A multi-dimensional integrated system for evaluating freezing effect of composite ground of subway

Abstract

A kind of multidimensional integrated system for evaluating the freezing effect of subway composite ground, which comprises a plurality of freezing pipes in the field and a software part running on a host computer outside the pipes; each multidimensional integrated monitoring device installed in the freezing pipes is arranged around the freezing pipes in the composite ground, including a data processing platform, a lifting system, a monitoring subsystem, a refrigeration cycle system and a device housing; the monitoring subsystem comprises a temperature sensor group, a camera system, a radar detector group and a frost heaving stress monitor group; the temperature sensor group, the camera system, the radar detector group and the frost heaving stress monitor group are used to monitor the freezing temperature value, the freezing original image, the electromagnetic parameter change and the frost heaving stress value in the composite ground at different depths and different directions around the freezing pipes, and provide the data to the data processing platform for data processing analysis, judgment and display; meanwhile, each monitoring system is controlled by the data processing platform. The freezing construction effect evaluation is quantified.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of subway shield freezing construction monitoring. BACKGROUND

[0002] In the construction of the connecting passage of the subway in the composite stratum, the freezing method is often used for reinforcement. The freezing method is to use refrigeration technology to reinforce the stratum around the subway construction area, so that a frozen wall with certain bearing capacity and water isolation effect is formed. Due to the uneven hardness characteristics of the composite stratum in the current subway construction process, such as soft on top and hard on bottom, hard on top and soft on bottom, soft on left and hard on right, and hard on left and soft on right, the quality of the frozen wall after the freezing method reinforcement cannot achieve the ideal effect, and major engineering accidents such as water and sand gushing, ground subsidence and damage to existing tunnels are often caused during construction. Therefore, the freezing construction of the composite stratum is a major hazard in the process of subway construction, and how to effectively monitor the effect of freezing is a difficult problem to be solved in the current subway construction process.

[0003] The existing monitoring of the freezing method construction in the subway composite stratum is mainly qualitative judgment through temperature measurement hole temperature, pressure relief hole pressure, salt water loop temperature and active freezing time. Temperature sensors and camera systems are arranged around the freezing pipe to monitor the temperature change around the frozen soil. The sensors need to be equipped with tracks and trolleys to move the sensors, and in actual construction, the installation workload of the tracks and trolleys is large and it is not convenient to operate the moving sensors. The existing sensors cannot monitor the frost heaving stress and the freezing state outside the freezing pipe, and the frost heaving stress and the freezing state outside the freezing pipe are also important construction parameters of the freezing construction, so the frost heaving stress and the freezing state outside the freezing pipe need to be monitored in the freezing construction.

[0004] Since the freezing pipe of the subway connecting passage is generally buried at a depth of 25m to 30m, and the number of buried freezing pipes is large, and the number of temperature measurement holes is very limited and unevenly distributed, it is difficult to quantitatively monitor the thickness of the frozen wall of the freezing pipe and the intersection of the frozen walls of multiple freezing pipes, and it is also impossible to monitor the displacement of the composite stratum soil caused by the frost heaving of the frozen soil, and it is also impossible to evaluate the strength of the frozen soil after freezing, especially it is impossible to visually and quantitatively track the whole process of the freezing of the subway connecting passage, and it is impossible to accurately judge the dynamic effect of the curtain freezing intersection under different freezing time and different freezing position conditions. Therefore, it is necessary to monitor the main construction parameters (such as freezing temperature, freezing deformation, frost heaving stress, etc.) around the freezing pipe to ensure the effect of the frost heaving construction. SUMMARY

[0005] In order to overcome the above prior art, the purpose of the present application is to provide a method for dynamically monitoring and evaluating the freezing effect of the composite stratum of the subway, which dynamically monitors the image of the soil around the freezing pipe, the freezing state outside the freezing pipe, the temperature of the soil around the freezing pipe, the stress of the soil around the freezing pipe and other multi-dimensional factors affecting the freezing construction from different positions in space, analyzes and judges the freezing stratum construction effect from the multi-dimensional factors, and provides data services for the freezing construction.

[0006] At the same time, in order to overcome the above prior art, the purpose of the present application is to provide a multi-dimensional integrated system for evaluating the freezing effect of the composite stratum of the subway, which can monitor and evaluate the freezing effect of the stratum in all directions and in multiple ways, and is convenient for guiding the freezing construction of the composite stratum.

[0007] Technical scheme one

[0008] A method for dynamically monitoring and evaluating the freezing effect of the composite stratum of the subway, characterized in that it comprises

[0009] Step 1, installing a multi-dimensional integrated monitoring device in a single freezing pipe, including a temperature sensor group 5, a camera system 3, a radar detector group 4 and a frost heaving stress monitor group 6 four subsystems;

[0010] Step 2, using the subsystems of the multi-dimensional integrated monitoring device, the temperature sensor group 5, the camera system 3, the radar detector group 4 and the frost heaving stress monitor group 6 to monitor and obtain the freezing temperature value, the freezing original image, the electromagnetic parameter change and the frost heaving stress value respectively, and provide these monitoring data to the core controller 101;

[0011] Step 3, the subsystems respectively evaluate the freezing stratum construction effect;

[0012] The temperature sensor group 5, the camera system 3, the radar detector group 4 and the frost heaving stress monitor group 6 respectively evaluate the freezing stratum construction effect, and respectively obtain four subsystem evaluation indexes of the temperature effect index, the connected area of the average freezing temperature, the radar freezing effect index and the frost heaving amount.

