Temperature control index optimization method for whole concrete dam pouring link

Abstract

The invention provides a concrete dam pouring full-link temperature control index optimization method. The method comprises the following steps: firstly, determining the allowable concrete highest temperature in the whole concrete dam pouring process; comprehensively considering the concrete temperature change of each link in the whole concrete dam pouring process, and establishing a concrete maximum temperature calculation model in the whole concrete dam pouring process; determining the concrete outlet temperature, the concrete warehousing temperature, the concrete temperature rise value in the pouring process and the upper and lower limit values of the concrete temperature rise value in the water supply temperature control stage after pouring; establishing a function relationship between the temperature of each link of concrete dam pouring and the temperature control cost; according to the allowable concrete highest temperature, an established concrete dam pouring whole-process concrete highest temperature calculation model, concrete temperature upper and lower limit values of a concrete production link, a transportation link, a pouring link and a water supply temperature control link, and a function relationship between the temperature of each link and the temperature control cost, dynamic optimization calculation is carried out, and the concrete dam pouring whole-process concrete highest temperature calculation model is established. And determining the temperature control index of the whole concrete dam pouring process.

Description

Technical Field

[0001] The invention relates to a method for optimizing temperature control indicators in all links of concrete dam pouring, and in particular to a method for optimizing temperature control indicators by considering factors in all links of the whole process of concrete dam pouring. Background Art

[0002] Temperature control during the construction of large-volume concrete structures plays a vital role in their quality and structural safety, especially for concrete dams, which are more complex and important due to their huge pouring volume. During the pouring process, excessively high or low concrete temperatures will lead to problems such as cracks and internal stress accumulation, affecting the overall stability and life of the concrete structure.

[0003] Traditional temperature control methods for concrete dams mainly rely on experience and simple temperature control, such as pre-cooling concrete and cooling by water after pouring. The temperature control process mostly relies on fixed cooling parameters and lacks the ability to comprehensively consider the dynamic adjustment of factors in various links. It is difficult to accurately control the temperature changes of concrete at different stages, which often leads to unsatisfactory temperature control effects. Traditional temperature control methods usually focus on temperature control in a certain link, such as temperature control of concrete before pouring, or temperature control of concrete after pouring, or temperature control during pouring, and the temperature control effect is not ideal.

[0004] In addition, traditional temperature control methods usually do not take into account the cost and expense of temperature control, and invest a lot of cooling resources and energy, which increases construction costs, often resulting in unsatisfactory temperature control effects and high project costs. Summary of the invention

[0005] In view of the above reasons, the purpose of the present invention is to provide a method for optimizing temperature control indicators in all links of concrete dam pouring. The method comprehensively considers the temperature changes in the concrete production process, the temperature changes in the transportation process, the temperature changes in the pouring process, the temperature changes in the water temperature control process after pouring, and the relationship between the concrete temperature and the temperature control cost in each link to optimize the temperature control indicators of the whole process of concrete dam pouring.

[0006] To achieve the above purpose, the present invention adopts the following technical scheme: a method for optimizing temperature control indicators in all links of concrete dam pouring, namely:

[0007] S1. Determine the maximum concrete temperature allowed during the entire concrete dam pouring process [T max ];

[0008] S2. Comprehensively consider the temperature changes of concrete in each link of the whole process of concrete dam pouring, and establish a calculation model for the maximum temperature of concrete in the whole process of concrete dam pouring;

[0009] The maximum temperature T of the concrete during the entire concrete dam pouring process is determined based on the concrete outlet temperature, the temperature change of the concrete during transportation, the temperature change of the concrete during pouring, and the temperature change of the concrete during the water temperature control process after pouring. max :

[0010] T 0 +ΔT 1 +AT 2 +ΔT 3 =T max

[0011] Where, T 0 is the concrete outlet temperature, ΔT 1 is the temperature increment of concrete during transportation, ΔT 2 is the temperature increment of concrete during the concrete pouring process, ΔT 3 is the temperature increment of concrete under the combined effect of water cooling temperature rise and concrete adiabatic temperature rise, T max It is the maximum temperature of concrete during the whole process of pouring concrete dam;

[0012] S3. Determine the upper limit value of concrete outlet temperature T according to the configuration of the temperature control equipment on site, on-site air temperature, water temperature and other external conditions. 0·max and the lower limit T 0·min , the upper limit of concrete temperature entering the warehouse ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , After pouring, the upper limit of the temperature rise of the concrete is ΔT 3·max and the lower limit ΔT 3·min ;

[0013] S4|, establish the functional relationship between the concrete temperature and the temperature control cost in each link of concrete dam pouring;

[0014] During the pouring of concrete dam, the temperature of concrete outlet, the temperature of concrete entering the warehouse during transportation, the temperature rise of concrete during pouring and the temperature rise of water temperature control after pouring and the temperature control cost of each link P i The functional relationship between them is:

[0015] P=P 0 (T 0·max -T 0x )+P 1 (ΔT 1·max -ΔT 1x )+P 2 (ΔT 2·max -ΔT 2x )+P 3 (ΔT3·max -ΔT 3x )

