Method for obtaining concrete in tunnel construction
By preparing concrete from tunnel rubble granite and adjusting parameters using a response surface model, the problem of utilizing tunnel rubble granite was solved, achieving efficient acquisition of concrete and cost reduction in tunnel construction.
Patent Information
- Application Number
- CN202511820656.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-04
- Publication Date
- 2026-01-02
AI Technical Summary
In tunnel construction, the use of granite slag as waste material, whether stockpiled or simply landfilled, results in high material costs, long transportation cycles, and the direct use of such material may affect the performance of concrete and fail to meet construction requirements. There is a lack of scientific and efficient utilization methods.
By obtaining rock slag from cave granite, multiple concrete samples were prepared. The influence of each factor on the quality parameters was determined using a response surface model. The concrete parameters were adjusted to meet engineering requirements, and a target model was established to manufacture concrete.
This enabled the on-site utilization of tunnel rubble granite, reduced the difficulty and cost of obtaining concrete, improved construction efficiency, simplified the parameter adjustment process, and met the quality parameter thresholds for tunnel construction.
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Figure CN121260291A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of concrete materials, and particularly relates to a method for obtaining concrete in tunnel construction. BACKGROUND
[0002] In tunnel engineering construction, concrete is one of the main building materials. In the traditional construction process, the aggregate required by the concrete usually needs to be transported from outside to the construction site. Especially in remote mountainous areas or areas with poor transportation, the transportation cost is high, the cycle is long, which seriously restricts the construction progress and increases the overall cost of the project.
[0003] A large amount of tunnel slag will be produced during tunnel excavation, especially granite tunnel slag. At present, most of these tunnel slags are piled up as waste or simply buried, which not only occupies land resources, but also may pollute the environment. If such tunnel slag can be processed into concrete aggregate and used in tunnel lining, supporting and other structures, the material cost will be greatly reduced, the material supply time will be shortened, and the recycling of resources will be realized. However, due to the differences in lithology and grain shape of the tunnel slag granite and the conventional aggregate, direct use may lead to the performance of the concrete not meeting the construction requirements. Therefore, it is urgent to provide a method for scientifically and efficiently utilizing the tunnel slag granite to prepare concrete meeting the engineering requirements. SUMMARY
[0004] In order to solve the above technical problems, the purpose of the present application is to provide a method for obtaining concrete in tunnel construction, and the technical scheme is as follows: The present application provides a method for obtaining concrete in tunnel construction, which comprises the following steps: Based on the tunnel slag granite excavated in tunnel construction, rock slag is obtained, and the rock slag comprises first aggregate and second aggregate with different particle sizes; Based on different concrete parameter combinations, a plurality of concrete samples are prepared, the concrete parameter combinations include sand ratio, aggregate ratio of first aggregate content and second aggregate content, and water-binder ratio; the quality parameters of the plurality of concrete samples are tested, the quality parameters include slump and compressive strength; Based on the plurality of concrete parameter combinations and the corresponding quality parameters, a sample set is constructed, a response surface model is established by using the sample set, and the order of the influence degree of each factor on the quality parameters is determined based on the response surface model, the factors include sand ratio, aggregate ratio, water-binder ratio and their interaction terms; obtaining a target model based on the sample set; inputting the to-be-determined concrete parameters into the target model to obtain a predicted quality parameter; judging whether the predicted quality parameter meets a preset quality parameter threshold, if not, adjusting a corresponding factor in the to-be-determined concrete parameters according to the order of the influence degree, and re-performing the prediction and the judgment; if yes, manufacturing the concrete based on the to-be-determined concrete parameters meeting the requirements.
[0005] Preferably, the obtaining of the target model based on the sample set comprises: obtaining fitting degrees of a plurality of models to the sample set based on the sample set; determining, as the target model, a model with the highest fitting degree to the sample set among all the models.
[0006] Preferably, the determining, as the target model, the model with the highest fitting degree to the sample set among all the models comprises: when a quadratic polynomial model among the plurality of models has the highest fitting degree to the sample set, determining the quadratic polynomial model as the target model; a fitting equation of the quadratic polynomial model is: ; ; wherein, is a slump of the concrete sample, is a compressive strength of the concrete sample, A is a sand ratio, B is an aggregate ratio, and C is a water-binder ratio.