[0013] Step 4, establishing a comprehensive evaluation system of the overall freezing stratum construction effect;

[0014] Within a certain monitoring time accumulation range, the core controller 101 respectively fits the correlation coefficients of the four subsystem evaluation indexes according to the monitored data; if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the freezing pipe continues to implement freezing and continues to monitor and determine.

[0015] In step 3, the temperature sensor group 5 evaluates the freezing stratum construction effect by the following method:

[0016] The freezing effect can also be evaluated by the temperature sensor group 5. The freezing temperature measured by the temperature sensors 501-505 in the core controller 101 is obtained to establish a temperature quantitative evaluation model for quantitative evaluation. The specific evaluation process is as follows:

[0017] S1: Collect the freezing temperature. The freezing temperature measured by the temperature sensors 501-505 in the core controller 101 is exported. According to the evaluation needs, the temperature data within any time period can be selected as the evaluation index.

[0018] S2: Establish a temperature quantitative evaluation model. The evaluation model is:

[0019]

[0020] In the above formula, I is the temperature effect index; Q i is the normalized value of the temperature data collected for the ith index; ω i is the weight coefficient of the ith index; and n is the number of temperature sensors, i.e., 5.

[0021] In step 3, the camera system 3 evaluates the freezing formation construction effect by the following method:

[0022] On the one hand, the temperature value is obtained from the temperature sensor group 5 subsystem and the freezing average temperature is calculated;

[0023] On the other hand, first, the original freezing formation image stored in the core controller 101 is exported; second, the original freezing formation image is grayed using the weighted average method; third, the correspondence between the gray value of the freezing image and the freezing average temperature is established using the background subtraction algorithm; and fourth, the connected area reaching the freezing average temperature is determined using the K-means clustering algorithm according to the correspondence between the gray value of the freezing image and the freezing average temperature.

[0024] In step 3, the radar detector group 4 evaluates the freezing formation construction effect by the following method:

[0025] R1: Collect and analyze the freezing effect related indexes. The five freezing effect related indexes of soil layer dielectric constant ε, electromagnetic wave frozen soil propagation speed v, electromagnetic wave reflection signal intensity difference Δ, freezing range s, and frozen pipe frost heaving deformation reflection strip number m can be selected as the evaluation index according to the evaluation needs.

[0026] The electromagnetic parameter values measured by the radar detector group 5 in the core controller 101 are obtained, and the soil layer dielectric constant, electromagnetic wave frozen soil propagation speed, electromagnetic wave reflection signal intensity difference, freezing range, and frozen pipe frost heaving deformation reflection strip are obtained through calculation and analysis by the core controller 101.

[0027] Soil layer dielectric constant ε: When the dielectric constant is less than 3.2, it indicates that the soil layer is in the frozen soil range, otherwise it is in the unfrozen soil range. The core controller 101 records the soil layer dielectric constant.

[0028] Electromagnetic wave frozen soil propagation speed v: When the electromagnetic wave frozen soil propagation speed is greater than 0.17 m / ns, it indicates that the soil layer is in the frozen soil range, otherwise it is in the unfrozen soil range. The core controller 101 records the electromagnetic wave frozen soil propagation speed.

[0029] Difference in electromagnetic wave reflection signal intensity Δ: Calculate the difference between the electromagnetic wave reflection signal intensity in the frozen soil range and the electromagnetic wave reflection signal intensity in the adjacent area outside the frozen soil range. The core controller 101 records the difference in electromagnetic wave reflection signal intensity.

[0030] Calculation of frozen range s: Calculate the frozen range s by the two-way travel time T of the electromagnetic wave from transmission to return and the average propagation speed V1 of the electromagnetic wave in the ice body, and the calculation formula is s = T * V1 / 2.

[0031] Number of frozen pipe frost heave deformation reflection bands m determination: If other frozen pipes around it are broken, the soil around other frozen pipes has high water content and is difficult to freeze, and the electromagnetic wave speed is correspondingly low. The electromagnetic wave suddenly appears frozen pipe frost heave deformation reflection bands around other frozen pipes, and the core controller 101 records the number of frozen pipe frost heave deformation reflection bands.

[0032] R2: Establish a quantitative evaluation model for radar freezing effect. The evaluation model established is:

[0033]

[0034] In the above formula, A is the radar freezing effect index; B i is the normalized value of the radar freezing data collected for the ith index; C i is the weight coefficient of the ith index, which can be established through testing and verification in the experimental stage before engineering application; n is the number of indexes, i.e. 5.

[0035] In step 3, the method for calculating the frost heave amount by the frost heave stress monitored by the frost heave stress monitor group 6:

[0036] First, obtain the frost heave stress values at different spatial positions (monitoring values of the first frost heave stress monitor 601 and the second frost heave stress monitor 602), the middle (monitoring values of the third frost heave stress monitor 603 and the fourth frost heave stress monitor 604), and the lower (monitoring values of the fifth frost heave stress monitor 605 and the sixth frost heave stress monitor 606) of the core controller 101; second, establish a calculation formula between the frost heave amount and the frost heave stress value; and finally, substitute the frost heave stress value into the calculation formula to obtain the frost heave amount.