[0016] Where P 0 The unit price for cooling the concrete outlet; P 1 P is the unit price of temperature control during transportation; 2 P is the unit price of temperature control during pouring process; 3 T is the unit price of temperature control during water flow temperature control; 0·max T is the upper limit of concrete outlet temperature; 0x is the target temperature of the concrete outlet; ΔT 1·max ΔT is the upper limit of the temperature of concrete entering the warehouse during transportation; 1·x T is the target temperature of concrete during transportation; 2·max ΔT is the upper limit of concrete temperature rise during the pouring process; 2·x ΔT is the target temperature of concrete during pouring; 3·max ΔT is the upper limit of temperature rise during the water temperature control process after concrete pouring; 3·x Target temperature of concrete during water temperature control process after concrete pouring;

[0017] S5. Based on the maximum concrete temperature allowed during the whole process of concrete dam pouring determined in step S1 and the calculation model for the maximum concrete temperature during the whole process of concrete dam pouring established in step S2, combined with the upper and lower limits of the concrete temperature during the concrete production, transportation, pouring and water temperature control stages determined in step S3, and the functional relationship between the concrete temperature and the temperature control cost during each stage established in step S4, the concrete temperature standard during each stage is dynamically optimized and calculated to determine the temperature control index during the whole process of concrete dam pouring;

[0018] The specific calculation steps are as follows:

[0019] S5.1. Set the upper limit of concrete outlet temperature T 0·max and the lower limit T 0·min , The upper limit of concrete temperature entering the warehouse during transportation ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , the upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max and the lower limit ΔT 3·min The temperature between is divided into n equal parts, and the concrete outlet temperature T 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rise value ΔT during pouring process 2i and the concrete temperature rise value ΔT during the water temperature control process after pouring 3i ;

[0020] S5.2, the concrete outlet temperature T obtained in step S5.1 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rise value ΔT during pouring process 2i and the concrete temperature rise value ΔT during the water temperature control process after pouring 3i Perform permutations and combinations, substitute all permutation and combination data into the concrete maximum temperature calculation model of the whole process of concrete dam pouring in step S2, and calculate the maximum concrete temperature T under each permutation and combination max ;

[0021] S5.3. When the calculated maximum concrete temperature T max Less than or equal to the maximum allowable concrete temperature [T max ], then the concrete outlet temperature, concrete entry temperature during transportation, concrete temperature recovery value during pouring, and concrete temperature recovery value during water temperature control after pouring of this group of combinations are retained; otherwise, this group of variable combinations is discarded;

[0022] S5.4, substitute the concrete outlet temperature that meets the maximum allowable concrete temperature retained in step S5.3, the concrete storage temperature during transportation, the concrete temperature recovery value during pouring, and the concrete temperature recovery value during water temperature control after pouring into the functional relationship between the temperature of each link in the whole process of concrete dam pouring and the temperature control cost in step S4, and calculate the temperature control cost of this group of variable combinations;

[0023] S5.5. Select the variable combination with the smallest temperature control cost as the optimized concrete outlet temperature, concrete entry temperature during transportation, concrete temperature recovery value during pouring and concrete temperature recovery value after water temperature control after pouring, that is, the optimized variables of temperature control measures for the entire concrete dam pouring process.

[0024] Among them, the maximum allowable concrete temperature [T max ]:

[0025]

[0026] In the formula, [T max ] is the maximum temperature of concrete allowed during the entire process of concrete dam pouring; μ is the Poisson's ratio of concrete; [σ] is the allowable tensile stress of concrete; R is the constraint coefficient of concrete foundation; E is the elastic modulus of concrete; α is the linear expansion coefficient of concrete; K p is the concrete creep stress coefficient; c 1is the influence coefficient of concrete autogenous volume deformation; G is the tensile stress caused by concrete autogenous volume deformation; T f The stable temperature of concrete.

[0027] Among them, the upper limit value of the concrete outlet temperature T 0·max and the lower limit T 0·min Calculation method:

[0028] Calculate the upper limit value of concrete outlet temperature T according to the temperature value of concrete raw materials in natural state 0·max :

[0029]

[0030] In the formula, c i is the specific heat of the i-th raw material of concrete; T i The temperature of the i-th raw material of concrete when no temperature control measures are taken; G i is the weight of the i-th raw material of concrete; Q is the mechanical heat generated during mixing;

[0031] Determine the minimum temperature T of the stone according to the mechanical configuration of the project site and the cooling raw materials. g·min , minimum sand temperature T s·min , minimum cement temperature T c·min , the lowest temperature of fly ash T f·min , minimum water temperature T w·min and the maximum ice addition rate α max , calculate the lower limit value of concrete outlet temperature T according to the temperature and water content of each raw material and the ice addition rate 0·min , the specific calculation formula is:

[0032]

[0033] Among them, T 0·min is the lower limit of concrete outlet temperature, T w·min is the lowest temperature of mixing water, T g·min is the lowest temperature of the stone, T s·min is the lowest temperature of sand, T f·min is the lowest temperature of fly ash, T c·min is the lowest temperature of cement, T b is the flake ice temperature, take -5℃; G w is the weight of water, G g is the weight of the stone, G s is the weight of sand, G f is the fly ash weight, G c is the weight of cement; g is the water content of stone, γ s is the water content of sand, α is the ice addition rate; c w is the specific heat of water, cg is the specific heat of stone, c s is the specific heat of sand, c f is the specific heat of fly ash, c c is the specific heat of cement; Q is the mechanical heat of mixing; α max is the maximum ice addition rate.

