Abstract
With the continuous update and iteration of Internet information technology, the application of BIM (Building Information Modeling) technology in the fields of project management, cost and construction is becoming more and more popular. The field of project cost relies on the significant advantages of BIM technology to realize the intelligence of project cost management. It can effectively promote the horizontal information collection and vertical information interaction of different participants, and achieve a good information exchange and interaction effect. This paper combines the characteristics of China nuclear power engineering projects, applies building information modeling (BIM) technology, and integrates it into the nuclear power engineering cost software framework. This paper firstly analyzes the basic characteristics of China nuclear power engineering cost software, and puts forward the key functional requirements for existing cost software. On this basis, the basic characteristics of foreign mainstream construction cost software with BIM technology and the feasibility of its application in China is also analyzed. The model consists of two parts, namely the BIM data management platform and the functional model of the construction project budget subsystem. Among them, the BIM data management platform realizes the analysis, storage and management of IFC (Industry Foundation Class) data, and provides a user interface for specific professional fields, such as the field of construction engineering budget, while the construction engineering budget subsystem provides users with cost budgeting expertise. In addition, this paper describes in detail the method of using BIM technology to create the most used pipe network model in cost assessment. Based on Revit software, combined with the use of visual programming tools Dynamo and Revit API, the repetitive and tedious manual modeling process is automated to compete the creation of the BIM model of a large number of pipe networks in a relatively short time, and make the model carry rich engineering information. This paper establishes a basic framework suitable for China nuclear power engineering cost software, which can lay the foundation for the subsequent development of corresponding software. The pipeline network BIM establishment method proposed in this paper can greatly improve the work efficiency of traditional CAD modeling, realize seamless connection with cost assessment, and has broad engineering application prospects.
Introduction
Background
For nuclear power engineering projects, carrying out construction cost analysis is an indispensable work. Improving its efficiency and accuracy is essential for improving the economics of the project and ensuring the project time cycle. With the development of computer technology, construction engineering cost software has been rapidly developed and widely used [1]. Nevertheless, the current project cost engineer still needs to spend a lot of time to budget for the construction project, and even need to work overtime to complete it on time.
The traditional methods are basically based on the two-dimensional CAD drawing measurement [2]. On this basis, the measured data is imported into the cost software to obtain the calculation results. The work efficiency is extremely low, and the entire work needs to be recalculated after the drawing is updated. Therefore, it is very necessary to open up the interface between design and cost analysis to achieve a seamless connection between design and cost. BIM is a very good method.
BIM is based on three-dimensional digital technology and integrates various related information of construction engineering. It is a detailed digital and standardized expression of construction engineering related information. At the same time, it is also a digital method applied to design, construction, and management [3]. As the mainstream standard of BIM data, the IFC rule is a standard for the expression and exchange of construction product data, and its purpose is to support the sharing and exchange of information at all stages of the life of a construction project [4]. Theoretical research shows that the construction project budget analysis based on BIM technology can be more rapid and accurate, and can be automatically updated with design changes. Especially for the latter, the efficiency of construction budget analysis can be increased by almost an order of magnitude [5]. There are also data that show that BIM technology-based construction engineering budget software can increase the efficiency of engineering cost engineer by as much as 3 times compared with traditional construction engineering budget software [6].
Literature review
As a way to realize modern informatization in the construction industry, BIM technology has been effectively used in the process of cost management. Zhang analyzed the advantages and future development trend of BIM technology in engineering cost management [7]. Wu et al. conducted a comprehensive evaluation of the functions of the three major cost software using fuzzy evaluation method from six aspects [8]. Han proposed the advantages and value of BIM technology application in project cost management [9]. Cai et al. took the actual project as an example, used the technical framework of the BIM platform and the BIM5D software to conduct practical discussions, summed up the advantages of BIM technology, such as high precision, high efficiency, dynamic management, etc., and put forward some suggestions for improvement [10]. Cao proposed the combination of BIM technology and project cost management, which provides the possibility to realize the whole process and all-round project cost management, and can also greatly improve the efficiency of project cost management [11].
