ELEMENTS OF EUROPEAN NORMATIVE IN THE DESIGN OF STRUCTURES AND THEIR APPLICATION IN ALBANIA

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1 Interdisplinary Journal of Research and Development Alexander Moisiu University, Durrës, Albania Vol (IV), No.2, 2017 Paper presented in 1 -st International Scientific Conference on Professional Sciences, Alexander Moisiu University, Durres November 2016 ELEMENTS OF EUROPEAN NORMATIVE IN THE DESIGN OF STRUCTURES AND THEIR APPLICATION IN ALBANIA FLORENC DABERDAKU 1, DENADA CUNGE 2 1 Department of Engineering Sciences, Professional Studies Faculty, Alexander Moisiu University, Durres, Albania 2 Water supply sanitation, Tirana Municipality, Tirana, Albania Corresponding author florencd@gmail.com Abstract This study aims to show the most important elements of the design process. In the beginning there are some sets of factors to be selected. This may be done in accordance with respect to the location of the facility, its exposure factors and its seismic resistance required. Firstly, it is the Eurocode 0(also known as EN 1990) that gives anyone of us a deep insight about principles of the design in the Ultimate States, the classification of loads and the importance of environmental influences. There are also descriptions of the structural analysis which might include static and dynamic actions. Going further, in the Eurocode 1 we are shown a wide range of loads (live loads, wind loads, snow loads ect.) and their characteristic values. These are preceded by tables of construction materials (that will have their share in the permanent loads) in which weight per unit volume are shown. As per seismic calculations, Eurocode 8 furnishes us with ground conditions and seismic zones followed by the basic representation of the seismic action including the horizontal elastic response spectrum (and the vertical one) expressions followed by the design spectrum for elastic analysis with a particular emphasize of the behavior factor. It should be noted that in Eurocode 7 we are shown the main two formulas that engineers can use in order the value the capacity bearing of soils for design of foundations. Key words: Structural Engineering, European Normative, Static& Dynamic Loads, Environmental Factors, Seismic action, Capacity Bearing of Soils. Short history of European Normative The structural Eurocodes make up an updated normative body whose purpose is the design of civil and industrial engineering facilities. Inside these normatives it is found the synthesis of the experience and traditions of 25 countries of the European Union (EU) and that of 3 countries of EFTA (European Free Trade Association). The above cooperation has given life to a set of unified design rules of worldwide level. In 1975 the Commission of the CEE began a program which aimed to eliminate the technical obstacles represented by the different Technical Normatives of each single state. Those differences were not always justified by solid motives but simply by traditions and consolidated customs. This initiativegave birth to the publication of the first documents series between 1975 and In 1989 the CEE decided to transfer the elaboration of the Eurocodes to CEN (ComitéEuropéen de Normalisation) for their publication as European Standarts. The Eurocodes were first published as experimental documents (ENV); a period which lasted from 1992 to Nowadays they all are published as definitive normative (EN) Objective of eurocodes At this point we might say that the Eurocodes are offered to us as basic instruments for the achievement of the following objectives: Improve the competitions of European construction industry both within EU and outside it. Constitute the base for the European contracts in civil engineering works. Serve as reference for the determination of the performance of structural elements in front of the essential requirements. Associated with the attainment of the above scopes are the following attended benefits: Facilitate the free circulation of constructions materials and products within 79

2 Elements of European normative F. Daberdaku & D.Çunge the EU, which improves the running of the internal market. Make up the basics of comprehension between designers, customers, operators, users, business companies and producers. Make up of a common base for research and development in the field of structural engineering Table 1. Abbreviation Determination Title EN 1990 Eurocode 0 Basis of structural design EN 1991 Eurocode 1 Actions on EN 1992 Eurocode 2 Design of concrete EN 1993 Eurocode 3 Design of steel Allow the preparation of reliable software s. Eurocodes General Plan and Specified Parts The general plane is represented by 58 documents of the Eurocode regrouped in the following Eurocodes: EN 1994 Eurocode 4 Design of composite steel and concrete EN 1995 Eurocode 5 Design of timber EN 1996 Eurocode 6 Design of masonry EN 1997 Eurocode 7 Geotechnical design EN 1998 Eurocode 8 Design of for earthquake resistance EN 1999 Eurocode 9 Design of aluminium Each of the Eurocodes includes the following parts shown in the table below: Eurocode Eurocode 0 Basis of structural design Eurocode 1 Actions on Eurocode 2 Design of concrete Parts of each: Table 2. EN 1990 Basis of structural design EN 1990-A1 Basis of structural design for road bridges, footbridges and railway bridges EN Densities, self-weight, imposed loads for buildings. EN Actions on exposed to fire EN Snow loads EN Wind actions EN Thermal actions EN Actions during execution EN Accidental actions due to hit and explosion EN Traffic loads on bridges EN Actions induced by cranes and machinery EN Actions on silos and tanks EN General rules and rules for buildings EN Structural fire design EN Concrete bridges Design and detailing rules EN Liquid retaining and containment 80