[0007] Preferably, the obtaining of the plurality of concrete parameter combinations comprises: the sand ratio is 0.37, 0.39 or 0.41, the aggregate ratio between the first aggregate and the second aggregate is 3:7, 4:6 or 5:5, and the water-binder ratio is 0.33, 0.37 or 0.41; based on the three sand ratios, the three aggregate ratios and the three water-binder ratios, a plurality of concrete parameter combinations are obtained by using an orthogonal test method.
[0008] Preferably, the predicted quality parameter comprises a slump predicted value and a compressive strength predicted value. The manufacturing of the concrete based on the to-be-determined concrete parameters meeting the requirements comprises: manufacturing a target concrete sample based on the to-be-determined concrete parameters; testing the target concrete sample to obtain a corresponding target slump and a target compressive strength; when the relative error between the target slump and the slump predicted value and the relative error between the target compressive strength and the compressive strength predicted value are both less than a corresponding preset error threshold, manufacturing the engineering concrete based on the to-be-determined concrete parameters.
[0009] Preferably, the order of the influence degree of each factor on the quality parameter based on the response surface model comprises: Based on the response surface model, the characteristic value of each factor in the plurality of factors is obtained. According to the characteristic value of each factor, the order of the influence degree is determined, and the characteristic value of each factor is positively correlated with the influence degree of each factor on the quality parameter of the concrete sample. All influence degrees are sorted in descending order of influence degree to obtain the order of influence degree.
[0010] Preferably, the characteristic value of each factor in the plurality of factors is obtained based on the response surface model, comprising: Based on the sample set, a first response surface model reflecting the slump and a second response surface model reflecting the compressive strength are established. Based on the first response surface model, the first characteristic value of each factor in the plurality of factors in the sample set for the slump is obtained; and based on the second response surface model, the second characteristic value of each factor in the plurality of factors in the sample set for the compressive strength is obtained; the first characteristic value and the second characteristic value are the ratio of the corresponding regression mean square to the corresponding error mean square of each factor. The average of the first characteristic value and the second characteristic value of each factor is determined as the characteristic value of each factor.
[0011] Preferably, in the concrete sample, the cement is Portland cement, the sand is river sand, and the water reducing agent is polyhydroxy acid water reducing agent; wherein the solid content of the polyhydroxy acid water reducing agent is 15.2%, and the water reducing rate is 24.2%.
[0012] Preferably, the interaction term comprises the product of the aggregate ratio and the water-binder ratio, the product of the sand ratio and the water-binder ratio, and the product of the sand ratio and the aggregate ratio.
[0013] Preferably, the rock slag is obtained based on the tunnel construction, comprising: crushing and processing the tunnel slag granite to obtain the rock slag.
[0014] The present application has at least the following advantages: This invention utilizes granite excavated during tunnel construction to produce concrete that meets quality parameter thresholds. This eliminates the need to transport rock debris from a distant location to the tunnel construction site, thus reducing the difficulty of concrete acquisition. Furthermore, it lowers concrete acquisition costs and avoids the manpower and resources wasted on discarding and disposing of the excavated granite, improving tunnel construction efficiency. The method provided by this invention establishes a response surface model based on a sample set to determine the order of influence of various factors on the quality parameters of the concrete sample. Then, a target model is obtained, and the parameters of the undetermined concrete input to the target model are adjusted based on the order of influence. This adjustment method limits the adjustment of factors with a higher degree of influence, thereby accelerating the adjustment speed of the undetermined concrete parameters, thus speeding up concrete acquisition and simplifying the adjustment process. Attached Figure Description
[0015] To more clearly illustrate the technical solutions and advantages in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 This is a flowchart of a method for obtaining concrete during tunnel construction provided by an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the influence of aggregate ratio and water-cement ratio on slump obtained from a response model provided in an embodiment of the present invention. Figure 3 for Figure 2 A simplified planar schematic diagram; Figure 4 This is a schematic diagram illustrating the influence of aggregate ratio and sand ratio on slump obtained from a response model provided in an embodiment of the present invention. Figure 5 for Figure 4 A simplified planar schematic diagram; Figure 6 A schematic diagram illustrating the influence of sand ratio and aggregate ratio on compressive strength obtained from a response model provided in an embodiment of the present invention; Figure 7 for Figure 6 A simplified planar schematic diagram; Figure 8 This is a schematic diagram illustrating the influence of water-cement ratio and aggregate ratio on compressive strength obtained from a response model provided in an embodiment of the present invention. Figure 9 for Figure 8 A simplified planar schematic diagram. DETAILED DESCRIPTION
[0017] In order to further clarify the technical means and effects taken by the present application to achieve the predetermined inventive objectives, the following will be described in detail below in combination with the drawings and preferred embodiments, a method for obtaining concrete in tunnel construction according to the present application.
