Shibuya Station on the Tokyo Metro Ginza Line is located in the center of Shibuya, a popular area in Tokyo. As an important metropolitan subway line along with the Hanzomon Line and the Fukutoshin Line, approximately 220,000 people use this subway line daily. Due to the difficulties of large-scale improvements since opening in 1938 and concerns regarding congestion, safety and services, considerations were made for renovation in line with the redevelopment of Shibuya. A new Ginza Line Shibuya Station is opened on January 3, 2020. The new Ginza Line Shibuya Station is barrier-free with eased congestion and easier transfer to and from other railway lines.
We were in charge of relocating the platform 130 meters due east, which included decreasing the number of columns (decrease from 7 to 3 columns on the east side of the station), and building an island-type platform with track service on both sides, which had been a separate one-track platform. This construction work made active use of the 3D model BIM/CIM (*1), which was highly rated and won the 2019 i-Construction Outstanding Award from the Ministry of Land, Infrastructure, Transport, and Tourism.
- Project name
Tokyo Metro Ginza Line Shibuya Station Railroad Track Switching Project
Tokyo Metro Co., Ltd.
- East Tower Section
Tokyu, Kajima, Shimizu, Tekken JV
- East Exit, Meiji-Dori Ave.
Section Roof installation work Section
Tokyu, Shimizu, Kajima JV
- Konno, Pithead Section
Tokyu, Taisei JV
- Project overview
Tokyo Metro Ginza Line Shibuya Station that was located in a building of Tokyu Department Toyoko Store is moved 130 meters and the station building is built over Meiji-Dori Ave.
The Platform is changed from separate platforms to an island platform servicing two lines, as well as establishing barrier-free facilities.
The number of columns over Meiji-Dori is reduced from 7 units to 3 units.
The construction work carried out in line with relocating the platform involved switching three railroad tracks. Work for the railroad track switching operations required suspending the operation of the Ginza line temporarily, and this increased the need for sound construction. In particular, there were three major issues involved with switching the railroad track.
Three Major Issues with This Project
(1) Limited time
The work was done in the heart of Tokyo, and the work had to follow detailed plans as part of the Shibuya Station redevelopment project in coordination with the open times of bus lane and transportation restrictions of Meiji-Dori Avenue. Points of concern had to be extracted and resolutions were established and implemented promptly.
(2) Three-layer construction
The construction involved multiple crane operations on the ground surface, track surface and (Temporary Structure Surface). It was difficult to render this three-layer construction work in a two-dimensional drawing only.
A Detailed working plan for the Boom turning order was required to prevent the booms of each crane from hitting each other.
(3) Reliable information sharing
The construction work proceeded for an extended period of time with projects moving forward at several sites. Many Support Engineers from other sites came for support to work together with Project operators, Site Engineers, and workers at the construction site. All participating workers had to quickly and fully understand the complicated work schedule and construction process. Furthermore, because track switching operations that involved suspension of train service had to be completed within a limited time, all members of the large staff involved in this construction work had to share the same visualization of the work and have a full understanding of the process and procedures.
Deploying 3D Model BIM/CIM (*1) to Ensure Accurate Construction
Using conventional processes, there were concerns that costs would increase and work would be delayed when flaws in the design were identified or workability needed to be reviewed, requiring modifications or changes.
With this project, we asked the client to cooperate with us during the review process. At the schematic design stage, we created a 3D model including perspectives from the contractor, and then executed concurrent engineering (*2) with design by parallel consultation. We also consulted in advance with the transportation agencies for operational safety such as the location of signals using 3D models.
Furthermore, by carrying out reviews with VR (Virtual Reality) and 4D models which add timelines in minutes and movement to 3D models, front-loading (*3) was carried out. Front - loading focuses on the validity of construction work and checking construction procedures at an early stage of the project, which enabled speedy decision making, prevented the need for reworking and allowed for consistent information to be shared among a large number of staff members involved in the construction, whereby productivity was boosted.
The number of days required for the construction manager to understand the project was reduced to about half, and we successfully reduced labor costs by approximately 60% when calculated by each class of worker.
Our company did not depend on outside companies specializing in these efforts to make use of BIM/CIM. We used general software and moved forward with worksites and their employees being the main players. We created manuals for employees to acquire skills and provided initial training to more than 200 engineers working on-site, so that work sites could take the initiative.
The effect of using BIM/CIM not only improves productivity, but there are additional benefits for clients, facility users and other people involved. We will make our efforts in practicing
BIM/CIM, and going forward expect this initiative to be generalized, led by worksites, and expanded company-wide.
- BIM/CIM (Building/ Construction Information Modeling, Management) is workflow deploying 3D models starting from the research and design stages, as well as in the construction, maintenance, and management stages. It is used in construction, production, and management system series, while adding attribute information (material, strength, etc.), so as to ensure quality management and improved productivity.
Concurrent engineering is a method designed to shorten the development period and reduce cost by concurrently executing multiple tasks comprising the development process in manufacturing and other industries, and to share information and perform group work among various departments.The following effects are expected in CIM.
- Ensuring workability and quality after operation by reflecting opinions of persons responsible in construction at the design stage and changes in the plan, improving appearance and amenity in facility use.
- Reflecting opinions of persons in charge of maintenance and management in the design stage to give consideration for maintenance and management (such as material and not having sections that may be weak points). Providing information that will be needed in the maintenance and management stage in a usable form during the design and construction stages results in efficiency and upgrading of maintenance and management.
- Individuals involved in the project working together speed up decision making and reduce wait times, thereby shortening the construction period and the period for the entire project. (Ministry of Land, Infrastructure, Transport, and Tourism CIM Guideline Common Edition)
- Frontloading, is, in the field of system development and product manufacturing industries, to consider in advance potential specification changes in later processes, etc. at the initial stage with the aim of improving quality and shortening the construction period.
For CIM, the expected effect can be obtained through checking of rebar interference of RC construction and consideration of the validity of temporary construction methods at the design stage, examination by the construction side to prevent reworking, examination such as checking construction procedures, and changing specifications through examination from the perspective of maintenance and the management side at the design and construction stages. (From the Japan Construction Information Center Foundation Website)