Advances on structural design with timber in Uruguay:Towards a proposal for a National Annex to Eurocode 5
Vanesa BañoLeandro DomenechGonzalo CetrangoloHugo O’NeillLaura Moya
Corresponding author:[email protected]
Presenter:Andrea Cardoso
1. Uruguayan forestry
Uruguayan forestry
The Uruguayan forestry sector has had a significant increase in wood volume during thelast thirty years as a result of a government policy to promote forest plantations
1. Uruguayan forestry
Uruguayan forestry
The Uruguayan forestry sector has had a significant increase in wood volume during thelast thirty years as a result of a government policy to promote forest plantations
The main industrial use of eucalyptus species is the production of pulp, while pineand part of the eucalyptus are used for construction products
1. Uruguayan forestry
Uruguayan forestry
An important volume of wood (1.7 million m3 of pine and 0.4million m3 of eucalyptus) have not current industrial destination
1. Uruguayan forestry
Uruguayan forestry
An important volume of wood (1.7 million m3 of pine and 0.4million m3 of eucalyptus) have not current industrial destination
The Uruguayan government has impulse the incorporation of timber for structural use, which implies the need for a national system of codes for timber products and for design and construction with timber
2. Design process 2.1. Stages in structural design
Design process of a structure
Structural planning
Definition of external loads
Determination of internal forces
Design of structural members
Detailing, drawing and preparation of schedules
2. Design process 2.1. Stages in structural design
Design process of a structure
Structural planning
Definition of external loads
Determination of internal forces
Design of structural members
Detailing, drawing and preparation of schedules
Design codes
Introduction of security
2. Design process 2.1. Stages in structural design
Design process of a structure
Structural planning
Definition of external loads
Determination of internal forces
Design of structural members
Detailing, drawing and preparation of schedules
Design codes
Introduction of security
ASD
or
LRFD
2. Design process 2.2. ASD and LRFD methods
ASD and LRFD methods
ASD:Allowable Strength Design
LRFD:Load and Resistance Factor Design
2. Design process 2.2. ASD and LRFD methods
ASD and LRFD methods
ASD:Allowable Strength Design
LRFD:Load and Resistance Factor Design
The LRFD method accounts separately for the predictability of applied loads through the use of load factors and for material and construction variability through resistance factors. TheASD method combines the two factors into a single factor of safety.
2. Design process 2.2. ASD and LRFD methods
ASD and LRFD methods
The variable factor of safety associated with the LRFD method is considered to be more consistent with probability since structures that have highly predictable loads (predominately dead load for example) do not require the same factor of safety as structures subjected to loads that are not very predictable (live and wind loads for example).
ASD:Allowable Strength Design
LRFD:Load and Resistance Factor Design
3. Codes 3.1. United States
Codes in the United States
In the USA the ASD method has been gradually replaced by the LRFD method
3. Codes 3.1. United States
Codes in the United States
In the USA the ASD method has been gradually replaced by the LRFD method
LRFD was introduced for:
• reinforced concrete structures in 1970 (ACI 318:1970)
3. Codes 3.1. United States
Codes in the United States
In the USA the ASD method has been gradually replaced by the LRFD method
LRFD was introduced for:
• reinforced concrete structures in 1970 (ACI 318:1970)
• steel structures in 1986 (AISC 360:1986)
3. Codes 3.1. United States
Codes in the United States
In the USA the ASD method has been gradually replaced by the LRFD method
LRFD was introduced for:
• reinforced concrete structures in 1970 (ACI 318:1970)
• steel structures in 1986 (AISC 360:1986)
• timber structures in 2005 (NDS 2005)
3. Codes 3.1. United States
Codes in the United States
In the USA the ASD method has been gradually replaced by the LRFD method
The most recent editions of the United States codes for the design of timber and steel structures was developed in a dual format
LRFD was introduced for:
• reinforced concrete structures in 1970 (ACI 318:1970)
• steel structures in 1986 (AISC 360:1986)
• timber structures in 2005 (NDS 2005)
3. Codes 3.2. Europe
The Eurocodes are a set of European standards with the objectives of the elimination of technical obstacles to tradeand the harmonization of technical specifications
What Eurocodes are?
