Designing an Earthquake Resistant Stadium in Ten Months with Constructible BIM

Japan sits in the Pacific Ring of Fire, where several continental and oceanic plates meet, making it highly susceptible to earthquakes and tidal waves. From the Great Kanto earthquake in 1923 to the Great East Japan earthquake in 2011, Japan has endured the devastating effects of natural disasters time and time again. The country experiences approximately 1,500 earthquakes each year, driving the need for seismic resistant building design and construction.

Approximately 25 million tons of steel is used for construction in Japan every year. As a highly ductile material, steel can flex and deform to dissipate the seismic energy of an earthquake and compared to other building materials, has a higher strength-to-weight ratio.

When the region of Saga kicked off plans to build a swimming stadium for the 2024 Japan Games, DAIZO Engineering was tasked with designing the stadium’s steel frame.

Daizo’s founder and managing director, Hongbin Li moved from China to Japan in 2009 to pursue a master’s degree in Engineering from Kyushu University. After graduating, he began working for a structural design company in Nagasaki and began using Trimble’s BIM software, Tekla Structures, to create steel designs.

Li set up DAIZO in 2015, first opening an office in China and then another in Japan. Today, the company employs 40 people in both countries and has completed more than 100 projects in Japan, as well as 30 projects in Canada and the U.S.

“I like the Japanese style of design and production of steel structures,” said Li. “It’s extremely detailed and very demanding compared to other styles, but this is the design challenge that makes our work so interesting.”

Overcoming Complex Design Challenges with Constructible BIM

A 1,300-ton structure, the Saga Natatorium will have the capacity for 1,800 people and will include an Olympic-sized pool, diving pool and sub-pool, along with diving platforms.

In addition to its location in a high-seismic area, the stadium’s biggest design challenges include complex ‘Y’ shaped exterior pillars. Due to their complexity, the pillars were difficult for the manufacturer to produce, making accuracy incredibly important. DAIZO detailed the pillars in Tekla Structures to ensure constructability of the stadium’s steel frame.

The stadium is a combination of steel reinforced concrete (SRC) columns and a steel roof. Complex reinforcement holes, which required numerous design changes throughout, were needed in parts of the structure. By utilizing Tekla Structure’s intelligent connections, Diazo’s engineers created connections at the SRC to steel frame nodes in the model that adapted automatically to varying and changing situations. Using the software’s open application programming interface (API), Daizo also automated the creation of custom parts and connections.

Constructible BIM has played an important role throughout the design process, allowing teams to visualize and explore how the completed structure will fit together and identify any problems before work begins on site. Using the software’s automatic clash detection, Daizo could ensure installation of the inclined pillars without clashes and identify conflicts in the model before they turned into costly errors. According to Li, the constructible model ensured the design could be built in the field. “There were lots of hidden collisions we picked up by doing the steel detailing in Tekla Structures,” he said.

Throughout the process, Daizo engineers used content from Tekla Warehouse, an online platform that contains 3D model parts, profiles and materials such as steel and concrete grades, bolts, rebar, mesh, embeds and tools, as well as templates that can be used in the model.  This ability to design and plan with actual, as-manufactured 3D model parts and profiles accelerates design and provides engineers with the peace of mind that the finished product and the design will match.

Using Tekla Structures, the model was created by a team of five in just 10 months. Working with a constructible 3D model as the single source of information saved time and reduced rework. Drawing views were automatically generated from the 3D model, ensuring that the information was consistent and accurate throughout the process. Because the constructible model contains the structural data needed to fabricate, build and maintain the stadium, the information within the model will be used by other stakeholders downstream.

The Saga Natatorium is due for completion in April 2021.