[0037] The displacement caused by frost heaving stress is calculated as follows:

[0038] The frost heaving displacement caused by frost heaving is the frost heaving amount. The calculation formula of the frost heaving amount η is as follows:

[0039] η = η max - δ (Formula I)

[0040] Wherein, η max is the free frost heaving amount, which can be calculated according to Formula II; δ is the restrained frost heaving amount, which can be calculated by Formula VIII.

[0041]

[0042] Wherein, ε can be calculated by Formula III, and ε x represents the strain value of ε in the x direction, and ε y represents the strain value of ε in the y direction; γ xy can be obtained by simultaneously solving Formula IV-Formula VII; R can be represented as ω is a constant, indicating the angle of rotation of the frozen body, η0 is the initial frost heaving amount. x represents the frost heaving development path along the length direction of the freezing pipe; y represents the frost heaving development path perpendicular to the length direction of the freezing pipe.

[0043]

[0044] Wherein, σ max is taken in the following manner: the frost heaving stress monitor one 601 and the frost heaving stress monitor two 602 at the upper part, the larger of the two measured values is set as σ max ; or the frost heaving stress monitor three 603 and the frost heaving stress monitor four 604 at the middle part, the larger of the two measured values is set as σ max ; or the frost heaving stress monitor five 605 and the frost heaving stress monitor six 606 at the lower part, the larger of the two measured values is set as σ max . E is the elastic modulus of frozen soil.

[0045]

[0046]

[0047]

[0048]

[0049]

[0050] In the formula, p represents the frozen strength, and is the maximum value of the frost heaving stress monitor 601, the frost heaving stress monitor 602, the frost heaving stress monitor 603, the frost heaving stress monitor 604, the frost heaving stress monitor 605, and the frost heaving stress monitor 606; κ is the designed Poisson's ratio of frozen soil; π is the circular constant; E is the designed elastic modulus of frozen soil; and r is the designed thickness of the frozen wall.

[0051] Technical solution two

[0052] A multi-dimensional integrated system for evaluating the freezing effect of a composite stratum of a subway, characterized in that a multi-dimensional integrated monitoring device is installed in a plurality of freezing pipes on site, and a software part running on an upper computer is installed outside the pipes.

[0053] The multi-dimensional integrated monitoring device installed in each freezing pipe is arranged around the freezing pipes of the composite stratum, and includes a data processing platform 1, a lifting system 2, a monitoring subsystem, a refrigeration circulation system 7, and a device shell 8.

[0054] The monitoring subsystem includes a temperature sensor group 5, a camera system 3, a radar detector group 4, and a frost heaving stress monitor group 6; the temperature sensor group 5, the camera system 3, the radar detector group 4, and the frost heaving stress monitor group 6 are respectively used for monitoring the freezing temperature value, the freezing original image, the electromagnetic parameter change, and the frost heaving stress value in the composite stratum at different depths and different directions around the freezing pipes, and providing the data to the data processing platform 1 for data processing analysis, judgment, and display, while each monitoring system is controlled by the data processing platform 1.

[0055] The software part of the data processing platform 1 includes a data processing system, a comprehensive analysis and evaluation system, a display system, and a control system; the control system is used for controlling the start and stop of the lifting system 2 and the refrigeration circulation system 7; the data processing system is used for obtaining four evaluation indexes of a temperature effect index, a connected area of a freezing average temperature, a radar freezing effect index, and a frost heaving amount after processing the monitoring data of the monitoring subsystem, and transmitting the evaluation indexes to the comprehensive analysis and evaluation system; the comprehensive analysis and evaluation system is used for fitting and determining the correlation coefficients of the four evaluation indexes within a certain monitoring time accumulation range, and analyzing and judging that if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the control system controls the refrigeration circulation system 7 to continue freezing and monitoring and judging. The display system is used for providing a display interface for the monitoring data obtained by the data processing system and the comprehensive analysis and evaluation system, and the data processed and analyzed, and can display the monitoring data of the monitoring subsystem, the evaluation index values, and the correlation coefficient values in real time.

[0056] The refrigeration circulation system 7 provides a freezing circulation pipeline for the stratum around the freezing circulation pipeline.

[0057] The camera system 3 and the radar detector group 4 are arranged in the space of the device shell 8, are divided into a plurality of monitoring areas in the depth and horizontal direction, are connected with the lifting system 2 in different monitoring areas, and are controlled to control the lifter group in the lifting system 2, so that the camera system 3 and the radar detector group 4 are moved up and down; and the purpose is to obtain the frozen original image and electromagnetic parameter change in the frozen soil construction range at different heights and different directions.

[0058] Beneficial effects

[0059] The method of the present application utilizes the frozen temperature value, the frozen original image, the electromagnetic parameter change and the frost heaving stress value monitored by each multidimensional integrated monitoring device, establishes different analysis methods according to the above five monitoring dimensions, evaluates the frozen soil construction effect, quantifies the frozen soil construction effect evaluation, and the evaluation result is more accurate, which makes up for the deficiency of the construction effect evaluation method in the frozen soil construction field.

[0060] The system for evaluating the freezing effect of the composite stratum of the subway according to the present application can detect the frozen temperature value, the frozen original image, the electromagnetic parameter change and the frost heaving stress value at different depths and different directions, and process, analyze, judge and display the data, so as to facilitate the monitoring, evaluation and control of the freezing stratum construction effect and the freezing construction period; therefore, the system can monitor and evaluate the freezing stratum construction effect in a comprehensive and multiple way, and has high practicability. BRIEF DESCRIPTION OF DRAWINGS

[0061] Figure 1 It is a front view of the multidimensional integrated monitoring device.

