Disclosure of Invention
The invention provides a bridge temperature measuring method, a bridge temperature measuring device, bridge temperature measuring equipment and a readable storage medium, which aim to solve the problems in the prior art.
In order to achieve the purpose, the invention is realized by the following technical scheme:
in a first aspect, the present invention provides a bridge temperature measurement method, including:
determining a target time sequence corresponding to a bridge to be detected, wherein the target time sequence is used for representing solar weather data in the environment where the bridge to be detected is located;
determining the initial temperature of the bridge to be detected and the radiation temperature of the bridge to be detected based on the target time sequence;
determining the temperature of a first surface fluid of the bridge to be detected according to a preset first condition;
determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface;
determining the temperature of the bridge to be tested based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature.
Optionally, the target time sequence includes a solar radiation sequence, an atmospheric temperature sequence, a wind speed sequence, and a structural internal air temperature sequence of the bridge to be tested.
Optionally, the determining the initial temperature and the radiation temperature of the bridge to be measured based on the target time series includes:
determining the initial atmospheric temperature in the atmospheric temperature sequence as the initial temperature of the bridge to be measured;
determining the radiation temperature of the bridge to be detected according to the solar radiation sequence and the atmospheric temperature sequence;
recording the radiation temperature of the bridge to be measured as TeSaid T iseThe following calculation relationship is satisfied:
in the formula, Ta,sIs a sequence of atmospheric temperatures, qsIs a solar radiation sequence, gamma is the radiance of the surface of the concrete structure, h is the comprehensive heat exchange coefficient of the surface of the concrete structure, and Te,sIs a radiant temperature sequence.
Optionally, the first condition satisfies the following calculation relationship:
wherein x represents the position of the outer surface of the bridge concrete member, T (x, T) represents the temperature value to be obtained of the bridge concrete member, h
1Represents the value of the overall heat transfer coefficient of the outer surface of the bridge concrete member,
showing T (x, T) to calculate the partial derivative of the variable x, and k represents the heat conductivity coefficient of the bridge concrete member;
the first surface fluid temperature satisfies the following calculation relationship:
f1(t)=T1,v-T1,wcos(w1(t-δ1)),t∈(t1~t2);
in the formula (f)1(T) denotes the first surface fluid temperature, T1,vExpressed as a function uniform value, T1,wRepresenting the fluctuation value of the function, w1Representing the frequency, δ, of the function1Representing the phase of the function, t representing the current time, t1Indicates the start time, t2Indicating the end time.
Optionally, the second condition satisfies the following calculation relationship:
in the formula: x is the position of the inner surface of the bridge structure, h2The value of the comprehensive heat exchange coefficient of the inner surface of the bridge structure is obtained;
the second surface fluid temperature satisfies the following calculation relationship:
f2(t)=T2,v-T2,wcos(w2(t-δ2)),t∈(t1~t2);
in the formula: t is2,vFor a gas temperature sample T in a bridge structurebAverage air temperature of (T)2,wIs the fluctuating air temperature in the cavity, w2Is the frequency of the cosine function, delta2Is the phase of the cosine function.
Optionally, when the temperature of the bridge to be measured is determined based on the initial temperature, the radiation temperature, the first surface fluid temperature, and the second surface fluid temperature, the following calculation relationship is satisfied:
in the formula (f)
i,n(t) a form of variation of the temperature of the fluid at the internal and external surfaces of the bridge structure, C
i,n、
β
n、X(β
nX) are all calculated coefficients, T
0Alpha is the thermal diffusivity of the bridge concrete member, which is the initial temperature of the bridge structure.
In a second aspect, an embodiment of the present application further provides a bridge temperature measuring device, including:
the system comprises a first processing unit, a second processing unit and a third processing unit, wherein the first processing unit is used for determining a target time sequence corresponding to a bridge to be detected, and the second target time sequence is used for representing solar weather data in the environment where the bridge to be detected is located;
the second processing unit is used for determining the initial temperature of the bridge to be detected and the radiation temperature of the bridge to be detected based on the target time sequence;
the third processing unit is used for determining the temperature of the first surface fluid of the bridge to be detected according to a preset first condition;
the fourth processing unit is used for determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface;
and the fifth processing unit is used for determining the temperature of the bridge to be measured based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature.