[0034] Among them, the upper limit of the concrete temperature entering the warehouse is ΔT 1·max and the lower limit ΔT 1·min Method for determining:

[0035] According to the temperature rise of concrete during transportation under natural conditions, the upper limit of concrete storage temperature ΔT is determined. 1·max :

[0036] ΔT 1·max =(T a +R / β-T 0·min )(φ 1·max +φ 2·max +…+φ n·max )

[0037] Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·max is the maximum temperature recovery coefficient of the transport machinery during transportation, which is determined by the minimum thickness and maximum thermal conductivity of the insulation material under the insulation state during transportation, the simulation calculation value and the measured value. n represents the number of times the concrete is transported by the transport machinery during transportation;

[0038] During transportation, the transportation time of concrete is a fixed value. According to the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material, the lower limit of the temperature rise during transportation, that is, the lower limit of the concrete storage temperature ΔT, is determined. 1·min ,

[0039] ΔT 1·min =(T a +R / β-T 0·min )(φ 1·min +φ 2·min +…+φ n·min )

[0040] Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·minis the minimum temperature recovery coefficient of the transport machinery during transportation, which is determined by the maximum thickness and minimum thermal conductivity of the insulation material under the insulation state during transportation, through simulation calculation values ​​and measured values. n represents the number of times the concrete is transported by the transport machinery during transportation.

[0041] The concrete temperature rise limit ΔT during the pouring process 2·max and the lower limit ΔT 2·min Method for determining:

[0042] The temperature rise during concrete pouring under natural conditions is taken as the upper limit of the concrete temperature rise during pouring ΔT. 2·max :

[0043] ΔT 2·max =(T a +R / β-T 1·min )(φ 1 +φ 2·max )

[0044] Where, T a is the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; φ 2·max Temperature recovery coefficient after closing a position;

[0045] The lowest temperature T of the warehouse surface environment formed by the spraying measures during the pouring process a·min The maximum thickness of the insulation material after unpacking and the minimum thermal conductivity of the insulation material are used to calculate the lower limit of the temperature rise of the concrete during the pouring process ΔT 2·min :

[0046] ΔT 2·min =(T a·min +R / β-T 1·min )φ 1 +(T a +R / β-T 1·min )φ 2·min

[0047] Where, T a·min is the lowest temperature in the warehouse after spraying measures are taken during warehouse closing; R is solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; T a is the temperature in the warehouse after closing the position; 2·min The lowest temperature recovery coefficient after taking insulation measures after closing the position is obtained by simulation calculation based on the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material.

[0048] The concrete temperature rise limit ΔT during the water temperature control process after pouring is 3·max and the lower limit ΔT 3·min Method for determining:

[0049] Without taking any water temperature control measures after concrete pouring, the temperature rise value of concrete in the natural heating state calculated by simulation is used as the upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max :

[0050] ΔT 3·max =θ 0 f(τ)

[0051] In the formula, θ 0 is the final adiabatic temperature rise of concrete, f(τ) is the adiabatic temperature rise function of concrete;

[0052] According to the minimum spacing of water pipes, the lowest water temperature and the maximum flow rate during the water temperature control process, the lower limit of the temperature rise of the water temperature controlled concrete after pouring ΔT is calculated. 3·min :

[0053] ΔT 3·min =T w·min +(T 2 -T w·min )φ(t) min +θ 0 ψ(t)-ΔT 2·max

[0054] Where, T w·min is the lowest water temperature during the water flow process; T 2 is the pouring temperature of concrete; φ(t) min The minimum water cooling function is determined by the minimum water pipe spacing and the maximum flow rate during the water flow process; θ 0 is the final adiabatic temperature rise of concrete, ψ(t) is the adiabatic temperature rise function of concrete;

[0055] ΔT 2·max =(T a +R / β-T 1·min )(φ 1 +φ 2·max )

[0056] Where, T a is the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; φ 2·max Temperature recovery coefficient after closing a position. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 The present invention is a flow chart of the method for optimizing temperature control indicators in all links of concrete dam pouring. DETAILED DESCRIPTION

[0058] The structure and features of the present invention are described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that various modifications can be made to the embodiments disclosed herein, and therefore, the embodiments disclosed in the specification should not be regarded as limiting the present invention, but are merely examples of embodiments, the purpose of which is to make the features of the present invention obvious.

[0059] Since traditional temperature control methods usually only consider the temperature change of concrete in a certain link, lack a global concept, and the temperature control effect is not ideal, the present invention comprehensively considers the temperature of each link in the whole process of concrete dam pouring, from the outlet temperature of concrete when it is transported from the mixing plant, to the temperature change during concrete transportation, the temperature change during concrete pouring, and finally the temperature change during the water temperature control process after the concrete pouring is completed, that is, the temperature change of concrete in each link in the whole pouring process of the concrete dam, and the relationship between the temperature control measures in each link and the construction cost; while achieving the ideal temperature control purpose, the construction cost is optimized.

