BIM (Building Information Modeling)-based subway engineering muck output and carbon emission calculation system

Abstract

The invention, which relates to the technical field of carbon emission calculation, discloses a BIM-based subway engineering muck output and carbon emission calculation system comprising a muck output calculation module, a muck landfill land occupation calculation module, a parameter setting module and a muck carbon emission calculation module. The muck generation amount calculation module is used for automatically obtaining BIM model structure parameter data and automatically calculating the muck generation amount through a subway engineering muck generation amount calculation model; the muck landfill occupied area calculation module is used for automatically calculating the landfill occupied area by combining the landfill proportion, the loosening coefficient and the landfill depth data; the parameter setting module is used for setting various carbon emission factor parameters and energy consumption parameters and laying a data foundation for carbon emission calculation; the muck carbon emission calculation module is used for calculating the muck full-life-cycle carbon emission according to the data of the three modules in combination with a full-life-cycle carbon emission quantitative model; according to the method provided by the invention, the calculation process is optimized, and the calculation period is shortened.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon emission calculation, and in particular to a BIM-based subway engineering slag generation and carbon emission calculation system. Background Art

[0002] As urban rail transit systems develop rapidly, their carbon emissions are also increasing. However, the current models for carbon emission accounting are basically targeted at building types, and the calculation system for the amount of slag generated and carbon emissions in subway projects is not perfect enough, especially in terms of slag resource utilization and carbon emission intensity assessment. Existing studies have established a building carbon emission accounting method based on BIM-LCA (integration of building information modeling and life cycle assessment), which shows that the application of BIM technology in carbon emission accounting in the construction field has made certain progress. However, the automatic carbon emission accounting plug-in for underground space development such as subways is not yet mature; at the same time, the current carbon emission measurement methods for waste are all calculated manually, and fail to make full use of intelligent technologies such as BIM. Therefore, it is necessary to use emerging technologies to improve work efficiency and enhance the industry's intelligence level. Therefore, a BIM-based subway project slag generation and carbon emission calculation system is urgently needed to overcome the problems existing in the existing technology. Summary of the invention

[0003] The purpose of the present invention is to provide a BIM-based calculation system for subway engineering slag generation and carbon emissions, so as to solve the problems in the prior art that the calculation system for subway engineering slag generation and carbon emissions is imperfect and it is difficult to evaluate the resource utilization of slag and the carbon emission intensity.

[0004] To achieve the above-mentioned purpose, the present invention provides a BIM-based subway engineering slag generation and carbon emission calculation system, including a slag generation calculation module, a slag landfill area calculation module, a parameter setting module and a slag carbon emission calculation module; The slag generation amount calculation module is used to automatically obtain the structural parameter data of the BIM model and automatically calculate the slag generation amount through the subway project slag generation amount calculation model; The landfill area calculation module is used to automatically calculate the landfill area by combining the landfill ratio, the results of the landfill generation calculation module, the loose coefficient and the landfill depth data; Parameter setting module, used to set various carbon emission factor parameters and energy consumption parameters, laying a data foundation for carbon emission calculation; The construction waste carbon emission calculation module is used to calculate the carbon emission of construction waste over its entire life cycle based on the data from the previous three modules and the carbon emission quantification model for the entire life cycle.

[0005] Preferably, the full life cycle carbon emission quantification model includes a carbon emission quantification model for the subway engineering waste generation stage, a carbon emission quantification model for the subway engineering waste on-site resource utilization stage, a carbon emission quantification model for the subway engineering waste transportation stage, and a carbon emission quantification model for the subway engineering waste disposal stage.

[0006] Preferably, the calculation model for the amount of subway engineering slag generated includes the engineering slag generated by subway stations and shield tunnel construction, and the calculation expression is as follows: ; in, The total amount of slag generated by subway projects, unit: m 3 ; is the excavation diameter of the shield machine, in m; is the length of the shield tunnel, in m; is the looseness coefficient of engineering slag; is the length of the subway station, in m; is the width of the subway station, in meters; is the height of the subway station, in meters; is the correction factor.

