CN116718629A - Monitoring system of prestressed concrete lining - Google Patents
Monitoring system of prestressed concrete lining Download PDFInfo
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- CN116718629A CN116718629A CN202310621262.9A CN202310621262A CN116718629A CN 116718629 A CN116718629 A CN 116718629A CN 202310621262 A CN202310621262 A CN 202310621262A CN 116718629 A CN116718629 A CN 116718629A
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- 238000012544 monitoring process Methods 0.000 title claims abstract description 125
- 239000011513 prestressed concrete Substances 0.000 title claims abstract description 86
- 238000004458 analytical method Methods 0.000 claims abstract description 34
- 230000008859 change Effects 0.000 claims abstract description 15
- 238000010276 construction Methods 0.000 claims abstract description 15
- 239000004567 concrete Substances 0.000 claims description 48
- 238000000034 method Methods 0.000 claims description 23
- 229910001294 Reinforcing steel Inorganic materials 0.000 claims description 15
- 230000008569 process Effects 0.000 claims description 14
- 229910000831 Steel Inorganic materials 0.000 claims description 12
- 239000010959 steel Substances 0.000 claims description 12
- 238000004891 communication Methods 0.000 claims description 11
- 238000004088 simulation Methods 0.000 claims description 11
- 238000009413 insulation Methods 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 230000002787 reinforcement Effects 0.000 claims 1
- 238000012545 processing Methods 0.000 abstract description 5
- 230000009467 reduction Effects 0.000 description 15
- 238000004364 calculation method Methods 0.000 description 13
- 238000005336 cracking Methods 0.000 description 9
- 239000003570 air Substances 0.000 description 6
- 238000005266 casting Methods 0.000 description 5
- 101100176675 Xenopus laevis gs17 gene Proteins 0.000 description 3
- 230000008878 coupling Effects 0.000 description 3
- 238000010168 coupling process Methods 0.000 description 3
- 238000005859 coupling reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 238000003860 storage Methods 0.000 description 3
- 238000012360 testing method Methods 0.000 description 3
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 230000006870 function Effects 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000006467 substitution reaction Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 230000002411 adverse Effects 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 239000004746 geotextile Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000036571 hydration Effects 0.000 description 1
- 238000006703 hydration reaction Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000003287 optical effect Effects 0.000 description 1
- 238000005457 optimization Methods 0.000 description 1
- 239000011150 reinforced concrete Substances 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N25/00—Investigating or analyzing materials by the use of thermal means
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
- G01N33/38—Concrete; Lime; Mortar; Gypsum; Bricks; Ceramics; Glass
- G01N33/383—Concrete or cement
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Abstract
The application provides a monitoring system of a prestressed concrete lining, which comprises an acquisition module, a monitoring module and a monitoring module, wherein the acquisition module is used for acquiring monitoring data arranged on a target scale section of the prestressed concrete lining; the inversion module is used for inverting based on the monitoring data sent by the acquisition module so as to acquire target thermodynamic parameters; the analysis module is used for determining temperature change information of the prestressed concrete lining according to the monitoring data sent by the acquisition module and the target thermodynamic parameters sent by the inversion module, determining the type of cracks and influence factors generated by the prestressed concrete lining, and the temperature change information is used for determining the pouring temperature of the prestressed concrete lining, so that the acquisition and processing efficiency of engineering actual data and the tracking inversion efficiency of the tunnel construction period are improved.
Description
Technical Field
The application relates to the technical field of buildings, in particular to a monitoring system for prestressed concrete lining.
Background
Inversion analysis of corresponding concrete adiabatic temperature rise is carried out, real concrete adiabatic temperature rise parameters reflecting engineering reality are obtained, feedback analysis of a concrete structure is carried out according to inversion parameters, and engineering construction can be guided more accurately. In the prior art, the simulation is relatively independent of the processing of engineering actual data, the acquisition of the engineering actual data is more required to consume a large amount of manpower to measure large-volume data, and the inversion analysis calculation efficiency is low.
Disclosure of Invention
In view of the above, the present application aims to provide a monitoring system for prestressed concrete lining, so as to improve the calculation efficiency of inversion analysis.
In a first aspect, the present application provides a monitoring system for a prestressed concrete lining, the monitoring system comprising:
the acquisition module is used for acquiring monitoring data arranged on a target scale section of the prestressed concrete lining;
the inversion module is used for inverting based on the monitoring data sent by the acquisition module so as to acquire target thermodynamic parameters;
the analysis module is used for determining temperature change information of the prestressed concrete lining according to the monitoring data sent by the acquisition module and the target thermodynamic parameter sent by the inversion module, and determining the type of cracks and influence factors generated by the prestressed concrete lining, wherein the temperature change information is used for determining the pouring temperature of the prestressed concrete lining.
