Design of masonry structures Eurocode 3 For Dummies

Design of masonry structures Eurocode 3 For Dummies This edition has been fully revised and extended to cover blockwork and Eurocode 6 on masonry structures. This valued textbook: discusses all aspects of design of masonry structures in plain and reinforced masonry summarizes materials properties and structural principles as well as descibing structure and content of codes presents design procedures, illustrated by numerical examples includes considerations of accidental damage and provision for movement in masonary buildings. This thorough introduction to design of brick and block structures is the first book for students and practising engineers to provide an introduction to design by EC6.

Eurocode for Dummies The Opportunities and Traps a brief guide on element design to EC3 Tim McCarthy Email tim.mccarthy@umist.ac.uk Manchester Centre for Civil & Construction Engineering Slides available on the web http://www2.umist.ac.uk/construction/staff/ mccarthy/index.htm Follow the link from my home page From 21 March 2003 21/03/2003 © 2003 Tim McCarthy Overview Eurocode n n Current status Coverage Pitfalls n Major and minor differences with BS5950 Element Design n Beams, Struts Capacity comparisons 21/03/2003 Manchester Centre for Civil & Construction Engineering EC3 Current Status 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering E-SCI News March 2003 21/03/2003 Eurocode terminilogy EN – EuroNorm n mandatory standard ENV – EuroNorm Voluntaire n You can use it if you wish DD – Draft for development DC – Draft for public comment prEN n PrePre-EuroNorm between DD and EN 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering EC3 Current Published Status DD ENV 19931993-1-1:1992 Eurocode Design of steel structures General rules and rules for buildings (together with United Kingdom National Application Document) DD ENV 19931993-1-2:2001 Eurocode Design of steel structures General rules Structural fire design (together with United Kingdom National Application Document) DD ENV 19931993-1-3:2001 Eurocode Design of steel structures General rules Supplementary rules for cold formed thin gauge members and sheeting 21/03/2003 Manchester Centre for Civil & Construction Engineering Other EC’s Published Status prEN 19941994-1-1:2002 Design of composite steel and concrete structures Part 1.1 General rules and rules for buildings Stage 49 Examination Document DD ENV 19981998-3:1997 Eurocode 8: Design provisions for earthquake resistance of structures Towers, masts and chimneys 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering Potential pitfalls Terminology n Restricted vocabulary Change in symbols n n More logical symbol name conventions Lots of subscripts Changes in values n Young’ Young’s Modulus etc Multiple documents n Need to consult more than one part 21/03/2003 Manchester Centre for Civil & Construction Engineering Terminology BS5950 Force Capacity n Mc n Design strength n py © 2003 Tim McCarthy Manchester Centre for Civil Mc,Rd Yield strength n Dead load Live load Wind load 21/03/2003 EC3 Action Resistance fy Permanent load Variable load Another variable load & Construction Engineering 10 Terminal…ogy BS5950 in wonderland Words evolved over time Inconsistent at times No link with concrete structural codes 21/03/2003 Manchester Centre for Civil EC3 Vocabulary consistent with meaning Consistent across all Eurocodes Easy to translate & Construction Engineering 11 Symbols BS5950 Eurocode Elastic Modulus Z Wel Plastic Modulus S Wpl Radius of Gyration Torsion constant r i J H It Iw Warping constant 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering 12 Changes in Values Young’ Young’s Modulus n n Changes in load factors BS - 205000 N/mm² N/mm² EC - 210000 N/mm² N/mm² n Shear