Structural Masonry Designers' Manual

Chapter 1 Introduction; 1.1 Present structural forms; 1.2 Examples of structural layout suiting masonry; 1.3 Reinforced and post-tensioned masonry; 1.4 Arches and vaults; 1.5 The robustness of masonry structures; 1.6 Prefabrication; 1.7 Future tradesmen; 1.8 Engineering education; Chapter 2 Advantages & disadvantages of structural masonry; 2.1 Engineering education; 2.1.1 Cost; 2.1.2 Speed of erection; 2.1.3 Aesthetics; 2.1.4 Durability; 2.1.5 Sound insulation; 2.1.6 Thermal insulation; 2.1.7 Fire resistance and accidental damage; 2.1.8 Capital and current energy requirements; 2.1.9 Resistance to movement; 2.1.10 Repair and maintenance; 2.1.11 Ease of combination with other materials; 2.1.12 Availability of materials and labour; 2.1.13 Recyclability; 2.2 Disadvantages; 2.2.1 Lack of education in masonry; 2.2.2 Increase in obstructed area over steel and reinforced concrete; 2.2.3 Problems with some isolated details; 2.2.4 Foundations; 2.2.5 Large openings; 2.2.6 Beams and slabs; 2.2.7 Control joints; 2.2.8 Health & safety considerations; Chapter 3 Design philosophy; 3.1 Strength of material; 3.2 Exploitation of cross-section; 3.3 Exploitation of essential building elements; Chapter 4 Limit state design; Chapter 5 Basis of design (1): vertical loading; 5.1 Compressive strength of masonry; 5.2 Characteristic strength and characteristic load; 5.3 Partial safety factors for loads; 5.4 Characteristic compressive strength of masonry; 5.4.1 Brickwork; 5.4.2 Blockwork; 5.4.3 Natural stone masonry and random rubble masonry; 5.4.4 Alternative construction techniques; 5.5 Partial safety factors for material strength; 5.5.1 Manufacturing control (BS 5628, clause 27.2.1); 5.5.2 Construction control; 5.6 Slenderness ratio; 5.7 Horizontal and vertical lateral supports; 5.7.1 Methods of compliance: Walls - horizontal lateral supports; 5.7.2 Methods of compliance: Walls - vertical lateral supports; 5.8 Effective height or length: Walls; 5.9 Effective thickness of walls; 5.9.1 Solid walls; 5.9.2 Cavity walls; 5.10 Loadbearing capacity reduction factor; 5.11 Design compressive strength of a wall; 5.12 Columns; 5.12.1 Slenderness ratio: Columns; 5.12.2 Columns formed by openings; 5.12.3 Design strength; 5.12.4 Columns or walls or small plan area; 5.13 Eccentric loading; 5.14 Combined effect of slenderness and eccentricity of load; 5.14.1 Walls; 5.14.2 Columns; 5.15 Concentrated loads; Chapter 6 Basis of design (2): lateral loading - tensile and shear strength; 6.1 Direct tensile stress; 6.2 Characteristic flexural strength (tensile) of masonry; 6.2.1 Orthogonal ration; 6.3 Moments of resistance: General; 6.3.1 Moments of resistance; uncracked sections; 6.3.2 Moments of resistance; Cracked sections; 6.4 Cavity Walls; 6.4.1 Vertical twist ties; 6.4.2 Double-triangle and wire butterfly ties; 6.4.3 Selection of ties; 6.4.4 Double-lead (collar-jointed) walls; 6.4.5 Grouted cavity walls; 6.4.6 Differing orthogonal ratios; 6.5 Effective eccentricity method of design; 6.6 Arch method of design; 6.6.1 Vertical arching; 6.6.2 Vertical arching: return walls; 6.6.3 Horizontal arching; 6.7 Free-standing walls; 6.7.1 General; 6.7.2 Design bending moments; 6.7.3 Design moment of resistance; 6.8 Retaining walls; 6.9 Panel walls; 6.9.1 Limiting dimensions; 6.9.2 Design methods; 6.9.3 Design bending moment; 6.9.4 Design moments of resistance; 6.9.5 Design of ties; 6.10 