Structural Engineering Design Calculations

1 Structural Engineering Design Calculations Lusaka Residential Perimeter Walls F488a33J off Mutende Road Lusaka Zambia Brian C Chutu Prepared for: Bsc (Hons) Civil Engineering (UK), REng, MEIZ, Bricch Consultants Limited MConsEZ. Checked By: Subject Drg. Ref GENERAL LOADING. Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. 1. Design STATEMENT. Introduction It is required to provide detailed Structural Engineering Design for a perimeter wall on plot no. F488a33J off Mutende Road, Kabulonga, Lusaka Zambia property belonging to Embassy of The United States of America.

2 Design Proposal Client proposed a solid masonry wall reinforced with steel bars for additional strength. The wall height to be not less than high according to Client's standards. A free standing wall shall be considered and designed to resist wind pressure and gravity load from its self weight. a) Foundation The wall shall be founded on traditional reinforced concrete strip footing. The foundation shall be designed using soil investigation parameters provided in the Geotechnical Report. b) Wall The wall shall be constructed using 7N concrete Hollow Blocks filled with Grade 10. (10 Mpa) mass concrete . The wall strength shall be enhanced by inserting vertical reinforcing bars through block cells.

3 Horizontal reinforcing bars shall be provided in every mortar joint and tied to vertical bars. The horizontal bars shall thus act as distribution bars to vertical main bars. Design Codes The following Standard Codes of Practice shall be employed for the Design of Structural elements: a) Structural concrete - BS 8110: Structural use of concrete b) Structural Masonry - BS 5628: Code of practice for use of masonry Subject Drg. Ref Design DATA. Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. Design DATA. Characteristic Dead Load concrete Density = 24 kN/m . 200mm thick Solid concrete Blockwork = kN/m.

4 Characteristic Imposed Load Wind Load (to Client's Standard) = kN/m . Soil Properties (obtained from Geotechnical Investigation Report). Ground Allowable Bearing Capacity = 100 kN/m . Angle of Internal Friction ( ) = 35 . Soil Density (assumed) = 18 kN/m . Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. CASE 1: WIND PRESSURE OUTSIDE OF PROPERTY. CHECK WALL STABILITY. Sliding Consider wind pressure acting on 1m wall length , = x 3 = kN. , = kN. Consider gravity loads acting on 1m wall length , = x = kN. , = x x 24 = kN. 1, 1 = x x 18 = kN.

5 2, 2 = x x 18 = kN. , = kN. Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. , = . = x = kN. , = 0.. Therefore factor of safety against sliding =.. = = x > OK Wall is satisfactory against sliding Overturning Take moments about Point P1. of overturning moment, . = x = x = kNm of restoring moment, . x = x = x = x = kNm Factor of Safety against Overturning, = = > OK Wall is satisfactory against overturning Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C.

6 GROUND BEARING PRESSURE. Consider Moment about centreline of base M = x = x = x = x = kNm N = = M = = N D. <. 6. = = m 6. Therefore, maximum ground pressure occurs at toe, which is given by: = N 6M. +. D D . = + = kN/m . < Allowable Ground Bearing Pressure (200kN/m ) OK. Ground pressure at the heel: N 6M. = - D D . = - = kN/m . Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. REINFORCEMENT. Wall Stem Height = m Horrizontal pressure on stem due to wind: = x = kNm Design Moment at Wall Base: . M =. 2. x x = = kNm 2. Effective Depth Assume Bar = 12 mm Thus d = 200 - 100 - 6 = 94 mm = x 15 x 10.

7 X 94 x 10 = kNm > , . Steel Area . =.. x 10 . = = 7 x 10 x 94 . Z = 94 [ + ( - / )]. = 76 mm x 10 Y10@200mm c/c A = = 262 mm /m x 500 x (393mm ) is adequate Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. REINFORCEMENT Cont'd Provide nominal reinforcement for horizontal or distribution bars = x 10 x 200 = 260 mm /m Y10@200mm c/c (393mm ) is adequate Base Toe Soil Pressure: 1 = x = kN/m . 2 = x = kN/m . ( - ). 3 = +. = kN/m . Loading: 1 = x = kN/m . 2 = x = kN/m . Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No.

8 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. REINFORCEMENT Cont'd Design Moment @ Point P2. x x x x M = +. 2 4. x x x - - 2 2 x 3. = kN/m . Steel Area Y10@200mm c/c x 10 . A = = 420 mm /m (393mm ) bottom is x 500 x adequate Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. CASE 2: CONSIDER REVERSE WIND PRESSURE. CHECK WALL STABILITY. Sliding Consider wind pressure acting on 1m wall length , = x 3 = kN. , = kN. Consider gravity loads acting on 1m wall length Weight of Wall, = x = kN. Weight of Base, = x x 24 = kN.

9 Weight of Soil 1, 1 = x x 18 = kN. Weight of Soil 2, 2 = x x 18 = kN. , = kN. Subject Drg. Ref WALL Design . Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. Stability of wall against sliding similar to CASE 1, therefore check not required Overturning Take moments about Point P1. of overturning moment, . = x = x = kNm of restoring moment, . x = x = x = x = kNm Factor of Safety against Overturning, = = > OK Wall is satisfactory against overturning GROUND BEARING PRESSURE. Consider Moment about centreline of base M = x = x = x = x = kNm Subject Drg. Ref WALL Design .

10 Sheet No. calculation SHEET Project LUSAKA RESIDENTIAL PERIMETER WALLS Job No. 1720 Made by BCC Rev F488a33J OFF MUTENDE ROAD KABULONGA Date Checked by C. GROUND BEARING PRESSURE Cont'd N = = kN. M = = N D. >. 6. = = m 6. Therefore, maximum ground pressure occurs at toe, which is given by: = N 6M. +. D D . = 77. + = kN/m . < Allowable Ground Bearing Pressure (100kN/m ) OK. Ground pressure at the heel: N 6M. = - D D . 77. = - = kN/m . REINFORCEMENT. Moments in CASE 2 would be similar but in reverse of CASE 1, therefore provide nominal reinforcement Y10@200mm c/c in Top, main and distribution bars