[0007] Preferably, the carbon emission quantification model for the generation stage of subway engineering slag includes the carbon emission quantification during the shield tunneling process and the carbon emission quantification during the subway station excavation process, and the calculation expression is as follows: ; In the formula, Carbon emissions during the construction waste generation phase, unit: kgCO 2 eq; is the shield machine power, in kw; is the duration of excavation work, unit: h; is the total number of shield sections; is the carbon emission factor of electricity, unit: kgCO 2 eq / (kw·h); is the unit working efficiency of the excavator, in m 3 / h; is the unit energy consumption of the excavator, in L / h; is the diesel carbon emission factor, unit: kgCO 2 eq / L; Indicates the amount of slag generated by subway stations, unit: m 3 .

[0008] Preferably, the carbon emissions in the on-site resource utilization stage of subway engineering slag are calculated using an alternative value algorithm for approximate inventory data. The calculation expression of the carbon emissions quantification model in the on-site resource utilization stage of subway engineering slag is as follows: ; In the formula, Carbon emissions during the on-site resource utilization phase, in kgCO2eq; It indicates the amount of carbon emissions that can be reduced by using x as raw material replacement compensation per cubic meter of subway construction waste soil under on-site management, in kgCO 2 eq / m 3 .

[0009] Preferably, the carbon emission quantification model of the subway project slag transportation stage includes two parts: vertical transportation and horizontal transportation. The calculation expression is as follows: ; In the formula, Carbon emissions from construction waste transportation, unit: kgCO 2 eq; is the power of vertical transportation equipment, in kw; is the working time of vertical transportation, unit: h; is the carbon emission factor of electricity, unit: kgCO 2 eq / (kw·h); is the carbon emission factor of transport vehicles, unit: kgCO 2 eq / (t·km); is the transport mass, unit: t; is the transport distance, in km; is the empty car return coefficient.

[0010] Preferably, the carbon emission quantification model for the subway project waste disposal stage includes the landfill process and the resource utilization process.

[0011] Preferably, the carbon emission calculation expression of the landfill process in the carbon emission quantification model of the subway project slag disposal stage is as follows: ; in, Carbon emissions from construction waste disposal, unit: kgCO 2 eq; is the landfill rate; is the unit work efficiency of the bulldozer, unit: m 3 / h; It is the hourly fuel consumption of bulldozer, in L / h.

[0012] Preferably, the carbon emissions in the resource utilization process in the carbon emission quantification model of the subway project slag disposal stage are calculated using an alternative value algorithm of approximate inventory data, and the calculation expression is as follows: ; In the formula, Carbon emissions from the resource recovery process in the disposal phase, in kgCO 2 eq; is the specific gravity of the slag, unit: t / m 3 ; The resource utilization rate in the disposal stage; It indicates the amount of carbon emissions that can be reduced by recycling 1 ton of subway construction waste when y is used as a replacement for the recycled product, in kgCO 2 eq / t.

[0013] Therefore, the present invention adopts the above-mentioned BIM-based subway engineering slag generation and carbon emission calculation system, which has the following beneficial effects: (1) This invention uses advanced building information modeling (BIM) technology to significantly improve the efficiency and accuracy of calculation work. Through this innovative application, we can effectively avoid various potential errors and omissions that may occur in traditional manual calculations and ensure accurate data processing; the introduction of BIM technology not only optimizes the calculation process and shortens the calculation cycle, but also greatly enhances the transparency and coordination of project management, laying a solid data foundation for the smooth implementation of engineering projects, and bringing more efficient and reliable solutions to the industry; (2) The present invention quantifies the carbon emissions of subway engineering waste. The calculation results are based on the full life cycle theory and can clearly calculate the carbon emissions at each stage, providing guidance for carbon emission reduction in the field of engineering waste. (3) Although the present invention is aimed at subway engineering waste, in fact, the carbon emission calculation part is applicable to the calculation of waste in underground space development, and is also of reference value for carbon emission reduction work in underground space development.