[0060] like Figure 1 As shown, the method for optimizing temperature control indexes in all links of concrete dam pouring of the present invention is:

[0061] S1. Determine the maximum concrete temperature allowed during the entire concrete dam pouring process [T max ].

[0062] According to the basic material parameters of concrete, including the concrete foundation constraint coefficient, elastic modulus, creep stress coefficient, Poisson's ratio, autogenous volume deformation influence coefficient and its influence on concrete tensile stress, allowable tensile stress and concrete stable temperature, the maximum concrete temperature [T max ]:

[0063]

[0064] In the formula, [T max ] is the maximum allowable concrete temperature; μ is the Poisson's ratio of concrete; [σ] is the allowable tensile stress of concrete; R is the concrete foundation constraint coefficient; E is the concrete elastic modulus; α is the concrete linear expansion coefficient; K p is the concrete creep stress coefficient; c 1 is the influence coefficient of concrete autogenous volume deformation; G is the tensile stress caused by concrete autogenous volume deformation; T f The stable temperature of concrete.

[0065] S2. Comprehensively consider the temperature changes of concrete in each link of the whole process of concrete dam pouring, and establish a calculation model for the maximum temperature of concrete in the whole process of concrete dam pouring.

[0066] The maximum concrete temperature T during the entire concrete dam pouring process is determined based on the concrete outlet temperature, temperature changes during transportation, temperature changes during pouring, and temperature changes during water temperature control after pouring. max Computational model:

[0067] T 0 +ΔT 1 +ΔT 2 +ΔT 3 =T max

[0068] Where, T 0 is the concrete outlet temperature, ΔT 1 is the temperature increment during concrete transportation, ΔT 2 is the temperature increment during concrete pouring, ΔT 3 T is the temperature increment due to the combined effect of the water cooling temperature rise and the concrete adiabatic temperature rise during the water flow process after pouring. max The maximum temperature of concrete.

[0069] S3. Determine the upper limit value of concrete outlet temperature T according to the configuration of the temperature control equipment on site, on-site air temperature, water temperature and other external conditions. 0·max and the lower limit T 0·min , the upper limit of concrete temperature entering the warehouse ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , the upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max and the lower limit ΔT 3·min .

[0070] S3.1. Determine the upper limit value of concrete outlet temperature T 0·max and the lower limit T 0·min .

[0071] Calculate the upper limit value of concrete outlet temperature T according to the temperature value of concrete raw materials in natural state 0·max :

[0072]

[0073] In the formula, c i is the specific heat of the i-th raw material of concrete; T i The temperature of the i-th raw material of concrete when no temperature control measures are taken; G iis the weight of the i-th raw material of concrete; Q is the mechanical heat generated during mixing.

[0074] Determine the minimum temperature T of the stone according to the mechanical configuration of the project site and the cooling raw materials. g·min , minimum sand temperature T s·min , minimum cement temperature T c·min , the lowest temperature of fly ash T f·min , minimum water temperature T w·min and the maximum ice addition rate α max , calculate the lower limit value of concrete outlet temperature T according to the temperature and water content of each raw material and the ice addition rate 0·min , the specific calculation formula is:

[0075]

[0076]

[0077] Among them, T 0·min is the lower limit of concrete outlet temperature, T w·min is the lowest temperature of mixing water, T g·min is the lowest temperature of the stone, T s·min is the lowest temperature of sand, T f·min is the lowest temperature of fly ash, T c·min is the lowest temperature of cement, T b is the flake ice temperature, take -5℃; G w is the weight of water, G g is the weight of the stone, G s is the weight of sand, G f is the fly ash weight, G c is the weight of cement; c w is the specific heat of water, c g is the specific heat of stone, c s is the specific heat of sand, c f is the specific heat of fly ash, c c is the specific heat of cement; Q is the mechanical heat of mixing; α max is the maximum ice addition rate; g is the water content of stone, γ s is the water content of sand, and α is the ice addition rate.

[0078] S3.2. Determine the upper limit of concrete temperature entering the warehouse ΔT 1·max and the lower limit ΔT 1min .

[0079] According to the temperature rise of concrete during transportation under natural conditions, the upper limit of concrete storage temperature ΔT is determined. 1·max :

[0080] ΔT 1·max =(Ta +R / β-T 0·min )(φ 1·max +φ 2·max +…+φ n·max )

[0081] Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·max is the maximum temperature recovery coefficient of the transport machinery during transportation, which is determined by the minimum thickness and maximum thermal conductivity of the insulation material under the insulation state during transportation, the simulation calculation value and the measured value. n represents the number of times the concrete is transported by the transport machinery during transportation.

[0082] During transportation, the transportation time of concrete is a fixed value. According to the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material, the lower limit of the temperature rise during transportation, that is, the lower limit of the concrete storage temperature ΔT, is determined. 1·min ,

[0083] ΔT 1·min =(T a +R / β-T 0·min )(φ 1·min +φ 2·min +…+φ n·min )

[0084] Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·min The minimum temperature recovery coefficient of the transport machinery during transportation is determined by simulation calculation values ​​and measured values ​​based on the maximum thickness and minimum thermal conductivity of the insulation material under the insulation state during transportation.