Preferably, the acquisition module comprises at least:
the output end of each monitoring unit is connected with the communication unit;
and the communication unit is used for uploading the received monitoring data acquired by all the monitoring units to the cloud.
Preferably, the monitoring unit is a combination of one or more of strain gauge, stress gauge, seam gauge, thermometer, the monitoring unit being arranged in the prestressed concrete lining by: determining the position of at least one monitoring section in the corresponding prestressed concrete lining structure according to the type of the prestressed concrete lining standard section; determining buried nodes of a plurality of monitoring units in each monitoring section according to each monitoring section; and presetting corresponding monitoring units in the determined embedded nodes for each monitoring section.
Preferably, the segment length of the prestressed concrete lining is 11.84 meters, wherein the first monitoring section is a lining thickness section at a distance of 0.42 meter from the segment edge of the prestressed concrete lining, the second monitoring section is a lining thickness section at a distance of 2.42 meters from the segment edge of the prestressed concrete lining, and the third monitoring section is a lining thickness section at a distance of 5.92 meters from the segment edge of the prestressed concrete lining.
Preferably, the step of determining buried nodes of a plurality of monitoring units in any one of the thickness sections of the lining specifically includes: embedding circumferential strain gauges on the thickness section of the prestressed concrete lining along the circumferential direction within the range of 90-360 degrees at intervals of 45 degrees, wherein each circumferential strain gauge is positioned on the thickness central ring surface of the prestressed concrete lining; embedding radial strain gauges at intervals of 45 degrees in the range of 90-360 degrees along the circumferential direction on the inner side of an anchor cable on the thickness section of the pre-stressed concrete lining, wherein each radial strain gauge is arranged at 10 millimeters in the target direction of the corresponding pre-stressed steel strand, and the axial center of each radial strain gauge is positioned on the ring surface where the corresponding pre-stressed steel strand is positioned; and embedding reinforcing steel bar stress meters at intervals of 45 degrees in the range of 0-315 degrees along the circumferential direction on the inner circumferential reinforcing steel bar and the outer circumferential reinforcing steel bar of the prestressed concrete lining, wherein no reinforcing steel bar stress meters are arranged at embedded nodes of 45 degrees along the circumferential direction on the inner circumferential reinforcing steel bar.
Preferably, the target thermodynamic parameter at least includes a temperature expansion coefficient, a temperature conductivity coefficient, a surface heat release coefficient, and an adiabatic temperature rise value, and the inversion module obtains the target thermodynamic parameter by: determining a temperature expansion coefficient according to stress data acquired by a stress meter; according to the temperature data collected by the thermometer, determining a temperature conductivity coefficient; determining a surface heat release coefficient according to the air heat conduction coefficient, the wind speed, the viscosity coefficient of the concrete and the roughness coefficient of the concrete; and determining the heat insulation temperature rise value according to the content and proportion of the concrete and the casting temperature of the concrete.
Preferably, the analysis module comprises: the temperature analysis unit is used for drawing a temperature process comparison curve corresponding to each monitoring section according to the temperature data acquired by the thermometer, and the temperature process comparison curve is used for indicating the temperature change of all the embedded nodes in the corresponding monitoring section; the concrete deformation analysis unit is used for determining the width value and/or the length value of at least one crack generated by the prestressed concrete lining according to the stress data acquired by the stress meter.
Preferably, the monitoring system further comprises a model construction module, wherein the model construction module is used for constructing a finite element simulation model of the prestressed concrete according to the input temperature stress parameters and the actual pouring information; and the feedback module is used for simulating the pouring process according to the target thermodynamic parameters and the finite element simulation model of the prestressed concrete so as to obtain the highest temperature value, the tensile stress value and the safety coefficient value of each monitoring section at different ages.
Preferably, the method further comprises the step of synchronously arranging one thermometer when arranging each circumferential strain gauge, radial strain gauge and reinforcing steel bar stress timer.
Preferably, the monitoring data includes at least a displacement value, a stress value, and a temperature value for each embedded node.
The application provides a monitoring system of a prestressed concrete lining, which comprises an acquisition module, wherein the acquisition module is used for acquiring monitoring data arranged on a target scale section of the prestressed concrete lining; the inversion module is used for inverting based on the monitoring data sent by the acquisition module so as to acquire target thermodynamic parameters; the analysis module is used for determining temperature change information of the prestressed concrete lining and determining the type of cracks and influence factors generated by the prestressed concrete lining according to the monitoring data sent by the acquisition module and the target thermodynamic parameters sent by the inversion module, and the temperature change information is used for determining the pouring temperature of the prestressed concrete lining, so that the acquisition and processing efficiency of engineering actual data and the tracking inversion efficiency of the tunnel construction period are improved.
