NCREE Newsletter Issue 136 Highlights Seismic Retrofit Benefits, Model Converters, and Fault-Crossing Pipes

The National Center for Research on Earthquake Engineering (NCREE) released Issue 136 of its newsletter in December 2025. The publication presents evaluations of Taiwan's private building soft-story retrofits, demonstrating that localized shear wall installations offer the most economical option, while steel frame retrofits showed high benefit ratios in select cases. Investigating damage from the January 21, 2025 Chiayi-Dapu earthquake at Nanxi Junior High School, researchers observed that rigid diaphragm assumptions may fail in cantilever corridor structures retrofitted with exterior shear walls. The issue also details the standalone release of TEASPA V5, the development of the ETABS-to-PISA3D (E2P) model conversion workflow, and mechanical testing of large-diameter corrugated steel pipes crossing active faults for the Da'an-Dajia River Water Pipeline Project.

Key takeaways

• Analysis of private building retrofit cases showed Scheme A (localized shear walls) cost between 39,727 and 66,667 NTD per household (1,445 to 1,932 NTD per ping), while Scheme B achieved seismic capacity over 80 percent of design code standards with benefit ratios up to 402.
• Post-earthquake investigation of Nanxi Junior High School following the 0121 event revealed that interior columns sustained heavier damage further away from exterior retrofit shear walls, indicating rigid diaphragm assumptions are invalid for such configurations.
• NCREE introduced TEASPA V5 as a standalone program with bidirectional PMM hinges and steel structure modules, alongside the E2P Converter to automate structural model translation from ETABS to PISA3D for modal and pushover comparisons.
• The Da'an-Dajia River Water Pipeline Project introduced fault-crossing corrugated steel pipes (SPF) with diameters up to 3000 mm into Taiwan, verifying deformability and fabrication methods through experimental testing.