[0014] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a system block diagram of a BIM-based subway engineering slag generation and carbon emission calculation system of the present invention; Figure 2 A Revit model diagram established in an embodiment of the present invention; Figure 3 This is a diagram showing the interface of a system slag generation calculation module according to an embodiment of the present invention; Figure 4 This is a diagram showing the interface of a system landfill area calculation module according to an embodiment of the present invention; Figure 5 This is a diagram showing the interface of a system parameter setting module according to an embodiment of the present invention; Figure 6This is a diagram showing the interface of a system slag carbon emission calculation module according to an embodiment of the present invention. DETAILED DESCRIPTION

[0016] The following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] See also Figure 1-Figure 6 , a BIM-based subway engineering slag generation and carbon emission calculation system, including slag generation calculation module, slag landfill area calculation module, parameter setting module and slag carbon emission calculation module; the connection between each module is as follows: first create the Revit BIM model of the subway station and shield tunnel to lay the model foundation for the subsequent system; then extract the size parameters of the subway station and shield tunnel through the Revit API interface in the slag generation calculation module to automatically calculate the slag generation; then in the slag landfill area calculation module, combine the landfill ratio, compaction coefficient and landfill depth data to calculate the engineering slag landfill area; then in the parameter setting module, the user completes the relevant carbon emission factor parameters and energy consumption parameters; finally, in the slag carbon emission calculation module, the carbon emissions of slag at different stages of the whole life cycle can be obtained, and there is an intuitive bar chart output; among them, the Revit BIM model is a subway station and shield tunnel model created based on the actual project construction drawings. The introduction of each module is as follows: The slag generation calculation module is used to automatically obtain the structural parameter data of the BIM model, and automatically calculate the slag generation through the subway project slag generation calculation model; specifically: automatically extract the length, width and height structural parameters of the subway station model, the user defines the shield machine excavation diameter, tunnel length and total number of intervals parameters, considers the looseness of the slag, multiplies the looseness coefficient in the calculation process, and also considers the slag generated by ancillary projects such as subway station entrances and exits, wind shaft pavilions, etc., so the calculation process also adds a correction coefficient, thereby outputting the amount of slag generated by shield tunnel excavation and subway station excavation, and outputting a pie chart.

[0018] The landfill area calculation module is used to automatically calculate the landfill area based on the landfill ratio, the results of the landfill generation calculation module, the loose coefficient and the landfill depth data; specifically: automatically obtain the results of the landfill generation calculation module. The calculation principle of the landfill area is the generation amount divided by the landfill depth. Therefore, according to the landfill ratio, compaction coefficient and average burial depth data of the landfill, the landfill area can be output. The specific calculation formula of the internal logic of the module is: ; In the formula, The area required for landfill of subway construction waste, unit: m 2 ; The total amount of slag generated by subway projects, unit: m 3 ; The proportion of waste sent to landfills; is the average burial depth of the landfill, in m 2 ; is the actual pressure coefficient; The parameter setting module is used to set various carbon emission factor parameters and energy consumption parameters to lay a data foundation for carbon emission calculation; all parameters have default values, and users can adjust these parameters according to their needs; carbon emission factor parameters include electricity, raw coal, diesel, gasoline, electric transport heavy trucks (load capacity 30t), light gasoline transport trucks (load capacity 2t), medium gasoline transport trucks (load capacity 8t), heavy gasoline transport trucks (load capacity 10t), and heavy diesel transport trucks (load capacity 30t); energy consumption parameters include the power of the shield machine, the thickness of the shield segment, the excavation time of each ring of the shield machine, the unit work efficiency of the excavator, the diesel consumption of the excavator per hour, the unit work efficiency of the bulldozer, the diesel consumption of the bulldozer per hour, the power of the vertical transportation machinery, the transportation distance, the empty car return coefficient, the working time of transporting each ring of slag, the resource utilization rate, the loose coefficient of the slag, the specific gravity of the slag and the density of diesel.

[0019] The carbon emission calculation module of slag is used to calculate the carbon emission of slag in the whole life cycle according to the data of the previous three modules and the carbon emission quantification model of the whole life cycle. Among them, the carbon emission quantification model of the whole life cycle includes the carbon emission quantification model of the subway engineering slag generation stage, the carbon emission quantification model of the subway engineering slag on-site resource stage, the carbon emission quantification model of the subway engineering slag transportation stage and the carbon emission quantification model of the subway engineering slag disposal stage.

