NL مواصفة لبنانية

NORME LIBANAISE 135

LEBANESE STANDARD IDT Deuxième édition

Second edition

2012

: القواعد العامةزالزلوقاية من الال

Construction parasismique : règles générales

Protection from Earthquakes: General Rules

ؤسسة المقاييس والمواصفات اللبنانيةم

-------- LIBNOR --------

Numéro de référence

Reference number

NL 135

2012

ICS: 13.220.50

NL 135:2012

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The Lebanese Standards Institution (LIBNOR) is a public institution attached to the

Ministry of Industry. It was established in 23-7-1962 by a law giving it solely the

right to prepare, publish and amend national standards, as well as to grant the

Lebanese Conformity Mark NL.

Lebanese standards are prepared by technical committees formed by LIBNOR. They

include setting the dimensions, conventions, symbols, and the definition of products

quality, as well as the methods of testing and analysis. They also include the codes of

practice for professional and structural work.

Lebanese standards are voluntary in principle. However, for reasons of public health,

public safety or national interest, a standard can be rendered mandatory by a decree

from the council of ministers.

LIBNOR is a member of the International Organization for Standardization (ISO) and

the Arab Industrial Development and Mining Organization (AIDMO), an Affiliate

Member of the European Committee for Standardization (CEN), as well as the Codex

Alimentarius Contact Point in Lebanon.

– Copyright - All rights reserved –

Apart from exceptions provided by the law, nothing from this publication may be

duplicated and/or published by means of photocopy, microfilm, storage in computer

files or otherwise, which also applies to full or partial processing, without the written

consent of the Lebanese Standards Institution - LIBNOR.

Lebanese Standards Institution – LIBNOR

City Rama Street, Libnor Bldg,

P.O.BOX. 55120 Sin El Fil, Lebanon

Phone: +961-1-485927- Fax: +961-1-485929

Website : www.libnor.org

E-mail : libnor@libnor.org

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TABLE OF CONTENTS

Introduction …………………………………………………………………………..6

Part 1: Scope – Applicability …………………………………………………………7

1.1 – New Structures ………………………………………………………….………7

1.2 – Existing Structures subject to « works »………………………………...………7

1.3 – Existing Structures …………………………………………………………...…7

Part 2: Applicable Referenced Documents …………………………………...………8

2.1 – French Referenced Documents ………… ……………………………...………8

2.2 – American Referenced Documents ………………….…………………...………8

Part 3: National Requirements …………………………...……………………..……9

3.1 – Minimum Seismic Protection Level ………………………….................………9

3.2 – Adaptation to French Referenced Documents ………….…………………….…9

3.3 – Adaptation to American Referenced Documents …………………….………...9

3.4 – Guidance rules for the Seismic Design of Structures ……………………….…11

3.5 – Requirements for Existing Structures..…………………….…………………..11

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Foreword

The Lebanese standards are elaborated according to the internal procedures of

LIBNOR.

The board of directors of LIBNOR approved this standard, on …/…/…… without

modification, as a Lebanese standard, based on the recommendation of LIBNOR

technical committee: “Earthquakes safety” in its meeting held on …/…/2012.

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Technical committee – Approval Signature

President Signature

Socotec-Lebanon Roland Maarri

Coordinator :

Lebanese Standards Institution - Libnor Jawad Abi Akl

Members:

Ministry of Public works and transports -

General Directorate of Roads and

Buildings

Ministry of Public works and transports –

General Directorate of Urban Planning

National Centre for Scientific Research -

Lebanon

Council for Development &

Reconstruction

Order of Engineers & Architects of

Beirut

Order of Engineers & Architects of

Tripoli

Qualiconsult- Middle-East

Bureau Veritas - Lebanon

Apave-Lebanon

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INTRODUCTION

The Standard NL135 : 2012 presents the seismic rules for the design of buildings and

civil works structures that complement the general rules related to different types of

construction :concrete, steel, wooden,…

It refers to the seismic hazard level specified in the decree 7964 dated April 7th

, 2012

which considers the national territory as one seismic zone. This decree does not define

the earthquake of reference but rather a minimum design seismic level. Therefore, the

present standard will be revised based on the upcoming national scientific advances in

this field.

The Standard NL135: 2012 takes into account the presence in Lebanon of two major

French and American schools in terms of structural seismic engineering. It presents

some flexibility by offering to the designers the possibility either to adopt the French

Norm (PS 92) or the American codes (UBC97 or IBC) while conceiving their

structures.