Propped cantilever wall design; 6.10.1 Geometric and other sections in shear; 6.11 Eccentricity of loading in plane of wall; 6.11.1 Design of walls loaded eccentrically in the plane of the wall; 6.12 Walls subjected to shear forces; 6.12.1 Characteristic and design shear strength; 6.12.2 Resistance to shear; Chapter 7 Strapping, propping and tying of loadbearing masonry; 7.1 Structural action; 7.2 Horizontal movement; 7.3 Shear keying between wall and floors; 7.4 Holding down roofs subject to upward forces; 7.5 Areas of concern; 7.6 Other factors influencing the details of connections; 7.7 Illustrated examples of strapping and tying; 7.8 Design examples: Straps and ties for a three-storey masonry building; Chapter 8 Stability, accidental damage and progressive collapse ;8.1 Progressive collapse; 8.2 Stability; 8.3 Accidental forces (BS 5628, clause 20); 8.4 During construction; 8.5 Extent of damage; 8.6 Design for accidental damage; 8.6.1 Partial safety factors; 8.6.2 Methods (options) of checking; 8.6.3 Loadbearing elements; 8.6.4 Protected member; 8.6.5 General notes; Chapter 9 Structural elements and forms; 9.1 Single-leaf walls; 9.2 Double-leaf collar-jointed walls; 9.3 Double-leaf cavity walls; 9.4 Double-leaf grouted cavity walls; 9.5 Faced walls; 9.6 Veneered walls; 9.7 Walls with improved section modulus; 9.7.1 Chevron or zig-zag walls; 9.7.2 Diaphragm walls; 9.7.3 Mass filled diaphragms; 9.7.4 Piered walls; 9.7.5 Fin walls; 9.8 Reinforced walls; 9.9 Post-tensioned walls; 9.10 Columns; 9.11 Arches; 9.12 Circular and elliptical tube construction; 9.13 Composite construction; 9.14 Horizontally reinforced masonry; 9.15 Chimneys; 9.16 Crosswall construction; 9.17 Cellular construction; 9.18 Column and plate floor construction; 9.19 Combined forms of construction; 9.20 Diaphragm wall and plate roof construction; 9.21 Fin wall and plate roof construction; 9.22 Miscellaneous wall and plate roof construction; 9.23 Spine wall construction; 9.24 Arch and buttressed construction; 9.25 Compression tube construction; Chapter 10 Design of masonry elements (1): Vertically loaded; 10.1 Principle of design; 10.2 Estimation of element size required; 10.3 Sequence of design; 10.4 Design of solid walls; 10.5 Design of cavity walls; 10.5.1 Ungrouted cavity walls; 10.5.2 Grouted cavity walls; 10.5.3 Double-leaf (or collar-jointed) walls; 10.6 Design of walls with stiffening piers; 10.7 Masonry columns; 10.8 Diaphragm walls; 10.9 Concentrated loads; Chapter 11 Design of masonry elements (2): Combined bending and axial loading; 11.1 Method of design; Chapter 12 Design of single-storey buildings; 12.1 Design considerations; 12.2 Design procedure; Chapter 13 Fin and diaphragm walls in tall single-storey buildings; 13.1 Comparison of fin and diaphragm walls; 13.2 Design and construction details; 13.3 Architectural design and detailing; 13.3.1 Services; 13.3.2 Sound and thermal insulation; 13.3.3 Damp proof courses and membranes; 13.3.4 Cavity cleaning; 13.4 Structural detailing; 13.4.1 Foundations; 13.4.2 Joints; 13.4.3 Wall opening; 13.4.4 Construction of capping beam; 13.4.5 Temporary propping and scaffolding; 13.5 Structural design: General; 13.5.1 Design principles: Propped cantilever; 13.5.2 Calculate design loadings; 13.5.3 Consider levels of critical stresses; 13.5.4 Design bending moments; 13.5.5 Stability moment of resistance; 13.5.6 Shear lag; 13.5.7 Principal tensile stress; 