[0020] The calculation model for the amount of subway engineering slag includes the engineering slag generated by subway stations and shield tunnel construction. The calculation expression is as follows: ; in, The total amount of slag generated by subway projects, unit: m 3 ; is the excavation diameter of the shield machine, in m; is the length of the shield tunnel, in m; is the looseness coefficient of engineering slag; is the length of the subway station, in m; is the width of the subway station, in meters; is the height of the subway station, in meters; is the correction factor.

[0021] The carbon emission quantification model for the generation of subway engineering slag includes the carbon emission quantification during the shield tunneling process and the carbon emission quantification during the subway station excavation process. The calculation expression is as follows: ; In the formula, Carbon emissions during the construction waste generation phase, unit: kgCO 2 eq; is the shield machine power, unit: kw; is the duration of excavation work, unit: h; is the total number of shield sections; is the carbon emission factor of electricity, unit: kgCO 2 eq / (kw·h); is the unit working efficiency of the excavator, unit m 3 / h; is the unit energy consumption of the excavator, in L / h; is the diesel carbon emission factor, unit: kgCO 2 eq / L; Indicates the amount of slag generated by subway stations, unit: m 3 , calculated by the following formula: .

[0022] The carbon emissions in the on-site resource utilization stage of subway engineering waste are calculated using the substitution value algorithm of approximate inventory data. The calculation expression of the carbon emission quantification model in the on-site resource utilization stage of subway engineering waste is as follows: ; In the formula, Carbon emissions during the on-site resource utilization phase, in kgCO2eq; It indicates the amount of carbon emissions that can be reduced by using x as raw material replacement compensation per cubic meter of subway construction waste soil under on-site management, in kgCO 2 eq / m 3 , The value is set to 13.8, specifically: using the replacement value algorithm of approximate inventory data, using feldspar as raw material replacement compensation, in principle, on-site management 1m 3 Subway construction waste can reduce 13.8kgCO2eq / m 3 Carbon emissions.

[0023] The carbon emission quantification model of subway engineering slag transportation stage includes vertical transportation and horizontal transportation. The calculation expression is as follows: ; In the formula, Carbon emissions from construction waste transportation, unit: kgCO2 eq; is the power of vertical transportation equipment, in kw; is the working time of vertical transportation, unit: h; is the carbon emission factor of electricity, unit: kgCO 2 eq / (kw·h); is the carbon emission factor of transport vehicles, unit: kgCO 2 eq / (t·km); is the transport mass, unit: t; is the transport distance, in km; is the empty car return coefficient.

[0024] The carbon emission quantification model for the subway project waste disposal stage includes the landfill process and the resource utilization process.

[0025] The calculation expression of carbon emissions from the landfill process in the carbon emission quantification model of subway project slag disposal stage is as follows: ; in, Carbon emissions from construction waste disposal, unit: kgCO 2 eq; is the landfill rate; is the unit work efficiency of the bulldozer, unit: m 3 / h; It is the hourly fuel consumption of bulldozer, in L / h.

[0026] The carbon emissions in the resource utilization process in the carbon emission quantification model of the subway project slag disposal stage are calculated using the substitution value algorithm of the approximate inventory data. The calculation expression is as follows: ; In the formula, Carbon emissions from the resource recovery process in the disposal phase, in kgCO 2 eq; is the specific gravity of the slag, unit: t / m 3 ; The resource utilization rate in the disposal stage; It indicates the amount of carbon emissions that can be reduced by recycling 1 ton of subway construction waste when y is used as a replacement for the recycled product, in kgCO 2 eq / t, The value is set to 59, specifically: using environmentally friendly unburned bricks as alternative compensation recycled products, 1t of subway project waste is recycled and utilized, which can reduce carbon emissions by 59kgCO2eq / t.