It is however important to mention that the progress of knowledge in terms of seismic

construction engineering has shown that some of the dispositions of the seismic rules

mentioned above needs to be reviewed on continuous basis in order to bring a

sensitive improvement to the reliability of structures; the Eurocode 8 constitutes, at

this level, the European consecration of this considerable progress in this domain.

Accordingly, the present Standard NL135: 2012 will be induced to adopt in the five

upcoming years the Eurocode 8 as the only and unique seismic code applicable in

Lebanon.

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Part 1: Scope – Applicability

1.1 – New Structures

The present Standard is applicable to all construction projects including buildings and

civil works in both public and private sectors.

1.2 – Existing Structures subject to « works »

Shall equally satisfy the requirements of the present Standard the rehabilitation of

existing structures (in public and private sectors) that are subject to works of the

following types:

- modifications

- additional levels

- total or partial modification of the type of occupancy

1.3 – Existing Structures

The requirements of the present Standard apply equally to the existing structures

subject to the mandatory technical control as per the Decree 7964 of April 7th, 2012

and notably:

- Power plants

- Electrical substations exceeding 33 Kvolt

- Pumping and water treatment stations

- Water tanks of a capacity >1000m3

and water towers of a capacity >500 m

3

- Educational occupancies >700 students (Schools and universities)

- Hospitals and health centres

- Fire stations (civil defence and fire brigades)

- Public buildings and civil works

- Structures including cantilevers > 20m or spans > 40m or underground parts > 15m

depth or deep foundations > 30m or necessitating underpinning works.

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Part 2: Applicable Referenced Documents

2.1 – French Referenced Documents

The seismic design of buildings and various structures shall be done according to the

following in force French rules and standards:

Règles PS applicables aux bâtiments - PS92 Normes NF P 06-013

Guide AFPS 1992.

Are equally applicable all in force French regulations and standards that are related to

the above mentioned rules and standards notably:

- BAEL91 (Modified 99)

- BPEL91 (Modified 99)

- Règles CM66 Steel Structures

- Règles CB 71 Wooden Structures

- Norms related to steel

- Norms related to concrete and aggregates

- Norms related to Hydraulic binders

- DTU concerning concrete works (DTU14.1, 20.1, 21, 23.1, 25.31)

- Structures basis of calculation (NFP06-001, Règles Neige et Vent NV65

modifiées 99 …) or related in force norms issued by LIBNOR (wind

design and snow loads)

- Fascicules du CCTG applicables aux marchés publics de travaux de

bâtiments et de génie civil.

- Mandatory in force Norms issued by LIBNOR : NL49, NL50, NL51,

NL53

- Lebanese Norm NL134 :1998 (Chapters 2 to 6)

- Lebanese in force Norm related to wind design and snow loads

2.2 – American Referenced Documents

The seismic design of buildings and various structures shall be done according to one

of the following two American codes:

Uniform Building Code UBC 97

International Building Code IBC 2009 (or the latest edition in force)

Are equally applicable all in force American regulations and standards that are related

to the above mentioned codes notably:

- Building Code Requirements for structural Concrete (ACI318-08 or the

latest edition in force)

- ASTM Standards related to concrete

- ASTM Standards related to steel reinforcement

- AASHTO

- Mandatory in force Norms issued by LIBNOR : NL49, NL50, NL51,

NL53

- Lebanese Norm NL134 :1998 (Chapters 2 to 6)

- Lebanese in force Norm related to wind design and snow loads

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Part 3: National Requirements

3.1 – Minimum Seismic Protection Level

Lebanon is considered as one seismic zone.

The seismic aggression level to be taken into account in the design and the execution

of buildings and civil works projects of the “normal hazard” category (buildings,

equipments and installations for which the consequences of an earthquake remain

confined to their occupants and their direct neighborhood) is specified by a unique

parameter aN defining the minimum level of peak ground acceleration: the value of aN

is fixed at 0.25g (be it 2.5 m/s2) as per the Decree 7964 of April 7

th, 2012.

Each structure shall be assigned a class of hazard according to its Occupancy

Category as per the prescriptions of the applicable “referenced Documents” specified

in Part 2 of the present Standard.

Concerning the buildings and particular structures of the “special hazard” category

(buildings, equipments and installations for which the impact on persons, properties

and environment of damages even minor resulting from an earthquake could not be

contained to the direct neighborhood of these buildings, equipments and installations:

petrochemical plants, nuclear plants,… ),they should satisfy preventive measures

notably seismic rules in terms of construction, fitting out and operation, whose

application is determined by means of ministerial orders or decrees defining the type

and characteristics of the buildings, equipments and installations, the technical

preventive dispositions as well as the level of seismic aggression to be considered for

such type of structures.