In order to make the above objects, features and advantages of the present application more comprehensible, preferred embodiments accompanied with figures are described in detail below.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a block diagram of a monitoring system for prestressed concrete lining provided by an embodiment of the present application;
FIG. 2 is a schematic view of a monitoring section according to an embodiment of the present application;
FIG. 3 is a schematic view of a placement of a monitoring unit in a fourth monitoring section according to an embodiment of the present application;
FIG. 4 is a schematic diagram showing details of the embodiment of FIG. 3A;
FIG. 5 is a point location layout of a test cross section of prestressed concrete with a B2 standard according to an embodiment of the present application;
fig. 6 is a temperature process comparison curve of a second monitoring section B according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are only some embodiments of the present application, not all embodiments. The components of the embodiments of the present application generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the application, as presented in the figures, is not intended to limit the scope of the application, as claimed, but is merely representative of selected embodiments of the application. Based on the embodiments of the present application, every other embodiment obtained by a person skilled in the art without making any inventive effort falls within the scope of protection of the present application.
First, an application scenario to which the present application is applicable will be described. The method can be applied to on-site temperature control inversion analysis of tunnel lining engineering.
Inversion analysis of corresponding concrete adiabatic temperature rise is carried out, real concrete adiabatic temperature rise parameters reflecting engineering reality are obtained, feedback analysis of a concrete structure is carried out according to inversion parameters, and engineering construction can be guided more accurately. In the prior art, the simulation is relatively independent of the processing of engineering actual data, the acquisition of the engineering actual data is more required to consume a large amount of manpower to measure large-volume data, and the inversion analysis calculation efficiency is low. Based on the above, the embodiment of the application provides a monitoring system for prestressed concrete lining, so as to improve the calculation efficiency of inversion analysis.
Referring to fig. 1, fig. 1 is a block diagram of a monitoring system for prestressed concrete lining according to an embodiment of the present application. As shown in fig. 1, the monitoring system of the prestressed concrete lining provided by the embodiment of the application at least comprises an acquisition module 10, an inversion module 20 and an analysis module 30, wherein the acquisition module 10 is used for acquiring monitoring data arranged on a target scale segment of the prestressed concrete lining; the inversion module 20 is used for inverting based on the monitoring data sent by the acquisition module 10 to acquire target thermodynamic parameters; the analysis module 30 is configured to determine temperature change information of the prestressed concrete lining according to the monitoring data sent by the acquisition module 10 and the target thermodynamic parameter sent by the inversion module 20, and determine a type of a crack and an influencing factor generated by the prestressed concrete lining, where the temperature change information is used to determine a pouring temperature of the prestressed concrete lining.
The monitoring data at least comprises a displacement value, a stress value and a temperature value of each embedded node.
The monitoring system for the prestressed concrete lining provided by the embodiment of the application can automatically acquire the acquired monitoring data and perform concrete temperature control inversion analysis so as to provide a data basis for a construction scheme of lining pouring, thereby improving the calculation efficiency of inversion analysis.
In one embodiment of the present application, the acquisition module 10 includes at least a plurality of monitoring units and a communication unit. The output end of each monitoring unit is connected with the communication unit, and the communication unit is used for uploading the monitoring data acquired by all the received monitoring units to the cloud. The communication unit may also be used to send monitoring data to an analysis module 30 or the like in the system.
Specifically, the monitoring unit is one or a combination of a plurality of strain gauges, stress gauges, seam gauges and thermometers, and is arranged in the prestressed concrete lining in the following way:
and determining the position of at least one monitoring section in the corresponding prestressed concrete lining structure according to the type of the prestressed concrete lining standard section. For each monitoring section, the buried nodes of a plurality of monitoring units in the monitoring section are determined. And presetting corresponding monitoring units in the determined embedded nodes for each monitoring section.
And the method further comprises the step of synchronously arranging a thermometer when arranging each circumferential strain gauge, radial strain gauge and steel bar stress timer.
In the construction of prestressed concrete, a batch of monitoring units are buried in different parts of a lining, and mainly comprise a thermometer, a seam meter, a strain gauge and the like.
In one embodiment of the application, the segment length of the prestressed concrete lining is 11.84 meters, wherein the first monitoring section is a lining thickness section at 0.42 meters from the segment edge of the prestressed concrete lining, the second monitoring section is a lining thickness section at 2.42 meters from the segment edge of the prestressed concrete lining, and the third monitoring section is a lining thickness section at 5.92 meters from the segment edge of the prestressed concrete lining.
In this embodiment, as shown in fig. 2, a first monitoring section a (gs17+ 134.788, 0.42m from the segment edge, located at the center of the segment lined 1# anchor groove) is located at B3, a second monitoring section B (gs17+ 129.288, 5.92m from the segment edge, length-wise middle section, located at the center of the segment lined 12# anchor groove), located at B3; the third monitoring section C (gs17+ 125.788, 2.42m from the segment edge, centered in the segment lining 19# anchor groove), is at B3. And a fourth test section D (5.92 m from the segment edge, the middle section in the length direction) is positioned at the B2 mark.