[0027] Example A subway station and shield tunnel section of Shenzhen Metro were selected as case study objects; According to the general method of model creation, the BIM model of the station is created with reference to the construction drawings provided by the project. The established Revit model is as follows: Figure 2 As shown; load the plug-in in Revit, enter the muck generation module, and automatically obtain the structural parameters of the station, that is, the station is 276.34m long, 29.212m wide, and 22.010m high. After comparison, the obtained data is consistent with the design data in the drawing. The next step is to improve the custom parameter input. The diameter of the slurry balance shield machine used for shield section excavation is 6450mm, the section length is 729.572m, and there are 2 shield sections in total. Finally, click "Calculate" to get the muck generated by shield tunnel excavation as 71515.260 m 3 The amount of soil generated by the subway station excavation is 266511.741 m 3 The total amount of slag produced is 354928.352m 3 The system automatically draws the corresponding fan chart, such as Figure 3 As shown; then enter the landfill area calculation module. In this case, based on the 80% landfill ratio and the average landfill depth of 5m, the required area for landfill is about 0.057 km 2 ,like Figure 4 As shown; then enter the parameter setting module. After investigation, the loose coefficient of the engineering slag in this section is 1.5, the shield machine power used is 2600kw, the shield machine segment thickness is 1.5m, the excavation time of each ring is about 0.42h, and the carbon emission factor of electricity is 0.85 kgCO 2 eq / kwh. The excavator on the construction site adopts a crawler-type single-bucket hydraulic excavator with a unit working efficiency of 8m 3 / h, diesel consumption per hour is 7.875kg, diesel density is 0.84kg / L, and the carbon emission factor generated by each diesel consumption is 3.76 kgCO 2 eq / L. Electric heavy trucks (30t) are used for horizontal transportation, and the carbon emission factor is 0.033kgCO 2 eq / (t·km), the geological slag weight of the project site is 1.5 t / m 3 The transportation distance is assumed to be 50km. The vertical transportation machinery uses a gantry crane with an average power of 210kw. The transportation time of each ring of slag is 1.25 hours. The resource utilization rate of this project is set at 5%. The landfill disposal process uses a crawler bulldozer with a power of 135kw, and its unit work efficiency is 30m 3 / h, diesel consumption per hour is 8.15kg. After completing the parameter settings, click "OK", the data will be automatically stored, and you can enter the calculation of the next module, such as Figure 5As shown; Finally, enter the slag carbon emission calculation module. The system automatically calculates the carbon emissions of the slag throughout its life cycle based on the results of the previous modules. Among them, the shield tunnel section generates 1806000 kgCO 2 eq., subway station excavation produces 1,174,000 kgCO 2 eq, the carbon dioxide emitted during the production phase is approximately 2980000 kgCO 2 eq; If all the construction waste is managed on-site, the carbon emissions in the on-site recycling stage can be reduced by 4898000 kgCO 2 eq; During the transportation phase, a total of about 1,684,000 kgCO2 is produced 2 eq; During the disposal phase, the landfill process will generate 345,300 kg CO 2 eq, the resource recovery process will reduce 1571000 kgCO 2 The total carbon emission reduction in the disposal phase is about 1,225,000 kgCO 2 eq; The carbon emission reduction brought by the whole life cycle of slag resource treatment is about 1459000 kgCO 2 eq, such as Figure 6 shown.

[0028] Therefore, the present invention adopts the above-mentioned BIM-based subway engineering slag generation and carbon emission calculation system, through the mutual cooperation between the slag generation calculation module, the slag landfill area calculation module, the parameter setting module and the slag carbon emission calculation module, and based on the full life cycle theory, it clearly calculates the carbon emission status of each stage, and provides guidance for carbon emission reduction work in the field of engineering slag.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A BIM-based subway engineering slag generation and carbon emission calculation system, characterized in that: It includes a slag generation calculation module, a slag landfill area calculation module, a parameter setting module and a slag carbon emission calculation module; The slag generation amount calculation module is used to automatically obtain the structural parameter data of the BIM model and automatically calculate the slag generation amount through the subway project slag generation amount calculation model; The landfill area calculation module is used to automatically calculate the landfill area by combining the landfill ratio, the results of the landfill generation calculation module, the loose coefficient and the landfill depth data; Parameter setting module, used to set various carbon emission factor parameters and energy consumption parameters, laying a data foundation for carbon emission calculation; The construction waste carbon emission calculation module is used to calculate the carbon emission of construction waste over its entire life cycle based on the data from the previous three modules and the carbon emission quantification model for the entire life cycle.