[0018] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
[0019] The specific scheme of the method for obtaining concrete in tunnel construction provided by the present application will be specifically described below in combination with the drawings.
[0020] Embodiment of a method for obtaining concrete in tunnel construction: The present embodiment proposes a method for obtaining concrete in tunnel construction, as shown in Figure 1 The method for obtaining concrete in tunnel construction of the present embodiment includes the following steps: Step S1, obtaining rock debris based on the tunnel construction excavated hole debris granite, the rock debris includes first aggregate and second aggregate of different particle sizes.
[0021] The rock debris includes first aggregate with a particle size greater than or equal to 5mm and less than 10mm, and second aggregate with a particle size greater than or equal to 10mm and less than 15mm.
[0022] This step can include: 1. Obtain the tunnel construction excavated hole debris granite; 2. Crush and process the hole debris granite to obtain rock debris.
[0023] The hole debris granite can be crushed and processed to obtain first aggregate with a particle size greater than or equal to 5mm and less than 10mm, and second aggregate with a particle size greater than or equal to 10mm and less than 15mm.
[0024] In an exemplary embodiment, the method provided by the present embodiment can be applied to the Tangshan Road Tunnel Construction Project of Qingdao-Yinchuan Expressway, and the hole debris rock generated in the tunnel construction of this project is crushed and processed to be used as coarse aggregate to prepare rock debris concrete. The response surface method and other methods are used to select sand ratio, aggregate ratio and water-binder ratio to establish a three-factor three-level regression model, and through multi-objective mix proportion optimization, in subsequent similar tunnel excavation, the method provided by the present embodiment can also be used to prepare concrete using rock debris, so as to reduce the difficulty and cost of obtaining concrete in the tunnel construction process.
[0025] Step S2, based on different concrete parameter combinations, a plurality of corresponding concrete samples are prepared, the concrete parameter combinations include sand rate, aggregate ratio of first aggregate content and second aggregate content, and water-binder ratio; test the quality parameters of the plurality of concrete samples, the quality parameters include slump and compressive strength.
[0026] Firstly, a plurality of concrete parameter combinations are determined. Each concrete parameter combination includes sand rate, aggregate ratio of first aggregate content and second aggregate content, and water-binder ratio in the concrete sample.
[0027] The acquisition of the concrete parameter combination can include: 1. Three sand rates are obtained, which are 0.37, 0.39 and 0.41; 2. Three aggregate ratios are obtained, which are 3, 4 and 5. The aggregate ratio of 3 means that the ratio of the first aggregate content to the second aggregate content is 3 to 7, the aggregate ratio of 4 means that the ratio of the first aggregate content to the second aggregate content is 4 to 6, and the aggregate ratio of 5 means that the ratio of the first aggregate content to the second aggregate content is 5 to 5; 3. Three water-binder ratios are obtained, which are 0.33, 0.37 and 0.41; 4. Based on the three sand rates, the three aggregate ratios, and the three water-binder ratios, a plurality of concrete parameter combinations are obtained by using the orthogonal test method.
[0028] Next, a plurality of corresponding concrete samples are prepared based on different concrete parameter combinations.
[0029] In the plurality of concrete samples, the cement is Portland cement, the sand is river sand, the water reducing agent is polyhydroxy acid water reducing agent, and the solid content of the polyhydroxy acid water reducing agent is 15.2%, and the water reducing rate is 24.2%.
[0030] Among them, the cement is P.O 42.5 Portland cement, and the mixing water is referable underground water. The chemical composition of the cement can refer to Table 1: Table 1
[0031] Among them, the content of each component is a percentage of the total mass.
[0032] Further, the quality parameters of each concrete sample are tested, including slump and compressive strength.
[0033] Specifically, the Standard Test Method for Properties of Freshly Mixed Concrete can be used to measure the slump of the fresh concrete based on the above concrete parameters (in this case, the concrete sample is the fresh concrete). The Standard Test Method for Physical and Mechanical Properties of Concrete can be used to test the compressive strength of the 100 mm x 100 mm x 100 mm concrete cube (in this case, the concrete sample is the concrete cube).