modulus n n n BS – 79000 N/mm² N/mm² EC - 81000N/mm² 81000N/mm² Many extra load combinations in EC n n 21/03/2003 Manchester Centre for Civil BS 1.4Gk + 1.6 Qk EC 1.35Gk + 1.5 Qk Main variable action Secondary variable action & Construction Engineering 13 Axes redefined in Eurocodes Major axis is y-y Vertical axis is z-z X direction is along the member This is consistent with most FE and Frame analysis software EC3 Definitions 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering 14 BS Section classification ε = (275/py)0.5 21/03/2003 Manchester Centre for Civil & Construction Engineering 15 prEN1993 Classification Different outstand Different ε ε = (235/fy)0.5 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Construction Engineering 16 Multiple documents The DD ENV 1993:11993:1-1 contained all the information in one 300 page document It also contained the National Application Document prEN1993prEN1993-1-1 Contains member and frame design but omits fasteners prEN1993 must be read in conjunction with the UK National Annex 21/03/2003 Manchester Centre for Civil & Construction Engineering 17 Element Design Beams n n n Moment capacity/resistance Shear Deflections Compression members z Lateral Torsional Buckling u x y 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil & Constructionφ Engineering 18 Moment Resistance BS5950 EC3 Class and n M = p S c y Class and n M c,Rd = fy W pl /γM1 n γ M1 = 1.05 in UK Class n M c,Rd = fy W el,min /γM1 Class semi-compact n M = p Z or c y Mc = pySeff Class slender n M = p Z c y eff Low shear n F < 60 % P v v 21/03/2003 Manchester Centre for Civil Class n M c,Rd = fy W eff,min /γM1 Low shear n V Ed < 50% VplRd & Construction Engineering 19 Shear Resistance BS5950 Pv = 0.6 py Av Shear area n Av = tD EC3 Vpl,Rd = Av (fy/ √3)/γ 3)/γM1 Shear area n n Shear buckling if n d/t > 70ε 70ε 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil Av = A – 2btf +(tw+2r)tf Approx = 1.04tD Shear buckling if n hw/tw > 72ε 72ε & Construction Engineering 20 10 Deflections BS5950 Serviceability LS n n n EC3 ? EN1990 Serviceability LS Imposed load only Span/360 - brittle Span/200 - generally n n n n n n 21/03/2003 Manchester Centre for Civil Permanent action, δ1 Variable action, δ2 PrePre-camber, δ0 δmax < L/ 250 δ2 < L / 350 brittle δ2 < L / 300 generally & Construction Engineering 21 Deflections BS5950 Serviceability LS n n n EC3 ? EN1990 Serviceability LS Imposed load only Span/360 - brittle Span/200 - generally n n n n n δmax = δ1 + δ2 - δ0 δ1 δ2 21/03/2003 © 2003 Tim McCarthy Manchester Centre for Civil n Permanent action, δ1 Variable action, δ2 PrePre-camber, δ0 δmax < L/ 250 δ2 < L / 350 brittle δ2 < L / 300 generally δ0 δmax & Construction Engineering 22 11 Compression Members Nb,Rd=χ A fy/γM1 χ is a reduction factor χ depends on Pc = Ag pc from Tables 23 and 24 pc is a function of λ BS5950 requires a large number of tables 21/03/2003 n n Manchester Centre for Civil nonnon-dimensional slenderness PerryPerry-Robertson approach ? & Construction Engineering 23 Compression members N b , Rd = χβ a A f y γ M ? = [ f + f [ −? ] 0.5 ( ? ≤1 but ) f = 0,5 + a ? − 0,2 + ? [ λ = βa A f y Ncr 21/03/2003 © 2003 Tim McCarthy ] 0.5 ] = λ λ1 , λ1 = π E f y Manchester Centre for Civil & Construction Engineering 24 12 Compression members N b, Rd = χβ a A f y γ M 21/03/2003 Manchester Centre for Civil & Construction Engineering 25 Example UC 203x203x60 of grade S275 is axially loaded and pinned at each end of its 6m length A = 76.4 cm² cm², flange thickness, tf = 14.2mm, radius of gyration about minor axis, izz = 5.2 cm, depth, h = 209.6mm, width b = 205.8 h/b= h/b= 1.01 => H section Table 3.1: 3.1: tf = 14.2mm < 40mm therefore fy=275N/mm fy=275N/mm²² for S275 grade E = 210000 N/mm² N/mm² Slenderness - λzz= zz= 600/5.2 = 115