In a third aspect, an embodiment of the present application further provides an electronic device, which includes a processor, a memory, and a program or an instruction stored on the memory and executable on the processor, where the program or the instruction, when executed by the processor, implements the steps of the bridge temperature measurement method according to the first aspect.
In a fourth aspect, embodiments of the present application further provide a readable storage medium, on which a program or instructions are stored, and when executed by a processor, the program or instructions implement the steps of the bridge temperature measurement method according to the first aspect.
Has the advantages that:
the invention provides a bridge temperature measuring method, a device, equipment and a readable storage medium, wherein the bridge temperature measuring method comprises the steps of determining a target time sequence corresponding to a bridge to be measured, wherein the target time sequence is used for representing solar weather data in the environment where the bridge to be measured is located; determining the initial temperature of the bridge to be detected and the radiation temperature of the bridge to be detected based on the target time sequence; determining the temperature of a first surface fluid of a bridge to be measured according to a preset first condition; determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface; and determining the temperature of the bridge to be measured based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature. Therefore, the temperature field distribution of different structures and different construction stages of the bridge can be rapidly calculated by combining the solar weather data in the environment where the bridge is located and the internal temperature of the bridge structure.
Detailed Description
The technical solutions of the present invention are described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
As shown in fig. 1, the present invention provides a bridge temperature measurement method, including:
step 101, determining a target time sequence corresponding to the bridge to be detected, wherein the target time sequence is used for representing solar weather data in the environment where the bridge to be detected is located.
In this embodiment, the target time series includes, but is not limited to, a solar radiation series, an atmospheric temperature series, a wind speed series, and a structural interior air temperature series of the bridge under test. The method is only used as an example and is not limited, and alternatively, in other possible embodiments, other types of parameters may be selected as the target time sequence, and only the temperature of the bridge is required to be represented, but the method is within the protection scope of the embodiments of the present application regardless of the change of the parameter.
In a possible implementation, when acquiring the target time sequence, a small-sized weather station including a solar radiation meter, an anemometer and two temperature sensors may be installed at the bridge to be measured; the solar radiation meter is used for measuring a solar radiation sequence, the anemometer is used for measuring a wind speed sequence, and the temperature sensor is used for measuring an atmospheric temperature sequence and can also be used for measuring an internal temperature sequence of the structure. The sequence refers to a period of measurement values, in other words, the sequence is a set including a plurality of measurement values, and details are not described herein. The measurement condition can be satisfied by that the small-sized meteorological station is positioned in an open field at the bridge site, is not shielded by surrounding structures, and is erected on the ground by a special meteorological support. The temperature sensor of the inside temperature of bridge structures is placed in the meteorological shutter and placed inside the bridge structures, and the temperature sensor is connected with the cables of the meteorological station. This is by way of example only and not by way of limitation.
In practice, when a target time sequence corresponding to a bridge to be measured is determined, carrying out statistical calculation on samples within a solar irradiation time range, specifically, determining an average value of atmospheric temperature and an average value of wind speed; the time series samples of the weather data are then used to determine the initial temperature and the radiant temperature of the bridge structure, for example, the atmospheric temperature at the time of rising sun may be used as the initial temperature of the bridge structure, and the radiant temperature of the bridge structure may be calculated from the time-by-time sample data, in a manner to be described in detail in the following steps.
Step 102, determining the initial temperature of the bridge to be measured and the radiation temperature of the bridge to be measured based on the target time sequence;
103, determining the temperature of a first surface fluid of the bridge to be detected according to a preset first condition;
104, determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface;
and 105, determining the temperature of the bridge to be measured based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature.
The bridge temperature measuring method comprises the steps of firstly determining the initial temperature of a bridge to be measured and the radiation temperature of the bridge to be measured through a target time sequence, and then determining the first surface fluid temperature of the bridge to be measured according to a preset first condition; determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface; and determining the temperature of the bridge to be measured based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature. The solar weather data in the environment where the bridge is located and the internal temperature of the bridge structure can be combined, and the temperature field distribution of different structures and different construction stages of the bridge can be rapidly calculated.