Based on the research over the years, most of them only analyzed the applicability and advantages of BIM technology in engineering cost management, while the construction of cost information management system based on BIM technology was rarely reported. Although some foreign software companies have developed some BIM technology-based construction project budget software, due to the different restrictions on construction project budgets in various countries and regions, the software cannot be widely used in all countries and regions. Therefore, this paper aims to establish a nuclear power engineering cost software framework based on BIM technology that is suitable for Chinese regulation.
Basic characteristics of China current construction engineering budget software
Nuclear power engineering budget work can be divided into two parts, which are engineering quantity calculation and pricing. Although the engineering quantity calculation time varies from project to project, it generally occupies 50% to 80% of the entire budget work [12], in order to improve the efficiency of the budget, improving the efficiency of the engineering quantity calculation is the key.
With the development of computer technology, engineering quantity calculation software has gone through three important stages in China [13]. The first stage, the earliest form engineering quantity calculation software that appeared in the early 1990s, the second stage, the two-dimensional graphics-based engineering quantity calculation software that appeared after 1995, and the third stage, with the continuous development of three-dimensional simulation technology after 2000. Due to the importance of engineering quantity calculation in budget work, its development stage also represents a stage division standard of China construction engineering budget software. It can be considered that the new generation of construction engineering budget software will be based on the application of BIM technology [14].
Restricted by work patterns, China current construction engineering budget software includes engineering quantity calculation software and engineering pricing software. Although there is no software that can integrate the two, some software companies have realized the interface and integrated application of engineering quantity calculation and engineering pricing software. Of course, this integration is not based on common standards but on the company’s internal standards. For example, Glodon’s engineering pricing software GBQ4.0 can directly import GCL project files, that is, the engineering quantity files generated by the company’s graphics calculation software, and complete project pricing on this basis [15]. In foreign countries, according to user needs, there are independent engineering quantity calculation software and engineering pricing software, as well as construction engineering budget software that integrates engineering quantity calculation and engineering pricing. In this study, the current mainstream nuclear power engineering budget software in China, including engineering quantity calculation software and engineering pricing software, was investigated, and their basic characteristics were summarized, as shown in Table 1.
Basic characteristics of the current mainstream construction budget software in China
Basic characteristics of the current mainstream construction budget software in China
Generally speaking, compared with the second-stage budget software, the current construction engineering budget software can quickly enter data, and the user operation is more convenient and intuitive. Due to the very rigorous mathematical spatial model, the calculation accuracy and speed are higher. It is faster, and can directly identify and use the electronic files of construction drawings of the design institute, which further improves work efficiency.
Key functional requirements of the new generation of construction engineering budget software
On the basis of investigating and summarizing the characteristics of the current nuclear power engineering budget software, we visited 5 typical construction companies and asked the cost engineer of the companies to understand the problems in the current application. At the same time, we also visited relevant professional forums through the Internet to collect relevant information. Then, combined with the possibilities provided by BIM technology, the key functional requirements of the next-generation nuclear power engineering budget software are analyzed, and the key functional requirements formed are shown in Table 2.
Key functional requirements of next-generation nuclear construction engineering budget software
Key functional requirements of next-generation nuclear construction engineering budget software
This research mainly focuses on the American software with mature development of BIM technology as the research object. The main software investigated are Innovaya Viusal Estimating, US Success Design Exchange from Cost Company, Timberline Extended from Sage Company, ICE from MC2 Company, DesignEst Pro from Winest Company, Toktmo Production System from Tokmo Company, Vico Estimator from Vico Company, etc. [16, 17, 18, 19]. Table 3 summarizes their basic characteristics.