Determining buried nodes of a plurality of monitoring units in any lining thickness section, specifically including:
embedding circumferential strain gauges on the thickness section of the prestressed concrete lining along the circumferential direction within the range of 90-360 degrees at intervals of 45 degrees, wherein each circumferential strain gauge is positioned on the thickness central ring surface of the prestressed concrete lining; embedding radial strain gauges at intervals of 45 degrees in the range of 90-360 degrees along the circumferential direction on the inner side of an anchor cable on the thickness section of the pre-stressed concrete lining, wherein each radial strain gauge is arranged at 10 millimeters in the target direction of the corresponding pre-stressed steel strand, and the axial center of each radial strain gauge is positioned on the ring surface where the corresponding pre-stressed steel strand is positioned; and embedding reinforcing steel bar stress meters at intervals of 45 degrees in the range of 0-315 degrees along the circumferential direction on the inner circumferential reinforcing steel bar and the outer circumferential reinforcing steel bar of the prestressed concrete lining, wherein no reinforcing steel bar stress meters are arranged at embedded nodes of 45 degrees along the circumferential direction on the inner circumferential reinforcing steel bar.
As shown in fig. 3 to 5, taking a fourth monitoring section as an example, the fourth monitoring section penetrates through the 12# anchorage groove 5.92m away from the edge of the section, and circumferential strain gauges are embedded at intervals of 45 degrees along the circumferential direction of 90 degrees to 360 degrees on the central annular surface of the thickness of the lining. And burying the circumferential reinforcing steel bar stress gauges on the inner and outer circumferential reinforcing steel bars of the lining at intervals of 45 degrees along the circumferential direction between 0 and 315 degrees, wherein the inner 45 degrees are not affected by an anchor. Radial strain gauges are buried inside the anchor cable at the positions of sections of between 90 and 360 degrees at intervals of 45 degrees, the radial strain gauges are arranged at the positions of 10 millimeters beside the prestressed steel strand, the axial centers of the strain gauges are positioned on the ring surface where the steel strand is located, and other monitoring sections are arranged similarly.
In one embodiment, the B2 standard prestressed concrete first warehouse is 20:12, opening a warehouse for pouring, 8 in the morning the next day: 50, pouring is completed, and the pouring time is 12 hours and 38 minutes. The demolding completion time is 6 months, 29 days and night 21:00, and the distance pouring is completed for 60 hours and 10 minutes. And (5) starting curing after removing the mould, wherein the curing mode is to spray concrete curing agent and spray water for curing. And according to the concrete temperature monitoring data, finishing to obtain the B2 standard prestressed concrete section B temperature monitoring result.
From the temperature monitoring data, it can be seen that: the temperature of the outlet of the B2 marking machine is between 27 and 28.1 ℃, the warehouse entry temperature is between 30.1 and 30.9 ℃, and the time is 23 after 6 months and 29 days: 00, the highest temperature of the 0-degree point position of the temperature measuring point of the section B occurs in 6 months and 27 days 16:11, at 70.5 ℃, the highest temperature occurs 7 hours 21 minutes after pouring is completed; the highest 180 ° spot temperature occurs at 6 months, 27 days 23:11, 69.7℃and the highest temperature occurs 14 hours 21 minutes after casting is completed. The highest temperature of the monitoring point of the section B is 61.3-71.5 ℃, and basically reaches the highest temperature in the 1-day age after pouring is finished, which indicates that the heat insulation temperature of the concrete is increased and the temperature rise speed is very high. No. 27-29, the change of the ambient temperature in the hole is small, and the fluctuation is 2.2 ℃ at maximum; the ambient temperature in the cavity is basically stabilized at about 28 ℃. The maximum temperature is 28-7 months and 4 days after 6 months, the temperature is reduced by 27.8-35.8 ℃ within 7 days, the maximum temperature reduction rate of the 180-degree point position of the top arch is 10.5 ℃/day, the average temperature reduction rate is 5.1 ℃/day, the average temperature reduction rate of other point positions is 4.0-5.0 ℃/d, and the large temperature reduction rate is generated in the period of 8-9 days, so that the structure shrinkage is large.
