In 1975, American Chuck Astman first proposed the concept of Building computer simulation System (BDS). Subsequently, the concept of Building Information Modeling (BIM) technology has been continuously and rapidly developed, and has been widely promoted in Europe, Japan, Singapore and other countries.

BIM technology starts relatively late in our country, and has only developed for more than ten years, but it has developed rapidly. On the one hand, thanks to the guidance of national macro policies, on May 20, 2011, the Ministry of Housing and Urban-Rural Development made it clear in the "2011-2015 Construction Informatization Development Outline" that "During the 12th Five-Year Plan period, the popularization and application of construction enterprise information system will be basically realized, and the application of new technologies such as building information modeling (BIM) and network-based collaborative work will be accelerated in engineering". On February 21, 2017, The General Office of the State Council mentioned in the "Opinions on Promoting the Sustainable and healthy development of the Construction Industry" that "strengthen technology research and development and application." Accelerate the integrated application of building information modeling (BIM) technology in the whole process of planning, survey, design, construction and operation and maintenance, realize the data sharing and information management of the whole life cycle of engineering construction projects, provide a basis for project optimization and scientific decision-making, and promote the quality and efficiency of the construction industry. On November 23, 2017, Chengdu Urban and Rural Construction Commission issued the "Notice of Chengdu Urban and Rural Construction Commission on Further regulating the construction drawing design and Review work of housing construction projects in the city" and on January 18, 2018 issued the "BIM design of municipal engineering and industrial prefabrication construction conditions as the basic situation of the project into the whole construction process. The application of BIM technology (Building information model) as a powerful measure to promote the green development of urban and rural construction and the improvement of building quality in Chengdu, design units should be carried out in strict accordance with the relevant requirements of the design; at the same time, the construction drawing review institution should be the application of BIM technology as a building construction drawing design document review content. Ensure that BIM design is adopted in municipal engineering roads, tunnels, Bridges, rail transit, underground integrated pipe corridors and other projects, and construction is carried out in accordance with industrial production and prefabricated construction conditions.

On the other hand, as a development trend, BIM technology can be applied throughout the entire construction cycle (design stage, prefabrication stage, construction stage and operation and maintenance stage), and is an efficient management tool for construction, design, prefabrication production, construction and operation and maintenance units. At present, the state vigorously promotes prefabricated industrial buildings, and the collaborative work function of BIM technology can achieve fine design as a premise. The data of prefabricated components is the guarantee of high-efficiency coordination of design, production and construction, and can realize the management of the whole industry chain and the whole life cycle.

For construction units, BIM technology provides comprehensive, in-depth and efficient support from design scheme, investment, construction (quality, cost, schedule) and late operation and maintenance, and has obvious effects on promoting the progress of the entire project, improving quality and reducing costs. The construction unit can participate in all aspects and supervise and guide, and control the progress, quality and cost of each part of the project. For example, the application of BIM technology in the pre-planning stage of prefabricated buildings can better control the use of project funds, such as counting project components, efficiently completing engineering volume statistics, and formulating reasonable project budgets. Its 5D simulation realizes the fine management of construction process cost.

Compared with the traditional two-dimensional design of CAD, the three-dimensional design of BIM technology is more intuitive and clear, which can effectively eliminate communication barriers, simplify the complex and changeable communication, and clearly present building information. The most direct application is collision inspection.

Taking the Zhuzong Vanke Plaza as an example, the project is located in Jiugong, Daxing District, Beijing, close to the subway Yizhuang Line Jiugong station, with a total construction area of 129,000 square meters, commercial building 5 floors above the ground, local 6~7 floors, office building 12~13 floors, 4 floors underground. In terms of architectural design, the design concept of "village" is used to create a feeling like outdoor shopping on the fourth and fifth floors, but you can enjoy the comfortable indoor shopping environment and create an experiential shopping atmosphere. At the same time, the shopping center is set up with two first floors, and a crossing bridge is set up on the second floor to connect the shopping mall with the subway entrance and exit, so as to achieve seamless connection of subway traffic.

The project has been put into operation on May 1, 2016, taking the lead in introducing BIM technology and building a BIM management platform. By integrating the resources of the owner, the designer and the construction side, the project quality is effectively improved and the construction period is shortened.

Traditional construction is based on the understanding of two-dimensional blueprints and pre-processing by technicians through three-dimensional spatial thinking ability imagination. With the increase of building volume and professional complexity, the three-dimensional spatial imagination ability of human brain is difficult to effectively deal with, even if the most experienced design teams and construction units at home and abroad have passed on detailed construction drawing technology. It can not completely avoid the collision problem of various professions. Through the BIM visual model, the construction process can be virtually displayed, which breaks through the two-dimensional limitation, carries out three-dimensional and four-dimensional technical disclosure, and visually displays the pre-effect of the project, so that technicians can more intuitively understand the positioning of components and the direction of pipelines, and can also assist roaming animation, effectively improving the efficiency of civil construction and installation.

BIM technology's control of costs through collision inspection is intuitive and quantifiable. In engineering, the conflict between the structure profession and each profession is a very common thing, to analyze the actual case, such as the collision between the ramp platform and the structural wall, the platform is insufficient. Assuming there is no BIM early warning, there are two solutions to this situation:

[Method 1] Design changes, let the design institute redesign and calculate the beam, change the beam height; The cost calculation of this method is very simple, the cost of dismantling the workload cost and the cost of redoing the combination, plus the cost of the worker can be, the total cost of this is 45053.00 yuan.

[Method 2] Reinforce the beam in this position after smashing the beam (add the upper reverse beam after chiseling this part of the beam and part of the plate); The cost of this method can also be calculated, and the total cost of this method is 34,920.62 yuan.

In addition, this does not take into account the overhead costs caused by schedule delays, financial costs, administrative costs, etc. From this, we can see the value of early warning and collaborative sharing of BIM.

In the construction stage, BIM technology can be used to guide the site layout, integrating many factors such as materials, sites, machinery and equipment, personnel and weather. It can simulate the construction process, directly reflect the various processes of construction, facilitate the coordination of various professions and units, reduce the construction land, ensure the smooth transportation road on the site, and avoid secondary handling and accidents.

Use BIM technology for site layout

Through the above analysis, we can conclude that the advantages of BIM technology application are as follows:

As the best mainstream building information technology in the current development trend, BIM also has certain defects. For example, BIM technology is a complete system, which requires the cooperation of various units and professions. At the same time, as a new technology, the shortage of relevant talents makes it difficult to promote in small and medium-sized enterprises with weak technical strength. However, as the trend of the development of the industry, as the entrance of intelligent buildings in the future, as CAD rendering replaces manual drawing, it must be the trend of The Times.