Turkish Building Earthquake Code (TBDY 2018)

Overview

The Turkish Building Earthquake Code (TBDY 2018) was issued by AFAD and published in Resmî Gazete no. 30364 (repeated issue) on 18.03.2018. It applies to the design and construction of new, altered or enlarged buildings and to the assessment and retrofit of existing ones. It has been in force since 1.1.2019 and repeals the 2007 code. It is essential for data centres in Turkey's high-seismicity regions.

The code defines four ground-motion levels derived from AFAD hazard maps: DD-1 (2% in 50 years; 2475-year return period), DD-2 (10% in 50 years; 475-year), DD-3 (50%; 72-year) and DD-4 (68%; 43-year). Seismic hazard data come from the Türkiye Deprem Tehlike Haritaları (tdth.afad.gov.tr). It also defines building use classes with importance factors, design classes and performance targets. Buildings needed immediately after an earthquake (BKS=1), including communication facilities and energy generation and distribution facilities, have an importance factor of I = 1.5; BKS=2 is 1.2 and others 1.0.

The most relevant provision for data centres is that non-structural elements and mechanical and electrical equipment, with their attachments, must be designed for seismic loads (except in DTS=4 buildings); friction may not be counted in anchor capacity. Equipment heavier than 10% of its floor's weight is treated as part of the structural system. As a limit, this record rests on a summary and key clauses of the code; detailed calculations need the full text and an earthquake engineer's assessment.

Key points

1. Applies to new, altered or enlarged buildings and to assessment/retrofit of existing ones; in force 1.1.2019; repeals the 2007 code.
2. Ground-motion levels: DD-1 2% in 50 yr (2475-yr), DD-2 10% (475-yr), DD-3 50% (72-yr), DD-4 68% (43-yr).
3. Hazard data come from the Türkiye Deprem Tehlike Haritaları (tdth.afad.gov.tr), enacted by decision 2018/11275.
4. Importance factor I = 1.5 for BKS=1 buildings needed immediately after an earthquake (incl. communication, energy generation and distribution), 1.2 for BKS=2, 1.0 for others.
5. Non-structural elements and mechanical/electrical equipment and attachments must be designed for seismic loads (except DTS=4); friction may not be counted in anchor capacity.
6. Equipment heavier than 10% of its floor's weight is treated as part of the structural system.

Using it in design

• In the site/structure module (TR profile), pull DD-2 spectral values from the AFAD map by coordinates.
• Propose BKS=1 (I=1.5) for critical and telecom data centres.
• Generate seismic anchorage demand for racks, UPS, batteries, chillers and generators per Section 6.
• Flag heavy plant above 10% of floor weight for structural modelling.
• Do not add friction to anchor capacity.

Who should read it

Architects, civil and earthquake engineers and mechanical and electrical designers planning data centre sites and structures in Turkey.

Related standards

• ISO/IEC TS 22237-30
• ASCE 7 Chapter 13
• Eurocode 8

Publication details

Authors

Afet ve Acil Durum Yönetimi Başkanlığı (AFAD)

Publisher

Afet ve Acil Durum Yönetimi Başkanlığı (AFAD)

Year

2018

Document number

RG 30364 mükerrer (18.03.2018)

Document language

Turkish

Source type

Turkish regulation

Access

Free to read

Licence

Bibliographic reference only — the document is not redistributed here; confirm reuse terms at the original source

Citation