[0062] Figure 2 It is a test section view of the multidimensional integrated monitoring device.

[0063] Figure 3 It is a section view of the multidimensional integrated monitoring device rotated counterclockwise by 45 degrees.

[0064] Figure 4 It is a section view of the multidimensional integrated monitoring device rotated counterclockwise by 135 degrees.

[0065] Figure 5 It is Figure 1 It is a front view along the A-A' tangent;

[0066] Figure 6 It is a process diagram of the monitoring method using the multidimensional integrated monitoring device.

[0067] Figure 7 It is a flowchart of the evaluation of the freezing stratum construction effect using the camera system 3.

[0068] Figure 8For the temperature effect index correlation coefficient fitting graph in Example 1;

[0069] Figure 9 For the frozen average temperature connection area correlation coefficient fitting graph in Example 1;

[0070] Figure 10 For the radar freezing effect index correlation coefficient fitting graph in Example 1;

[0071] Figure 11 For the frost heaving amount correlation coefficient fitting graph in Example 1;

[0072] Figure 12 For the system structure diagram using multi-dimensional integration for evaluating the freezing effect of the subway composite stratum;

[0073] Digital label annotation:

[0074] Central control processing system 1, core controller 101, data transmission line 102, external power supply interface 103, transmission channel one 104, transmission channel two 105, transmission channel three 106, transmission channel four 107; lifting system 2, lifter one 201, lifter two 202, lifter three 203, lifter four 204, lifting rope 205, monitoring area one 206, monitoring area two 207, monitoring area three 208, monitoring area four 209, motor one 210, motor two 211, motor three 212, motor four 213, fixed frame 214; camera system 3, camera one 301, camera two 302, cold light source one 303, cold light source two 304; radar detector group 4, radar detector one 401, radar detector 402; temperature sensor group 5, temperature sensor one 501, temperature sensor two 502, temperature sensor three 503, temperature sensor four 504, temperature sensor five 505, frost heaving stress monitor group 6, frost heaving stress monitor one 601, frost heaving stress monitor two 602, frost heaving stress monitor three 603, frost heaving stress monitor four 604, frost heaving stress monitor five 605, frost heaving stress monitor six 606, freezing circulation system 7, central water inlet pipe 701, water outlet pipe 702, central freezing warehouse 703, liquid inlet controller 704, liquid outlet controller 705, freezing liquid storage 706, hose 707, device housing 8, transparent tempered glass shell 801, wear-resistant conical head 802; soil 9, soft soil 901, hard soil 902. DETAILED DESCRIPTION

[0075] The technical solutions of the present application are described in detail below in conjunction with the drawings.

[0076] The monitoring device is used for dynamically monitoring and evaluating the freezing effect of the subway composite stratum, such as Figure 6 The method is as follows:

[0077] Step 1, install the multi-dimensional integrated monitoring device in a single freezing pipe, including the temperature sensor group 5, the camera system 3, the radar detector group 4, and the frost heaving stress monitor group 6 four subsystems;

[0078] Step 2, use the subsystems of the multi-dimensional integrated monitoring device, the temperature sensor group 5, the camera system 3, the radar detector group 4, and the frost heaving stress monitor group 6 to monitor and obtain the freezing temperature value, the freezing original image, the electromagnetic parameter change, and the frost heaving stress value respectively, and provide these monitoring data to the core controller 101;

[0079] Step 3, the subsystems respectively evaluate the freezing stratum construction effect;

[0080] The subsystems of the temperature sensor group 5, the camera system 3, the radar detector group 4, and the frost heaving stress monitor group 6 respectively evaluate the freezing stratum construction effect, and respectively obtain four subsystem evaluation indexes of the temperature effect index, the connected area of the freezing average temperature, the radar freezing effect index, and the frost heaving amount.

[0081] Step 4, establish a comprehensive evaluation system for the overall freezing stratum construction effect;

[0082] Within a certain monitoring time accumulation range, the core controller 101 respectively fits and determines the correlation coefficients of the four subsystem evaluation indexes according to the monitored data; if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the freezing pipe continues to implement freezing and continues to monitor and determine.

[0083] In step 3, the method for the temperature sensor group 5 to evaluate the freezing stratum construction effect is as follows:

[0084] The freezing effect can also be evaluated by the temperature sensor group 5, the freezing temperature measured by the temperature sensor one 501 to the temperature sensor five 505 in the core controller 101 is obtained, a temperature quantitative evaluation model is established, and quantitative evaluation is performed. The specific evaluation process is as follows:

[0085] S1: collect the freezing temperature. The freezing temperature measured by the temperature sensor one 501 to the temperature sensor five 505 in the core controller 101 is exported, and the temperature data within any time can be selected as the evaluation index according to the evaluation needs.

[0086] S2: establish a temperature quantitative evaluation model. The established evaluation model is as follows:

[0087]

[0088] In the above formula, I is the temperature effect index; Q i is the normalized value of the temperature data collected by the i-th index; ω i is the weight coefficient of the i-th index; and n is the number of temperature sensors, i.e. 5.