It should be noted that when determining the target time sequence corresponding to the bridge to be measured, it is necessary to satisfy the weather conditions of cloudless and breeze on a sunny day, and in this embodiment, the sunrise time, for example, 7 am, is taken as the first time, the sunset time, for example, 7 pm, is taken as the second time, and the target time sequence corresponding to the bridge to be measured within the time range of the first time and the second time is determined. Wherein, the collection frequency is once an hour, and the number of samples is m ═ t2-t1) The intensity q of solar radiation and the atmospheric temperature T are formedaAir temperature T in bridge structural cavitybAnd time series samples of wind speed v.
Then, the time series samples of the atmospheric temperature are calculated statistically, and the average value T of the atmospheric temperature in one day is determinedavThe calculation formula satisfies the following relation:
s=1,2...m;
in the formula, Ta,sTime-by-time samples for atmospheric temperature, Ta=[Ta,1,Ta,2…Ta,m-1,Ta,m]M, m is the number of samples, and s is the time series of the samples.
Carrying out statistical calculation on the obtained time series samples of the wind speed, and determining the average value v of the wind speedaThe calculation formula satisfies the following relation:
s=1,2...m;
in the formula, va,sFor the wind speed time-by-time sample, v ═ va,1,va,2…va,m-1,va,m],s=1,2...m。
Further, the obtained solar radiation q is subjected tosAtmospheric temperature TaThe time series samples are subjected to statistical calculation to determine the radiation air temperature T of the outer surface of the bridge structureeTime series samples of (a);
s=1,2...m
in the formula, Te,sFor radiating a temperature sequence, Te=[Te,1,Te,2…Te,m-1,Te,m],s=1,2...m。
For the radiation air temperature T obtained in the above stepeIn the calculation formula, a value taking method of the parameter gamma is explained, wherein the gamma is the radiance of the surface of the concrete structure, the value taking range is 0.4-0.7, and the judgment is carried out according to the coating color of the surface, the cleanness of the surface and the roughness of the surface. For example, the darker the coating color of the structure surface, the larger the coefficient value; the neater the structure surface is, the smaller the coefficient value is; the rougher the structure surface, the larger the coefficient value.
Wherein the obtained radiation air temperature TcIn the calculation formula of e, h is the comprehensive heat exchange coefficient of the surface of the concrete structure and the comprehensive heat exchange coefficient h of the outer surface of the concrete structure1Value 15.5, comprehensive heat exchange coefficient h of comprehensive heat exchange coefficient of inner surface of concrete structure2Value 12 is taken.
In this embodiment, the initial atmospheric temperature in the atmospheric temperature sequence is determined as the initial temperature of the bridge to be measured, for example, the atmospheric temperature Ta=[Ta,1,Ta,2…Ta,m-1,Ta,m]Determining the initial temperature T of the bridge structure0Value, T0=Ta,1I.e. the first atmospheric temperature collected at the sunrise time of the sun is the initial temperature of the concrete element.
Then, determining a fluid temperature function formula of the outer surface of the bridge structure: the radiant air temperature T of the bridge structure obtained in the stepeFitting time series samples T for the fluid temperature of the outer surface of the bridge by using Fourier functioneThe second order Fourier function is as follows.
f1(t)=T1,v+acos(w1t)+bsin(w1t),t∈(t1~t2);
In the formula, T1,v、a、b、w1Fitting parameters of a Fourier function;
the above equation is converted to the form of a cosine function as follows:
f1(t)=T1,v+T1,wcos(w1(t-δ1)),t∈(t1~t2);
in the formula, T
1,wFor uniform values of the cosine function, using the formula
Calculating; delta
1As a function of phase, using formula
Calculating; t is t
1、t
2Sunrise and sunset times, respectively.
It should be noted that, because the outer surface and the inner surface of the bridge structure are both in a composite heat exchange state, the heat flow boundary is nonlinear, and the equation cannot be effectively used for solving. Therefore, it is necessary to determine a convection boundary condition (a preset first condition) of the outer surface of the bridge structure and a convection boundary condition (a preset second condition) of the inner surface of the bridge structure.