3 Interdisplinary Journal of Research and Development Alexander Moisiu University, Durrës, Albania Vol (IV), No.2, 2017 Eurocode 3 Design of steel Eurocode 4 Design of composite steel and concrete Eurocode 5 Design of timber Eurocode 6 Design of masonry Eurocode7 Geotechnical design Eurocode 8 Design of for earthquake resistance EN Rules for buildings EN Structural fire design EN Supplementary rules for cold-formed members and sheeting EN Supplementary rules for stainless steels EN Plated structural elements EN Strength and Stability of Shell Structures EN Strength and stability of planar plated subject to out of plane loading EN Design of joints EN Fatigue EN Material toughness and through-thickness properties EN Design of with tension components EN Additional rules for the extension of EN 1993 up to steel grades S 700 EN Steel Bridges EN Towers and masts EN Chimneys EN Silos EN Tanks EN Pipelines EN Piling EN Crane supporting EN Rules for buildings EN Structural fire design EN Bridges EN Rules for buildings EN Structural fire design EN Bridges EN Common rules for reinforced and unreinforced masonry EN Structural fire design EN Design considerations, selection of materials and execution of masonry EN Simplified calculation methods for unreinforced masonry EN General rulesen Ground investigation and testing EN General rules, seismic actions and rules for buildings EN Bridges EN Assessment and retrofitting of buildings EN Silos, tanks and pipelines EN Foundations, retaining and geotechnical aspects EN , Towers, masts and chimneys Eurocode 9 Design of aluminum EN General structural rules EN Structural fire design EN Structures susceptible to fatigue EN Cold formed structural sheeting EN Shell 81

4 Elements of European normative F. Daberdaku & D.Çunge Definition of limit states, Eurocode 0 The limit states connected with: The safety of people The safety of the structure should be classified as ultimate limit states. In certain circumstances the limit states concerned with the protection of the content should also classified as ultimate limit state. When of importance, the following limit states should be verified: Loss of equilibrium of the structure or parts of it with the whole structure considered as e rigid body Collapse due to excessive deformation, transformation of the structure or parts of it Collapse due to fatigue or from other effects depending on time The limit states connected with: The functioning of the structure or its structural parts Table 3. The comfort of the people The aesthetics of the construction should be classified as serviceability limit state. The verification according to serviceability limit state (SLS) should be based on criteria which are related to the following aspects: a) Deformations which influence on: Ø The appearance Ø The users comfort Ø The functioning of the structure b) Vibrations Ø Which may harm the users comfort Ø Which may limit the effectiveness of the functioning of the structure To be noted is the recommended values of ψ factors for buildings are according to the table below: Where: Ψ 0 is the combination value of the live load. Ψ 1 is the frequent value of the live load. Ψ 2 is the quasi-permanent value of the live load. Live loads, Eurocode 1 According to the specific use of buildings the table below shows the categories: 82

