] Grouting duration refers to the length of time a grouting pump operates continuously during a single grouting operation.

[0016] In a preferred embodiment, in the support correction module, the result of multiplying the grouting pressure by the grouting volume is divided by the grouting duration to obtain the support reinforcement index.

[0017] The tilt angle data of the pipe shed is collected by the tilt sensor set on the pipe shed installation and positioning device. The tilt angle of the pipe shed is the actual installation angle of the pipe shed axis relative to the design reference direction.

[0018] The support reinforcement index was corrected using the pipe roof inclination angle to obtain the corrected support reinforcement index: ;

[0019] in, The revised support reinforcement index. The original support reinforcement index was used. This is a preset correction factor. The angle of inclination of the pipe shed.

[0020] In a preferred embodiment, in the surrounding rock assessment module, the reinforced surrounding rock after grouting support treatment in the current construction area is scanned and detected. The internal structure of the surrounding rock is scanned and collected by geological scanning equipment deployed at the tunnel face and around the arch to obtain surrounding rock reflection signal data.

[0021] The surrounding rock reflection signal data is the intensity of the surrounding rock reflection signal formed after the geological scanning equipment transmits a detection signal into the surrounding rock and receives the reflection signal of the surrounding rock medium at a certain spatial location inside the surrounding rock;

[0022] The average reflection intensity is obtained by constructing a reflection signal intensity sequence from all the surrounding rock reflection signal intensity values ​​obtained in the scanning area and calculating the average value of the reflection signal intensity sequence.

[0023] The standard deviation of the reflected signal intensity sequence is calculated to obtain the dispersion of the reflected signal;

[0024] Calculation of surrounding rock reinforcement uniformity based on average reflection intensity and reflection signal dispersion: ;

[0025] in, To improve the uniformity of surrounding rock reinforcement, The discreteness of the reflected signal, This represents the average reflection intensity.

[0026] In a preferred embodiment, in the surrounding rock assessment module, the modified support reinforcement index is combined with the surrounding rock reinforcement uniformity to generate the support risk level: ;

[0027] in, To support the risk level, The revised support reinforcement index. To improve the uniformity of surrounding rock reinforcement;

[0028] When the support risk index is greater than the support risk threshold, it is determined that support densification treatment should be carried out in the current construction area.

[0029] Conversely, if the condition is not met, the protection encryption process will not be triggered.

[0030] Support reinforcement refers to engineering measures that improve the overall stability of the surrounding rock by increasing the density of support components or strengthening the reinforcement of the surrounding rock. These measures include grouting reinforcement and pipe roof reinforcement.

[0031] Grouting densification treatment involves adding supplementary grouting holes between the original grouting holes;

[0032] The pipe roof densification treatment involves adding supplementary pipe roofs between the existing pipe roof support structures.

[0033] In a preferred embodiment, the railway analysis module accesses the railway operation table to retrieve the train type, train axle load, and train formation length of different trains passing through the current construction area;

[0034] The baseline axle load and basic impact value corresponding to different train types are retrieved from the impact calibration library;

[0035] Calculation of longitudinal impact coefficient based on train axle load: ,in, As the reference axle load, For train axle load, To preset the impact correction weight, Basic impact value, This represents the longitudinal impact coefficient.

[0036] In a preferred embodiment, the vertical displacement of the track corresponding to the current construction area is collected by a displacement sensor in the railway analysis module.

[0037] The average value of the track vertical displacement within a preset pre-construction time window before the passing train enters the current construction area is used as the initial displacement reference, and the peak value of the track vertical displacement within a preset post-construction time window after the passing train passes through the current construction area is used as the response displacement value.

[0038] The difference between the response displacement value and the initial displacement reference is calculated to obtain the foundation settlement displacement corresponding to the train passing through the route.

[0039] The track settlement response was calculated based on the basic settlement displacement, longitudinal impact coefficient, and train formation length.

[0040] In a preferred embodiment, the resonance identification module compares the track settlement response with a preset settlement response threshold to filter and mark passing trains.

[0041] If the track settlement response exceeds the preset settlement response threshold, the passing train will be marked.

[0042] Conversely, no markings are made for passing trains;

[0043] Access the construction control log to obtain the construction disturbance period of the current construction area, including the construction start time and construction end time;

[0044] By reading the arrival and departure times of marked trains in the current construction area from the railway operation table, and combining this with the construction disturbance period, the disturbance superposition time is determined.

[0045] Among them, the later of the construction start time and the entry time is used as the superimposed start time, and the earlier of the construction end time and the departure time is used as the superimposed end time.

[0046] When the time difference between the end time of the superposition and the start time of the superposition is greater than 0, the corresponding time difference is determined as the disturbance superposition time of the marked passing train.