The prestressed concrete first warehouse of the B3 standard is 15 pm in 22 days of 5 months: 58, pouring in a warehouse, and 3 in the morning the next day: 30, pouring is completed, and the time for pouring is 11 hours and 32 minutes. The demolding time is 5 months 25 days afternoon 17:15. and (3) after the die is removed, curing is started, wherein the curing time is 5 months 25 days to 6 months 22 days, and the curing mode is manual watering curing. And according to the concrete temperature monitoring data, finishing to obtain the temperature monitoring results of each section of the B3-standard prestressed concrete. From the temperature monitoring data, it can be seen that: the outlet temperature of the standard head bin of B3 is between 29 and 30.6 ℃, the inlet temperature is between 31 and 32 ℃ and the time of 6 months and 25 days is 23:00, highest temperature of J1 point of the A section seam meter appears in 5 months, 23 days and 16 days: 00, 66.0 ℃, the highest temperature occurs 12 hours and 30 minutes after pouring is completed; the highest temperature of the J5 point of the B section joint meter appears in the 5 month and 23 days 13:00, 60.3 ℃, the highest temperature occurs 9 hours and 30 minutes after pouring is completed; the highest temperature of the SC1 point position of the C section strain gauge occurs at 16 days of 5 months and 23 days: 00, 70.2 ℃, the highest temperature occurs 12 hours and 30 minutes after pouring is completed; the highest temperature of the monitoring point is 51.3-70.2 ℃, and the highest temperature is basically reached in the 1-day age after pouring is finished, which indicates that the heat insulation temperature of the prestressed concrete is increased, and the temperature rise speed is very high. The temperature change of the environment in the hole is small, and the temperature is basically stabilized at about 28 ℃. The temperature is reduced by 24-30 days of 5 months to 5 months after the highest temperature is exceeded, the temperature is reduced by 24.4-41.0 ℃ within 7 days, the maximum temperature reduction rate of the C section strain gauge SC1 point position is 11.6 ℃/day, the average temperature reduction rate is 5.9 ℃/day, the average temperature reduction rate of other point positions is 3.5-5.3 ℃/d, and the temperature reduction rate is large when the temperature is reduced by 8-9 days.
The analysis module 30 includes a temperature analysis unit and a concrete deformation analysis unit.
The temperature analysis unit is used for drawing a temperature process comparison curve corresponding to each monitoring section according to the temperature data acquired by the thermometer, and the temperature process comparison curve is used for indicating the temperature change of all the embedded nodes in the corresponding monitoring section. As shown in fig. 6, fig. 6 is a temperature process comparison curve of a second monitoring section B according to an embodiment of the present application.
The concrete deformation analysis unit is used for determining the width value and/or the length value of at least one crack generated by the prestressed concrete lining according to the stress data acquired by the stress meter.
In one embodiment, according to the crack monitoring data provided by the construction, the B3 mark finds 18 cracks, wherein 3# bins (first bin) are 3, 10 # bins (second bin) are 4, and 5# bins (third bin) are 5. The crack type is basically an arch-side vertical crack and is near the middle position of the length.
In one embodiment of the present application, the target thermodynamic parameters include at least a temperature expansion coefficient, a temperature conductivity coefficient, a surface heat release coefficient, and an adiabatic temperature rise value, and the inversion module 20 obtains the target thermodynamic parameters by: determining a temperature expansion coefficient according to stress data acquired by a stress meter; according to the temperature data collected by the thermometer, determining a temperature conductivity coefficient; determining a surface heat release coefficient according to the air heat conduction coefficient, the wind speed, the viscosity coefficient of the concrete and the roughness coefficient of the concrete; and determining the heat insulation temperature rise value according to the content and proportion of the concrete and the casting temperature of the concrete.
The adiabatic temperature rise of concrete is an important parameter affecting the temperature stress in the construction period, and general parameters are obtained by fitting test results of 28d, and may be different from actual adiabatic temperature rise parameters. And (3) combining actual information such as actual concrete temperature, ambient air temperature, warehouse-in temperature, pouring time and the like in field engineering, calling a simulation analysis program by using an optimization method to perform a great number of repeated positive analyses, and finally minimizing errors between the temperature distribution calculated by the positive analyses and the actual measured temperature distribution of the selected multiple measuring points.
The inversion calculation model may be B2 and B3. The lining model mainly comprises lining segments and prestressed concrete. Wherein, the thickness of the prefabricated reinforced concrete pipe piece is 400mm, and the concrete strength grade is C55; the thickness of the prestressed concrete lining is 550mm, the inner diameter is 6.4m, and the concrete strength grade is C50. The tunnel parting length is 11.84m. And correcting the adiabatic temperature rise parameters measured in a laboratory by inverting thermodynamic parameters of the concrete, so as to construct a real temperature field. The inversion of thermodynamic parameters is based on actual monitoring data of the site, the actual casting progress of the site concrete, the performance of the concrete material, construction measures (casting temperature, water spraying maintenance) and the like are simulated in simulation calculation, and the actual measured air temperature in a hole is taken as a temperature boundary so as to reflect the actual condition of the engineering.