[0034] For example, refer to Table 2: Table 2
[0035] In the table, the units of cement, river sand, slag, water, and water reducing agent are kilograms per cubic meter, the unit of slump is millimeters, and the unit of compressive strength is megapascals. The compressive strength referred to in this embodiment can be the strength of the concrete sample 28 days after the sample is manufactured. A is the sand ratio, B is the aggregate ratio, and C is the water-cement ratio.
[0036] In step S3, a sample set is constructed based on the plurality of concrete parameter combinations and the corresponding quality parameters. A response surface model is established using the sample set, and the order of the influence degree of each factor on the quality parameter is determined based on the response surface model. The factors include the sand ratio, the aggregate ratio, the water-cement ratio, and their interaction terms.
[0037] First, a sample set is constructed based on all the concrete parameter combinations and the corresponding quality parameters. The sample set can be as shown in Table 2.
[0038] Then, a response surface model is established using the sample set.
[0039] Specifically, a first response surface model reflecting the slump is established based on the sample set. First characteristic values of each factor in the plurality of factors in the sample set with respect to the slump are obtained based on the first response surface model. A second response surface model reflecting the compressive strength is established based on the sample set. Second characteristic values of each factor in the plurality of factors in the sample set with respect to the compressive strength are obtained based on the second response surface model. The first characteristic value and the second characteristic value are the ratio of the regression mean square corresponding to each factor to the error mean square corresponding to each factor. The average of the first characteristic value and the second characteristic value of each factor is determined as the characteristic value of each factor.
[0040] In the table, A is the sand ratio, B is the aggregate ratio, C is the water-cement ratio, BC is the product of the aggregate ratio and the water-cement ratio, AC is the product of the sand ratio and the water-cement ratio, and AB is the product of the sand ratio and the aggregate ratio.
[0041] Next, the order of the influence degree of each factor on the quality parameter is determined according to the characteristic value of each factor.
[0042] Specifically, according to the characteristic value of each factor, the influence degree of each factor on the quality parameter is determined, and the characteristic value of each factor is positively correlated with the influence degree of each factor on the quality parameter of the concrete sample. In this embodiment, the normalized result of the characteristic value is taken as the influence degree of each factor on the quality parameter of the concrete sample, and the maximum and minimum value normalization method is used in the normalization process of the characteristic value. As other embodiments, other methods can also be used for processing. The influence degrees are arranged in descending order to obtain the order of the influence degrees. As shown in Table 3: Table 3
[0043] Table 3 is a variance analysis table obtained based on the response model, wherein df is the degree of freedom, F value is the first characteristic value, P value is the probability of model failure, R2 is the determination coefficient, and is the proportion of inter-group variation to total variation.
[0044] It can be found from Table 3 that the R2 of the slump and the compressive strength is greater than 0.96, which indicates that the difference between the response value and the true value is small and basically the same. At the same time, the significance of each factor in the model is verified. It is considered that P<0.0001 is extremely significant and P<0.05 is significant through the size of the P value. The P values of the slump and strength models of the concrete in Table 3 are less than 0.0001 and 0.0002, which indicates that the model fitting is good, the regression effect is significant, and it also indicates that the response value of the slag concrete and the actual measured value have a good fitting degree, and the model is reliable and can be used to predict the relationship between each factor and the result.
