To: Central Construction Joint Stock Company

The Ministry of Construction has received Official Letter No. 324/2020/CV dated August 22, 2020 from Central Construction Joint Stock Company requesting an opinion on the application of low ductility class (DCL) in seismic resistant design of structures. After reviewing the matter, the Ministry of Construction provides the following opinions:

1. Regarding the application of national technical regulations, national standards, and foreign construction standards in construction investment activities:

• The design must comply with the current national technical regulations. In this case, the earthquake data, which is the peak ground acceleration value, must be taken accurately according to the national technical regulation “QCVN 02:2009/BXD Natural Condition Data for Construction”.
• According to Article 23 of the Law on Standards and Technical Regulations 2006, the application of standards is voluntary (except when all or part of a specific standard becomes mandatory when referenced in a legal document or technical regulation).
• The investor shall consider, decide, and take responsibility for the application of the system of national standards, corporate standards, or foreign construction standards for construction activities under their management, in accordance with Circular No. 18/2010/TT-BXD dated October 15, 2010 of the Ministry of Construction, which regulates the application of technical regulations and standards in construction activities.

2. Regarding the application of low ductility class (DCL) in seismic resistant design of structures:

According to the guidance of the national standard “TCVN 9386:2012 Seismic Resistant Design of Structures”, for strong earthquakes (ag≥0.08g), seismic resistant calculation and detailing must be performed. This standard recommends the use of medium or high ductility classes and does not prohibit the use of low ductility class for seismic resistant design of structures. Therefore, if the low ductility class is chosen for seismic resistant design, the design consulting unit must take responsibility for their solution to ensure that the design is safe, reasonable, and compliant with regulations.

In case a foreign standard is applied to the project, the seismic resistant design must take into account load combinations that include seismic loads, noting that the peak ground acceleration value is specified in the national technical regulation “QCVN 02:2009/BXD Natural Condition Data for Construction”, as well as other load combinations according to the standard applied to the project.

The above are the opinions of the Ministry of Construction. Central Construction Joint Stock Company is requested to study and design the structure to ensure safety, efficiency, and compliance with legal regulations.