[0047] In a preferred embodiment, in the resonance identification module, during the disturbance superposition time, the vibration acceleration signal of the marked passing train is detected by the vibration acceleration sensor. After the vibration acceleration signal is processed by fast Fourier transform, the vibration amplitude corresponding to different frequency components is obtained. The frequency value with the largest vibration amplitude among each frequency component is selected as the wheel-rail vibration data.

[0048] Access the structural frequency calibration library to retrieve the reference frequency of the construction structure corresponding to the current construction area, and calculate the frequency proximity coefficient using the reference frequency of the construction structure and wheel-rail vibration data.

[0049] If the frequency proximity coefficient is greater than the preset frequency proximity threshold, the resonance risk level is in the resonance trigger state, and a resonance risk alarm signal is generated.

[0050] Conversely, the resonance risk level is a resonance-not-triggered state.

[0051] The technical effects and advantages of this invention are as follows:

[0052] This invention uses a support correction module to collect grouting support data and calculate the support reinforcement index. It then uses the pipe roof inclination angle to correct the geometric deviation of the support structure, reflecting the actual compensation capacity of the grouting reinforcement system. A surrounding rock assessment module obtains surrounding rock reflection signal data to evaluate the uniformity of the surrounding rock reinforcement. Combined with the corrected pipe roof inclination angle, it generates a support risk level to determine whether support densification is necessary. After support densification, a railway analysis module retrieves train operation data such as axle load and train formation length, calculates the train's longitudinal impact coefficient, and analyzes the track settlement response to characterize the dynamic impact of train operation loads on the construction area. A resonance identification module further filters high-disturbance trains based on the track settlement response, identifies the disturbance superposition time, and detects wheel-rail vibration data to generate a resonance risk level for the train's impact on the tunnel underpass project. Through collaborative analysis, a dynamic risk classification evaluation of the coupling effect between the tunnel construction support status and train operation disturbance is achieved. Attached Figure Description

[0053] Figure 1 This is a flowchart illustrating the implementation of a tunnel construction risk classification and evaluation system based on risk level division, as per the present invention.

[0054] Figure 2 This is a schematic diagram illustrating the steps of a tunnel construction risk classification and evaluation system based on risk level division according to the present invention. Detailed Implementation

[0055] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0056] This invention uses a support correction module to collect grouting support data and calculate the support reinforcement index. It then uses the pipe roof inclination angle to correct the geometric deviation of the support structure, reflecting the actual compensation capacity of the grouting reinforcement system. A surrounding rock assessment module obtains surrounding rock reflection signal data to evaluate the uniformity of the surrounding rock reinforcement. Combined with the corrected pipe roof inclination angle, a support risk level is generated to determine whether support densification is necessary. After support densification, a railway analysis module retrieves train operation data such as axle load and train formation length, calculates the train's longitudinal impact coefficient, and analyzes the track settlement response to characterize the dynamic impact of train loads on the construction area. A resonance identification module further filters high-disturbance trains based on the track settlement response, identifies the disturbance superposition time, and detects wheel-rail vibration data to generate the resonance risk level of the train for the tunnel underpass project.

[0057] Example 1, such as Figures 1 to 2 As shown, a tunnel construction risk classification and evaluation system includes a support correction module, a surrounding rock assessment module, a railway analysis module, and a resonance identification module. The functions of each module are as follows:

[0058] When the support correction module performs tunnel underpass project under railway operation status, it collects grouting support data of the tunnel underpass project, calculates the support reinforcement index based on the grouting support data, detects the pipe roof inclination angle of the tunnel underpass project, corrects the support reinforcement index using the pipe roof inclination angle, and transmits the corrected support reinforcement index to the surrounding rock assessment module.

[0059] The surrounding rock assessment module scans the reinforced surrounding rock, detects the surrounding rock reflection signal data, assesses the uniformity of the surrounding rock reinforcement based on the surrounding rock reflection signal data, generates the support risk level by combining the corrected support reinforcement index, and determines whether to perform support densification treatment on the current construction area. The judgment result is then transmitted to the railway analysis module.

[0060] After performing the support densification process, the railway analysis module accesses the railway operation table to retrieve the axle load and train formation length of different trains passing through the current construction area. Based on the axle load, it calculates the longitudinal impact coefficient of each train passing through, analyzes the track settlement response in combination with the train formation length, and transmits the track settlement response to the resonance identification module.

[0061] The resonance identification module filters and marks passing trains based on the track settlement response, identifies the disturbance superposition time of the marked passing trains, detects the wheel-rail vibration data of the marked passing trains within the disturbance superposition time, and generates the resonance risk level of the marked passing trains for the tunnel underpass project.