In a specific embodiment, by comparing the measured temperature with the inversion temperature, it can be seen that the measured maximum temperature of the 0-degree point location of the B2 standard B section on site is 70.5 ℃, and the maximum temperature of the point location is 70.46 ℃ by inversion calculation; the 180-degree point position on-site measured highest temperature of the B2 standard B section is 69.7 ℃, and the point position highest temperature is calculated to be 69.64 ℃ in an inversion mode; the maximum temperature measured on site of the SC1 point of the C section marked by B3 is 70.2 ℃, and the maximum temperature of the point is 70.16 ℃ by inversion calculation. The simulation calculation temperature process is basically consistent with the actual measurement point temperature process, and the calculated temperature can better reflect the temperature space-time change rule of the structure. On the basis of reasonable and accurate mechanical parameters, the stress calculated based on the calculated temperature is more realistic and can reflect the stress characteristic of the structure.
In one embodiment of the application, the monitoring system further includes a model building module 50, and a feedback module 40.
The model construction module 50 is used for constructing a finite element simulation model of the prestressed concrete according to the input temperature stress parameters and the actual pouring information. The feedback module 40 is used for simulating the pouring process according to the target thermodynamic parameters and the finite element simulation model of the prestressed concrete, so as to obtain the highest temperature value, the tensile stress value and the safety coefficient value of each monitoring section at different ages.
Based on the better fit between the calculated temperature and the measured temperature, temperature stress feedback can be performed. In a specific embodiment, the temperature inversion calculation results indicate that: the highest temperature of the 0-degree point of the section B of the standard B is 70.46 ℃ (the measured highest temperature is 70.5 ℃); the highest temperature of the 180-degree point of the section B of the standard B is 69.64 ℃ (the highest temperature is measured to be 69.7 ℃); the highest temperature of the point position of the section SC1 of the standard C of the B3 is 70.16 ℃ (the measured highest temperature is 70.2 ℃), and exceeds the highest temperature standard of the recommended temperature control scheme. The highest temperature occurs in the age of 1d after pouring, and the curve fitting with the measured temperature is good; the temperature is rapidly reduced under the influence of the ambient temperature, the temperature reduction range in the 28d age is more than 40 ℃, and then the temperature in the hole is gradually reached.
The parting length of the concrete of the B3 standard is 11.84m, the temperature stress is larger, the maximum tensile stress in the length direction of the point position of the SC1 of the C section is 3.23MPa, and the minimum safety coefficient is 1.26; the tensile stress of the 0-degree point position 8d age direction of the bottom plate of the section B lane platform is 4.22MPa, the tensile strength of the concrete is exceeded, the safety coefficient is 0.96 and is less than 1.0, and the risk of cracking exists in early stage; the maximum tensile stress appears in 21d age, the maximum tensile stress in the length direction is 5.35MPa, and the safety coefficient is 0.93. The tensile stress of the 180-degree point position of the top arch of the section B in the length direction of the age 5d is 3.70MPa, the safety coefficient is 0.94 and less than 1.0, and the risk of cracking exists in the early stage; the maximum tensile stress appears in the age of 11d, the maximum tensile stress in the length direction is 4.54MPa, and the safety coefficient is 0.97.
The parting length of the prestressed concrete of the B2 standard is 11.84m, the temperature stress is larger, under the measures of laying geotextile and plugging hand holes, the tensile stress of the 0-degree point position of the bottom plate of the B section lane platform in the 7d age length direction is 4.07MPa, the tensile strength of the prestressed concrete exceeds that of the concrete, the safety coefficient is 0.95, and the early cracking risk exists; the maximum tensile stress appears in the 28d age, the maximum tensile stress in the length direction is 4.66MPa, and the safety coefficient is 1.11. The tensile stress of the 180-degree point position 7d age length direction of the section B top arch is 3.77MPa, and the safety coefficient is 1.03; the maximum tensile stress appears in the 28d age, the maximum tensile stress in the length direction is 4.09MPa, and the safety coefficient is 1.26.
Because the highest temperature and the temperature drop process are different, the overall safety coefficient of the B3 standard is lower than that of the B2 standard, and the cracking risk is higher than that of the B2 standard. The tensile stress of the 0-degree point position 7d age of the base plate of the B2 standard lane platform exceeds the tensile strength, and the cracking risk exists. The stress of the B3 standard lane platform and the stress of the side top arch exceed the anti-cracking strength, the tensile stress of the top arch at 180-degree point location at the age 5d exceeds the tensile strength, and the tensile stress of the lane platform bottom plate at the age 0-degree point location at the age 8d exceeds the tensile strength, so that the risk of cracking exists.