Basic characteristics of mainstream nuclear power engineering budget software based on BIM technology
Basic characteristics of mainstream nuclear power engineering budget software based on BIM technology
If the factors of construction project budget specifications are not taken into consideration, in general, this budget software can meet the key functional requirements of China new generation of construction project budget software to a large extent. For example, Sage’s Timberline Extended can use the company’s CAD Integrator component to directly use the design results in IFC format to budget for construction projects. The IFC standard is a data expression standard for construction products issued by the International Alliance for the construction industry. It uses an object-oriented, standardized data description language EXPRESS as the data description language to define all the data used. EXPRESS language is described through a series of instructions, these instructions mainly include type description (Type), entity description (Entity), rule description (Rule), function description (Function) and procedure description (Procedure). The budget data formed by Innovaya Visual Estimating can be stored in accordance with the company’s unified data format (.INV), so as to realize information sharing among the same series of software developed by the company. For example, the company’s construction progress simulation software can directly use Innovaya Visual Budget data generated by Estimating.
After analysis, it is learned that in order to apply the mainstream foreign construction engineering budget software based on BIM technology to the practice, the following problems need to be solved:
Coding system. The construction project budget needs to be based on the budget coding system. Currently, the more widely used coding systems in the construction industry in the United States are UNIFORMAT II and MASTERFORMAT. China current related coding systems mainly include the “Construction Engineering Quantity List Valuation Specification” used for the inventory valuation method, the “National Unified Construction Engineering Basic Quota” for the quota valuation method and the local budget quota coding system. After comparison, it is found that the content of each coding system is quite different. For example, the American coding system MASTERFORMAT II divides the construction project into 16 sections, and each section is composed of many chapters. However, in Chinese “Construction Engineering Quantity List”, the Code is first divided into five majors according to different majors: architecture, decoration, installation, municipal administration, landscaping, and mining engineering. Each major includes many professional projects, and the professional projects are divided into many sub-projects underneath. Calculation method of engineering quantity. In the United States, there is no unified engineering quantity calculation rule for the calculation of engineering quantities. When using American construction engineering budget software based on BIM technology, the engineering quantity calculation is mainly based on the type of building components and three-dimensional geometric data, and the building will be calculated. The area, volume and other data of the component are used as the engineering quantity of the construction project budget. In China, regardless of whether it is the inventory valuation method or the quota valuation method, there are unified rules for the calculation of engineering quantities. In addition to the types of building components and three-dimensional geometric data, the calculation of Chinese engineering quantities also considers construction information, such as construction technology and construction methods. Pricing basis. At present, the United States does not have a unified budget quota for construction projects, and the price is determined by the market. In China, due to objective reasons, the basis for pricing is mainly based on the national and local budget quotas, such as the “Beijing Construction Project Budget Quota”, and bidders cannot make budgets out of the construction project budget quota.
It can be seen that in order to apply the current mainstream foreign engineering budget software based on BIM technology to China, a lot of work including coding system implantation, database preparation, engineering quantity calculation function adjustment, etc. needs to be done, which leads to even the need to adjust the entire software architecture. Therefore, even if only from a technical point of view, instead of localizing foreign BIM technology-based construction engineering budget software, it is better to directly develop software suitable for China conditions.
Overall model
The basic assumption of the new generation of nuclear power engineering budget software in this study is that the software directly uses the IFC format data file generated by the BIM technology-based design software for construction engineering budget, and finally the budget data can be exported in the IFC standard data format for subsequent software.
Based on the above basic assumptions, the overall model of the software is established, as shown in Fig. 1. The model consists of two parts, namely the BIM data management platform and the functional model of the construction project budget subsystem. Among them, the BIM data management platform realizes the analysis, storage and management of IFC data, and provides a user interface for specific professional fields, such as the field of construction engineering budget, while the construction engineering budget subsystem provides users with cost budgeting expertise. It realizes the management and application of BIM data by calling the user interface provided by the BIM data management platform, including the import of design results. The advantage of adopting this method is that the BIM data is appropriately packaged, making the BIM data management platform versatile and applicable to the expansion of functions in different professional fields.