[0062] The specific implementation is as follows:

[0063] In the support correction module, when tunnel underpass construction is carried out under the condition that the existing railway line is in operation, data is collected on the grouting support process of large pipe sheds and small pipes in the construction area.

[0064] Specifically, during the grouting process, the grouting pressure is collected by a pressure sensor installed on the grouting pump outlet pipeline, the grouting volume per unit time is recorded by a grouting metering device, and the grouting duration is obtained through a construction record system. These parameters together constitute the grouting support data.

[0065] Among them, grouting pressure refers to the fluid pressure formed when grout is injected into the surrounding rock fissure structure through the grouting pump. It reflects the driving force for the grout to diffuse into the interior of the surrounding rock. The larger the value, the stronger the ability of the grout to overcome the resistance of the surrounding rock and diffuse into the fissure space.

[0066] Grouting volume refers to the volume of grout injected into the surrounding rock during a single grouting operation cycle. It reflects the degree to which the grout fills the fissures in the surrounding rock. The larger the value, the wider the range of grout filling the pore space of the surrounding rock.

[0067] Grouting duration refers to the length of time that the grouting pump works continuously during a single grouting operation. It reflects the time conditions under which the grout forms a continuous solidified body inside the surrounding rock. The larger the value, the longer the diffusion process of the grout in the surrounding rock fissures lasts.

[0068] It should be noted that the pressure sensor is a pressure detection device installed on the grouting pump outlet pipeline, used to measure the fluid pressure of the grout in the delivery pipeline in real time; the grouting metering device is a flow metering device installed in the grouting pump outlet pipeline, used to continuously measure the volume of grout per unit time during the grout delivery process; and the construction record system is an information recording and management system deployed at the tunnel construction site, used to automatically record key time parameters during the construction process.

[0069] The support correction module calculates the support reinforcement index based on grouting pressure, grouting volume, and grouting duration. Specifically, the support reinforcement index is obtained by multiplying the grouting pressure by the grouting volume and dividing the result by the grouting duration.

[0070] The support reinforcement index is used to characterize the overall reinforcement capacity of the surrounding rock formed by the grouting support system in the current construction area. The larger the value, the stronger the overall reinforcement effect of the grouting support on the surrounding rock structure, and the higher the possibility of forming a continuous reinforced body inside the surrounding rock.

[0071] After calculating the support reinforcement index, the support correction module further detects the installation posture of the large pipe roof structure. Specifically, the pipe roof inclination angle is collected by an inclination sensor installed on the pipe roof installation positioning device. The pipe roof inclination angle is the actual installation angle of the pipe roof axis relative to the design reference direction, reflecting the degree of installation offset of the pipe roof support structure during spatial layout. The larger the value, the greater the deviation of the actual layout direction of the pipe roof from the design direction, which may lead to reinforcement blind spots in the surrounding rock reinforcement area, thereby reducing the overall support capacity of the grouting reinforcement body for the surrounding rock structure. When the pipe roof inclination angle is smaller, it means that the pipe roof layout direction is closer to the design direction, the surrounding rock reinforcement coverage is closer to the design reinforcement area, and the overall constraint capacity of the support structure on the surrounding rock is more stable.

[0072] It should be noted that the tilt sensor is an attitude detection device installed on the pipe roof installation positioning device or the pipe roof drilling rig guide mechanism, used to measure the tilt angle of the pipe roof axis relative to the spatial reference direction; the design reference direction refers to the pipe roof design installation direction determined in the tunnel construction design stage according to the tunnel axis position, the distribution of the stratum structure and the requirements of the support structure layout, which is given by the construction design drawings.

[0073] The support correction module uses the detected pipe roof inclination angle to correct the previously calculated support reinforcement index, reflecting the impact of pipe roof installation deviation on the grouting reinforcement effect, thus obtaining the corrected support reinforcement index, the specific expression of which is as follows:

[0074] ;

[0075] in, The revised support reinforcement index. The original support reinforcement index was used. This is a preset correction factor. The angle of inclination of the pipe shed.

[0076] It should be noted that the preset correction coefficient was determined through statistical analysis of historical engineering data. Multiple sets of construction case data with different pipe roof inclination angle deviations were selected, and the deformation of the support structure and the grouting reinforcement effect in each case were statistically analyzed. A functional relationship between the pipe roof inclination angle deviation and the change in surrounding rock stability was established using regression analysis, thus obtaining the preset correction coefficient reflecting the sensitivity of both. The product of the preset correction coefficient and the pipe roof inclination angle must satisfy the following condition: The constraints are to ensure that the modified support reinforcement index maintains a non-negative physical meaning. When the actual measured pipe roof inclination angle leads to... At that time, then The cutoff value is 1, at which point the corrected support reinforcement index is 0, indicating that the pipe roof installation deviation caused the grouting reinforcement system to fail. The above boundary conditions are set based on the basic principle of non-negativity of support capacity in the mechanical analysis of support structures, so as to ensure that the corrected support reinforcement index is always within a range of values ​​that have practical engineering significance.