2. According to the BIM-based subway engineering slag generation and carbon emission calculation system of claim 1, it is characterized by: The carbon emission quantification model for the entire life cycle includes the carbon emission quantification model for the generation stage of subway engineering waste, the carbon emission quantification model for the on-site resource utilization stage of subway engineering waste, the carbon emission quantification model for the transportation stage of subway engineering waste, and the carbon emission quantification model for the disposal stage of subway engineering waste.

3. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 2 is characterized in that: The calculation model for the amount of subway engineering slag includes the engineering slag generated by subway stations and shield tunnel construction. The calculation expression is as follows: ； in, The total amount of slag generated by subway projects, unit: m 3 ; is the excavation diameter of the shield machine, in m; is the length of the shield tunnel, in m; is the looseness coefficient of engineering slag; is the length of the subway station, in m; is the width of the subway station, in meters; is the height of the subway station, in meters; is the correction factor.

4. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 3 is characterized in that: The carbon emission quantification model for the generation of subway engineering slag includes the carbon emission quantification during the shield tunneling process and the carbon emission quantification during the subway station excavation process. The calculation expression is as follows: ； In the formula, Carbon emissions during the construction waste generation phase, unit: kgCO2eq; is the shield machine power, in kw; is the duration of excavation work, unit: h; is the total number of shield sections; is the carbon emission factor of electricity, unit: kgCO2eq / (kw·h); is the unit working efficiency of the excavator, in m 3 / h; is the unit energy consumption of the excavator, in L / h; is the diesel carbon emission factor, unit: kgCO2eq / L; Indicates the amount of slag generated by subway stations, unit: m 3 .

5. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 4 is characterized in that: The carbon emissions in the on-site resource utilization stage of subway engineering waste are calculated using the substitution value algorithm of approximate inventory data. The calculation expression of the carbon emission quantification model in the on-site resource utilization stage of subway engineering waste is as follows: ； In the formula, Carbon emissions during the on-site resource utilization phase, in kgCO2eq; It indicates the amount of carbon emissions that can be reduced by using x as raw material replacement compensation per cubic meter of subway construction waste soil under on-site management, in kgCO2eq / m 3 .

6. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 5 is characterized by: The carbon emission quantification model of subway engineering slag transportation stage includes vertical transportation and horizontal transportation. The calculation expression is as follows: ； In the formula, Carbon emissions during the construction waste transportation phase, unit: kgCO2eq; is the power of vertical transportation equipment, in kw; is the working time of vertical transportation, unit: h; is the carbon emission factor of electricity, unit: kgCO2eq / (kw·h); is the carbon emission factor of transport vehicles, unit: kgCO2eq / (t·km); is the transport mass, unit: t; is the transport distance, in km; is the empty car return coefficient.

7. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 6 is characterized by: The carbon emission quantification model for the subway project waste disposal stage includes the landfill process and the resource utilization process.

8. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 7 is characterized in that: The calculation expression of carbon emissions from the landfill process in the carbon emission quantification model of subway project slag disposal stage is as follows: ； in, Carbon emissions during the construction waste disposal phase, unit: kgCO2eq; is the landfill rate; is the unit work efficiency of the bulldozer, unit: m 3 / h; It is the hourly fuel consumption of bulldozer, in L / h.

9. The BIM-based subway engineering slag generation and carbon emission calculation system according to claim 8 is characterized in that: The carbon emissions in the resource utilization process in the carbon emission quantification model of the subway project slag disposal stage are calculated using the substitution value algorithm of the approximate inventory data. The calculation expression is as follows: ； In the formula, Carbon emissions from the resource recovery process in the disposal phase, in kgCO2eq; is the specific gravity of the slag, unit: t / m 3 ; The resource utilization rate in the disposal stage; It indicates the amount of carbon emissions that can be reduced by recycling 1 t of subway construction waste when y is used as a replacement for the compensatory recycled product, in kgCO2eq / t.

Images