In this embodiment, the functional formula f for obtaining the boundary of the outer surface (first surface) of the bridge structure is described above1(t), determining that the convection boundary condition of the outer surface of the bridge structure meets the following formula:
wherein x is 0 and T (x, T) is the temperature value to be determined for the concrete bridge memberIn the embodiment h1Taking the value of 15.5. The method is only used as an example and is not limited, and alternatively, in other feasible embodiments, the value of k may be adjusted within a certain range, k represents the thermal conductivity of the bridge concrete member, and the value is determined by the concrete material of the actual engineering, and generally ranges from 1.2 to 1.8.
Further, the fluid temperature function of the inner surface of the bridge structure is determined as follows:
to obtain an internal temperature sequence sample T of the bridge structurebFor the fluid temperature at the inner surface of the bridge, the transformation is expressed in the form of a cosine function as follows:
f2(t)=T2,v-T2,wcos(w2(t-δ2)),t∈(t1~t2);
in the formula, T
2,vIs a sequence sample T
bAverage value of (1) using
Calculating to obtain; t is
2,wIs a sequence sample T
bFluctuation value of (1) is
Calculating to obtain; t is
b,maxIs a sequence sample T
bThe highest air temperature, i.e. T
b,max=max[T
b,1,T
b,2…T
b,m-1、T
b,m];T
b,minIs a sequence sample T
bOf the lowest air temperature, i.e. T
b,min=min[T
b,1,T
b,2…T
b,m-1、T
b,m];w
2For frequencies of the cosine function, use
m is the number of samples in a day; delta
2The phase of the middle cosine function is obtained by the time when the highest air temperature appears on the inner surface air temperature of the bridge structure, for example, if the time when the highest air temperature appears is 15:00, delta is obtained
2=15。
Determining the convection boundary conditions of the inner surface of the bridge structure as follows:
wherein x ═ d is the position of the inner surface of the bridge structure, T is the temperature field of the bridge structure to be evaluated, h2Is the comprehensive heat exchange coefficient value h of the inner surface of the bridge structure2Value 12 is taken. The present invention is not limited to the above embodiments, and the values may be adjusted within a certain range in other possible embodiments.
Further, according to the fluid temperature function formulas of the inner surface and the outer surface of the bridge structure, the fluid temperature function formula of the surface of the bridge structure obtained in the step is converted as follows:
when i is 1, the temperature function of the fluid on the outer surface of the bridge structure is expressed, and accordingly, f1(t)=ΔTf,1+Tf,1(t)。
When i is 2, the temperature function of the fluid on the inner surface of the bridge structure is expressed, and accordingly, f2(t)=ΔTf,2+Tf,2(t)。
Wherein:
ΔTf,i=Ti,v-T0;
Tf,i(t)=-Ti,wcos(wi(t-δi));
in the formula, Ti,vIs the mean value of the sequence samples, wiI is 1,2, which is the frequency of the function. In the formula of this embodiment, when i is 1, the formula indicates a fluid temperature function formula of the outer surface of the bridge structure, that is, i is 1. When i is 2, the functional formula of the fluid temperature of the outer surface and the inner surface of the bridge structure is shown, namely i is 2.
Establishing a relation model of a bridge structure temperature field: the relation model for predicting the bridge structure temperature field obtained according to the steps is as follows:
(4)θ(x,t)=T(x,t)-T0;
in the formula, α and k are the thermal diffusivity and the thermal conductivity of concrete respectively, and θ (x, t) is the temperature of the bridge structure to be obtained, is a variable and is related to the position x inside the bridge structure and the time t. d is the position of the inner surface of the bridge structure and x is the position inside the bridge structure.
The above-described relational model is a thermal conduction partial differential equation in heat transfer science, and in this embodiment, by establishing the above-described relational model, the equation can be made solvable. The temperature of the bridge can be rapidly determined.
Specifically, a value taking method of the parameters alpha and k is explained, the specific value is determined by the thermophysical property parameter of the concrete material, and if field test conditions exist, the value can be taken in the thermophysical property test of the concrete material; if no field test condition exists, values can be obtained according to the common values of alpha being 0.0032 and k being 1.8.