13.6 Design symbols: Fin and diaphragm walls; 13.7 Fin walls: Structural design considerations; 13.7.1 Interaction between leaves; 13.7.2 Spacing of fins; 13.7.3 Size of fins; 13.7.4 Effective section and trial section; 13.8 Example 1: fin wall; 13.8.1 Design problem; 13.8.2 Design approach; 13.8.3 Characteristic loads; 13.8.4 Design loads; 13.8.5 Design cases (as shown in figure 13.42); 13.8.6 Deflection of roof wind girder; 13.8.7 Effective flange width for T profile; 13.8.8 Spacing of fins; 13.8.9 Trial section; 13.8.10 Consider propped cantilever action; 13.8.11 Stability moment of resistance; 13.8.12 Allowable flexural compressive stresses; 13.8.13 Calculate MRs and compare with Mb; 13.8.14 Bending moment diagrams; 13.8.15 Consider stresses at level Mw; 13.8.16 Design flexural stress at Mw levels; 13.8.17 Consider fins and deflected roof prop; 13.9 Diaphragm wall: Structural design considerations; 13.9.1 Determination of rib centres, Br; 13.9.2 Depth of diaphragm wall and properties of sections; 13.9.3 Shear stress coefficient, K1; 13.9.4 Trial section coefficients, K2 and Z; 13.10 Example 2: Diaphragm wall; 13.10.1 Design problem; 13.10.2 Characteristic and design loads; 13.10.3 Select trial section; 13.10.4 Determine wind and moment MRs at base; 13.10.5 Consider the stress at level Mw; 13.10.6 Consider diaphragm with deflected roof prop; 13.10.7 Calculate the shear stress; 13.10.8 Stability of transverse shear walls; 13.10.9 Summary; 13.11 Other applications; Chapter 14 Design of multi-storey structures; 14.1 Structural forms; 14.1.1 Stability; 14.1.2 External walls; 14.1.3 Provision for services; 14.1.4 Movement joints; 14.1.5 Vertical alignment of loadbearing walls; 14.1.6 Foundations; 14.1.7 Flexibility; 14.1.8 Concrete roof slab/loadbearing wall connections; 14.1.9 Accidental damage; 14.1.10 Choice of brick, block and mortar strengths; 14.2 Crosswall construction; 14.2.1 Stability; 14.2.2 External cladding panel walls; 14.2.3 Design for wind; 14.2.4 Openings in walls; 14.2.5 Typical applications; 14.2.6 Elevational treatment of crosswall structures; 14.2.7 Podiums; 14.3 Spine construction; 14.3.1 Lateral stability; 14.3.2 Accidental damage; 14.4 Cellular construction; 14.4.1 Comparison with crosswall construction; 14.4.2 Envelope (cladding) area; 14.4.3 Robustness; 14.4.4 Flexibility; 14.4.5 Height of structure; 14.4.6 Masonry stresses; 14.4.7 Foundations; 14.5 Column structures; 14.5.1 Advantages; 14.5.2 Cross-sectional shape; 14.5.3 Size; 14.6 Design procedure; 14.7 Example 1: Hotel bedrooms, six floors; 14.7.1 Characteristic loads; 14.7.2 Design of internal crosswalls; 14.7.3 Partial safety factor for material strength (table 4, BS 5628 - see table 5.11); 14.7.4 Choice of brick in the two design cases, at ground floor level; 14.7.5 Choice of brick in the two design cases, at third flood level; 14.7.6 Design of gable cavity walls to resist lateral loads due to wind; 14.7.7 Uplift on roof; 14.7.8 Design of wall; 14.7.9 Calculation of design wall moment; 14.7.10 Resistance moment of wall (figure 14.46); 14.7.11 Overall stability check; 14.7.12 Eccentricity of loading; 14.7.13 Accidental damage; 14.8 Example 2: four-storey school building; 14.8.1 Characteristic loads; 14.8.2 Design of wall at ground floor level; 14.9 Example 3: four-storey office block; 14.9.1 Column structure for four-storey office block; 14.9.2 Characteristic loads; 14.9.3 Design of brick