[0045] In an exemplary embodiment, refer to Figure 2 , Figure 3 , Figure 4 and Figure 5 , Figure 2 is a schematic diagram of the influence of the aggregate ratio and the water-binder ratio on the slump obtained by a response model in this embodiment, Figure 3 is a planar simplified schematic diagram of the schematic diagram shown in Figure 2 , Figure 4 is a schematic diagram of the influence of the aggregate ratio and the sand ratio on the slump obtained by a response model in this embodiment, Figure 5 is a planar simplified schematic diagram of the schematic diagram shown in Figure 4 , wherein the 5-10 volume ratio is the aggregate ratio. Table 3 and Figure 2 , Figure 3 , Figure 4 and Figure 5It can be seen that the sand ratio, aggregate ratio and water-binder ratio have significant influence on the slump, and there is interaction among the three factors. According to the F value, the influence order of the factors on the slump is C>AB>A>B>BC>AC, wherein A is the sand ratio, B is the aggregate ratio, C is the water-binder ratio, BC is the product of the aggregate ratio and the water-binder ratio, AC is the product of the sand ratio and the water-binder ratio, and AB is the product of the sand ratio and the aggregate ratio. Figure 2 、 Figure 3 、 Figure 4 and Figure 5 The response surface can show that when the sand ratio is near 0.39, the contour lines become sparse, and the proportion of 5-10 mm slag and 10-15 mm slag has a significant influence on the slump of the concrete mixture. When the proportion is 3:7, the slump of the mixture gradually decreases with the increase of the sand ratio. On the contrary, when the proportion is 5:5, the slump of the mixture gradually increases with the increase of the sand ratio. The two factors have an interaction on the slump of the concrete mixture. The slump of the mixture gradually increases with the increase of the water-binder ratio. When the water-binder ratio is small, it is not enough to provide sufficient mixing water, and the slump decreases. When the sand ratio is below 0.39, it has no obvious influence on the slump of the concrete mixture. When the sand ratio is above 0.39, the slump gradually decreases with the increase of the sand ratio. When the sand ratio is appropriate and the aggregate ratio is reasonable, the slump increases. When the water-binder ratio and the aggregate ratio are compared, it is obvious that the water-binder ratio is the main factor because the change of the slump is basically consistent with the change of the water-binder ratio, and the change of the aggregate ratio is not obvious.
[0046] In an exemplary embodiment, please refer to Figure 6 、 Figure 7 、 Figure 8 and Figure 9 , Figure 6 is a schematic diagram of the influence of the sand ratio and the aggregate ratio on the compressive strength obtained by a response model in the embodiment, Figure 7 is Figure 6 a plane simplified schematic diagram of the schematic diagram shown in Figure 8 is a schematic diagram of the influence of the water-binder ratio and the aggregate ratio on the compressive strength obtained by a response model in the embodiment, Figure 9 is Figure 8 a plane simplified schematic diagram of the schematic diagram shown in Figure 6 、 Figure 7 、 Figure 8 and Figure 9It can be seen that the sand ratio, aggregate ratio and water-binder ratio have significant effects on the concrete strength, and there is an interaction among the three factors. The influence order of each factor on the slump is C > B > BC > A > AC > AB. When the aggregate ratio is at a low level, the sand ratio has no significant effect. When the aggregate ratio is at a high level, the compressive strength of the concrete gradually increases with the increase of the sand ratio. When the sand ratio and the water-binder ratio are considered simultaneously, when the water-binder ratio is large, the compressive strength of the concrete and the sand ratio have no significant relationship. When the water-binder ratio is large, there is sufficient cement paste to meet the pouring requirements. When the water-binder ratio is low, the compressive strength gradually increases with the increase of the sand ratio. A reasonable water-binder ratio and sand ratio can increase the compactness of the concrete and improve the compressive strength of the concrete. When the water-binder ratio and the aggregate ratio are compared, when the water-binder ratio is low, the compressive strength of the concrete gradually increases with the increase of the content of the 5-10 mm rock slag. When the water-binder ratio is large, the change of the concrete strength is not significant.
[0047] Step S4, obtaining a target model based on the sample set; inputting the to-be-determined concrete parameters into the target model to obtain a predicted quality parameter; judging whether the predicted quality parameter meets a preset quality parameter threshold, if not, adjusting the corresponding factor in the to-be-determined concrete parameters according to the order of the influence degree, and re-predicting and judging; if yes, manufacturing the concrete based on the to-be-determined concrete parameters meeting the requirements.
[0048] In this embodiment, based on the sample set shown in Table 2, the fitting degrees of various models to the sample set are obtained. For example, as shown in Table 4: Table 4
[0049] Table 4 shows the fitting degrees of various models obtained based on the sample set, wherein the fitting degree is reflected by the misfit and the corrected and predicted values of R2, and the greater the misfit and the corrected and predicted values of R2, the higher the fitting degree.
[0050] As can be seen from Table 4, the quadratic polynomial model in the model fits well, and the misfit and the corrected and predicted values of R2 are large. When the fitting degree of the quadratic polynomial model in the various models to the sample set is the highest, the quadratic polynomial model is determined as the target model, and the fitting equation of the quadratic polynomial model includes: ; ; wherein, is the slump of the concrete sample, is the compressive strength of the concrete sample, A is the sand ratio, B is the aggregate ratio, and C is the water-binder ratio.