5 Interdisplinary Journal of Research and Development Alexander Moisiu University, Durrës, Albania Vol (IV), No.2, 2017 Category A B Table 4. Areas for domestic and residential activities Areas for offices Intended specific use C Areas where people can assemble (excluding areas belonging to category A,C or D) D Areas for commercial activities While the characteristic values of the distributed q k and concentrated load Q k are as follows: Table 5. Category of loaded area q k [kn/m 2 ] Q k [kn] Category A -slabs -stairs -balconies from 1.5 to 2.0 from 2.0 to 4.0 from 2.5 to 4.0 from 2.0 to 3.0 from 2.0 to 4.0 from 2.0 to 3.0 Category B from 2.0 to 3.0 from 1.5 to 4.5 Category C -C1 -C2 -C3 -C4 -C5 from 2.0 to 3.0 from 3.0 to 4.0 from 3.0 to 5.0 from 4.5 to 5.0 from 5.0 to 7.5 from 3.0 to 4.0 from 2.5 to 7.0 from 4.0 to 7.0 from 3.5 to 7.0 from 3.5 to 4.5 Category D -D1 -D2 from 4.0 to 5.0 from 4.0 to 5.0 from 3.5 to 7.0 from 3.5 to 7.0 To be noted is that for local verifications a single concentrated load of Q k should be considered. Horizontal elastic and design spectrums, Eurocode 8 response spectrum, are as follows: 0 T T B S e (T) = a g *S*[1+T/T B *(η*2.5-1) ]EN (3.2) T B T T C S e (T) = a g *S*η*2.5EN (3.3) T C T T D S e (T) = a g *S*η*2.5*[T C /T] EN (3.4) T D T 4sec S e (T) = a g *S*η*2.5*[T C *T D /T2] EN (3.5) While the expressions for the horizontal design spectrum are: 0 T T B S d (T) = a g *S*[2/3+T/T B *(2.5/q- 2/3)] EN (3.13) T B T T C S d (T) = a g *S*2.5/q EN (3.14) T C T T D S d (T) = a g *S*2.5/q*[T C /T] β*a g EN (3.15) T D T 4sec S d (T) = a g *S*2.5/q*[T C *T D /T2] β*a g EN (3.16) Table 6. Type 1 (M>5.5), parameters Soil Category S T B T C T D A B C D E

6 Elements of European normative F. Daberdaku & D.Çunge Table 7. Type 2 (M 5.5), parameters Soil Category S T B T C T D A B C D E Bearing resistance calculation, eurocode 7 The design bearing resistance may be calculated from: R/A' = (π+2) c u b c s c i c + q (D.1) with the dimensionless factors for: s c = 1+ 0,2 (B'/L'), for a rectangular shape; s c = 1,2, for a square or circular shape. the inclination of the load, caused by a horizontal load H: the inclination of the foundation base: b c = 1 2α / (π + 2); the shape of the foundation: 84

7 Interdisplinary Journal of Research and Development Alexander Moisiu University, Durrës, Albania Vol (IV), No.2, 2017 With H A c u For Drained conditions, the design bearing resistance may be calculated from: R/A' = c' N c b c s c i c + q' N q b q s q i q + 0,5 γ' B 'N γ b γ s γ i γ (D.2) with the design values of dimensionless factors for: the bearing resistance: N q = e π tanφ' tan 2 (45 + Φ'/2) N c = (N q - 1) cot Φ' N γ = 2 (N q - 1) tan Φ', where δ Φ'/2 (rough base) the inclination of the foundation base: b c = b q - (1 - b q ) / (N c tan Φ ) b q = b γ = (1 - α tan Φ )2 the shape of foundation: s q = 1 + (B' / L' ) sin Φ', for a rectangular shape; s q = 1 + sin Φ', for a square or circular shape; s γ = 1 0,3 (B'/L ), for a rectangular shape; s γ = 0,7, for a square or circular shape s c = (s q N q -1)/(N q - 1) for rectangular, square or circular shape; the inclination of the load, caused by a horizontal load H: i c = i q - (1 - i q ) / (N c. tan Φ' ); i q = [1 - H/(V + A'c'cotΦ')]m; i γ = [1 - H/(V + A'c'cotΦ')]m+1. where: m = m B = [2 + (B '/ L' )]/[1 + (B' / L' )] when H acts in the direction of B'; m = m L = [2 + (L' / B' )]/[1 + (L' / B' ] when H acts in the direction of L'. In cases where the horizontal load component acts in a direction forming an angle θ with the direction of L', m may be calculated by: m = m θ = m L cos 2 θ + m B sin 2 θ. References 1. Eurocode 0 Basis of structural design (UNI EN 1990: 2004) 2. Eurocode 1 Action on (UNI EN : 2004) 3. Eurocode 7 Geotechnical design (UNI EN :2005) 4. Eurocode 8 Design of for earthquake resistance (UNI EN :2005) 5. Progettazione di strutture in calcestruzzo armato. Guida all uso dell Eurocodice 2. (A cura di aicap, 2008) 85

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