[0089] In step 3, the camera system 3 evaluates the freezing ground construction effect by the method as follows:

[0090] On one hand, the temperature value is obtained from the temperature sensor group 5 subsystem and the freezing average temperature is calculated;

[0091] On the other hand, firstly, the original freezing ground image stored in the core controller 101 is derived; secondly, the original freezing ground image is processed by the weighted average method; thirdly, the corresponding relationship between the freezing image gray value and the freezing average temperature is established by the background subtraction algorithm; and fourthly, the connected area reaching the freezing average temperature is determined by the K-means clustering algorithm according to the corresponding relationship between the freezing image gray value and the freezing average temperature. The weighted average method, the background subtraction algorithm and the K-means clustering algorithm are all known algorithms in the field of computer image processing, which are used for image analysis of frozen soil here.

[0092] In step 3, the radar detector group 4 evaluates the freezing ground construction effect by the method as follows:

[0093] R1: The freezing effect related indexes are collected and analyzed. The five freezing effect related indexes of soil dielectric constant ε, electromagnetic wave frozen soil propagation speed v, electromagnetic wave reflection signal intensity difference Δ, freezing range s and frozen pipe frost heave deformation reflection strip number m can be selected as the evaluation indexes according to the evaluation needs.

[0094] The electromagnetic parameter values measured by the radar detector group 5 in the core controller 101 are obtained, and the soil dielectric constant, the electromagnetic wave frozen soil propagation speed, the electromagnetic wave reflection signal intensity difference, the freezing range and the frozen pipe frost heave deformation reflection strip are obtained by the core controller 101.

[0095] Soil dielectric constant ε: When the dielectric constant is less than 3.2, it indicates that the ground is in the frozen soil range s, otherwise it is in the unfrozen soil range. The core controller 101 records the soil dielectric constant.

[0096] Electromagnetic wave frozen soil propagation speed v: When the electromagnetic wave frozen soil propagation speed is greater than 0.17 m / ns, it indicates that the ground is in the frozen soil range, otherwise it is in the unfrozen soil range. The core controller 101 records the electromagnetic wave frozen soil propagation speed.

[0097] Electromagnetic wave reflection signal intensity difference Δ: The difference between the electromagnetic wave reflection signal intensity of the frozen soil range and the electromagnetic wave reflection signal intensity of the adjacent area outside the frozen soil range is calculated. The core controller 101 records the electromagnetic wave reflection signal intensity difference.

[0098] The calculation of the frozen range s: the frozen range s is calculated by the two-way time T of the electromagnetic wave from transmission to return and the average propagation speed V1 of the electromagnetic wave in the ice body, and the calculation formula is H=T*V1.

[0099] The determination of the number m of the frost heave deformation reflection bands of the freezing pipe: if the surrounding other freezing pipes are broken, the surrounding stratum of the other freezing pipes has high water content and is difficult to freeze, the electromagnetic wave speed is correspondingly low, the electromagnetic wave suddenly appears the frost heave deformation reflection bands of the freezing pipe around the other freezing pipes, and the core controller 101 records the number of the frost heave deformation reflection bands of the freezing pipe.

[0100] R2: establishing a quantitative evaluation model of the radar freezing effect. The established evaluation model is:

[0101]

[0102] In the above formula, A is the radar freezing effect index; B i is the normalized value of the radar freezing data collected by the i-th index; C i is the weight coefficient of the i-th index, which can be established through testing and verification in the experimental stage before engineering application; and n is the number of indexes, that is, 5.

[0103] In step 3, the method for calculating the frost heave amount by the frost heave stress monitored by the frost heave stress monitor group 6 is as follows:

[0104] First, the frost heave stress values at different spatial positions (the monitoring values of the frost heave stress monitor one 601 and the frost heave stress monitor two 602), the middle (the monitoring values of the frost heave stress monitor three 603 and the frost heave stress monitor four 604), and the lower (the monitoring values of the frost heave stress monitor five 605 and the frost heave stress monitor six 606) of the core controller 101 are obtained; second, a calculation formula between the frost heave amount and the frost heave stress value is established; and finally, the frost heave stress value is substituted into the calculation formula to obtain the frost heave amount.

[0105] The displacement caused by the frost heave stress is calculated as follows:

[0106] The frost heave displacement caused by the frost heave is the frost heave amount. The calculation formula of the frost heave amount η is:

[0107] η = η max - δ (Formula One)

[0108] Among them, η max is the free frost heave amount, which can be calculated according to Formula Two; and δ is the restrained frost heave amount, which can be calculated by Formula Eight.

[0109]

[0110] Among them, ε can be calculated by Formula Three, and ε xrepresents the strain value of ε in the x direction, ε y represents the strain value of ε in the y direction; γ xy It can be obtained by combining formulas 4 to 7; R can be expressed as ω is a constant, representing the angle of rotation of the frozen body, and η0 is the initial frost heave.

[0111]

[0112] Among them, σ max The value is obtained as follows: the upper frost heave stress monitor 1 601 and the upper frost heave stress monitor 2 602 take the larger value as σ max Or select the frost heave stress monitor 3 603 and the frost heave stress monitor 4 604 in the middle, and set the larger value of the two as σ max Or select the lower frost heave stress monitor five 605, frost heave stress monitor six 606, take the larger of the two measured values ​​and set it as σ max . E is the elastic modulus of frozen soil.