3.2 – Adaptation to French/European Referenced Documents

Apply the Seismic Design Rules PS92 & Guide AFPS 1992 considering a minimum

value of the peak ground acceleration (accélération nominale) equal to aN = 2.5 m/s2

corresponding to seismic zone II (zone de sismicité II) and to an occupancy category

of normal hazard (catégorie d’ouvrages dits à risque normal). The above mentioned

value is subject to an increase based on the class of hazard of the structure.

3.3 – Adaptation to American Referenced Documents

3.3.1 Uniform Building Code UBC 97

The seismic zone factor to be adopted is Z =0.25

Apply the following table to define the Seismic Coefficient Ca taking into account

the Seismic Zone Factor Z and the Soil Profile type :

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TABLE 16-Q – SEISMIC COEFFICIENT Ca

SOIL PROFILE TYPE

SEISMIC ZONE FACTOR, Z

Z = 0.25

SA 0.2

SB 0.25

SC 0.29

SD 0.32

SE 0.35

SF See Footnote 1

1Site-specific geotechnical investigation and dynamic site response analysis shall be performed to determine

seismic coefficients for Soil Profile Type SF.

Apply the following table to define the Seismic Coefficient Cv taking into

account the Seismic Zone Factor Z and the Soil Profile type:

TABLE 16 – R – SEISMIC COEFFICIENT Cv

SOIL PROFILE TYPE

SEISMIC ZONE FACTOR, Z

Z = 0.25

SA 0.2

SB 0.25

SC 0.4

SD 0.47

SE 0.74

SF See Footnote 1

1Site-specific geotechnical investigation and dynamic site response analysis shall be performed to determine

seismic coefficients for Soil Profile Type SF.

As per decree 7964 of April 7th

, 2012, the structural design and detailing should

adhere, as minimum, to the requirements of zones of “Moderate seismic Risk”

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3.3.2 International building Code IBC

Adopt the following spectral response acceleration parameters Ss (short period)

and S1 (1-second period) :

COUNTRY 2009 IBC MCE SPECTRAL

RESPONSE ACCELERATION

Ss

S1

LEBANON 1.20

0.40

Apply the following table to determine the Site Coefficient Fa taking into account

the Ss parameter and the Site Class :

TABLE 1613.5.3 (1)

VALUES OF SITE COEFFICIENT Fa

SITE CLASS

MAPPED SPECTRAL RESPONSE ACCELERATION AT SHORT PERIOD

SS = 1.20

A 0.8

B 1.0

C 1.0

D 1.0

E 0.9

F Note b

b- Values shall be determined in accordance with Section 11.4.7of ASCE 7.

Apply the following table to determine the Site Coefficient Fv taking into account

the S1 parameter and the Site Class:

TABLE 1613.5.3 (2)

VALUES OF SITE COEFFICIENT FV

SITE CLASS

MAPPED SPECTRAL RESPONSE ACCELERATION AT 1 SECOND PERIOD

S1 = 0.40

A 0.8

B 1.0

C 1.4

D 1.6

E 2.4

F Note b

b- Values shall be determined in accordance with Section 11.4.7of ASCE 7.

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3.4 – Guidance rules for the Seismic Design of Structures

Refer to chapter 2 and 6 of Lebanese Norm NL134:1998.

In case of any contradiction between, some of the technical provisions included in

these chapters and the requirements of the applicable referenced documents

mentioned in Part 2 of the present Standard, these latter shall prevail (e.i: minimum

width of seismic joints between blocks or adjacent structures to be of 6cm instead of

4cm, minimum small dimension of column: 25cm instead of 20cm, etc…)

The provisions of chapters 2 and 6 of the Lebanese Norm NL134:1998 are considered

as helpful guidance general rules for the seismic design of structures; they are either

minimal rules or recommendations; consequently they could not in any way be

substituted to a comprehensive seismic analysis and a justification of the structures as

per the applicable referenced documents mentioned in Part 2 of the present Standard.

3.5 – Requirements for Existing Structures.

The existing structures subject to « works » as well as the Strategic existing structures

referred to respectively in paragraph 1.2 and 1.3 – Part 1 of the present Standard

should comply with the requirements of the present Standard without any exception.

If other existing structures (notably residential buildings) are to be put into conformity

from a seismic protection point of view, the requirements of the present Standard shall

then be applied except other else specified by the authority having jurisdiction.