When the hand hole is not blocked, the maximum tensile stress of different points of the lining concrete is 6.05 MPa-7.08 MPa, and the minimum safety coefficient is about 0.64. The hand hole plugging-free constraint effect is obvious, the stress is increased by 32% -35% compared with the hand hole plugging working condition, the tensile strength of the concrete is exceeded, and the cracking risk is high. If the internal temperature of the concrete is high, the hand hole is recommended to be plugged in advance.
The temperature inversion calculation result shows that the concrete is internally subjected to inversion analysis, the result of actually measured temperature of 70 ℃ shows that the original construction mix proportion parameter, the final value of adiabatic temperature rise of 62 ℃ and the half-cooked age of 1.05d. The measured temperature shows that the adiabatic temperature rise is higher and the temperature rise is faster (particularly, the half-cooked age determines the highest temperature and the heating speed of concrete, the same final value of adiabatic temperature rise is different for different concrete in the half-cooked age, and the smaller the half-cooked age is, the higher the highest temperature is and the faster the temperature rise is).
Further, inversion analysis is performed according to the measured concrete temperature and the air temperature in the hole, crack cause analysis is performed by taking the parameter and the air temperature in the hole as boundaries, and a calculation result shows that:
(1) The highest temperature is too high. The highest temperature in the lining concrete reaches 70 ℃, basically reaches the highest temperature in the 1-day age after pouring is finished, and then gradually reduces the temperature to the temperature in the hole, mainly because of surrounding foundation constraint. The concrete has high heat insulation temperature, high temperature rising speed and adverse temperature control. (optimizing the mixing ratio and reducing the hydration heat are particularly important).
(2) The temperature is reduced within 7 days from 24 days to 5 months and 30 days after the highest temperature of the standard B3 is reached, the maximum temperature reduction rate of the point position of the strain gauge SC1 on the section C is 11.6 ℃/day, the average temperature reduction rate is 5.9 ℃/day, and the average temperature reduction rate of other point positions is 3.5 to 5.3 ℃/d.
The maximum temperature of the B2 standard is 28 to 7 months and 4 days after the highest temperature is passed, the temperature is reduced by 27.8 to 35.8 ℃ within 7 days, the maximum temperature reduction rate of the top arch 180 DEG point position is 10.5 ℃/day, the average temperature reduction rate is 5.1 ℃/day, and the average temperature reduction rate of other point positions is 4.0 to 5.0 ℃/d;
factors that decrease the temperature faster include: the thin layer structure, the high highest temperature value and the low outside air temperature, so the important point of controlling the temperature drop rate is as follows: the highest temperature is controlled, and the temperature in the environment of the hole is controlled to be relatively stable.
(3) Hand hole restraint. When the hand hole is not plugged, the restraint effect is obvious, the point positions of the left arch and the right arch have large temperature stress, the temperature stress exceeds the tensile strength of concrete, the stress is increased by about 35% compared with the working condition of plugging the hand hole, and the cracking risk of the positions is increased. In the recommended site construction process, when the internal temperature of the monitored concrete is high, the hand hole can be plugged in advance subsequently, and the crack resistance of the structure is improved.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.
In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. The above-described apparatus embodiments are merely illustrative, for example, the division of the units is merely a logical function division, and there may be other manners of division in actual implementation, and for example, multiple units or components may be combined or integrated into another system, or some features may be omitted, or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be through some communication interface, device or unit indirect coupling or communication connection, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in the embodiments of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.
The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a non-volatile computer readable storage medium executable by a processor. Based on this understanding, the technical solution of the present application may be embodied essentially or in a part contributing to the prior art or in a part of the technical solution, in the form of a software product stored in a storage medium, comprising several instructions for causing a computer device (which may be a personal computer, a server, a network device, etc.) to perform all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-only memory (ROM), a random access memory (RandomAccessMemory, RAM), a magnetic disk, an optical disk, or other various media capable of storing program codes.
Finally, it should be noted that: the above examples are only specific embodiments of the present application, and are not intended to limit the scope of the present application, but it should be understood by those skilled in the art that the present application is not limited thereto, and that the present application is described in detail with reference to the foregoing examples: any person skilled in the art may modify or easily conceive of the technical solution described in the foregoing embodiments, or perform equivalent substitution of some of the technical features, while remaining within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.
Claims (10)
1. A monitoring system for a prestressed concrete lining, the monitoring system comprising:
the acquisition module is used for acquiring monitoring data arranged on a target scale section of the prestressed concrete lining;
the inversion module is used for inverting based on the monitoring data sent by the acquisition module so as to acquire target thermodynamic parameters;
the analysis module is used for determining temperature change information of the prestressed concrete lining according to the monitoring data sent by the acquisition module and the target thermodynamic parameters sent by the inversion module, determining the type of cracks and influencing factors generated by the prestressed concrete lining, and determining the pouring temperature of the prestressed concrete lining according to the temperature change information.