Also, relation database should be used for the whole design. The relational database is based on a relational database model. It uses concepts and methods such as set algebra to process the data in the database. It is also a group of tables organized into a set of formal descriptions. It is a special collection of data items. The data in these tables can be accessed or reconvened in many different ways without the need to reorganize the database tables. The definition of a relational database creates a table of metadata or a formal description of tables, columns, ranges, and constraints. Each table (sometimes called a relationship) contains one or more data types represented by columns. Each row contains a unique data entity, these data is the type defined by the column. When creating a relational database, you can define the range of possible values. The SQL language is the interface of relational databases. The advantage is that it is easy to expand, and after the initial database creation, a new data type can be added without modifying all existing application. Mainstream relational databases include oracle, db2, SQL server, sybase, mysql, etc.
The software model framework of nuclear power project cost based on BIM technology.
The functional model of the nuclear power project cost subsystem.
Functions of the construction project budget subsystem
Open Inventor should be used as a development platform for 3D models. Open Inventor is an OpenGL-based object-oriented 3D graphics software developed by SGI. Using the Open Inventor development kit, programmers can quickly and concisely develop various types of interactive 3D graphics software. Open Inventor is platform-independent, and it can be used in a variety of operating systems such as Microsoft Windows, Unix, and Linux. Open Inventor allows the use of C, C
Based on the key functional requirements of the above-mentioned new generation of nuclear power engineering budget software, combined with and considering the functional coverage of the current nuclear power engineering budget software, this study establishes a functional model of the nuclear power engineering budget subsystem supporting the inventory valuation method. It can be used to support the realization of quota pricing. The model includes 5 functional modules, namely, project setting module, list item setting module, engineering quantity generation module, engineering pricing module, report generation and management module, which realizes the integration of engineering quantity calculation and pricing, as shown in Fig. 2. In addition, the figure also reflects the order in which each module is used.
This platform supports Linux systems and can run on mainstream Linux operation system such as CentOS, Ubuntu, Fedora, Debian, and Redhat Linux.
The detailed description of each functional module is shown in Table 4. It can be seen that each functional module can meet the key functional requirements of the above-mentioned new generation of construction engineering budget software. It is worth noting that although the design results can be used directly, a lot of interactive operations are still required to input the necessary parameters. This is mainly determined by the China Construction Project Budget Code.
Engineering application examples
In order to illustrate the rationality of the established system design framework, this paper takes the construction of the most used pipe network model in cost assessment as an example, and gives its key implementation techniques.
This study uses Revit 2018 as the BIM model modeling platform, and cooperates with the Revit-based visual programming tool Dynamo 2.0.2 to design automation programs. After collecting and analyzing the blind exploration results of underground pipelines in multiple projects, this paper proposes a new method for the automatic construction of BIM information model of underground pipeline network. The general process is as follows: (1) First, based on the standard underground pipeline blind detection report, classify and organize the data, and build the required database for model generation; (2) Based on the standard pipe fittings and pipe well atlas, use Revit software to establish parametric pipe fittings and pipe well component families to form components; (3) Retrieve, exclude and filter pipeline point positioning data, and reconstruct pipeline connection direction data; (4) Write a program to read model creation data, and automatically generate BIM models of pipeline points and segmented pipelines respectively; give information.
The pipeline point BIM model is created by designing and writing the Dynamo execution program. The design execution program is mainly divided into three steps: data reading and processing, placement of pipeline points, Revit parametric family construction, and information parametric input. Running the program and setting of all pipeline points in the database.
For the pipeline model, there is no node in Dynamo’s built-in node library that can directly call the pipeline system family in Revit software. This paper uses Python language to write function programs:
TransactionManager.Instance.EnsureInTransaction(doc) for i in range(len(startPoint)): pipe=Plumbing.Pipe.Create(doc,systemType.Id,pipeType.Id,level.Id,startPoint[i].ToXyz(), endPoint[i].ToXyz()) pipes.append(pipe) TransactionManager.Instance.TransactionTaskDone() OUT=pipes
After completing the creation of each pipeline model, use the same method as the above for setting parameters for pipeline points, and add information such as point number, material, ownership unit, etc. to each pipeline segment.