[0051] It can be seen from the fitting equation that the slump and the compressive strength of the rock slag concrete have a quadratic relationship with the sand ratio, the aggregate ratio and the water-binder ratio.
[0052] The undetermined concrete parameter is input into the target model to obtain a predicted quality parameter of the concrete sample corresponding to the undetermined concrete parameter. Specifically, the undetermined concrete parameter can be input into the fitting equation of the above quadratic polynomial model to obtain the predicted quality parameter of the concrete sample corresponding to the undetermined concrete parameter. The predicted quality parameter includes a slump prediction value and a compressive strength prediction value.
[0053] Then, it is determined whether the predicted quality parameter meets a preset quality parameter threshold. In this embodiment, the preset error threshold includes a slump threshold and a compressive strength threshold, which can be determined according to the construction requirements of the tunnel construction.
[0054] When the predicted quality parameter is not greater than the quality parameter threshold, that is, the slump prediction value is less than or equal to the slump threshold and / or the compressive strength prediction value is less than or equal to the compressive strength threshold, the adjustment number n of the predicted quality parameter can be determined. For example, if the predicted quality parameter has not been adjusted, n is zero, if it has been adjusted once, n is 1, and so on. The factor of the undetermined concrete parameter in the order of n+1 is adjusted, and the step of inputting the adjusted undetermined concrete parameter into the target model, re-predicting and re-determining is performed.
[0055] For example, when the predicted quality parameter has not been adjusted, n is zero, the factor in the order of 1 can be adjusted at this time. If the orders of multiple factors are C, B, BC, A, AC and AB, the factor C, that is, the water-binder ratio, can be adjusted. When adjusting, the water-binder ratio can be increased by 5%. For other parameters, they can also be increased by 5% as the standard, or they can also be decreased, and the present application does not limit this.
[0056] If the predicted quality parameter meets the preset quality parameter threshold, the concrete is manufactured based on the undetermined concrete parameter meeting the requirements.
[0057] Specifically, it includes: manufacturing a target concrete sample based on the undetermined concrete parameter; testing the target concrete sample to obtain a target slump and a target compressive strength. When the relative error between the target slump and the slump prediction value is less than a preset error threshold, and the relative error between the target compressive strength and the compressive strength prediction value is also less than the preset error threshold, the engineering concrete is prepared based on the undetermined concrete parameter. In this embodiment, the preset error threshold is 4%, and in specific applications, the implementer can set it according to the specific situation.
[0058] This embodiment improves the success rate by actually preparing a target concrete sample and testing it to ensure that the obtained parameters of the concrete to be determined can meet the preset requirements.
[0059] In one exemplary embodiment, the determined parameters for the concrete to be tested included a sand ratio of 0.41, an aggregate ratio of 4.9:5.1, and a water-cement ratio of 0.38. To verify the accuracy of the data and for ease of use, an aggregate ratio of 5:5 was used, and target concrete samples were fabricated. The resulting test structures are shown in Table 5. Table 5
[0060] Table 5 compares the target slump with the predicted slump value and the target compressive strength with the predicted compressive strength value in this embodiment. The predicted values are the predicted slump and predicted compressive strength, while the actual values are the target slump and target compressive strength. The errors do not exceed 4%, indicating that concrete can be manufactured based on the undetermined concrete parameters.
[0061] In summary, the concrete acquisition method for tunnel construction provided in this embodiment produces concrete that meets quality parameter thresholds based on the excavated granite debris obtained during tunnel construction, eliminating the need to transport rock debris from a distant location to the tunnel construction site, thus reducing the difficulty of concrete acquisition. Furthermore, it reduces concrete acquisition costs and avoids the manpower and resources wasted on discarding and disposing of the excavated granite debris, thereby improving tunnel construction efficiency.
[0062] Furthermore, the method provided in this embodiment establishes a response surface model based on a sample set to determine the order of influence of various factors on the quality parameters of concrete samples. Then, a target model is obtained, and the parameters of the undetermined concrete input to the target model are adjusted based on the order of influence. This adjustment method limits the adjustment of factors with a greater influence, which can speed up the adjustment of the parameters of the undetermined concrete, thereby speeding up the acquisition of concrete and simplifying the adjustment process of the parameters of the undetermined concrete.
[0063] It should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the principles of the present invention should be included within the protection scope of the present invention.
