Article under construction
Education
In the context of buildings, Japanese structural engineers generally start by studying Architecture at university. In their 3rd year, they have to choose whether to specialise in Architecture, Structure or Mechanical Design. It is common to pursue a Masters (Post-Graduate) at a university and join a "Laboratory" dedicated to a specific topic e.g. structural health monitoring.
In the UK, structural engineers usually study Civil Engineering or Architectural Engineering at university. For those wishing to pursue a career in structural engineering, at minimum they may require a Masters (preferably in Structural Engineering).
Japan Structural Engineering Industry
- In Japan, there are many independent design firms. Largest firms integrate architecture, structural and MEP.
- Japan has 5 "super" general contractors: Shimizu Corporation; Obayashi Corporation; Taisei Corporation; Kajima Corporation; and, Takenaka Corporation.
Building Materials
Show proportion of buildings built using steel versus concrete versus timber
Design Philosophy
Allowable strength design
Very different design paradigm. Design routes.
Performance-based design approach
Lateral Loading (Wind)
For the basic wind speed definition, Japan uses a 10-minute mean at 10 m height in "Open" terrain. This is consistent to the approach across European countries including the UK.
Japan is located besides the Pacific Ocean and closer to the Tropics. Therefore it experiences tropical cyclones, referred to regionally as Typhoons. Therefore the basic wind speeds at the 50-year return period and usually much higher than the UK.
As an example, the 50-year return period wind speed in Tokyo is about 35 m/s depending on the location. In the UK, it is around 21.5 m/s.
Lateral Loading (Seismic)
Unlike Japan, the UK is located in a region of very low seismicity.
Japan is bordered by several tectonic plates and often experiences earthquakes. Therefore seismic design is a very important design consideration. In general, per the Japanese Building Standard Law, building structures must maintain elastic behaviour under a design ground acceleration of 20%g. They must also adhere to a no-collapse condition for a design ground acceleration of 100%g.
Analysis
- For seismic ground motion time-history analysis, designers consider the maximum response values of all the analysed ground motions. However, under the Eurocode, designers are allowed to consider the average of the response values.
Lateral Framing Systems
Steel Sections
Steel Frame Connections
Column-beam joints in moment-resisting buildings are usually framed using steel box (SHS) sections for the columns and standard I-shapes for the girders. The connections are usually made using a "through-diaphragm" and/or a "inner diaphragm" connection as illustrated below:
( illustration coming soon )
These connections are welding intensive and complicated, but steel manufacturers generally have automated robot welding in place to greatly speed up fabrication.
Concrete Grades
Steel Reinforcement Grades
In general, Japanese designers prefer to use mild steel reinforcement (e.g. SD290) over high-strength steel reinforcement (e.g. British Grade 500C). This is due to their ductility, seismic performance, availability, and compatibility with lower grades of concrete.