[0077] Through the above correction process, the corrected support reinforcement index can simultaneously reflect the formation capacity of the grouting reinforcement body and the degree of influence of the pipe roof installation deviation on the coverage of the surrounding rock reinforcement, thereby more accurately characterizing the actual reinforcement capacity of the current construction area support system for the surrounding rock structure.

[0078] Finally, the support correction module transmits the corrected support reinforcement index as a parameter for the stability analysis of the surrounding rock structure to the surrounding rock assessment module, so that the surrounding rock assessment module can further combine the surrounding rock reflection signal data to comprehensively evaluate the uniformity of the surrounding rock reinforcement and the support risk level.

[0079] In the surrounding rock assessment module, after receiving the corrected support reinforcement index, the reinforced surrounding rock in the current construction area after grouting support is scanned and detected. Specifically, geological scanning equipment deployed at the tunnel face and around the arch scans and collects data on the internal structure of the surrounding rock to obtain surrounding rock reflection signal data.

[0080] The surrounding rock reflection signal data is the intensity of the surrounding rock reflection signal formed after the geological scanning equipment transmits a detection signal into the surrounding rock and receives the reflected signal of the surrounding rock medium at a certain spatial location inside the surrounding rock. The intensity of the surrounding rock reflection signal reflects the propagation and reflection characteristics of the scanning signal in the surrounding rock medium. The larger the value, the denser and more continuous the structure of the surrounding rock medium is, and the stronger the signal reflection ability. The smaller the value, the more likely there are cracks, voids or areas that are not fully filled by grout inside the surrounding rock, which leads to the attenuation of the reflected signal.

[0081] It should be noted that geological scanning equipment refers to underground engineering geological testing devices used for non-destructive detection of the internal structural state of tunnel surrounding rock. It obtains information about the internal structure of the surrounding rock by transmitting detection signals into the surrounding rock and receiving the reflected signals from the surrounding rock medium.

[0082] After acquiring the surrounding rock reflection signal data, the surrounding rock assessment module performs statistical processing on the intensity of the surrounding rock reflection signals within the scanning area. Specifically, it constructs a reflection signal intensity sequence from all the surrounding rock reflection signal intensity values ​​obtained within the scanning area, and calculates the average value of the reflection signal intensity sequence to obtain the average reflection intensity. The average reflection intensity represents the average level of the overall reflection capacity of the surrounding rock within the scanning area, reflecting the density of the overall structure of the reinforced surrounding rock. The higher the value, the higher the degree of grout filling inside the surrounding rock and the higher the overall density of the surrounding rock structure.

[0083] After obtaining the average reflection intensity value, the surrounding rock assessment module further calculates the dispersion of the surrounding rock reflection signal intensity. Specifically, the standard deviation of the reflection signal intensity sequence is calculated to obtain the reflection signal dispersion. The reflection signal dispersion is used to characterize the spatial dispersion of the surrounding rock reflection signal intensity, reflecting the uniformity of the distribution of the solidified structure inside the surrounding rock. The larger the value, the more obvious the difference in reflection signals at different locations, indicating that the distribution of solidified structures inside the surrounding rock is uneven; the smaller the value, the closer the reflection signal intensity at each scanning location, indicating that the distribution of grouting solidified structures inside the surrounding rock is relatively uniform.

[0084] The uniformity of surrounding rock reinforcement is calculated based on the average reflection intensity and the dispersion of the reflection signal. The calculation expression is as follows:

[0085] ;

[0086] in, To improve the uniformity of surrounding rock reinforcement, The discreteness of the reflected signal, This represents the average reflection intensity.

[0087] The uniformity of surrounding rock reinforcement reflects the spatial uniformity of the grouting reinforcement within the surrounding rock. A larger value indicates a smaller dispersion of the reflected signal and a more uniform distribution of the reinforcement within the surrounding rock. A smaller value indicates a larger dispersion of the reflected signal and the possibility of unreinforced areas or reinforcement blind spots within the surrounding rock.