Discussion
The application software at the current design stage in China is still dominated by two-dimensional CAD software represented by AUTOCAD, and the design based on two-dimensional CAD technology is still the current mainstream working mode. Two-dimensional CAD-based design uses two-dimensional graphics to express three-dimensional concepts. It requires three two-dimensional graphics, vertical, horizontal, and cross-section to fully express the design intent. It is not intuitive and friendly for both designers and users. Moreover, the result data designed with two-dimensional CAD software is only a collection of vector information, which cannot express specific building component objects, and therefore cannot be effectively used by other software. Object-oriented 3D CAD technology can solve the inherent shortcomings of 2D CAD technology. Using 3D CAD technology, the designer can directly express the design idea in the software as a 3D model, which is more in line with the designer’s thinking habits. The intuitive 3D model also makes the design concept easier to communicate, thereby improving work efficiency and reducing errors. Because it contains object-oriented ideas, 3D CAD technology can support the realization of design intelligence. For example, in 3D CAD software, the 2D attributes of building components are related to their 3D attributes, and the 2D of any cross-section can be automatically generated according to the 3D model. Three-dimensional CAD technology has been well applied in the architectural design industry. The new generation of architectural design software using three-dimensional CAD technology represented by Revit and ARCHICAD is increasingly accepted and used by more and more architects. 3D CAD technology is also very important for cost budgeting software. In order to realize the calculation of building components, object-oriented 3D CAD technology has inherent advantages over 2D. For some complex engineering quantity calculation rules, such as the engineering of calculating components, it is necessary to consider the deduction of openings and the intersecting parts with other components, which are almost difficult to achieve with two-dimensional technology. Therefore, for efficient and accurate cost budgeting, object-oriented 3D graphics technology is the most basic technical requirement. The existing open 3D modeling platforms, such as OPENGL, Open Cascade, etc., have laid a solid foundation for this.
At the same time, in the cost budget system, a large amount of known quota information needs to be stored to facilitate the utilization and realization of system functions, and database technology is an indispensable technology. A database is an organized and shareable collection of data stored in a computer for a long time. Relational database is currently the most widely used database system. It has a simple structure, easy to understand, solid data theory foundation, and structured query language SQL (Structured Query Language) to provide a unified programming interface for relational databases.
The complete construction cost budgeting work requires the use of software in three areas, namely, building, structural design software, construction cost budgeting software, and schedule software that support IFC standards. IFC standard format data is used as a shared source of data, which can realize the seamless transmission of information at different stages. In addition, the introduction of progress information in the construction budget stage can realize process-oriented engineering pricing and provide data for the construction budget.
Compared with the current construction cost budgeting workflow, this process has the following three characteristics:
The entire process uses the same FC data source, and the cost budget software can directly use the information in the design stage, thus avoiding repetitive input of a large amount of data, and reducing the cost. Because the information of each stage in the IFC data model is highly correlated, the data result of each stage is no longer a one-time static output, which makes the entire workflow no longer one-way and irreversible: at the same time, if the upstream information changes, the downstream information only needs to be modified with the associated partial information, without regenerating all the information, thereby improving work efficiency. Due to the introduction of schedule information, the information in the process increases the time dimension, which greatly improves the accuracy of construction forecasts, and makes the construction budget more practical.
The application of BIM technology and IFC standards in construction cost budgeting software will provide an excellent technical foundation for solving the problems existing in current cost budget software, thereby bringing the following benefits:
It can provide a general cost information model with complete and highly relevant information for the system implementation of cost budgeting software and adapt to different pricing methods. The FC standard is organized in an object-oriented way. It is currently the most complete model describing all aspects of the building, and has a way to support software developers to implement custom extensions. The system functions based on the information model that conforms to the standard are naturally flexible and efficient, leading to a leap in work efficiency.
It can realize the standardization of the data exchange format between the construction cost budget software and other upstream and downstream software. The standardization of the data interaction format enables the seamless transmission of data in different stages, sharing the same data source with the design stage, eliminating repetitive modeling work, thereby avoiding human understanding deviation and wrong input, and improving work efficiency. At the same time, the budget result data can also be seamlessly transferred to downstream software for direct use.
