On Calculation Scheme for List Engineering Quantity of Highway Engineering Based on BIM Model

Abstract

This paper studies the ways to obtain the quantities of rebar, subgrade earthwork and other components in the field of highway engineering construction according to the relatively mature method of calculating quantities based on BIM model in the field of civil construction, and forms the calculation scheme for list engineering quantity of highway engineering based on BIM model that can be popularized and implemented. Introduction Engineering calculation is always the key and difficult point of the application of BIM technology. Domestic engineering quantity calculation software providers, such as Guanglianda, Luban, and Sville, have developed BIM quantity calculation software for civil construction projects, and have strong practicability. At the same time, the engineering quantity composition and the list pricing method of highway engineering are quite different from that of the housing construction project. At present, there is no mature BIM calculation software. 1. Research Background Hefei-Zongyang Expressway is part of the “Three Verticals” in the “Five Verticals and Nine Crosses” in Anhui Expressway Planning Network. The total length of the route is 134 km. The route is a two-way four lane highway with a design speed of 120 km / h. There are many interchanges, super bridges and bridges, one tunnel, and a number of auxiliary buildings and other supporting facilities, and the approved budget is 10.459 billion RMB. This project is a project for the application of BIM Technology. In order to improve the accuracy of project investment, technical research on extracting list engineering quantities from BIM model has been carried out, which provides a new implementation idea for list calculation of highway engineering based on BIM model. 2. Calculation Scheme for List Engineering Quantities "Full Materialization" The core of BIM is to build a virtual three-dimensional model of construction engineering and use digital technology to provide a complete information base of construction engineering consistent with the actual situation. The information base contains not only the geometric information, professional attribute and state information of building components, but also the state information of non component objects, such as space and motion behavior. 2.1 Calculation Plan According to the regulations on measurement rules in the “Bidding Engineering Standard Construction Bidding Documents” (2018 edition), the data required for the list engineering 2020 International Conference on Social and Human Sciences (ICSHS2020) DOI: 10.38007/Proceedings.0000053 ISBN: 978-1-80052-000-4 290 quantities of highway engineering are the basic geometric information of the engineering entity such as the number, volume, weight, area and length, which can be calculated and generated by modeling software or other BIM software for related data statistics and calculations. In theory, the data required for the list engineering quantities of highway engineering can be obtained from the BIM model. In the case where the relevant basic data is obtained, the combination of the list coding and the component process classification, the material classification, the specification classification or the above classification is performed, and the automatic generation of the list coding can be realized. In order to facilitate the distinction, the author refers to the above method of calculating the list as the calculation scheme for list engineering quantity of “full materialization”. By comparing the process classification, material classification, and specification classification information with the list engineering quantity, the list code of the bored pile can be automatically configured as 405-1-a-1 with the engineering quantity of 12m. The means by which the component is associated with the manifest is implemented by a customized information base, as shown in Table 1, Table 2. Table 1 Example of pile foundation property of a bridge member Process classification Material classification Specification classification length 1#Pile 3#pile drilling piles C30Underwater concrete diameter1.2m 12m Note: in BIM model, "process classification", "material classification" and "specification classification" are stored in coding form. Table 2 Example of pile foundation of highway component library Classification code Component type model List code Calculation rule description 030102 Pile foundation Bored pile onshore φ1200 405-1-a-1 Pile length 2.2 Disadvantages of Calculation Schemes for List Engineering Quantity of "Full Materialization" The calculation scheme for list engineering quantity of “full materialization” is proposed based on the theory. In the actual operation process, there are some shortcomings, which are embodied in the following aspects: 2.2.1. The Current BIM Model does not have the Conditions to Build to the Part Level. The calculation scheme for list engineering quantity of “full materialization” is based on the premise that the model achieves the accuracy of the part level. However, with current hardware and software conditions and manpower conditions, it is difficult to achieve part-level modeling of highway engineering, especially the modeling of rebar. The amount of list engineering quantity included in these part-level models is naturally not extracted. 2.2.2. It is Difficult to Establish Subgrade, Ancillary Works and Non-solid Models Accurately. Subgrade engineering involves a large number of earthworks, and the treatment methods are complicated, such as digging steps, dredging, throwing stones, and geotextiles. The above engineering entities can not achieve refined modeling, and can not achieve the calculation scheme for list engineering quantity of “full materialization”. In addition, the list engineering quantity of “full materialization” also contains some non-physical categories, such as "contractor resident construction", "toll system application software", "database system", and "work injury insurance", which can not obtain the relevant list engineering quantity through the model.