[0085] S3.3. Determine the upper limit of concrete temperature rise during pouring ΔT 2·max and the lower limit ΔT 2·min .

[0086] The temperature rise during concrete pouring under natural conditions is taken as the upper limit of the concrete temperature rise during pouring ΔT. 2·max :

[0087] ΔT 2·max =(T a +R / β-T 1·min )(φ 1 +φ 2·max )

[0088] Where, T ais the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; φ 2·max Temperature recovery coefficient after closing a position.

[0089] The lowest temperature T of the warehouse surface environment formed by the spraying measures during the pouring process a·min The maximum thickness of the insulation material after unpacking and the minimum thermal conductivity of the insulation material are used to calculate the lower limit of the temperature rise of the concrete during the pouring process ΔT 2·min :

[0090] ΔT 2·min =(T a·min +R / β-T 1·min )φ 1 +(T a +R / β-T 1·min )φ 2·min

[0091] Where, T a·min is the lowest temperature in the warehouse after spraying measures are taken during warehouse closing; R is solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; T a is the temperature in the warehouse after closing the position; 2·min The lowest temperature recovery coefficient after taking insulation measures after closing the position is obtained by simulation calculation based on the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material.

[0092] S3.4. Determine the upper limit of concrete temperature rise ΔT during water temperature control after pouring 3·max and the lower limit ΔT 3·min .

[0093] Without taking any water temperature control measures after concrete pouring, the temperature rise value of concrete under natural heating state is simulated and calculated as the upper limit of temperature rise of concrete after pouring with water temperature control ΔT 3·max :

[0094] ΔT 3·max =θ 0 f(τ)

[0095] In the formula, θ 0 is the final adiabatic temperature rise of concrete, f(τ) is the adiabatic temperature rise function of concrete;

[0096] According to the minimum spacing of water pipes, the lowest water temperature and the maximum flow rate during the water temperature control process, the lower limit of the temperature rise of the water temperature controlled concrete after pouring ΔT is calculated. 3·min :

[0097] ΔT 3·min =T w·min +(T 2 -T w·min )φ(t) min +θ 0 ψ(t)-ΔT 2·max

[0098] Where, T w·min is the lowest water temperature during the water flow process; T 2 is the pouring temperature of concrete; φ(t) min The minimum water cooling function is determined by the minimum water pipe spacing and the maximum flow rate during the water flow process; θ 0 is the final adiabatic temperature rise of concrete, ψ(t) is the adiabatic temperature rise function of concrete.

[0099] ΔT 2·max =(T a +R / β-T 1·min )(φ 1 +φ 2·max )

[0100] Where, T a is the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; 1 is the closing temperature coefficient; φ 2·max Temperature recovery coefficient after closing a position.

[0101] S4|, establish the functional relationship between the concrete temperature and temperature control cost in each link of concrete dam pouring.

[0102] During the pouring of concrete dam, the temperature of concrete outlet, the temperature of concrete entering the warehouse during transportation, the temperature rise of concrete during pouring and the temperature rise of water temperature control after pouring and the temperature control cost of each link P i The functional relationship between them is:

[0103] P=P 0 (T 0·max -T 0x )+P 1 (ΔT 1·max -ΔT 1x )+P 2 (ΔT 2·max -ΔT 2x )+P 3 (ΔT 3·max -ΔT 3x )

[0104] Where P 0 The unit price for cooling the concrete outlet; P 1P is the unit price of temperature control during transportation; 2 P is the unit price of temperature control during pouring process; 3 T is the unit price of temperature control during water flow; 0·max T is the upper limit of concrete outlet temperature; 0x is the target temperature of the concrete outlet; ΔT 1·max ΔT is the upper limit of the temperature of concrete entering the warehouse during transportation; 1·x T is the target temperature of concrete during transportation; 2·max ΔT is the upper limit of concrete temperature rise during the pouring process; 2·x ΔT is the target temperature of concrete during pouring; 3·max ΔT is the upper limit of the temperature rise after the concrete is poured. 3·x The target temperature of concrete during the water temperature control process after concrete pouring.

[0105] S5. Based on the maximum concrete temperature allowed during the entire concrete dam pouring process determined in step S1 and the calculation model for the maximum concrete temperature during the entire concrete dam pouring process established in step S2, combined with the upper and lower limits of the concrete temperature in the concrete production, transportation, pouring and water temperature control links determined in step S3, and the functional relationship between the concrete temperature and the temperature control cost of each link established in step S4, the concrete temperature standard of each link is dynamically optimized and calculated to determine the temperature control index for the entire concrete dam pouring process.

[0106] The specific calculation steps are as follows:

[0107] S5.1. Set the upper limit of concrete outlet temperature T 0·max and the lower limit T 0·min , The upper limit of concrete temperature entering the warehouse during transportation ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , After pouring, the upper limit of the temperature rise of the concrete is ΔT 3·max and the lower limit ΔT 3·min The temperature between is divided into n equal parts, and the concrete outlet temperature T 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rises during pouring ΔT 2i After pouring, the temperature of the concrete rises by ΔT 3i .