Claims
1. A method for obtaining concrete during tunnel construction, characterized in that, The method includes the following steps: Rock debris is obtained from granite excavated during tunnel construction, and the rock debris includes first and second aggregates of different particle sizes; Multiple concrete samples were prepared based on different combinations of concrete parameters, including sand ratio, aggregate ratio of first aggregate to second aggregate content, and water-cement ratio. The quality parameters of the multiple concrete samples were tested, including slump and compressive strength. A sample set is constructed based on the multiple concrete parameter combinations and their corresponding quality parameters. A response surface model is established using the sample set. Based on the response surface model, the order of influence of each factor on the quality parameter is determined. The factors include sand ratio, aggregate ratio, water-cement ratio, and their interaction terms. The target model is obtained based on the sample set; the undetermined concrete parameters are input into the target model to obtain the predicted quality parameters; it is determined whether the predicted quality parameters meet the preset quality parameter threshold. If not, the corresponding factors in the undetermined concrete parameters are adjusted according to the order of influence, and the prediction and judgment are performed again; if yes, concrete is manufactured based on the undetermined concrete parameters that meet the requirements.
2. The method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The process of obtaining the target model based on the sample set includes: Based on the sample set, obtain the fit degree of various models to the sample set; The model with the highest fit to the sample set among all models is determined as the target model.
3. The method for obtaining concrete during tunnel construction according to claim 2, characterized in that, The step of determining the model with the highest fit to the sample set among all models as the target model includes: The quadratic polynomial model that best fits the sample set among multiple models is selected as the target model; the fitting equation of the quadratic polynomial model is: ； ； in, The slump of the concrete sample. A represents the compressive strength of the concrete sample, B represents the sand ratio, C represents the aggregate ratio, and C represents the water-cement ratio.
4. The method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The acquisition of the multiple concrete parameter combinations includes: The sand ratio is 0.37, 0.39, and 0.41; the aggregate ratio between the first and second aggregates is 3:7, 4:6, and 5:5; and the water-cement ratio is 0.33, 0.37, and 0.
41. Based on three sand ratios, three aggregate ratios, and three water-cement ratios, multiple combinations of concrete parameters were obtained using orthogonal experimental methods.
5. A method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The predicted quality parameters include predicted slump and predicted compressive strength. The process of manufacturing concrete based on desired concrete parameters includes: A target concrete sample is manufactured based on the undetermined concrete parameters; the target concrete sample is tested to obtain the corresponding target slump and target compressive strength; When the relative error between the target slump and the predicted slump value and the relative error between the target compressive strength and the predicted compressive strength value are both less than the corresponding preset error thresholds, engineering concrete is prepared based on the undetermined concrete parameters.
6. A method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The determination of the order of influence of each factor on the quality parameter based on the response surface model includes: Based on the response surface model, the feature values of each of the multiple factors are obtained; Based on the magnitude of the characteristic values of each factor, the order of the degree of influence is determined, and the characteristic value of each factor is positively correlated with the degree of influence of each factor on the quality parameters of the concrete sample; The impact levels are sorted in descending order to obtain the order of impact.
7. A method for obtaining concrete during tunnel construction according to claim 6, characterized in that, The step of obtaining the feature values of each of the multiple factors based on the response surface model includes: Based on the sample set, a first response surface model reflecting the slump and a second response surface model reflecting the compressive strength are respectively established; Based on the first response surface model, obtain the first characteristic value of each factor in the sample set for slump; based on the second response surface model, obtain the second characteristic value of each factor in the sample set for compressive strength; the first characteristic value and the second characteristic value are the ratio of the regression mean square to the error mean square corresponding to each factor; The average of the first characteristic value and the second characteristic value of each factor is determined as the characteristic value of each factor.
8. A method for obtaining concrete during tunnel construction according to claim 1, characterized in that, In the concrete sample, the cement was silicate cement, the sand was river sand, and the water-reducing agent was polyhydroxy acid water-reducing agent; among them, the solid content of the polyhydroxy acid water-reducing agent was 15.2%, and the water reduction rate was 24.2%.
9. A method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The interaction terms include the product of aggregate ratio and water-cement ratio, the product of sand ratio and water-cement ratio, and the product of sand ratio and aggregate ratio.
10. A method for obtaining concrete during tunnel construction according to claim 1, characterized in that, The method of obtaining rock debris from granite excavated during tunnel construction includes: crushing and processing the granite to obtain the rock debris.