Tongji University Successfully Completes Modular CLT Structure Shaking Table Test

By: Lance Tao

Export Development Program, Canada Wood Group

Tongji University’s College of Civil Engineering, led by Professor Xiong Haibei, recently achieved a significant milestone with the completion of the shaking table test for a modular Cross-Laminated Timber (CLT) structure. This test, conducted in the university’s Multi-functional Shaking Tables Lab, received financial support from the National Natural Science Foundation of China (NSFC) and the Joint Laboratory for International Cooperation in Earthquake Engineering (JLICE). Additionally, international research institutions such as the University of British Columbia and the West Japan Institute of Technology, along with industry organization Canada Wood China (CW China), provided strong support for the project. The modular CLT structures used in the test were constructed using Canadian lumber.

New Structure System: FaM

Professor Xiong Haibei’s team introduced a groundbreaking structure system known as “FaM,” which is an innovative hybrid building system that combines modular wood boxes with a concrete frame-and-core structure. This innovative system allows for the incorporation of modular units, which can be constructed offsite using light wood frame, mass timber, or glulam post and beam structures, and placed on the concrete slab. The main concrete structure serves as the primary load-bearing element, supporting the overall structural weight. It possesses high stiffness in the vertical direction to carry the load and exhibits seismic resistance in the horizontal direction. The substructure, on the other hand, provides load-bearing capacity and seismic resistance for the modular units themselves. A unique feature of the FaM (Fire and Movement) system is the incorporation of a concrete floor slab with a concrete core on every third floor. This design ensures compliance with fire protection requirements and enables safe evacuation in high-rise wooden structures. By implementing this innovative approach, the FaM system not only enhances fire safety but also reduces the cost of fire protection in wooden constructions. The FaM system provides a promising solution for achieving efficient, sustainable, and adaptable construction practices in various architectural projects.

Performance Results Exceeding Goals:

The shaking table tests proved the exceptional performance of the modular CLT structure, especially when combined with new energy dissipating connectors. Under varying seismic loads with different spectral characteristics, the system exceeded the team’s preset goals. The successful test showcases the structural integrity and stability of the modular CLT design, highlighting its potential for widespread adoption in seismic-prone regions.

Contributing to the Dual Carbon Strategy:

This experiment holds great significance in supporting universities’ active response to China’s national goal of a dual carbon strategy. By providing a scientific basis for the design and promotion of modern timber structures in China, the research results contribute to the development of sustainable practices. Furthermore, the valuable scientific data obtained from this test will inform future enhancements of the FaM system, further advancing the growth of green buildings, prefabrication, and industrialized construction in China.

The completion of the modular CLT structure shaking table test at Tongji University represents a major breakthrough for the mass timber construction industry. With its exceptional performance under seismic loads and alignment with China’s dual carbon strategy, this experiment paves the way for the design and implementation of modern timber structures in the country. The collaboration among international research institutions, industry organizations, and academic institutions underscores the commitment to advancing sustainable and efficient construction practices. Tongji University’s achievement marks a significant milestone in the development of mass timber construction and sets the stage for further advancements in the field.