ISO 16711:2015

Seismic assessment and retrofit of concrete structures

The purpose of ISO 16711:2015 is to reduce the risk of seismic damage by structural collapse or turnover during a seismic event. It provides frameworks and principles of methods of detailed seismic assessment and the judgment, seismic retrofit plan and design, seismic retrofit execution of existing reinforced concrete structures before the occurrence of a severe earthquake and of the structures struck by an earthquake. It is applicable to reinforced concrete structures and pre-stressed concrete structures that have been designed on the basis of the structural design criteria set in a specific country or region. It is not applicable to either unreinforced concrete or masonry structures.

Évaluation sismique et réhabilitation de structures en béton

General Information

• Status: Withdrawn
• Publication Date: 07-May-2015
• Withdrawal Date: 07-May-2015
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: ISO/TC 71/SC 7 - Maintenance and repair of concrete structures
• Drafting Committee: ISO/TC 71/SC 7 - Maintenance and repair of concrete structures
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 04-Mar-2021

Relations

• Revised: ISO 16711:2021 - Requirements for seismic assessment and retrofit of concrete structures
• Effective Date: 10-Dec-2016

Standards Content (Sample)

INTERNATIONAL ISO
STANDARD 16711
First edition
2015-05-01
Seismic assessment and retrofit of
concrete structures
Évaluation sismique et réhabilitation de structures en béton
Reference number
ISO 16711:2015(E)
©
ISO 2015

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ISO 16711:2015(E)

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© ISO 2015, Published in Switzerland
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ii © ISO 2015 – All rights reserved

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ISO 16711:2015(E)

Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Framework of Assessment and Retrofit . 3
5 Preliminary assessment . 5
5.1 General . 5
5.2 Investigation items . 6
5.3 Judgment . 6
6 Detailed seismic assessment . 7
6.1 General . 7
6.2 Detailed investigation . 7
6.3 Analysis. 7
6.4 Seismic performance objectives. 8
6.5 Judgment . 8
6.6 Documentation . 8
7 Seismic retrofit plan . 9
7.1 General . 9
7.2 Selection of performance objectives of the seismic retrofit . 9
7.3 Selection of basic strategy for seismic retrofit . 9
7.4 Planning of retrofit .10
7.5 Seismic re-evaluation .10
7.6 Confirmation .10
7.7 Documentation .10
8 Seismic retrofit execution .11
8.1 General .11
8.2 Detailed inspection for construction .11
8.3 Planning of retrofit construction .11
8.4 Quality assurance.11
8.5 Documentation .11
Bibliography .13
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ISO 16711:2015(E)

Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical Barriers
to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 71, Concrete, reinforced concrete and pre-stressed
concrete, Subcommittee SC 7, Maintenance and repair of concrete structures.
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ISO 16711:2015(E)

Introduction
Earthquakes bringing damage to structures have occurred frequently in many areas of the world. Heavy
damage caused by earthquakes are concentrated on vulnerable structures. Due to these damaging
earthquakes, human lives are lost and confusion in everyday life and stagnation of economic activities occur.
As the result of the direct action of earthquakes, structures may collapse or overturn in earthquake-
prone areas. However, given a main shock occurs, it is expected that through seismic assessment and
retrofit of concrete structures, human life losses, economical losses, and structural collapses could be
mitigated and/or prevented and quick recovery could be attained.
In some nations, such as Japan and USA, the framework for the identification of vulnerable structures
before and after an earthquake, seismic retrofit decision-making and construction exists. In addition, the
standards for seismic assessment technology and for seismic retrofit technology are already established
in those nations. Furthermore, technical manuals, in order to apply the standards to practical work, are
established. Therefore, based on these standards, the social system is built where a country, a district
and a local administrative agency (authorities), the owner of the structure, a user, a retrofit designer,
a retrofit work supervisor, a retrofit work supplier, and other people concerned on this matter share a
purpose of the seismic retrofit and the information about the effect of seismic retrofit, and the owner of
the structure can judge the necessity of appropriate retrofit, and a seismic retrofit execution is carried
out smoothly.
However, it is not so frequent that a huge earthquake disaster occurs in a specific country or an area. These
conditions disturb conducting seismic assessment, seismic retrofit work, and smooth social decision
making to conduct seismic retrofit. As a result, it is feared that the earthquake disaster will expand and
the recovery from the disaster will be delayed when a large earthquake disaster happens once.
Therefore, it is necessary to establish a principle of seismic assessment, decision making for seismic
retrofit, the framework of the procedure for screening the vulnerable structures, and seismic retrofit
execution. This International Standard provides comprehensive principle on the evaluation of the
seismic damage/expected damage of existing reinforced concrete structures and repair/retrofit. In other
words, this International Standard provides the standard work items related to seismic assessment and
retrofit, and standard procedures in each stage, and makes contents and the scope of each duty clear.
In this International Standard, the seismic performance of existing reinforced concrete structures is
expressed in terms of the intensity of earthquake motions that will lead the structures to the safety limit
1)
state in principle. As the result, whether the existing RC structures fulfill the provisions of the design
standard in the specific country or area does not matter. That is the feature of this International Standard.
The retrofit can be also conducted based on seismic performance, not on whether the seismic retrofit
meets an existing standard. Because this International Standard set such a rational performance
requirement mentioned above, the vulnerable parts which should be reinforced are clearly identified.
1) Ultimate limit state is mainly considered. However, other limit states may be considered such as seismic damage
control limit state when time history analysis is used.
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INTERNATIONAL STANDARD ISO 16711:2015(E)
Seismic assessment and retrofit of concrete structures
1 Scope
The purpose of this International Standard is to reduce the risk of seismic damage by structural collapse
or turnover during a seismic event.
This International Standard provides frameworks and principles of methods of detailed seismic
assessment and the judgment, seismic retrofit plan and design, seismic retrofit execution of existing
reinforced concrete structures before the occurrence of a severe earthquake and of the structures
struck by an earthquake.
This International Standard is applicable to reinforced concrete structures and pre-stressed concrete
structures that have been designed on the basis of the structural design criteria set in a specific country
or region. It is not applicable to either unreinforced concrete structures or masonry structures.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
There are no normative references.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
assessment
set of activities performed in order to verify the reliability of an existing structure for future use
[SOURCE: ISO 13822:2010]
3.2
collapse
loss of the load-carrying capacity of a component or member within a structure or of the structure itself
3.3
damage control limit state
ability of a structure or structural element to be repaired physically and economically when damaged
under the effects of considered actions
3.4
design documents
results of structural calculation and design drawings
3.5
design service life
period for which the structure is assumed to be in adequate condition for its intended purpose or
function with anticipated maintenance but without requiring substantial repair being necessary
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ISO 16711:2015(E)

