New technologies are emerging that will change the way the construction industry works. That is “Building Information Modeling (BIM)”. It can solve all kinds of problems such as the need for productivity improvement in the industry and the prolongation of projects. It can be used in many processes from building design and construction to maintenance and management, and BIM is expected to become the mainstream in the construction industry in the future.
Addition of information to 3D shape Utilization from construction to maintenance
What is BIМ is to use a 3D model that has attribute information such as specifications and performance of materials/members, finish, cost, etc. in addition to 3D (3D) shape information of the building created on a computer. The created building information model (BIМ model) can be used at all stages from planning to design, construction, maintenance, and management. Since the building information can be integrated centrally, it can be utilized throughout the life cycle of the building.
The major difference from conventional CAD is that the BIM model contains attribute information. CAD data is digital data of drawing lines, and information is no different from handwritten drawings. On the other hand, the BIM model can include not only 3D shape information but also a lot of information other than drawings. For example, building material parts can include material, assembly process, etc. in addition to width, depth, and height.
Until now, it was the mainstream to make 3D computer graphics (CG) and animation after making 2D drawings. If some of the corrections were made, it was necessary to re-correct all the related 2D drawings, which took a lot of time and effort.
In BIM, 3D CAD that supports BIM creates a 3D model from the beginning. You can cut out the necessary parts from this model and create 2D drawings and perspectives such as plan views and sectional views. Even if the BIM model is partially modified, all related parts are automatically reflected, so that consistency is always maintained between the drawings. By utilizing these features, it is possible to prevent inconsistency between drawings and improve work efficiency.
For man-hour reduction and labor-saving
It has been a few years since BIM has become fully utilized in Japan. Recently, BIM is being utilized not only at the design stage but also at the construction stage. According to the results of a questionnaire conducted by the Japan Federation of Construction Companies in 62 member companies in 2016, the work that uses BIM during the construction stage is the process of consensus building with the orderer/designer. There were many reviews and confirmations). The 3D model can be viewed from any angle, and the cross-section can be cut at the required position, which facilitates understanding of the shape.
It is often used for “interference check” to confirm that members do not overlap in design. As a result of designing for each person in charge of design, structure, and equipment, it was found that structural members and piping collided during construction, and drawings were often corrected. In addition, it is difficult to imagine three-dimensionally from a plan view and a cross-sectional view a part where ducts and pipes are overlapped in a plan view and a piping space that penetrates vertically. It is effective to use BIM to solve these problems. By overlaying 3D models on a computer, interference areas can be identified and resolved before construction starts.
The effect of the construction BIM in which a subcontractor and a specialized construction company cooperate is being demonstrated. For example, the BIM model is used to adjust the steel frame and lifting equipment in steel frame construction, where the proportion of work requiring BIM cooperation is particularly high. In the conventional adjustment of the steel frame and the lifting equipment, the elevator manufacturer first creates the required drawings of the elevator steel member for the steel fabricator (FAB). Next, the steel frame FAB examines the joint between the steel frame and the elevator steel frame member. At that time, the elevator manufacturer also drew the steel mainframe, and the steel frame FAB made detailed drawings to check the elevator steel members. Since different types of drawings are created, a lot of man-hours are required for drawing, checking, and correcting. Depending on the size of the building, there may be hundreds of required drawings for checking. These 2D drawings can be omitted by adjusting the elevator steel members using only the BIM model.
Demonstration one after another by international standardization
The international standard specification format “IFC (Industry Foundation Classes)” has been developed to interoperate BIM models between different software, and BIM demonstration experiments and actual projects using IFC are being conducted in countries around the world. ..
In an experimental project conducted in Finland in 2000, IFC was used to link BIM data when adding a facility to a university building. Centered on IFC data output from 3D architectural CAD, data linkage between various different types of software was tried. For example, simulation of air conditioning and lighting in the hall space, analysis of life cycle costs and environmental loads, construction plan examination, design proposal examination using virtual reality (VR), etc. This is said to have been effective in increasing the efficiency of decision making by the purchaser and reducing the risk of investment decisions.
Public orderers are driving the spread of BIM in the United States. The Federal Procurement Agency (GSA) requires the use of BIM and IFC as an order condition for major projects after the 2007 budget. GSA is a federal agency that builds and manages federally owned facilities. BIM is used to streamline the management of a huge amount of facilities and to solve problems such as the cost of ordered projects and overruns in the construction period. In the demonstration project, IFC conducted various verifications of BIM utilization, such as air conditioning, energy, life cycle cost simulations, and construction plan reviews. It is expected that the direction of the GSA, one of the largest orderers in the United States, will lead to the development of new BIM technology by the private sector and its introduction into projects.
In the future, it is expected that BIM will be used not only for design and construction but also for maintenance and management. Yoshinobu Adachi, Chairman of the Building Smart Japan Technology Integration Committee, said, “In the future, technologies that utilize augmented reality (AR) and VR to visualize the equipment behind the ceiling and walls and utilize it for management will develop.” Say. BIM technology still in the development stage. It has the potential to create new applications in the future.