[0113]

[0114]

[0115]

[0116]

[0117]

[0118] In the above formula, p represents the freezing strength, and the maximum value among frost heave stress monitor 1 601, frost heave stress monitor 2 602, frost heave stress monitor 3 603, frost heave stress monitor 4 604, frost heave stress monitor 5 605, and frost heave stress monitor 6 606 is taken; κ is the designed frozen soil Poisson's ratio; π is pi, E is the designed frozen soil elastic modulus, and r is the designed frozen wall thickness.

[0119] Development system based on the method further developed:

[0120] like Figure 12 The system shown includes a data processing platform 1, a lifting system 2, a monitoring subsystem, a refrigeration cycle system 7, and a device housing 8;

[0121] The monitoring subsystem comprises a temperature sensor group 5, a camera system 3, a radar detector group 4, and a frost heaving stress monitor group 6; the temperature sensor group 5, the camera system 3, the radar detector group 4, and the frost heaving stress monitor group 6 are respectively used for monitoring the freezing temperature value, the freezing original image, the electromagnetic parameter change, and the frost heaving stress value in the composite stratum at different depths and different directions around the freezing pipe, and providing the data to the data processing platform 1 for data processing analysis, judgment, and display, while each monitoring system is controlled by the data processing platform 1.

[0122] The data processing platform 1 comprises a data processing system, a comprehensive analysis and evaluation system, a display system, and a control system; the control system is used for controlling the start and stop of the lifting system 2 and the refrigeration circulation system 7. The data processing system is used for obtaining four evaluation indexes of the temperature effect index, the connected area of the freezing average temperature, the radar freezing effect index, and the frost heaving amount after processing the monitoring data of the monitoring subsystem, and transmitting the evaluation indexes to the comprehensive analysis and evaluation system; the comprehensive analysis and evaluation system is used for fitting and determining the correlation coefficients of the four evaluation indexes within a certain monitoring time accumulation range, and analyzing and judging that if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the control system controls the refrigeration circulation system 7 to continue the freezing and continues the monitoring and judgment. The display system is used for providing a display interface for the monitoring data obtained by the data processing system and the comprehensive analysis and evaluation system, and the data after processing and analysis, and can display the monitoring data of the monitoring subsystem, the evaluation index value, and the correlation coefficient value in real time.

[0123] The refrigeration circulation system 7 provides a freezing circulation pipeline for the stratum around the freezing circulation pipeline;

[0124] The camera system 3 and the radar detector group 4 are arranged in the space of the device shell 8, are divided into multiple monitoring areas in the depth and horizontal directions, are connected with the lifting system 2 in different monitoring areas, and are moved up and down by controlling the lifter group in the lifting system 2, so as to obtain the freezing original image and the electromagnetic parameter change in the frozen soil construction range at different heights and different directions.

[0125] Each multi-dimensional integrated monitoring device, Figures 1-5The arrangement is in the soil 9, including data processing platform 1 hardware part, lifting system 2, camera system 3, radar detector group 4, temperature sensor group 5, frost heaving stress monitor group 6, frozen circulating system 7, device shell 8. The data processing platform 1 hardware includes core controller 101, data transmission line 102, external power supply interface 103, display screen; according to the different algorithms loaded in the core controller 101, the software is divided into data processing system, comprehensive analysis and evaluation system, display system, control system; the lifting system 2 includes lifter group, hanging rope 205, monitoring area, motor group, fixed frame 214; the camera system 3 includes two groups of camera devices; the radar detector group 4 includes radar detector one 401, radar detector 402; the temperature sensor group 5 includes temperature sensor one 501, temperature sensor two 502, temperature sensor three 503, temperature sensor four 504, temperature sensor five 505; the frost heaving stress monitor group 6 includes frost heaving stress monitor one 601, frost heaving stress monitor two 602, frost heaving stress monitor three 603, frost heaving stress monitor four 604, frost heaving stress monitor five 605, frost heaving stress monitor six 606; the frozen circulating system 7 includes central water inlet pipe 701, water outlet pipe 702, center freezing warehouse 703, liquid inlet controller 704, liquid outlet controller 705, frozen liquid storage 706, hose 707; the device shell 8 includes transparent tempered glass shell 801, wear-resistant conical head 802.

[0126] The device shell 8 is the shell of the monitoring device, the side is transparent tempered glass shell 801, which is cylindrical; the wear-resistant conical head 802 is installed on the top of the transparent tempered glass shell 801, which is conical.

[0127] The data processing platform 1 hardware is installed in the device shell 8 and close to the upper part, the core controller 101 is the center of monitoring data collection and controlling each subsystem, the upper part of which is installed with external power supply interface 103, the upper end of the core controller 101 in the data processing platform is connected with external power supply through the external power supply interface 103; the lower end of the core controller 101 is connected with the data transmission line 102; the data transmission line 102 is connected with the lifting system 2, the camera system 3, the radar detector group 4, the temperature sensor group 5, the frost heaving stress monitor group 6, the frozen circulating system 7 respectively, which is used for the control signal of the control system to the lifting system 2 and the frozen circulating system 7, and the measurement data of the camera system 3, the radar detector group 4, the temperature sensor group 5, the frost heaving stress monitor group 6 to the data processing system;

[0128] The elevator group of the lifting system 2 is installed on the upper part of the center freezing warehouse 703 through the fixing frame 214, the motor group is connected with the elevator group, and the motor group is connected with the control system through the data transmission line 102, and the rotation of the elevator group is controlled through the control system; the monitoring area is distributed between the freezing circulation system 7 and the device shell 8, which is a cuboid space, and is used for providing vertical movement space for the camera system 3 and the radar detector group 4; the camera system 3 and the radar detector group 4 are connected with the elevator group through the hanging rope 205.