columns; 14.9.4 Loading on column P; Chapter 15 Reinforced and post tensioned masonry; 15.1 General; 15.1.1 Design theory; 15.1.2 Comparison with concrete; 15.1.3 Applications; 15.1.4 Prestressing; 15.1.5 Methods of reinforcing walls; 15.1.6 Composite construction; 15.1.7 Economics; 15.1.8 Corrosion of reinforcement and prestressing steel; 15.1.9 Cover to reinforcement and prestressing steel; 15.1.10 Cover; 15.2 Choice of system; 15.3 Design of reinforced brickwork; 15.3.1 Partial factors of safety; 15.3.2 Strength of materials; 15.3.3 Design for bending: reinforced masonry; 15.3.4 Lateral stability of beams; 15.3.5 Design formula for bending: moments of resistance for reinforced masonry; 15.3.5.1 Walls with reinforcement concentrated locally, such as pocket type and similar walls; 15.3.5.2 Locally reinforced hollow blockwork; 15.3.6 Design formula: shear stress; 15.3.7 Shear reinforcement; 15.3.8 Design formula: local bond; 15.3.9 Characteristic anchorage bond strength fb; 15.3.10 Design for axial loading; 15.4 Example 1: Design of reinforced brick beam; 15.5 Example 2: Alternative design for reinforced brick beam; 15.6 Example 3: Reinforced brick retaining wall; 15.7 Example 4: Column design; 15.8 Design for post-tensioned brickwork; 15.8.1 General; 15.8.2 Post-tensioned masonry: design for flexure; 15.8.3 Design strengths; 15.8.4 Steel stresses; 15.8.5 Asymmetrical sections; 15.8.6 Losses of post-tensioning force; 15.8.7 Bearing stresses; 15.8.8 Deflection; 15.8.9 Partial safety factor on post-tensioning force; 15.9 Example 5: High cavity wall with wind loading; 15.9.1 Capacity reduction factor, b; 15.9.2 Characteristic strengths; 15.9.3 Design strengths (after losses); 15.9.4 Section modulus of wall; 15.9.5 Design method; 15.9.6 Calculation of required post-tensioning force; 15.9.7 Consider compressive stresses: after losses; 15.9.8 Consider compressive stresses: before losses; 15.9.9 Design of post-tensioning rods; 15.10 Example 6: Post-tensioned fin wall; 15.10.1 Design procedure; 15.10.2 Design post-tensioning force and eccentricity; 15.10.3 Characteristic strengths; 15.10.4 Loadings; 15.10.5 Design bending moments; 15.10.6 Theoretical flexural tensile stresses; 15.10.7 Calculations of P and e; 15.10.8 Spread of post-tensioning force; 15.10.9 Characteristic post-tensioning force Pk; 15.10.10 Capacity reduction factors, â; 15.10.11 Check combined compressive stresses; 15.10.12 Design flexural compressive strengths of wall: after losses; 15.10.13 Check overall stability of wall; 15.11 Example 7: Post-tensioned, brick diaphragm, retaining wall; 15.11.1 Design procedure; 15.11.2 Design loads; 15.11.3 Trial section; 15.11.4 Calculate theoretical flexural tensile stresses; 15.11.5 Minimum required post-tensioning force based on bending stresses; 15.11.6 Characteristic post-tensioning force Pk; 15.11.7 Capacity reduction factors; 15.11.8 Check combined compressive stresses; 15.11.9 Check shear between leaf and cross-rib; 15.11.10 Design of post-tensioning rods; Chapter 16 Arches; 16.1 General design; 16.1.1 Linear arch; 16.1.2 Trial sections; 16.1.3 Mathematical analysis; 16.2 Design procedures; 16.3 Design examples; 16.3.1 Example 1: Footbridge arch; 16.3.2 Example 2: Segmental arch carrying traffic loading; 16.3.3 Example 3: Repeat example 2 using a pointed arch; Appendix 1 Materials; Appendix 2 Components; Appendix 3 Movement joints; Appendix 4 Provision for services