[0108] S5.2, the concrete outlet temperature T obtained in step S5.1 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rises during pouring ΔT 2iAfter pouring, the temperature of the concrete rises by ΔT 3i Perform permutations and combinations, substitute all permutation and combination data into the maximum temperature calculation model of the concrete dam in step S2, and calculate the maximum temperature T of the concrete dam under each permutation and combination. max .

[0109] S5.3. When the calculated maximum temperature of the concrete dam is T max Less than or equal to the maximum allowable temperature of the concrete dam determined in step S1 [T max ], the concrete outlet temperature, concrete storage temperature during transportation, concrete temperature rise during pouring, and concrete temperature rise after pouring are retained; otherwise, the variable combination is discarded;

[0110] S5.4. Substitute the combination of the concrete outlet temperature that meets the maximum allowable temperature of the concrete dam retained in step S5.3, the concrete entry temperature during transportation, the concrete temperature rise during pouring, and the concrete temperature rise during water temperature control after pouring into the functional relationship between the temperature of each link in the concrete dam pouring and the temperature control cost of each link in step S4, and calculate the temperature control cost of this group of variable combinations.

[0111] S5.5 selects the variable combination with the smallest temperature control cost as the optimized concrete outlet temperature, concrete entry temperature during transportation, concrete temperature recovery value during pouring, and concrete temperature recovery value after pouring, that is, the optimal temperature control index for each link.

[0112] Compared with the traditional temperature control method, the innovation of the present invention is mainly reflected in the following aspects:

[0113] 1. Comprehensively consider the concrete temperature of each link in the whole process of concrete dam pouring, and the temperature control effect is good.

[0114] The temperature control index optimization method provided by the present invention takes into account the entire process of concrete dam pouring, and integrates the temperature changes of concrete in the concrete production process (concrete outlet temperature), transportation process, pouring process and water temperature control process after pouring, to ensure that the temperature of the entire pouring process is accurately controlled, and overcomes the problem of uncoordinated temperature control of only one link considered in the traditional method. The temperature control is accurate and the temperature control effect is good, thereby ensuring the overall quality of the concrete dam.

[0115] 2. The present invention fully considers the quality and temperature control cost, and achieves the dual improvement of temperature control effect and economic benefit under the premise of ensuring compliance with quality standards and temperature control requirements.

[0116] In summary, the present invention dynamically optimizes the temperature control indicators of each link by considering the temperature changes of concrete in each link of the whole process of concrete dam pouring, as well as the temperature control cost of each link, and achieves the lowest temperature control cost under the premise of achieving optimal temperature control. It overcomes the shortcomings of traditional temperature control methods, significantly improves the temperature control accuracy, optimizes the temperature control measures, and provides a scientific, efficient and reliable temperature control method for large-volume concrete projects.

[0117] Finally, it should be noted that the above-described embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for optimizing temperature control indicators in all aspects of concrete dam pouring, characterized by: S1. Determine the maximum concrete temperature allowed during the entire concrete dam pouring process [T max ]; S2. Comprehensively consider the temperature changes of concrete in each link of the whole process of concrete dam pouring, and establish a calculation model for the maximum temperature of concrete in the whole process of concrete dam pouring; The maximum temperature T of the concrete during the entire concrete dam pouring process is determined based on the concrete outlet temperature, the temperature change of the concrete during transportation, the temperature change of the concrete during pouring, and the temperature change of the concrete during the water temperature control process after pouring. max : T0+ΔT1+ΔT2+ΔT3=T max Where T0 is the temperature of the concrete outlet, ΔT1 is the temperature increment of the concrete during concrete transportation, ΔT2 is the temperature increment of the concrete during concrete pouring, ΔT3 is the temperature increment of the concrete under the combined effect of water cooling temperature rise and concrete adiabatic temperature rise, T max It is the maximum temperature of concrete during the whole process of pouring concrete dam; S3. Determine the upper limit value of concrete outlet temperature T according to the configuration of the temperature control equipment on site, the on-site air temperature and water temperature. 0·max and the lower limit T 0·min , the upper limit of concrete temperature entering the warehouse ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , After pouring, the upper limit of the temperature rise of the concrete is ΔT 3·max and the lower limit ΔT 3·mim ; S4|, establish the functional relationship between the concrete temperature and the temperature control cost in each link of concrete dam pouring; During the pouring of concrete dam, the temperature of concrete outlet, the temperature of concrete entering the warehouse during transportation, the temperature rise of concrete during pouring and the temperature rise of water temperature control after pouring and the temperature control cost of each link P i The functional relationship between them is: P=P0(T 0·max -T 0x )+P1(ΔT 1·max -ΔT 1x )+P2(4T 2·max –ΔT 2x )+P3(ΔT 3·max -ΔT 3x ) Where, P0 is the unit price of concrete outlet cooling; P1 is the unit price of temperature control during transportation; P2 is the unit price of temperature control during pouring; P3 is the unit price of temperature control during water flow control; T 0·max T is the upper limit of concrete outlet temperature; 0x is the target temperature of the concrete outlet; ΔT 1·max ΔT is the upper limit of the temperature of concrete entering the warehouse during transportation; 1·x T is the target temperature of concrete during transportation; 2·max ΔT is the upper limit of concrete temperature rise during the pouring process; 2·x ΔT is the target temperature of concrete during pouring; 3·max ΔT is the upper limit of temperature rise during the water temperature control process after concrete pouring; 3·x Target temperature of concrete during water temperature control process after concrete pouring; S5. Based on the maximum concrete temperature allowed during the whole process of concrete dam pouring determined in step S1 and the calculation model for the maximum concrete temperature during the whole process of concrete dam pouring established in step S2, combined with the upper and lower limits of the concrete temperature during the concrete production, transportation, pouring and water temperature control stages determined in step S3, and the functional relationship between the concrete temperature and the temperature control cost during each stage established in step S4, the concrete temperature standard during each stage is dynamically optimized and calculated to determine the temperature control index during the whole process of concrete dam pouring; The specific calculation steps are as follows: S5.