In order to explore the expression of the IFC standard for building products, the building products are divided into major categories, and the definition of building components in the shared layer of the FC standard is analyzed, such classification is very abstract. For example, for the element “wall” in the architectural design product category, it only expresses a general abstract concept in the construction industry, and cannot be applied to specific fields in the construction industry, such as the field of cost budgeting, so it must be classified and described. However, with the development of construction technology, the classification of building products has become more and more complicated. We cannot directly establish a unified attribute set for “walls”. For example, concrete walls and brick walls have completely different attribute descriptions, and a unified attribute set is established. It will make it unusually large and cause the duplication of a large amount of information and waste of space. The requirement for the establishment of the attribute set is to include the attributes of the building product with the same attribute description and keep the content refined. In order to better apply in specific fields, such as the field of cost budgeting, building products need to be further refined to meet specific application requirements and achieve refinement of the attribute set. In the refinement process, the division requirements and methods of different application areas need to be considered.
By comparing with the traditional modeling method, using this research method to implement automatic pipeline network modeling, the efficiency of manual modeling is increased by 2.5 times, and the data accuracy rate is 100%, which greatly increases the efficiency and accuracy of pipeline BIM model construction. After the accurate pipeline BIM model is obtained quickly, it brings great convenience to the project cost management, so that the project managers have sufficient time to make better use of the BIM model for cost analysis, and have a more accurate basis for design and construction.
Although BIM technology can greatly improve the work quality and efficiency of engineering cost, the existing BIM technology threshold is still high. It takes more time for technicians to fully master BIM-related skills, and the process of BIM modeling also depends on a lot of time.
With the continuous development and improvement of machine learning algorithms, in future research, we will improve the accuracy and work efficiency of cost analysis based on machine learning algorithms. SCI-Learn toolkit provides a complete set of solutions, which can be used for secondary development based on this package in the future.
Conclusion
This study presents an in-depth analysis of the current status of construction engineering budget software in China and other countries, and based on BIM technology, we propose a new generation of nuclear power engineering budget software framework in China, which makes full use of advanced information technology and can meet the project cost.
In this paper, based on Revit software, combined with the use of visual programming tools Dynamo and Revit API, we provide a framework for the BIM cost software. C
Study results show that, for the composition of the cost system, it should at least include basic settings, compile information input, engineering quantity calculation rule setting, entity list item generation and setting, add and set non-entity list items, engineering quantity generation, valuation by part of the bill of quantities, measure item list preparation and pricing, compilation and pricing of other items list, labor, materials machine summary and editing, expense summary and editing, report generation and management and other core function modules.
And for the future research, the subsequent introduction of artificial intelligence algorithms into the calculation and analysis of the entire project has been considered, and we plan to use the algorithms method in the SCI-Learn toolkit to implement it. Currently, the Python program is used to complete the compilation of the clustering code, and future improvements will be made. The regression algorithm is added to the calculation analysis.
Aiming at the current situation that the pipeline network model has a large workload in the existing cost analysis, this paper uses the BIM technology to quickly generate the pipeline network model, and seamlessly connect the information required by the cost. This research method significantly improves the work efficiency of BIM technology application in the construction of actual projects.
Footnotes
Acknowledgments
This work was performed at Shanghai Nuclear Engineering Research and Design Institute, Department of Consulting. The authors wish to thank the project coordinator, Mr Dufenglei, for his support for the assistance in developing the research program.
This work is supported by (National Natural Science Foundation of China) (No. 11805123, No. 11535009) and China Advanced Nuclear Power Standard System Research (No. 2017ZX06004001) and SMR EPZ Determination Method and Principle, Take CAP200 as a Case Study (IAEA Research Contract No. 22578) and Research on CAP1400 Safety and Economic Performance Intelligent Monitoring and Evaluation System (No. ZB15) and JRODOS system calculation comparison (Shidaowan site) (No. 19FW160), China Nuclear Energy Association Group Standardization Capacity Building (No. 20YW042) and Economic Research on BOP Sub-item of Nuclear Power Plant (No. 21YW053).