Design and drawing of RC Structures CV 61

Design and drawing of RC Structures CV 61 Dr. G. S. Suresh Civil Engineering Department The National Institute of Engineering Mysore-570 008 Mob: 9342188467 Email: gss_nie@yahoo. com 1

Learning out Come • • • Review of Lay out Drawing Problems on Lay out drawing of column and footing Problems on Lay out drawing of beams and slabs 2

Structural Lay-Out Drawing • • • Positioning and orientation of columns Positioning of beams Spanning of slabs Layout of stairs Selecting proper type of footing 3 Dr. G. S. Suresh

Structural Lay-Out Drawing • • Two axes marked one side with alphabets and the other with numbers. Columns are marked at the intersection of grids Beams are marked using two parallel lines Slabs are indicated either as one way or two way 4 Dr. G. S. Suresh

Structural Lay-Out Drawing: Column & Footing A B C D 1 2 3 4 5 Dr. G. S. Suresh

Structural Lay-Out Drawing A B C D 1 2 3 4 6 Dr. G. S. Suresh

Problem-1 Data For Column-Footing Lay out A clear dimension of factory floor is 11. 75 m x 19. 75 m Spacing of columns 4 m c/c Size of columns 250 mm x 450 mm Span of steel truss is 12. 25 m c/c At the ends to support the gable wall additional two RCC columns of size 250 mm x 450 mm are to be provided at 4 m c/c measured from end columns All the walls all-round are 250 mm thick Height of columns = 3 m Size of footing 1. 4 m x 1. 8 m Thickness of footing 300 mm uniform Depth of foundation 1. 2 m below ground level 7

Problem-1 Preliminary Calculations • External dimensions of the building: • Along X-direction = 11. 75 + 2 x 0. 25 = 12. 25 m • Along Z-direction = 19. 75 + 2 x 0. 25 = 20. 25 m • Centre line dimensions of the building: • Along X-direction = 12. 25 – 0. 45 = 11. 80 m • Along Z-direction = 20. 25 -0. 25 = 20. 00 m 8

Problem-1 Procedure • Draw the centerline of the building having 11, 800 mm along X-direction and 20, 000 mm along Z-directions • Mark these centre lines as grid lines A and D for lines parallel to Z-directions & grid lines 1 and 6 for lines parallel to X-axis • Measure 4000 mm from grid lines A and D to get grid line B and C • Measure 4000 mm c/c along Z-axis starting from grid line 1 to get grid lines 2, 3, 4 and 5 • Draw rectangular filled box of size 250 mm x 400 mm at the intersection of gird lines along A and D to indicate the position of column along these grid lines as shown in Fig. 9

Problem-1 Procedure Contd. • Draw rectangular filled box of size 250 mm x 400 mm at the intersection of grid lines 1, 6 with B and C respectively as shown in Fig. • Draw rectangles each of size 1400 mm x 1800 mm symmetrically with respect to centre of column to indicate excavation marking for all columns. Here the shorter side of this rectangle box is parallel to the shorter side of column as shown in Fig. 1. 8 • Sectional elevation and plan of the footing of column is drawn just to the right of the key plan drawn as shown in Fig. 10

Problem-1 Drawing: Key Plan 11

Problem-1 Drawing: Footing Details 12

Problem-2 Data For Beam-Slab Lay out Prepare a general layout showing the positions and sizes of Beams and Slabs to a suitable scale for a Community Hall: Clear dimension of hall is 12. 05 m x 19. 8 m Three rows of columns are to be provided along the width with spacing of 6 m c/c Six rows of columns are to be provided along the length with spacing of 4 m c/c All the walls all-round are 200 mm thick Size of columns 200 mm x 450 mm Main beams are of size 200 mm x 600 mm Secondary beams are of size 200 mm x 300 mm Thickness of slab = 150 mm 13

Problem-1 Preliminary Calculations • External dimensions of the building: • Along X-direction = 12. 05 + 2 x 0. 2 = 12. 45 m • Along Z-direction = 19. 8 + 2 x 0. 2 = 20. 2 m • Centre line dimensions of the building: • Along X-direction = 12. 45 - 0. 45 = 12 m • Along Z-direction = 20. 2 -0. 2 = 20. 00 m 14

Problem-1 Procedure • Draw the centerline of the building having 12, 000 mm along X-direction and 20, 000 mm along Z-directions • Mark these centre lines as grid lines A and C for lines parallel to Z-directions & grid lines 1 and 6 for lines parallel to X-axis • Measure 6000 mm from grid lines A to get grid line B • Measure 4000 mm c/c along Z-axis starting from grid line 1 to get grid lines 2, 3, 4 and 5 • Draw rectangular filled box of size 200 mm x 450 mm at the intersection of gird lines along A and C to indicate the position of column along these grid lines as shown in Fig. 15

Problem-1 Procedure Contd. • Draw parallel lines spaced at 200 mm symmetrically about the grid lines 1 to 6 to indicate main beams having effective span of 6 m as shown in Fig. 1. 9 • Draw parallel lines spaced 200 mm abutting to end columns to indicate secondary beams as shown in Fig. 1. 9. Also draw 200 mm wide secondary beam along grid line B as shown in Fig. 1. 9 • Mark all the main beams as B 1 and Secondary beams as B 2 • Indicate the slab as one way slab as shown in Fig. 1. 9 and mark the slabs as S 1. 16

Problem-1 Drawing: Key Plan 17

Problem-1 Drawing: CROSS-SECTION 18

Problem-1 Do it Yourself 1. Prepare a general layout drawing including the details of columns and foundation for a shopping complex with four shops in the ground floor with the following details: Column size : 230 x 450 mm Spacing : 3. 5 m c/c Span of the beam supported by columns = 6 m c/c Depth of foundation : 1. 2 m below GL Depth of Footing : 450 mm 19

Problem-1 Do it Yourself 2. Prepare a general lay out drawing for the ground floor of a community centre in a land measuring 35 m x 50 m for the following particulars: Plinth area to be limited to 450 m 2 (15 m x 30 m) Height of each column : 3. 5 m Size of columns : 300 mm x 450 mm Effective span of each continuous beam 5 m of size 300 mm x 500 mm Secondary beams to be provided for a span of 4 m and of size 300 mm x 400 mm Plinth beam 300 mm x 400 mm all-round 0. 6 m above ground level Footing of size 1. 2 m x 2. 8 m for each column has its uniform thickness= 600 mm 20

Problem-1 Do it Yourself 3. Prepare a key plan at foundation level of a community hall building. Building has an auditorium of clear dimensions 12 m x 19. 7 m. Corridor of 4 m wide on either side (Parallel to longer side) of auditorium have to be provided. The roofing for auditorium is AC sheets supported on steel trusses. The end gable walls are supported on wall foundations. Roofing for corridor is RCC slab at 3 m above floor level. Other details are: Clear span of roof truss = 12 m Size of all RCC columns = 300 mm x 600 mm BBM columns of size 300 mm x 300 mm at 4 m c/c is to be provided in corridors to support slab Assume suitable foundation for RCC columns and BBM columns 21

Summary • • Introduction to structural Drawing General Lay out Drawings Procedure for drawing column and foundation Lay-Out Drawings Procedure for drawing beam Lay-out Drawings Case Study on Lay out drawings Problems on Lay out of Column & Footing Problems on Lay out of Beams and Slabs 22 Dr. G. S. Suresh

Dr. G. S. Suresh Civil Engineering Department The National Institute of Engineering Mysore-570 008 Mob: 9342188467 Email: gss_nie@yahoo. com 23