[0088] It should be noted that the value of the uniformity of surrounding rock reinforcement is limited to between 0 and 1. When the dispersion of the reflected signal is greater than the average reflection intensity, the calculated uniformity of surrounding rock reinforcement will be negative. In this case, the uniformity of surrounding rock reinforcement is assigned to 0, indicating that the distribution of reinforced bodies inside the surrounding rock is extremely uneven, with significant reinforcement blind spots or unreinforced areas. The engineering basis for the above processing method is that when the spatial dispersion of the reflected signal exceeds the average reflection intensity, it indicates that the reinforcement effect in a local area of ​​the surrounding rock is far below the overall average level. At this time, the uniformity has lost its uniformity characteristic in an engineering sense, so it is identified as a reinforcement failure state, and therefore, the value is taken as 0. As a boundary representation of the most unfavorable working condition.

[0089] After obtaining the uniformity of the surrounding rock reinforcement, the surrounding rock assessment module further combines the corrected support reinforcement index transmitted by the support correction module to comprehensively evaluate the support stability of the current construction area. Specifically, the support risk level is generated by combining the corrected support reinforcement index with the uniformity of the surrounding rock reinforcement; the calculation expression is as follows:

[0090] ;

[0091] in, To support the risk level, The revised support reinforcement index. To improve the uniformity of the surrounding rock reinforcement.

[0092] The support risk level is used to reflect the degree of risk to the stability of the support structure in the current construction area. When the support risk level value is larger, it indicates that the modified support reinforcement index is smaller or the uniformity of the surrounding rock reinforcement is lower, which indicates that the surrounding rock reinforcement capacity formed by the grouting support system is insufficient and there is a higher risk of support failure in the current construction area.

[0093] The smaller the support risk level value, the higher the uniformity of the surrounding rock reinforcement and the larger the support reinforcement index, indicating that a stable reinforcement structure has been formed inside the surrounding rock.

[0094] The surrounding rock assessment module then compares the support risk index with a preset support risk threshold:

[0095] When the support risk index is greater than the support risk threshold, the stability of the support structure in the current construction area is determined to be insufficient, and support densification treatment is carried out in the current construction area.

[0096] When the support risk index is less than or equal to the support risk threshold, the stability of the support structure in the current construction area is determined to meet the construction safety requirements, and the support densification process is not triggered.

[0097] It should be noted that the support risk threshold is a risk assessment benchmark value used to determine whether the stability of the support structure in the current construction area meets safety requirements. It is dynamically adjusted according to the construction stage. Specifically, several different historical construction stages (such as the excavation period of the working face, the initial support period, and the secondary lining period) are selected, and the corresponding support risk level is calculated for each historical construction stage to form a historical risk level sample set. Subsequently, statistical analysis is performed on the historical risk level sample sets of different historical construction stages to calculate the average and standard deviation of the historical risk levels. The sum of the average and standard deviation is used as the support risk threshold for different historical construction stages. In specific implementation, the current construction stage identifier is obtained by reading the construction schedule to retrieve the corresponding support risk threshold.

[0098] Support densification refers to engineering measures that improve the overall stability of the surrounding rock by increasing the density of support components or strengthening the reinforcement of the surrounding rock. It includes two types of measures: The first type is grouting densification, which involves adding supplementary grouting holes between the original grouting holes. By reducing the spacing between the grouting holes, the diffusion coverage of grout inside the surrounding rock is increased, making the surrounding rock form a more continuous reinforced structure. The second type is pipe roof densification, which involves adding supplementary pipe roofs between the original pipe roof support structures. By reducing the spacing between the pipe roofs, the overall bearing capacity of the arch structure is improved.

[0099] Finally, the surrounding rock assessment module transmits the judgment results of the support densification treatment to the railway analysis module, so that the railway analysis module can use it as a basis for judging the support status of the construction area during the subsequent train operation load analysis.

[0100] In the railway analysis module, after performing support encryption processing, the railway operation table is accessed to retrieve the train type, train axle load and train formation length of different trains passing through the current construction area;

[0101] Among them, the axle load of the train reflects the static load level of the track structure when the passing train passes; the train formation length reflects the duration and range of the continuous action of the passing train on the track in the construction area.

[0102] Access the impact calibration library to retrieve the reference axle load and basic impact value corresponding to different train types. The reference axle load refers to the allowable axle load of the line under standard operating conditions for different train types. The basic impact value refers to the standard dynamic impact coefficient generated when the train passes through the track structure under the reference axle load condition. It can be calibrated and stored based on historical track dynamic test data or line design dynamic coefficient.

[0103] Calculation of longitudinal impact coefficient based on train axle load: ,in, As the reference axle load, For train axle load, To preset the impact correction weight, Basic impact value, The longitudinal impact coefficient;

[0104] The longitudinal impact coefficient reflects the strength of the longitudinal dynamic impact of passing trains on the track structure of the current construction area. The larger the value, the higher the possibility that passing trains will cause additional track impact when passing through the current construction area.

[0105] The vertical displacement of the track in the current construction area is collected by displacement sensors. The vertical displacement of the track refers to the vertical displacement of the top of the rail relative to the calibrated top position of the rail.