1. Set the upper limit of concrete outlet temperature T 0·max and the lower limit T 0·min , The upper limit of concrete temperature entering the warehouse during transportation ΔT 1·max and the lower limit ΔT 1·min , the upper limit of concrete temperature rise during pouring process ΔT 2·max and the lower limit ΔT 2·min , the upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max and the lower limit ΔT 3·min The temperature between is divided into n equal parts, and the concrete outlet temperature T 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rise value ΔT during pouring process 2i and the concrete temperature rise value ΔT during the water temperature control process after pouring 3i ; S5.2, the concrete outlet temperature T obtained in step S5.1 0i , Concrete temperature in the warehouse during transportation ΔT 1i , Concrete temperature rise value ΔT during pouring process 2i and the concrete temperature rise value ΔT during the water temperature control process after pouring 3i Perform permutations and combinations, substitute all permutation and combination data into the maximum concrete temperature calculation model of the whole process of concrete dam pouring in step S2, and calculate the maximum concrete temperature T under each permutation and combination max ; S5.

3. When the calculated maximum concrete temperature T max Less than or equal to the maximum allowable concrete temperature [T max ], then the concrete outlet temperature, concrete entry temperature during transportation, concrete temperature recovery value during pouring, and concrete temperature recovery value during water temperature control after pouring of this group of combinations are retained; otherwise, this group of variable combinations is discarded; S5.4, substitute the concrete outlet temperature that meets the maximum allowable concrete temperature retained in step S5.3, the concrete storage temperature during transportation, the concrete temperature recovery value during pouring, and the concrete temperature recovery value during water temperature control after pouring into the functional relationship between the temperature of each link in the whole process of concrete dam pouring and the temperature control cost in step S4, and calculate the temperature control cost of this group of variable combinations; S5.

5. Select the variable combination with the smallest temperature control cost as the optimized concrete outlet temperature, concrete entry temperature during transportation, concrete temperature recovery value during pouring and concrete temperature recovery value after water temperature control after pouring, that is, the optimized variables of temperature control measures for the entire concrete dam pouring process.

2. The method for optimizing temperature control indexes in all aspects of concrete dam pouring according to claim 1 is characterized in that: According to the basic material parameters of concrete, including the concrete foundation constraint coefficient, elastic modulus, creep stress coefficient, Poisson's ratio, autogenous volume deformation influence coefficient and its influence on concrete tensile stress, allowable tensile stress and concrete stable temperature, the maximum concrete temperature [T max ]: In the formula, [T max ] is the maximum temperature of concrete allowed during the entire process of concrete dam pouring; μ is the Poisson's ratio of concrete; [σ] is the allowable tensile stress of concrete; R is the constraint coefficient of concrete foundation; E is the elastic modulus of concrete; α is the linear expansion coefficient of concrete; K p is the concrete creep stress coefficient; c1 is the influence coefficient of concrete autogenous volume deformation; G is the tensile stress caused by concrete autogenous volume deformation; T f The stable temperature of concrete.

3. The method for optimizing temperature control indexes in all aspects of concrete dam pouring according to claim 1 is characterized in that: The upper limit value of concrete outlet temperature T 0·max and the lower limit T 0·min Calculation method: Calculate the upper limit value of concrete outlet temperature T according to the temperature value of concrete raw materials in natural state 0·max : In the formula, c i is the specific heat of the i-th raw material of concrete; T i The temperature of the i-th raw material of concrete when no temperature control measures are taken; G i is the weight of the i-th raw material of concrete; Q is the mechanical heat generated during mixing; Determine the minimum temperature T of the stone according to the mechanical configuration of the project site and the cooling raw materials. g·min , minimum sand temperature T s·min , minimum cement temperature T c·min , the lowest temperature of fly ash T f·min , minimum water temperature T w·min and the maximum ice addition rate α max , calculate the lower limit value of concrete outlet temperature T according to the temperature and water content of each raw material and the ice addition rate 0·min , the specific calculation formula is: Where T 0·min is the lower limit of concrete outlet temperature, T w·min is the lowest temperature of mixing water, T g·min is the lowest temperature of the stone, T s·min is the lowest temperature of sand, T f·min is the lowest temperature of fly ash, T c·min is the lowest temperature of cement, T b is the flake ice temperature, take -5℃; G w is the weight of water, G g is the weight of the stone, G s is the weight of sand, G f is the fly ash weight, G c is the weight of cement; g is the water content of stone, γ s is the water content of sand, α is the ice addition rate; c w is the specific heat of water, c g is the specific heat of stone, c s is the specific heat of sand, c f is the specific heat of fly ash, c c is the specific heat of cement; Q is the mechanical heat of mixing; α max is the maximum ice addition rate.