2. The monitoring system of claim 1, wherein the acquisition module comprises at least:
the output end of each monitoring unit is connected with the communication unit;
and the communication unit is used for uploading the received monitoring data acquired by all the monitoring units to the cloud.
3. The monitoring system of claim 2, wherein the monitoring unit is a combination of one or more of strain gauge, stress gauge, seam gauge, thermometer, the monitoring unit being arranged in a prestressed concrete lining by:
determining the position of at least one monitoring section in the corresponding prestressed concrete lining structure according to the type of the standard section of the prestressed concrete lining;
determining buried nodes of a plurality of monitoring units in each monitoring section according to each monitoring section;
and presetting corresponding monitoring units in the determined embedded nodes for each monitoring section.
4. A monitoring system according to claim 3, wherein the segment length of the prestressed concrete lining is 11.84 meters, wherein the first monitoring section is a lining thickness section at 0.42 meters from the segment edge of the prestressed concrete lining, the second monitoring section is a lining thickness section at 2.42 meters from the segment edge of the prestressed concrete lining, and the third monitoring section is a lining thickness section at 5.92 meters from the segment edge of the prestressed concrete lining.
5. The monitoring system of claim 4, wherein the step of determining the embedded nodes of a plurality of monitoring units in any one of the lining thickness sections, specifically comprises:
embedding circumferential strain gauges on the thickness section of the prestressed concrete lining within the range of 90-360 degrees along the circumferential direction at intervals of 45 degrees, wherein each circumferential strain gauge is positioned on the thickness center ring surface of the prestressed concrete lining;
embedding radial strain gauges at intervals of 45 degrees in the range of 90-360 degrees along the circumferential direction on the inner side of an anchor cable on the thickness section of the lining of the prestressed concrete lining, wherein each radial strain gauge is arranged at 10 millimeters in the target direction of the corresponding prestressed steel strand, and the axial center of each radial strain gauge is positioned on the ring surface where the corresponding prestressed steel strand is positioned;
and embedding reinforcing steel bar stress meters at intervals of 45 degrees in the range of 0-315 degrees along the circumferential direction on the inner circumferential steel bar and the outer circumferential steel bar of the prestressed concrete lining, wherein no reinforcing steel bar stress meters are arranged at embedded nodes of 45 degrees along the circumferential direction on the inner circumferential steel bar.
6. The monitoring system of claim 3, wherein the target thermodynamic parameter comprises at least a temperature expansion coefficient, a temperature conductivity coefficient, a surface heat release coefficient, and an adiabatic temperature rise value, and wherein the inversion module obtains the target thermodynamic parameter by:
determining the temperature expansion coefficient according to stress data acquired by a stress meter;
determining the temperature conductivity coefficient according to temperature data acquired by a thermometer;
determining the surface heat release coefficient according to the air heat conduction coefficient, the wind speed, the viscosity coefficient of the concrete and the roughness coefficient of the concrete;
and determining the heat insulation temperature rise value according to the content and proportion of the concrete and the pouring temperature of the concrete.
7. The monitoring system of claim 1, wherein the analysis module comprises:
the temperature analysis unit is used for drawing a temperature process comparison curve corresponding to each monitoring section according to temperature data acquired by the thermometer, and the temperature passing Cheng Duibi curve is used for indicating temperature changes at all embedded nodes in the corresponding monitoring section;
the concrete deformation analysis unit is used for determining the width value and/or the length value of at least one crack generated by the prestressed concrete lining according to the stress data acquired by the stress meter.
8. The monitoring system of claim 1, wherein the monitoring system further comprises:
the model construction module is used for constructing a finite element simulation model of the prestressed concrete according to the input temperature stress parameters and the actual pouring information;
and the feedback module is used for simulating the pouring process according to the target thermodynamic parameters and the finite element simulation model of the prestressed concrete so as to obtain the highest temperature value, the tensile stress value and the safety coefficient value of each monitoring section at different ages.
9. The monitoring system of claim 5, further comprising:
and synchronously arranging a thermometer when arranging each circumferential strain gauge, each radial strain gauge and each reinforcement stress meter.
10. The monitoring system of claim 1, wherein the monitoring data includes at least a displacement value, a stress value, and a temperature value for each embedded node.
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| CN117540481A (en) * | 2024-01-09 | 2024-02-09 | 石家庄铁道大学 | Method and device for predicting lining damage of frozen soil area, electronic equipment and storage medium |
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| CN117540481A (en) * | 2024-01-09 | 2024-02-09 | 石家庄铁道大学 | Method and device for predicting lining damage of frozen soil area, electronic equipment and storage medium |
| CN117540481B (en) * | 2024-01-09 | 2024-03-12 | 石家庄铁道大学 | Method and device for predicting lining damage of frozen soil area, electronic equipment and storage medium |
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