[0106] The average value of the track vertical displacement within a preset pre-construction time window before the passing train enters the current construction area is used as the initial displacement benchmark. The peak value of the track vertical displacement within a preset post-construction time window after the passing train passes through the current construction area is used as the response displacement value. The difference between the response displacement value and the initial displacement benchmark is calculated to obtain the foundation settlement displacement corresponding to the passing train.

[0107] It should be explained that a displacement sensor is a displacement measurement device that monitors changes in the vertical displacement of a track structure; a preset pre-time window is used to extract the stable track displacement state before a passing train disturbance occurs, and a preset post-time window is used to extract the track settlement response interval after the train load is applied. The length of the time window can be set according to the allowable speed of the line, the length of the construction area, and the sensor sampling frequency; the preset impact correction weight can be set according to the historical statistical results of the influence of train axle load changes on the track dynamic response.

[0108] Access the train statistics database to retrieve the train formation reference length. The train formation reference length can be statistically set and stored based on the current line's regular train formation length or the historical statistical median value.

[0109] The ratio of the train formation length to the formation reference length is used as the formation length magnification ratio. The larger the formation length magnification ratio, the longer the load on the track in the construction area will last.

[0110] Calculation of track settlement response based on longitudinal impact coefficient and train formation length: ,in, Based on the settlement displacement The longitudinal impact coefficient is... The group length magnification ratio, This refers to the track settlement response.

[0111] The track settlement response reflects the intensity of the settlement response of the track structure in the current construction area under the influence of the axle load impact and the length of continuous action of passing trains; the larger the value, the higher the risk of track subsidence caused by passing trains and the higher the sensitivity to the disturbance of the underpass construction.

[0112] The track settlement response is transmitted to the resonance identification module.

[0113] It should be noted that the railway operation table is a data table structure used to record basic operational information of trains running on the line; the impact calibration library is a parameter database used to store reference parameters for dynamic impact corresponding to different train types; and the train statistics database is a database used to store historical train operation statistics information of the line.

[0114] In the resonance identification module, the track settlement response is compared with a preset settlement response threshold to filter and mark passing trains.

[0115] If the track settlement response exceeds the preset settlement response threshold, the passing train will be marked.

[0116] Conversely, no markings are made for passing trains;

[0117] Access the construction control log to retrieve the construction disturbance period of the current construction area. The construction disturbance period includes the construction start time and the construction end time.

[0118] The arrival and departure times of marked trains in the current construction area are read from the railway operation table. The arrival time is the time when the front of the marked train enters the boundary of the current construction area, and the departure time is the time when the rear of the marked train leaves the boundary of the current construction area.

[0119] Furthermore, the construction start time during the construction disturbance period is compared with the arrival time of the marked passing trains, and the later of the two times is taken as the superposition start time; the construction end time during the construction disturbance period is compared with the departure time of the marked passing trains, and the earlier of the two times is taken as the superposition end time.

[0120] The time difference between the end of the superposition and the start of the superposition is taken as the perturbation overlap duration.

[0121] When the disturbance overlap duration is greater than 0, the disturbance overlap duration is used as the disturbance superposition time of the marked passing train; when the disturbance overlap duration is less than or equal to 0, the marked passing train and the construction disturbance do not form an effective time overlap and will not be included in the subsequent wheel-rail vibration data detection process.

[0122] During the disturbance superposition time, the vibration acceleration signal of the marked passing train is detected by the vibration acceleration sensor. After the vibration acceleration signal is processed by fast Fourier transform, the vibration amplitude corresponding to different frequency components is obtained. The frequency value with the largest vibration amplitude among each frequency component is selected as the wheel-rail vibration data.

[0123] Fast Fourier Transform (FFT) is a spectral analysis method used to convert vibration signals from the time domain to the frequency domain. It obtains the vibration amplitude corresponding to each frequency component by performing discrete frequency decomposition on the vibration acceleration signal.

[0124] The closer the wheel-rail vibration data is to the reference frequency of the construction structure, the higher the degree of matching between the train vibration frequency and the vibration characteristics of the construction structure, and the greater the possibility of resonance.

[0125] Access the structural frequency calibration library to retrieve the reference frequency of the construction structure corresponding to the current construction area. The reference frequency of the construction structure refers to the dominant vibration frequency of the tunnel structure obtained from the historical monitoring data of the current construction area.

[0126] The frequency proximity factor was calculated using the reference frequency of the construction structure and wheel-rail vibration data. ,in, The reference frequency for the construction structure. For wheel-rail vibration data, Frequency proximity coefficient;

[0127] The frequency proximity coefficient reflects the degree of proximity between the vibration frequency of the train passing by the marked route and the vibration characteristics of the construction structure. The larger the value, the closer the two are, and the higher the possibility of resonance.

