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Learning

Earthquake Design
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Earthquake Tip
Construction

Why is Quality critical in Earthquake-Resistant Buildings?

Quality and Earthquake Safety (4) Selecting construction materials - Contractors need
Quality is critical for ensuring safety of buildings to take utmost care in selecting the intended
during earthquakes. Appropriate measures are construction materials, and adopting construction
required to control quality in all activities related to procedures as per standard specifications;
development of earthquake-resistant buildings; if not, (5) Converting structural drawings at site – Competent
the weakest link will fail. While quality control is Site Engineers need to faithfully follow structural
important also for buildings meant to resist effects drawings to ensure that the design intent is
other than those meant to resist earthquake shaking, actually realized in the building working with
there is a difference. Buildings meant to resist only Certified Artisans, as per good construction practices
gravity loads are designed to resist loads much higher laid down in standards and specifications; and
(say about 2 to 3 times more) than the gravity loads (6) Undertaking post-construction activities –
that may arise during lifetime of the building. And Maintenance Engineers need to embed long-term
hence, no damage occurs in buildings with minor maintenance steps (like preventing leaks), thereby
structural deficiencies in individual members, because avoiding structural damage) in post-construction
of availability of adequate margin in design. Thus, handling of structures, and preventing damage to
some error can be tolerated in design or workmanship buildings (especially to critical structural members).
without serious consequences or getting noticed. What is Quality Assurance?
On the other hand, buildings meant to resist Rigorous, independent monitoring and correction
earthquake effects are designed for lateral earthquake need to be undertaken by competent third party
loads much smaller (up to about 10 times smaller) than professionals or professional agencies (other than
what may be experienced during severe shaking, if the those involved in the Quality Control effort) to ensure
building were to sustain no damage during severe that the design intent is actually realized in buildings.
earthquake shaking. This is because earthquakes occur This is referred to as Quality Assurance, and is required
rarely. Hence, ordinary buildings are expected to in each of the activities mentioned above.
undergo damage during strong shaking. Every How Quality can be Ensured
structural element is expected to respond in a certain Owners and developers have the responsibility of
way, and is tested to its limit when strong shaking is ensuring that their buildings are functional, safe and
experienced. Thus, deficiencies in structural elements durable, in addition to being economical and aesthetic.
can result in premature, unwanted or unwarranted Quality must be ensured by all stakeholders involved
failures. Because there is no margin, effects of poor in the building delivery process, including architects,
quality are clearly noticed; the negative consequences structural engineers, draughtsman, contractors, site
of poor quality are most visible during severe shaking. engineers, artisans (e.g., bar benders, carpenters and
Therefore, quality is far more important in buildings masons), and maintenance engineers. Each activity
exposed to earthquake effects than in those exposed only needs to adhere to a pre-specified procedure laid
to other load effects (e.g., gravity loads). down in design codes and standards. There is no
What is Quality Control? single activity that is more important than the others,
Quality control means adopting and ensuring formal which alone determines the quality of the building
procedures and processes that are based on scientific being built. For instance, just designing the building
principles and professionally agreed norms. The need for a higher seismic lateral force to compensate for
to ensure quality arises at every step of the building poor quality in construction will not ensure a safe
development process. These steps include: building. Even if one of the key stakeholders fails to
(1) Conceptualizing structural configuration – Architects deliver quality, overall earthquake safety of building
and Structural Engineers need to work together to may be jeopardised.
adopt a good configuration; Building owners need to seek professional services
(2) Designing the structure – Structural Engineers need that comply with: (1) proper understanding and
to take utmost care while performing required estimation of earthquake hazard at the site, (2) rigorous
calculations as per sound structural safety concepts design, compliance with prevalent standards,
and relevant design standards; specifications and bye-laws, (3) independent design
(3) Preparing structural drawings – Structural Engineers review (peer review), (4) procurement of intended
and Draughtsmen need to comprehensively and quality materials, (5) careful construction of the
accurately present structural design intent in well building, (6) independent construction audit, and (7)
detailed drawings; approved occupancy and use of buildings. Any