3.6
inspection
conformity evaluation by observation and judgment accompanied as appropriate by measurement,
testing or gauging.
[SOURCE: ISO 16311-2:2014]
Note 1 to entry: For structures, this evaluation consists of actions collecting information on the current state
of a structure through observation and simplified non-destructive or destructive testing supplemented with
materials and structural testing, as required.
3.7
investigation
collection of information through inspection, document search, load testing and other testing
[SOURCE: ISO 16311-1:2014]
3.8
limit of displacement
allowable deformation of the structure in terms of parameters such as inter-story drift and overall
horizontal displacement, to control excessive deflection, cracking and vibration
3.9
limit state
critical state specified using a performance index, beyond which the structure no longer satisfies a
design performance requirement
[SOURCE: ISO 19338:2014]
3.10
maintenance
set of activities taken to check, evaluate, and preserve/restore structural performance so as to satisfy in
service performance requirements
[SOURCE: ISO 16311-1:2014]
3.11
structural repair
restoration of a structure or its components to an acceptable condition by the renewal or replacement of
worn, damaged or deteriorated components
[SOURCE: ISO 13823:2008]
Note 1 to entry: Repair is adopted to restore structural performance and to mitigate safety risks up to the initially
required design level and to achieve the intended service life.
3.12
restorability (or reparability)
ability of a structure or structural element to be repaired physically and economically when damaged
under the effects of considered actions
[SOURCE: ISO 19338:2014]
3.13
life safety performance level
ability of a structure or structural element to ensure no casualty to users of, and people around, the
structure, within the limits of acceptable probability
[SOURCE: ISO 19338:2014]
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ISO 16711:2015(E)

3.14
seismic capacity
force or displacement defined for the limit states
Note 1 to entry: Multiple limit states could be selected besides the life safety limit state, such as acceptable
economic loss limit state, reparability limit state, immediate occupancy limit state, or functionality limit state.
3.15
performance objective
required performance level (e.g. life safety) for a given earthquake hazard level (e.g. an earthquake with
a 10 % probability of exceedance in 50 years)
3.16
seismic damage
physical evidence of inelastic deformation, cracks or spalling of a structural component caused by
an earthquake
3.17
seismic retrofit
restoring or improving the seismic performance of a pre- or post-earthquake existing structure to meet
the seismic performance objective, including “structural repair” and “strengthening”
3.18
serviceability
ability of a structure or structural elements to provide appropriate behaviour or functionality in use
under the effects of considered actions at serviceability limit state
[SOURCE: ISO 19338:2014]
3.19
service life
actual period during which a structure meets the prescribed performance requirement
[SOURCE: ISO 16311-1:2014]
3.20
strengthening
measures taken to improve structural performance relating to load bearing capacity and deformation
of an existing structure and/or its members
[SOURCE: ISO 16311-1:2014]
4 Framework of Assessment and Retrofit
The seismic assessment and retrofit of an existing structure should obey the following procedures after
identifying the performance requirements and drafting an overall plan from investigation through
detailed seismic assessment, construction and documentation. The schematic of the process is shown in
Figure 1. Details of each item are described after Clause 5. All of these items are not necessarily executed;
the procedure should be initiated in order from (1), but it may be finished at any stage according to the
specific situation under consideration.
(1) Preliminary assessment
The possibility of a structure’s collapse or turnover un
...