3. Codes 3.2. Europe
Purposes of the Eurocodes:
• a means to prove compliance with the requirements for mechanical strength and stability and safety in case of fire established by European Union law
The Eurocodes are a set of European standards with the objectives of the elimination of technical obstacles to trade and the harmonization of technical specifications
What Eurocodes are?
3. Codes 3.2. Europe
Purposes of the Eurocodes:
• a means to prove compliance with the requirements for mechanical strength and stability and safety in case of fire established by European Union law
• a basis for construction and engineering contract specifications
The Eurocodes are a set of European standards with the objectives of the elimination of technical obstacles to trade and the harmonization of technical specifications
What Eurocodes are?
3. Codes 3.2. Europe
Purposes of the Eurocodes:
• a means to prove compliance with the requirements for mechanical strength and stability and safety in case of fire established by European Union law
• a basis for construction and engineering contract specifications
• a framework for creating harmonized technical specifications for building products
The Eurocodes are a set of European standards with the objectives of the elimination of technical obstacles to trade and the harmonization of technical specifications
What Eurocodes are?
Eurocode 0 (EN 1990)
Basis of structural design
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Actions on structures
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Design of concrete structures
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Design of steel structures
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Design of timber structures
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Geotechnical design
Eurocode 8 (EN 1998)
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990)
Eurocode 1 (EN 1991)
Eurocode 2 (EN 1992)
Eurocode 3 (EN 1993)
Eurocode 4 (EN 1994)
Eurocode 5 (EN 1995)
Eurocode 6 (EN 1996)
Eurocode 7 (EN 1997)
Eurocode 8 (EN 1998)
Design of structures for earthquake resistance
Eurocode 9 (EN 1999)
EN Eurocodes Parts
3. Codes 3.2. Europe
Eurocode 0 (EN 1990):Basis of structural design
Eurocode 1 (EN 1991):Actions on structures
Eurocode 2 (EN 1992): ConcreteEurocode 3 (EN 1993): SteelEurocode 4 (EN 1994): CompositeEurocode 5 (EN 1995): TimberEurocode 6 (EN 1996): MasonryEurocode 9 (EN 1999): Aluminum
Eurocode 7 (EN 1997): Geotechnical design
Eurocode 8 (EN 1998): Seismic design
Structural safety,serviceability
and durability
Actions on structures
Design and detailing
Geotechnical andseismic design
3. Codes 3.2. Europe
3. Codes 3.2. Europe
Eurocode 5:Design of timber structures
Part 1 - General
• Part 1-1: Common rules and rules for buildings (EN 1995-1-1:2004)
• Part 1-2: Structural fire design (EN 1995-1-2:2004)
Part 2 – Bridges (EN 1995-2:2004)
3. Codes 3.2. Europe
Eurocode 5:Design of timber structures
Part 1 - General
• Part 1-1: Common rules and rules for buildings (EN 1995-1-1:2004)
• Part 1-2: Structural fire design (EN 1995-1-2:2004)
Part 2 – Bridges (EN 1995-2:2004)
LRFD
3. Codes 3.2. Europe
What National Annexes (NA) are?
Technical documents of national implementation with the objectives of the definition of the Nationally Determined Parameters (NDP) and, optionally, Non-Contradictory Complementary Information (NCCI) to Eurocodes
3. Codes 3.2. Europe
What National Annexes (NA) are?
Technical documents of national implementation with the objectives of the definition of the Nationally Determined Parameters (NDP) and, optionally, Non-Contradictory Complementary Information (NCCI) to Eurocodes
Parameters that stay open in the Eurocodes for the election of one national option, either because they are ignored in the Eurocodes or because they depend directly on the country
3. Codes 3.2. Europe
What National Annexes (NA) are?
