Seismic Isolation & Bridge Bearing Standards: China, EU And USA Compared

1. Why Product Standards Matter in Seismic Isolation

Seismic isolation and damping devices-lead-rubber bearings (LRB), natural rubber bearings (LNR), high-damping rubber bearings (HDR), friction pendulum bearings (FPS), buckling-restrained braces (BRB) and energy dissipation dampers-together with bridge bearings must satisfy clearly defined product standards before they reach a project site. For an exporting manufacturer, the choice of standard is not academic: it decides which type tests are run, how the CE or compliance certificate is drafted, and whether the product is accepted by the client, the local authority and the structural engineer.

This guide compares the three dominant frameworks used in cross-border projects-China (GB/JT), the European Union (EN) and the United States (AASHTO/ASCE/AISC)-highlights their key differences, and lists the countries that follow each system.

2. China: GB/T and JT/T Product Standards

China regulates isolation bearings mainly through the GB/T 20688 series. Part 1 (2007) sets the unified test methods; Part 3 (2006) covers building elastomeric isolation bearings; Part 4 (2007) covers bridge elastomeric isolation bearings; Part 5 (2014) covers elastic sliding isolators. GB/T 37358 (2019) governs building friction pendulum bearings, while GB/T 32836 (2016) covers spherical bearings for steel structures. For damping devices, JG/T 209 (2012) specifies energy dissipation dampers for buildings.

For conventional highway bridge bearings, China uses three dedicated product standards: GB/T 17952 (2019) for plate elastomeric bearings, GB/T 17951 (2022) for pot bearings and GB/T 38344 (2019) for spherical bearings. Seismic bridge bearings have their own transport-industry standards: JT/T 852 (2013) for friction pendulum isolation bearings, JT/T 927 (2014) for high-damping rubber bearings and JT/T 1088 (2016) for lead-rubber bearings. Design is supported by GB 50011, GB/T 51408 and JTG/T 2231-01 for bridges.

3. EU: EN 1337, EN 15129 and Eurocode 8

The EU approaches seismic products and bridge bearings through two separate chains. Conventional structural bearings follow the EN 1337 series-Part 1 general rules, Part 2 sliding bearings, Part 3 elastomeric bearings, Part 5 pot bearings and Part 6 spherical bearings. These accommodate temperature movement, shrinkage and creep, but they are not seismic devices.

True anti-seismic devices are governed by EN 15129 (2018), the single harmonised product standard covering elastomeric isolators, friction pendulum bearings, viscous dampers, metallic yielding devices and BRBs. It demands cyclic hysteresis testing, equivalent damping evaluation and fatigue assessment, and is the basis for CE marking of seismic devices. Structural design runs on Eurocode 8 (EN 1998-1 for buildings, EN 1998-2 for bridges). For export projects, a seismic isolation bearing must usually satisfy both EN 1337 and EN 15129.

4. USA: AASHTO, ASCE/SEI 7 and AISC 341

The United States governs bridge bearings through AASHTO: the LRFD Bridge Design Specifications (2020) for general design, the Guide Specifications for Seismic Isolation Design (2014, 4th ed.) as the core reference for bridge isolators and dampers, and the M series product specs-AASHTO M 251 for elastomeric bearings, AASHTO M 253 for pot bearings and AASHTO M 325 for spherical bearings.

For buildings, ASCE/SEI 7 (2022) sets seismic loads and isolation system criteria, while steel dissipative members such as BRBs follow ANSI/AISC 341 (2022) and AISC 358 (2022) for cyclic testing, detailing and connection prequalification.

5. Key Differences Between the Three Systems

Structure of the standard framework. China and the US split product standards and design codes across many documents (GB/T 20688 vs GB 50011; AASHTO M-series vs LRFD), whereas the EU concentrates harmonised product requirements in a single standard (EN 15129) and keeps design separate in Eurocode 8.

How seismic performance is verified. EN 15129 is the most rigorous on device-level testing-cyclic hysteresis, equivalent damping and fatigue are mandatory for CE marking. The US relies on the AASHTO Seismic Isolation Guide for testing and on AISC 341 for steel members, while China mandates cyclic and type tests under GB/T 20688 plus transport standards JT/T 852/927/1088 for bridges.

Regional enforcement and certification. The EU requires CE marking through notified bodies-the strongest market-access gate. The US operates through state-adopted AASHTO codes without a single federal product certificate. China applies GB/T as national standards enforced on domestic projects, with conformity increasingly required for export contracts to markets like Türkiye and Iran.

6. Countries Following the EU (EN / Eurocode) System

The Eurocodes and EN product standards are adopted across all 27 EU Member States, the EFTA states (Iceland, Norway, Switzerland) and the United Kingdom. Beyond Europe, the Eurocodes are adopted or being adopted by countries whose national standards bodies are full CEN members, including Türkiye, Serbia, North Macedonia, Montenegro, Bosnia and Herzegovina, Albania, Georgia, Moldova and Uzbekistan. In Asia, Singapore and Malaysia have adopted the Eurocodes, with Thailand, Vietnam and other ASEAN states moving toward them. For seismic devices in particular, Türkiye is a major market that follows EN 15129 and Eurocode 8; Iran commonly references EN 1337, EN 15129 and Eurocode 8-2 alongside local requirements.

7. Countries Following the US (AASHTO) System

AASHTO standards are the default for US federal and state highway bridges and are widely adopted internationally. The LRFD specifications are referenced or adopted in Canada (the Canadian Highway Bridge Design Code is partly based on AASHTO LRFD), Mexico, and across the Middle East-Saudi Arabia, UAE, Qatar, Kuwait, Egypt and Jordan. They are also used in the Philippines, several Caribbean nations, and increasingly in Latin America (Argentina, Brazil) and donor-funded projects in Africa under World Bank procurement. In South Asia, projects such as the Karot hydropower bridge in Pakistan were designed to US AASHTO practice. Where a tender specifies AASHTO, bridge isolators and bearings must be tested and documented to the AASHTO Seismic Isolation Guide and M-series product specifications.

8. How to Choose for Your Export Project

Match the standard to the client's reference, not to your home code. For Türkiye and European tenders, plan around EN 15129 plus EN 1337 for bearings and Eurocode 8 for design, and be ready for CE assessment. For Iranian projects, prepare a hybrid file covering EN 1337, EN 15129 and Eurocode 8-2. For US, Gulf and Canadian projects, align testing and documentation with AASHTO and ASCE/AISC. Clear, bilingual technical documentation mapped to the governing standard is what wins acceptance on export projects.