[0128] It should be noted that the frequency proximity coefficient is limited to a range of 0 to 1. When the difference between the wheel-rail vibration data and the reference frequency of the construction structure is significant, it must meet the following conditions: When the conditions are met, the calculated frequency proximity coefficient will be negative. In this case, the frequency proximity coefficient is set to 0, indicating that the train vibration frequency and the vibration characteristics of the construction structure are completely mismatched and the risk of resonance can be ignored. The physical meaning of the above processing method is that the frequency proximity coefficient represents the degree of overlap between the two frequencies, rather than the absolute value of the frequency difference. Therefore, when the frequency difference exceeds the reference frequency itself, there is no possibility of resonance and it should be judged as a state of complete frequency mismatch.

[0129] The frequency proximity coefficient is compared with a preset frequency proximity threshold to generate a resonance risk level for the tunnel underpass project categorized by passing trains:

[0130] If the frequency proximity coefficient is greater than the preset frequency proximity threshold, the resonance risk level is a resonance trigger state.

[0131] Conversely, the resonance risk level is a resonance-not-triggered state;

[0132] When the resonance risk level is in the resonance triggered state, a resonance risk alarm signal is generated.

[0133] It should be noted that the preset settlement response threshold can be set based on the statistical distribution of track settlement response under historical normal operating conditions. For example, it can be set using a combination of the median and the absolute deviation of the median of historical track settlement response. The construction control log is a data file used to record construction operation time and the start and stop information of construction procedures. The vibration acceleration sensor is a dynamic monitoring device used to detect changes in the vibration acceleration of a structure or track. The structural frequency calibration library is a database used to store the structural vibration characteristic parameters of different construction areas. The preset frequency proximity threshold can be set based on the statistical results of the matching degree between historical train operation vibration data and tunnel structure vibration frequency. For example, the threshold range can be determined by statistically analyzing the distribution range of the frequency proximity coefficient under normal operating conditions.

[0134] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0135] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0136] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0137] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0138] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A tunnel construction risk classification and evaluation system, characterized in that: It includes a support correction module, a surrounding rock assessment module, a railway analysis module, and a resonance identification module. The functions of each module are as follows: When the support correction module performs tunnel underpass project under railway operation status, it collects grouting support data of the tunnel underpass project, calculates the support reinforcement index based on the grouting support data, detects the pipe roof inclination angle of the tunnel underpass project, corrects the support reinforcement index using the pipe roof inclination angle, and transmits the corrected support reinforcement index to the surrounding rock assessment module. In the support correction module, when tunnel underpass construction is carried out while the existing railway line remains in operation, grouting support data of the tunnel underpass project is collected, including grouting pressure, grouting volume and grouting duration. The support reinforcement index is obtained by multiplying the grouting pressure by the grouting volume and dividing the result by the grouting duration. The tilt angle data of the pipe shed is collected by the tilt sensor set on the pipe shed installation and positioning device. The tilt angle of the pipe shed is the actual installation angle of the pipe shed axis relative to the design reference direction. The support reinforcement index was corrected using the pipe roof inclination angle to obtain the corrected support reinforcement index: ; in, The revised support reinforcement index. The original support reinforcement index was used. The preset correction factor is used. The angle of inclination of the pipe shed; The surrounding rock assessment module scans the reinforced surrounding rock, detects the surrounding rock reflection signal data, assesses the uniformity of the surrounding rock reinforcement based on the surrounding rock reflection signal data, generates the support risk level by combining the corrected support reinforcement index, and determines whether to perform support densification treatment on the current construction area. The judgment result is then transmitted to the railway analysis module. In the surrounding rock assessment module, the reinforced surrounding rock in the current construction area after grouting support is scanned and detected. The internal structure of the surrounding rock is scanned and collected by geological scanning equipment deployed at the tunnel face and around the arch to obtain surrounding rock reflection signal data. The surrounding rock reflection signal data is the intensity of the surrounding rock reflection signal formed after the geological scanning equipment transmits a detection signal into the surrounding rock and receives the reflection signal of the surrounding rock medium at a certain spatial location inside the surrounding rock; The average reflection intensity is obtained by constructing a reflection signal intensity sequence from all the surrounding rock reflection signal intensity values ​​obtained in the scanning area and calculating the average value of the reflection signal intensity sequence. The standard deviation of the reflected signal intensity sequence is calculated to obtain the dispersion of the reflected signal; Calculation of surrounding rock reinforcement uniformity based on average reflection intensity and reflection signal dispersion: ; in, To improve the uniformity of surrounding rock reinforcement, The discreteness of the reflected signal, The average reflection intensity; The revised support reinforcement index is combined with the uniformity of surrounding rock reinforcement to generate the support risk level: ; in, To support the risk level, The revised support reinforcement index. To improve the uniformity of surrounding rock reinforcement; After performing the support densification process, the railway analysis module accesses the railway operation table to retrieve the axle load and train formation length of different trains passing through the current construction area. Based on the axle load, it calculates the longitudinal impact coefficient of each train passing through, analyzes the track settlement response in combination with the train formation length, and transmits the track settlement response to the resonance identification module. The resonance identification module filters and marks passing trains based on the track settlement response, identifies the disturbance superposition time of the marked passing trains, detects the wheel-rail vibration data of the marked passing trains within the disturbance superposition time, and generates the resonance risk level of the marked passing trains for the tunnel underpass project.