Technical documents of national implementation with the objectives of the definition of the Nationally Determined Parameters (NDP) and, optionally, Non-Contradictory Complementary Information (NCCI) to Eurocodes
Parameters that stay open in the Eurocodes for the election of one national option, either because they are ignored in the Eurocodes or because they depend directly on the country
Information that helps the user to apply the Eurocode and the National Annexes
3. Codes 3.3. Nearby countries
Argentina
CIRSOC 601 (2013)
Chile
NCh 1198 (2006)
Codes in nearby countries
ASD
ASD
3. Codes 3.3. Nearby countries
Argentina
CIRSOC 601 (2013)
Chile
NCh 1198 (2006)
Brazil
NBR 7190 (2010)
Codes in nearby countries
ASD
ASD
LRFD
3. Codes 3.4. Uruguay
Actions on structures
UNIT 33 (1991) – General actions on buildings
UNIT 50 (1984) – Wind actions on structures
Codes in Uruguay
3. Codes 3.4. Uruguay
Actions on structures
UNIT 33 (1991) – General actions on buildings
UNIT 50 (1984) – Wind actions on structures
Concrete design
UNIT 1050 (2005) – Design and construction of concrete structures
Codes in Uruguay
3. Codes 3.4. Uruguay
Actions on structures
UNIT 33 (1991) – General actions on buildings
UNIT 50 (1984) – Wind actions on structures
Concrete design
UNIT 1050 (2005) – Design and construction of concrete structures
Steel and timber design
IE3-53 (1953) – Design of steel structures
IE4-50 (1950) – Design of timber structures
Codes in Uruguay
3. Codes 3.4. Uruguay
There is not a national code for the design of timber structures in Uruguay
Codes in Uruguay
3. Codes 3.4. Uruguay
There is not a national code for the design of timber structures in Uruguay
This can cause inconsistencies between the determination of mechanical properties of the material and the method used for the design by engineers or architects
Codes in Uruguay
3. Codes 3.4. Uruguay
There is not a national code for the design of timber structures in Uruguay
This can cause inconsistencies between the determination of mechanical properties of the material and the method used for the design by engineers or architects
There is not a common criterion for all materials regarding deflection limits, acceptable vibration frequencies or time required of mechanical resistance in fire
Codes in Uruguay
3. Codes 3.4. Uruguay
There is not a national code for the design of timber structures in Uruguay
Codes in Uruguay
Objective of the work
Design a code for timber structures for Uruguay whether developing an own codeor adopting an existing one
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
Lines of work
1) Determining the physical and mechanical properties of timber in Uruguay
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
Lines of work
1) Determining the physical and mechanical properties of timber in Uruguay
2) Design a code for timber structures for Uruguay
The results of this second line are presented in this work.
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
Lines of work
1) Determining the physical and mechanical properties of timber in Uruguay
2) Design a code for timber structures for Uruguay
The results of this second line are presented in this work.
Tasks performed
Analysis of international codes for the design of timber structures
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
Lines of work
1) Determining the physical and mechanical properties of timber in Uruguay
2) Design a code for timber structures for Uruguay
The results of this second line are presented in this work.
Tasks performed
Analysis of international codes for the design of timber structures
Discussion about whether to develop an own code or adopt an existing one
4. Methodology
Research project:
Technical documents for standardization of timber structures and buildings
Lines of work
1) Determining the physical and mechanical properties of timber in Uruguay
2) Design a code for timber structures for Uruguay
The results of this second line are presented in this work.