[0129] Each camera group of the camera system 3 includes a camera and a cold light source, which is used for shooting the freezing state of the soil body 9 in the left and right directions of the device shell 8; the cold light source is installed on the camera, which is used for providing the cold light source required for the camera to shoot the freezing state of the soil body 9; the upper part of the cold light source is connected with the elevator group through the hanging rope 205.

[0130] The radar detector group 4 includes the radar detector 401 and the radar detector 402, which is used for monitoring the freezing state of the soil body 9 in the front and back directions of the device shell 8.

[0131] The temperature sensor group 5 is vertically distributed on the upper, middle and lower parts of the multi-dimensional integrated monitoring device, and is symmetrically distributed, and is arranged on the profile of the main view of the multi-dimensional integrated monitoring device which is counterclockwise rotated by 45° in space; wherein the temperature sensor 501 and the temperature sensor 502 are installed on the upper part of the multi-dimensional integrated monitoring device; the temperature sensor 503 and the temperature sensor 504 are installed on the middle part of the multi-dimensional integrated monitoring device; and the temperature sensor 505 is installed on the lower part of the multi-dimensional integrated monitoring device, which is in the shape of a circular truncated cone.

[0132] The frost heaving stress monitor group 6 is vertically distributed on the upper, middle and lower parts of the multi-dimensional integrated monitoring device, and is symmetrically distributed, and is arranged on the profile of the main view of the multi-dimensional integrated monitoring device which is counterclockwise rotated by 135° in space; wherein the frost heaving stress monitor 601 and the frost heaving stress monitor 602 are installed on the upper part of the multi-dimensional integrated monitoring device; the frost heaving stress monitor 603 and the frost heaving stress monitor 604 are installed on the middle part of the multi-dimensional integrated monitoring device; the frost heaving stress monitor 605 and the frost heaving stress monitor 606 are installed on the lower part of the multi-dimensional integrated monitoring device. Each frost heaving stress monitor is a vibrating wire soil pressure cell in the embodiment, and the working temperature is-25℃~+60℃.

[0133] The upper end of the central water inlet pipe 701 in the freezing circulation system 7 is connected with the freezing liquid reservoir 706 through the liquid inlet controller 704; the central freezing bin 703 is a columnar structure; the central water inlet pipe 701 passes through the upper part of the central freezing bin 703, and the bottom is arranged at a distance from the bottom end of the central freezing bin 703; the central freezing bin 703 is connected with the freezing liquid reservoir 706 in sequence through the water outlet pipe 702, the liquid outlet controller 705 and the hose 707, forming a circulation loop. The freezing liquid is arranged in the freezing circulation system 7, which is used to provide a cold source to the soil body 9 outside the device shell 8.

[0134] Based on the system, further give embodiment 1 and implementation effect verification:

[0135] The monitoring device and the system constructed by the upper computer software part are installed in a single freezing pipe.

[0136] The subsystem temperature sensor group (5), the camera system (3), the radar detector group (4) and the frost heaving stress monitor group (6) of the multi-dimensional integrated monitoring device are used to monitor and obtain the freezing temperature value, the freezing original image, the electromagnetic parameter change and the frost heaving stress value respectively, and provide these monitoring data to the data processing platform 1 software part.

[0137] The monitoring subsystem is continuously in the monitoring state, for example, the freezing circulation system 7 runs at 14h, and the specific subsystems are as follows:

[0138] The temperature sensor group 5 subsystem:

[0139] The temperature sensor 1-temperature sensor 5 measurement data in the data processing platform 1 is exported, and at the time point of 14h, the temperature sensor 1-temperature sensor 5 measurement values are-5℃, -8℃, -15℃, -4℃ and -20℃ respectively. The collected five temperature data are divided by-35℃ (design value) by using the data processing system for data processing and analysis, and there are 0.14, 0.23, 0.43, 0.11 and 0.57. After normalization processing, there are 0.10, 0.15, 0.29, 0.08 and 0.38. The temperature effect index I=0.20 is obtained and displayed on the display system.

[0140] At the same time point, the subsystem radar detector group 4:

[0141] The soil layer dielectric constant, the electromagnetic wave frozen soil propagation speed, the electromagnetic wave reflection signal intensity difference, the freezing range and the number of frost heaving deformation reflection strips of the freezing pipe in the data processing platform 1 are exported. The data collected in a certain time are 3, 0.18, 150, 3 and 2 respectively. The data processing system is used for data processing and analysis, and the radar freezing effect index A≈0.21 is obtained and displayed on the display system.

[0142] Similarly, the same time point, the average temperature of the frozen area and the amount of heave of the connected region can be obtained.

[0143] In the above monitoring time 14h accumulation range, the comprehensive analysis evaluation system determines the correlation coefficients of the four subsystem evaluation indexes according to the monitored data; if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the freezing pipe continues to implement freezing and continues to monitor and determine.