2. The tunnel construction risk classification and evaluation system according to claim 1, characterized in that: In the support and correction module, grouting pressure refers to the fluid pressure formed when grout is injected into the surrounding rock fissure structure through the grouting pump; Grouting volume refers to the volume of grout injected into the surrounding rock during a single grouting operation cycle; Grouting duration refers to the length of time a grouting pump operates continuously during a single grouting operation.

3. The tunnel construction risk classification and evaluation system according to claim 1, characterized in that: In the surrounding rock assessment module, when the support risk level is greater than the support risk threshold, it is determined that support densification treatment should be performed on the current construction area. Conversely, if the condition is not met, the protection encryption process will not be triggered. Support reinforcement refers to engineering measures that improve the overall stability of the surrounding rock by increasing the density of support components or strengthening the reinforcement of the surrounding rock. These measures include grouting reinforcement and pipe roof reinforcement. Grouting densification treatment involves adding supplementary grouting holes between the original grouting holes; The pipe roof densification treatment involves adding supplementary pipe roofs between the existing pipe roof support structures.

4. The tunnel construction risk classification and evaluation system according to claim 1, characterized in that: In the railway analysis module, access the railway operation table to retrieve the train type, train axle load, and train formation length of different trains passing through the current construction area; The baseline axle load and basic impact value corresponding to different train types are retrieved from the impact calibration library; Calculation of longitudinal impact coefficient based on train axle load: ,in, As the reference axle load, For train axle load, To preset the impact correction weight, Basic impact value, This represents the longitudinal impact coefficient.

5. The tunnel construction risk classification and evaluation system according to claim 4, characterized in that: In the railway analysis module, the vertical displacement of the track corresponding to the current construction area is collected by displacement sensors; The average value of the track vertical displacement within a preset pre-construction time window before the passing train enters the current construction area is used as the initial displacement reference, and the peak value of the track vertical displacement within a preset post-construction time window after the passing train passes through the current construction area is used as the response displacement value. The difference between the response displacement value and the initial displacement reference is calculated to obtain the foundation settlement displacement corresponding to the train passing through the route. The track settlement response was calculated based on the basic settlement displacement, longitudinal impact coefficient, and train formation length.

6. The tunnel construction risk classification and evaluation system according to claim 1, characterized in that: In the resonance identification module, the track settlement response is compared with a preset settlement response threshold to filter and mark passing trains. If the track settlement response exceeds the preset settlement response threshold, the passing train will be marked. Conversely, no markings are made for passing trains; Access the construction control log to obtain the construction disturbance period of the current construction area, including the construction start time and construction end time; By reading the arrival and departure times of marked trains in the current construction area from the railway operation table, and combining this with the construction disturbance period, the disturbance superposition time is determined. Among them, the later of the construction start time and the entry time is used as the superimposed start time, and the earlier of the construction end time and the departure time is used as the superimposed end time. When the time difference between the end time of the superposition and the start time of the superposition is greater than 0, the corresponding time difference is determined as the disturbance superposition time of the marked passing train.

7. The tunnel construction risk classification and evaluation system according to claim 1, characterized in that: In the resonance identification module, during the disturbance superposition time, the vibration acceleration signal of the marked passing train is detected by the vibration acceleration sensor. After the vibration acceleration signal is processed by fast Fourier transform, the vibration amplitude corresponding to different frequency components is obtained. The frequency value with the largest vibration amplitude is selected as the wheel-rail vibration data. Access the structural frequency calibration library to retrieve the reference frequency of the construction structure corresponding to the current construction area, and calculate the frequency proximity coefficient using the reference frequency of the construction structure and wheel-rail vibration data. If the frequency proximity coefficient is greater than the preset frequency proximity threshold, the resonance risk level is in the resonance trigger state, and a resonance risk alarm signal is generated. Conversely, the resonance risk level is a resonance-not-triggered state.

Images