Tasks performed
Analysis of international codes for the design of timber structures
Discussion about whether to develop an own code or adopt an existing one
Drafting of a proposal for the Uruguayan National Annex to Eurocode 5
5. Results 5.1. Nationally Determined Parameters
2.3.1.2(2)P: Assignment of loads to load-duration classes
2.3.1.3(1)P: Assignment of timber constructions to service classes
2.4.1.(1)P: Partial factors for material properties
6.4.3(8): Tensile stresses in double tapered, curved and pitched cambered beams
7.2.(2): Limiting values for deflections of beams
7.3.3(2): Vibrations in residential floors
8.3.1.2(4): Lateral load-carrying capacity of nails in end grain
8.3.1.2(7): Species sensitive to splitting in nailed joints
9.2.4.1(7): Racking resistance of wall diaphragms
9.2.5.3(1): Modification factors for bracing systems
10.9.2(3): Erection tolerances for trusses: maximum bow
10.9.2(4): Erection tolerances for trusses: maximum deviation from vertical alignment
EN 1995-1-1: Nationally Determined Parameters (NDP)
5. Results 5.1. Nationally Determined Parameters
2.3.1.2(2)P: Assignment of loads to load-duration classes
2.3.1.3(1)P: Assignment of timber constructions to service classes
2.4.1.(1)P: Partial factors for material properties
6.4.3(8): Tensile stresses in double tapered, curved and pitched cambered beams
7.2.(2): Limiting values for deflections of beams
7.3.3(2): Vibrations in residential floors
8.3.1.2(4): Lateral load-carrying capacity of nails in end grain
8.3.1.2(7): Species sensitive to splitting in nailed joints
9.2.4.1(7): Racking resistance of wall diaphragms
9.2.5.3(1): Modification factors for bracing systems
10.9.2(3): Erection tolerances for trusses: maximum bow
10.9.2(4): Erection tolerances for trusses: maximum deviation from vertical alignment
EN 1995-1-1: Nationally Determined Parameters (NDP)
5. Results 5.1. Nationally Determined Parameters
EN 1995-1-2: Nationally Determined Parameters (NDP)
2.1.3(2): Maximum temperature rise for separating function in parametric fire
2.3(1)P: Partial factor for material properties in fire
2.3(2)P: Partial factor for mechanical resistance of connections in a fire situation
2.4.2(3): Reduction factor for combinations of actions
4.2.1(1): Procedure for determining cross-sectional properties
5. Results 5.1. Nationally Determined Parameters
Partial factors for material properties
Quality control of
the timber
Quality control of
the construction
Factor for material
properties
Fundamental
combinations
NormalNormal 1,60
Intense 1,45
IntenseNormal 1,45
Intense 1,30
Accidental
combinations
Normal - 1,10
Intense - 1,00
5. Results 5.1. Nationally Determined Parameters
Partial factors for material properties
Quality control of
the timber
Quality control of
the construction
Factor for material
properties
Fundamental
combinations
NormalNormal 1,60
Intense 1,45
IntenseNormal 1,45
Intense 1,30
Accidental
combinations
Normal - 1,10
Intense - 1,00
Quality control of the timber: certification
Quality control of the construction: judgment of the designer (relevance of the building, structural complexity, etc.)
5. Results 5.1. Nationally Determined Parameters
Partial factors for material properties
Quality control of
the timber
Quality control of
the construction
Factor for material
properties
Fundamental
combinations
NormalNormal 1,60
Intense 1,45
IntenseNormal 1,45
Intense 1,30
Accidental
combinations
Normal - 1,10
Intense - 1,00
Eurocode 0 (EN 1990) – Annex 3
About 200 specimens of Uruguayan Pinus elliottii/taeda
5. Results 5.1. Nationally Determined Parameters
Limiting values for deflections of beams
Criteria Limiting values
Integrity of the
constructive
elements
Floors with brittle partitions 𝑤𝑎𝑐𝑡 ≤ 𝑙/500
Floors with ordinary partitions 𝑤𝑎𝑐𝑡 ≤ 𝑙/400
Other
cases
With ceiling or false
plasterboard ceiling𝑤𝑎𝑐𝑡 ≤ 𝑙/300
Without ceiling or false
plasterboard ceiling𝑤𝑎𝑐𝑡 ≤ 𝑙/200
User comfort Floors and beams of floors 𝑤𝑖𝑛𝑠𝑡 ≤ 𝑙/350
Appearance of the building work 𝑤𝑛𝑒𝑡,𝑓𝑖𝑛 ≤ 𝑙/300
5. Results 5.2. Non-Contradictory Complementary Information
Non-Contradictory Complementary Information
• Relationship between UNIT Actions Codes and Eurocode 1
• External forces and load combinations
• Definitions for calculation of vertical and horizontal deflections
• Procedure for verification of floor vibrations
5. Results 5.2. Non-Contradictory Complementary Information
Non-Contradictory Complementary Information
• Relationship between UNIT Actions Codes and Eurocode 1
• External forces and load combinations
• Definitions for calculation of vertical and horizontal deflections
• Procedure for verification of floor vibrations
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
2) Convert the characteristic wind velocity (𝑣𝑘), defined by UNIT 50, in the basic wind velocity (𝑣𝑏), defined by Eurocode 1, and establish the wind actions on structures according to Eurocode 1.