4. The method for optimizing temperature control indexes in all aspects of concrete dam pouring according to claim 1 is characterized in that: The upper limit of concrete temperature entering the warehouse ΔT 1·max and the lower limit ΔT 1·min Method for determining: According to the temperature rise of concrete during transportation under natural conditions, the upper limit of concrete storage temperature ΔT is determined. 1·max : ΔT 1·max =(T a +R / β-T 0·min )(φ 1·ma x+φ 2·max +…+φ n·max ) Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·max is the maximum temperature recovery coefficient of the transport machinery during transportation, which is determined by the minimum thickness and maximum thermal conductivity of the insulation material under the insulation state during transportation, the simulation calculation value and the measured value. n represents the number of times the concrete is transported by the transport machinery during transportation; During transportation, the transportation time of concrete is a fixed value. According to the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material, the lower limit of the temperature rise during transportation, that is, the lower limit of the concrete storage temperature ΔT, is determined. 1·min , ΔT 1·min =(T a +R / β-T 0·min )(φ 1·min +φ 2·min +…+φ n·min ) Where, T a is the temperature during concrete transportation; R is solar radiation heat; β is the surface heat release coefficient; T 0-min is the lower limit of concrete outlet temperature; φ n·min is the minimum temperature recovery coefficient of the transport machinery during transportation, which is determined by the maximum thickness and minimum thermal conductivity of the insulation material under the insulation state during transportation, through simulation calculation values ​​and measured values. n represents the number of times the concrete is transported by the transport machinery during transportation.

5. The method for optimizing temperature control indexes in all aspects of concrete dam pouring according to claim 1 is characterized in that: The upper limit of concrete temperature rise during the pouring process ΔT 2·max and the lower limit ΔT 2·min Method for determining: The temperature rise during concrete pouring under natural conditions is taken as the upper limit of the concrete temperature rise during pouring ΔT. 2·max : ΔT 2·max =(T a +R / β-T 1·min )(φ1+φ 2·max ) Where, T a is the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; φ1 is the closing temperature coefficient; φ 2·max Temperature recovery coefficient after closing a position; The lowest temperature T of the warehouse surface environment formed by the spraying measures during the pouring process a·min The maximum thickness of the insulation material after unpacking and the minimum thermal conductivity of the insulation material are used to calculate the lower limit of the temperature rise of the concrete during the pouring process ΔT 2·min : ΔT 2·min =(T a·min +R / β-T 1·min )φ1+(T a +R / β-T 1·min )φ 2·min Where, T a·min is the lowest temperature in the warehouse after spraying measures are taken during warehouse closing; R is solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; φ1 is the closing temperature coefficient; T a is the temperature in the warehouse after closing the position; 2·min The lowest temperature recovery coefficient after taking insulation measures after closing the position is obtained by simulation calculation based on the maximum thickness of the insulation material and the minimum thermal conductivity of the insulation material.

6. The method for optimizing temperature control indexes in all aspects of concrete dam pouring according to claim 1 is characterized in that: The upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max and the lower limit ΔT 3·min Method for determining: Without taking any water temperature control measures after concrete pouring, the temperature rise value of concrete in the natural heating state calculated by simulation is used as the upper limit of concrete temperature rise during water temperature control after pouring ΔT 3·max : ΔT 3·max =θ0f(τ) Where θ0 is the final adiabatic temperature rise of concrete, and f(τ) is the adiabatic temperature rise function of concrete; According to the minimum spacing of water pipes, the lowest water temperature and the maximum flow rate during the water temperature control process, the lower limit of the temperature rise of the water temperature controlled concrete after pouring ΔT is calculated. 3·min : ΔT 3·min =T w·min +(T2-T w·min )φ(t) min +θ0ψ(t)-ΔT 2·max Where, T w·min is the lowest water temperature during the water flow process; T2 is the pouring temperature of concrete; φ(t) min The minimum water cooling function is determined by the minimum water pipe spacing and the maximum flow rate during the water flow process; θ0 is the final adiabatic temperature rise of concrete, ψ(t) is the adiabatic temperature rise function of concrete; ΔT 2·max =(T a +R / β-T 1·min )(φ1+φ 2·max ) Where, T a is the temperature in the warehouse under natural conditions; R is the solar radiation heat; β is the surface heat release coefficient; T 1·min is the minimum pouring temperature of concrete; φ1 is the closing temperature coefficient; φ 2·min Temperature recovery coefficient after closing a position.

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