Then, based on the mathematical model of the temperature field of the bridge structure, the calculation formula of the temperature field of the bridge structure obtained by performing integral calculation on the mathematical model of the temperature field satisfies the following relation:
in the formula (f)i,n(t) is a variation of the fluid temperature at the inner and outer surfaces of the bridge structure, as follows:
i=1,2;
n=1,2,3,4,5;
wherein n represents the nth characteristic value,
for a calculation coefficient, it can be calculated by the following formula:
Ci,nthe calculation coefficient for one of the formulas can be calculated according to the following formula:
in the formula, hiThe comprehensive heat exchange coefficient of the outer (i ═ 1) or inner (i ═ 2) surface of the bridge structure, betanAs a characteristic value, X (. beta.)nxi) As a characteristic function, N (. beta.)n) Is the eigenvalue.
Herein C
i,nIt can be composed of several expressions:
2X(β
nx
i)、3N(β
n)
the calculation coefficient for one of the formulas can be calculated according to the following formula:
βnthe calculation coefficient for one of the formulas can be calculated according to the following formula:
wherein L is the thickness of the bridge concrete member in meters/m.
X(βnxi) The calculation coefficient for one of the formulas can be calculated according to the following formula:
X(βn,xi)=βncosβnxi+H1sinβnxi;
in the formula, xiIs the external or internal surface of a bridge structure, H1Is the ratio of the comprehensive heat exchange coefficient to the heat conductivity coefficient of the outer surface of the bridge structure, when i is 1, xi0; when i is 2, xi=L。
N(βn) The calculation coefficient for one of the formulas can be calculated according to the following formula:
the calculation formula for obtaining the bridge structure temperature field is a series superposition formula about a time variable t and a space variable x, can effectively solve the problems of distribution and prediction of the bridge structure temperature field in solar radiation, and can be conveniently applied to a high-speed railway cable-stayed bridge with large span and a complex system: and combining the actually measured meteorological data and the internal temperature of the bridge structure, and rapidly calculating the temperature field distribution of different structures and different construction stages. For example, the temperature field distribution and the temperature form of the concrete bridge deck in the construction stage, the box girder-track system in the operation stage or different members (concrete bridge pier, bridge tower and track slab) of the cable-stayed bridge at the same time are adopted.
It should be noted that the bridge temperature measurement method provided by the embodiment of the present application can be applied to, but is not limited to, cable-stayed bridge structures such as concrete track slabs, concrete piers and concrete pylons.
The invention discloses a bridge temperature measuring method which has certain universality, can predict a bridge structure temperature field only by meteorological data of local regions and the internal temperature of a bridge structure at a bridge site, and simultaneously meets the prediction of the bridge structure temperature at different construction stages. The method is simple and convenient to implement and has good feasibility.
The embodiment of the present application further provides a bridge temperature measuring device, including:
the system comprises a first processing unit, a second processing unit and a third processing unit, wherein the first processing unit is used for determining a target time sequence corresponding to a bridge to be detected, and the second target time sequence is used for representing solar weather data in the environment where the bridge to be detected is located;
the second processing unit is used for determining the initial temperature of the bridge to be detected and the radiation temperature of the bridge to be detected based on the target time sequence;
the third processing unit is used for determining the temperature of the first surface fluid of the bridge to be detected according to a preset first condition;
the fourth processing unit is used for determining the temperature of a second surface fluid of the bridge to be detected according to a preset second condition, wherein the second surface is a surface opposite to the first surface;
and the fifth processing unit is used for determining the temperature of the bridge to be measured based on the initial temperature, the radiation temperature, the first surface fluid temperature and the second surface fluid temperature.
The bridge temperature measuring device can realize the steps of the bridge temperature measuring method embodiment, and can obtain the same or similar beneficial effects, and the details are not repeated here.
Embodiments of the present application further provide an electronic device, which includes a processor, a memory, and a program or an instruction stored in the memory and executable on the processor, where the program or the instruction when executed by the processor implements the steps of the bridge temperature measurement method described above.
Embodiments of the present application also provide a readable storage medium, on which a program or instructions are stored, which when executed by a processor implement the steps of the bridge temperature measurement method as described above.
The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.