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
𝑣𝑏 = 0,858 ∙ 0,676 ∙ 1,149 ∙ 𝑣𝑘 = 0,667 ∙ 𝑣𝑘
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
2) Convert the characteristic wind velocity (𝑣𝑘), defined by UNIT 50, in the basic wind velocity (𝑣𝑏), defined by Eurocode 1, and establish the wind actions on structures according to Eurocode 1.
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
𝑣𝑏 = 0,858 ∙ 0,676 ∙ 1,149 ∙ 𝑣𝑘 = 0,667 ∙ 𝑣𝑘
Ground roughness
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
2) Convert the characteristic wind velocity (𝑣𝑘), defined by UNIT 50, in the basic wind velocity (𝑣𝑏), defined by Eurocode 1, and establish the wind actions on structures according to Eurocode 1.
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
𝑣𝑏 = 0,858 ∙ 0,676 ∙ 1,149 ∙ 𝑣𝑘 = 0,667 ∙ 𝑣𝑘
Ground roughness
Sampling interval
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
2) Convert the characteristic wind velocity (𝑣𝑘), defined by UNIT 50, in the basic wind velocity (𝑣𝑏), defined by Eurocode 1, and establish the wind actions on structures according to Eurocode 1.
5. Results 5.2. Non-Contradictory Complementary Information
Relationship between UNIT Actions Codes and Eurocode 1UNIT 50 (1984): Wind actions on structures
𝑣𝑏 = 0,858 ∙ 0,676 ∙ 1,149 ∙ 𝑣𝑘 = 0,667 ∙ 𝑣𝑘
Ground roughness
Sampling interval
Return period
Proposed methods:
1) Establish the wind actions on structures according to UNIT 50.
2) Convert the characteristic wind velocity (𝑣𝑘), defined by UNIT 50, in the basic wind velocity (𝑣𝑏), defined by Eurocode 1, and establish the wind actions on structures according to Eurocode 1.
5. Results 5.3. Research topics
Future research topics Study of the embedment strengthfor the design of connections
5. Results 5.3. Research topics
Future research topics Study of the embedment strength for the design of connections
Determination of the sensitivity to splitting of local cultivated species
5. Results 5.3. Research topics
Future research topics Study of the embedment strength for the design of connections
Determination of the sensitivity to splitting of local cultivated species
Study of the charring rates of local cultivated species
5. Results 5.3. Research topics
Future research topics Study of the embedment strength for the design of connections
Determination of the sensitivity to splitting of local cultivated species
Study of the charring rates of local cultivated species
Determination of the physical and mechanical properties of sawn timber and engineered wood products. Develop an UNIT standard for visual grading and establish the correlation with the strength classes
6. Conclusions
Conclusions
Eurocode 5 parts 1-1 and 1-2 were proposed to be used in Uruguay for the design of timber structures. The adoption of the Eurocode 5 establishes a precedent in Uruguay for other construction materials
6. Conclusions
Conclusions
Eurocode 5 parts 1-1 and 1-2 were proposed to be used in Uruguay for the design of timber structures. The adoption of the Eurocode 5 establishes a precedent in Uruguay for other construction materials
A National Annex to Eurocode 5 was proposed. This document contains the Nationally Determined Parameters and Non-Contradictory Complementary Information to Eurocode 5 for the Uruguayan conditions of timber design
6. Conclusions
Conclusions
Eurocode 5 parts 1-1 and 1-2 were proposed to be used in Uruguay for the design of timber structures. The adoption of the Eurocode 5 establishes a precedent in Uruguay for other construction materials
A National Annex to Eurocode 5 was proposed. This document contains the Nationally Determined Parameters and Non-Contradictory Complementary Information to Eurocode 5 for the Uruguayan conditions of timber design
In order to complete the National Annex to Eurocode 5 with information about local cultivated species and local conditions a list of research topicswas recommended
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