Wood Column Design: Length, Stresses, Bracing, and Analysis in Architectural Structures - , Study notes of Architecture

Download Wood Column Design: Length, Stresses, Bracing, and Analysis in Architectural Structures - and more Study notes Architecture in PDF only on Docsity! 1 Wood Columns 1 Lecture 14 Elements of Architectural Structures ARCH 614 S2009abn ELEMENTS OF ARCHITECTURAL STRUCTURES: FORM, BEHAVIOR, AND DESIGN ARCH 614 DR. ANNE NICHOLS SPRING 2009 lecture fourteen wood construction: column design Wood Columns 2 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Compression Members (revisited) • designed for strength & stresses • designed for serviceability & deflection • need to design for stability – ability to support a specified load without sudden or unacceptable deformations Wood Columns 3 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Effect of Length (revisited) • long & slender • short & stubby Wood Columns 4 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Critical Stresses (revisited) • when a column gets stubby, crushing will limit the load • real world has loads with eccentricity 2 Wood Columns 5 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Bracing (revisited) • bracing affects shape of buckle in one direction • both should be checked! Wood Columns 6 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Wood Columns • slenderness ratio = L/dmin = L/d1 – d1 = smaller dimension – le/d ≤ 50 (max) – where is the allowable compressive strength parallel to the grain – bracing common cc FA Pf ′≤= cF ′ Wood Columns 7 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Allowable Wood Stress • where: Fc = compressive strength parallel to grain CD = load duration factor CM = wet service factor (1.0 dry) Ct = temperature factor CF = size factor Cp = column stability factor ( )( )( )( )( )pFtMDcc CCCCCFF =′ (Table 5.2) ( )* c cE F Ff= Wood Columns 8 Lecture 14 Elements of Architectural Structures ARCH 614 S2007abn Strength Factors • wood properties and load duration, CD – short duration • higher loads – normal duration • > 10 years • stability, Cp – combination curve - tables ( ) pDcpcc CCFCFF ==′ *