[0144] Specifically, the correlation coefficients of the subsystem evaluation indexes are:

[0145] ①If the temperature effect index, the indexes collected within 1t, 2t, 3t, 4t, 5t, 6t, 7t, 8t, 9t, 14t are 0.2, 0.32, 0.36, 0.42, 0.43, 0.47, 0.51, 0.56, 0.61, 0.76 respectively, the correlation graph of the temperature freezing effect index within different time is drawn according to the collected data, and is displayed on the display system. As shown in Figure 8

[0146] It can be known from Figure 8 that the correlation coefficient of the temperature effect index is 0.96.

[0147] ②Set the average freezing temperature connected area, and the indexes collected within 1t, 2t, 3t, 4t, 5t, 6t, 7t, 8t, 9t, 14t are 1m2, 1.2m2, 1.3m2, 1.4m2, 1.5m2, 1.8m2, 2.4m2, 4m2, 5m2, 7.8m2 respectively, the correlation graph of the average freezing temperature connected area within different time is drawn according to the collected data, and is displayed on the display system. As shown in Figure 9

[0148] It can be known from Figure 9 that the correlation coefficient of the average freezing temperature connected area is 0.89.

[0149] ③Set the radar freezing effect index, and the indexes collected within 1t, 2t, 3t, 4t, 5t, 6t, 7t, 8t, 9t, 14t are 0.67, 0.62, 0.56, 0.45, 0.42, 0.35, 0.31, 0.24, 0.22, 0.13 respectively, the correlation graph of the radar freezing effect index within different time is drawn according to the collected data, and is displayed on the display system. As shown in Figure 10

[0150] It can be known from Figure 10 that the correlation coefficient of the radar freezing effect index is 0.90.

[0151] ​​​④ Set the frost heave amount. The indicators collected within 1t, 2t, 3t, 4t, 5t, 6t, 7t, 8t, 9t, and 14t are: 0.76, 0.53, 0.38, 0.45, 0.32, 0.073, 0.065, 0.06, 0.04, and 0.02 respectively. Draw relevant graphs of the frost heave amount at different times for the collected data and display them on the display system. Figure 11 As shown:

[0152] Therefore Figure 11 It can be seen that the correlation coefficient of frost heave is 0.68.

[0153] In summary, the correlation coefficients of the four indicators of the average freezing temperature connected area, radar freezing effect index, temperature effect index, and frost heave are 0.89, 0.96, 0.9, and 0.68, respectively. None of the correlation coefficients are greater than 0.9 at the same time. Therefore, the freezing effect in this time period is unqualified, and the entire refrigeration cycle system 7 needs to continue freezing operation.

Claims

1. A multi-dimensional integrated system for evaluating freezing effect of a composite ground stratum of a subway, characterized in that, A multi-dimensional integrated monitoring device is installed in multiple frozen pipes on site, and a software part operated on an upper computer is installed outside the pipes; The multi-dimensional integrated monitoring device installed in each frozen pipe is arranged around the frozen pipe in the composite ground, and includes a data processing platform (1), a lifting system (2), a monitoring subsystem, a frozen circulation system (7), and a device shell (8); The monitoring subsystem includes a temperature sensor group (5), a camera system (3), a radar detector group (4), and a frost heaving stress monitor group (6); the temperature sensor group (5), the camera system (3), the radar detector group (4), and the frost heaving stress monitor group (6) are respectively used for monitoring the frozen temperature value, the frozen original image, the electromagnetic parameter change, and the frost heaving stress value in the composite ground at different depths and different directions around the frozen pipe, and providing the data to the data processing platform (1) for data processing analysis, judgment, and display; meanwhile, each monitoring system is controlled by the data processing platform (1); The data processing platform (1) software part includes a data processing system, a comprehensive analysis and evaluation system, a display system and a control system; the control system is used for controlling the start and stop of the lifting system (2) and the refrigeration circulating system (7); the data processing system is used for obtaining four evaluation indexes of a temperature effect index , a frozen average temperature connected area, a radar freezing effect index and a frost heaving amount after processing the monitoring data of the monitoring subsystem, and transmitting the evaluation indexes to the comprehensive analysis and evaluation system; the comprehensive analysis and evaluation system is used for fitting and determining the correlation coefficients of the four evaluation indexes within a certain monitoring time accumulation range, and analyzing and judging that if the correlation coefficients of the four subsystem evaluation indexes are all greater than or equal to 0.9, the freezing effect is qualified, and the freezing construction is ended; otherwise, the control system controls the refrigeration circulating system (7) to continue to implement freezing and continue to monitor and determine; the display system is used for providing a display interface for the monitoring data obtained by the data processing system and the comprehensive analysis and evaluation system and the processed and analyzed data, and can display the monitoring data of the monitoring subsystem, the evaluation index values and the correlation coefficient values in real time; temperature effect index ; is the normalized value of the temperature data collected for the first index; is the weight coefficient of the first index; n is the number of temperature sensors; radar freeze effect index ; is the normalized value of the radar freeze data collected for the th index; is the weight coefficient of the th index; n is the number of indexes; The frozen circulation system (7) provides a frozen circulation pipeline for the ground around the frozen circulation pipeline; The camera system (3) and the radar detector group (4) are arranged in the space of the device shell (8), are divided into multiple monitoring areas in the depth and horizontal directions, are connected with the lifting system (2) in different monitoring areas, and are moved up and down by the lifter group in the lifting system (2), so as to realize the up-and-down movement of the camera system (3) and the radar detector group (4); and the purpose is to obtain the frozen original image and the electromagnetic parameter change in the frozen soil construction range at different heights and different directions.

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