Reinforced concrete design

THUYLOI UNIVERSITY Civil Engineering faculty Structural Engineering Division REINFORCED CONCRETE DESIGN I (CVEG4118) - C DESIGN OF REINFORCED CONCRETE STRUCTURES (CIVE4228) - N Instructor/coordinator of AP-CE: Dr Vũ Thị Thu Thủy Tel: 0963934519, email: thuy.kcct@wru.vn Fall 2019 TRƯỜNG ĐẠI HỌC THỦY LỢI KHOA CƠNG TRÌNH BỘ MƠN KẾT CẤU CƠNG TRÌNH THIẾT KẾ BÊ TƠNG CỐT THÉP I (CVEG4118) - C KẾT CẤU BÊ TÔNG CỐT THÉP (CIVE4228) - N Giảng viên/Điều phối viên CTTT-C: TS Vu Thi Thu Thuy Tel: 0963934519, email: thuy.kcct@wru.vn 9- 2019 Reinforced Concrete Design I Chapter Textbook • Text book: Reinforced Concrete- A fundamental approach: Edward G Nawy, 5th Edition 2003, Prentice Hall (#000016607) • Building Code Requirements for Structral Concrete (ACI 318 - 2002) & Commentary, ACI • Kết cấu Bê tơng cốt thép theo quy phạm Hoa Kỳ, TS Nguyễn Trung Hòa, Nhà xuất xây dựng, 2010 • TCVN 5574:2012 Kết cấu bê tông bê tông cốt thép – tiêu chuẩn thiết kế CIVE 4127 Design of Reinforced Concrete Structures, Spring 2014 (#000016607) Dr Vũ Thị Thu Thủy 1.1 Reinforced Concrete Design I Chapter Major topics • • • • • Introduction Reinforced Concrete Flexural in Beams Shear and Diagonal Tension in Beams Serviceability of beams and one-way slabs • Combined Compression and Bending • 11 Design of two-way slabs and plates Dr Vũ Thị Thu Thủy 1.2 Reinforced Concrete Design I Chapter Chapter Introduction Reinforced Concrete Structures - Civil engineering - Transportation engineering - Hydraulic engineering Dr Vũ Thị Thu Thủy 1.3 Reinforced Concrete Design I Chapter Petronat Twin tower, 452m, 88 Burj Dubai 828m 163 stories Vũ Thị Thu Thủy _ 4/ 2004 - 5/1/2010 stories , Kuala Lumpur, Malaysia Landmark 81 – HCM Kaengnam – Hanoi 336m 461.2m Dr Vũ Thị Thu Thủy 1.4 Reinforced Concrete Design I Chapter Tower Bridge - UK Dragon Bridge – Da Nang Vietnam Dr Vũ Thị Thu Thủy 1.5 Reinforced Concrete Design I Chapter Kết cấu BTCT giao thông Vũ Thị Thu Thủy _ Bộ môn KCCT Highway 11 Three Gorges Dam - China World largest dam- 39,3Mm3 Dr Vũ Thị Thu Thủy 1.6 Reinforced Concrete Design I Chapter Hoa Binh hydropower dam - Vietnam 128m Height, 1km length aqueduct Vũ Thị Thu Thủy _ Bộ môn KCCT Dr Vũ Thị Thu Thủy 14 1.7 Reinforced Concrete Design I Chapter Navigation lock Pumping station 16 Vũ Thị Thu Thủy _ Bộ môn KCCT Dr Vũ Thị Thu Thủy 1.8 Reinforced Concrete Design I Chapter Concrete Construction Site cast concrete poured, molded and cured on site - Dr Vũ Thị Thu Thủy 1.9 Chapter 11 Reinforced concrete design I Reinforced Concrete Design I CVEG 4118 & CIVE4228 CHAPTER 11 : DESIGN OF TWOWAY SLABS & PLATES Dr Vu Thi Thu Thuy Thuyloi University Dr Vu Thi Thu Thuy Topics covered in this course  Introduction (Chapter 1)  Reinforced Concrete (Chapter 4)  Flexure in Beams (Chapter 5)  Shear in Beams (Chapter 6)  Serviceability of Beams & One-way Slabs (8)  Combined Compression and Bending (9)  Design of Two-way Slabs and Plates (11) Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 11.1 Chapter 11 Reinforced concrete design I One-way slab (Chapter 5) long span l2  2 short span l1 l2 l1 One-way slab (Chapter 5) Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 11.2 Chapter 11 Reinforced concrete design I Two-way slab - Flat-plate long span l2  2 short span l1 Slabs supported directly on columns without beams Dr Vu Thi Thu Thuy Two-way slab - on beams l2 Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy l1 11.3 Chapter 11 Reinforced concrete design I Two-way slab - waffle Dr Vu Thi Thu Thuy Analysis & Design Methods  ACI Code: Direct design method (DDM-11.3) & Equivalent Frame Methods (EFM -11.6)  Yield line Theory  Limit Theory  Strip Method Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 11.4 Chapter 11 Reinforced concrete design I Behavior of two-way slabs - curvatures & moments at central area C more severe in shorter direction y with steeper contour than in longer direction x - Deflection of simply suported beam curvature & deflection contours in floor  5WL4  kWL4 384 EI strip AB =kWABL4 strip ED =kW EDS4 WAB  W=WAB+WED WS WL4 W  < ED 4 L4  S L S central strips in a two-way slab panel direct design method (DDM) - Determine M, V using simplified coefficient - EFM treat idealized frame as actual frame, gives more exact solution than Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 10 11.5 Chapter 11 Reinforced concrete design I Limitation of DDM (11.3.1) A minimum of continuous spans are necessary in each direction Ratio long span/ short span 2 Successive span lengths in each direction should not differ by more than 1/3 long span Columns may be offset a maximum of 10% of span in direction of offset from either axis between center lines of successive columns All load shall be due to gravity only & uniformly distributed over entire panel Live load  times dead load If panel is supported by beams on all sides, relative stiffness of beams in two perpendicular directions shall not Dr Vu Thi Thu Thuy 11 Basic major steps in design of floor panels Determine total factored statical moment in each of two perpendicular directions Distribute total factored design moment to the design of sections for negative & positive moment Distribute negative & positive design moments to the column, middle strips & panel beams - Column strip width =25% equivalent frame width on each side of column center line Proportion of size & distribution of reinforcement in two perpendicular directions Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 12 11.6 Chapter 11 Reinforced concrete design I The direct design method - Ln  0.65L Dr Vu Thi Thu Thuy 13 Total factored statical moment - Mo • x direction M o Wu L2  L n1  • M o Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy y direction Wu L1  Ln  14 11.7 Chapter 11 Reinforced concrete design I Distributed moments & reinforcement Negative & positive factored design moments of Flat- plate Dr Vu Thi Thu Thuy 15 Distributed moments & reinforcement a) a) b) b) c) c) d) e) d) Negative & positive factored design moments Dr Vu Thi Thu Thuy Dr Vu Thi Thu Thuy 16 11.8 Chapter 11 Reinforced concrete design I Distributed moments & reinforcement Dr Vu Thi Thu Thuy 17 Distribute design moments to column strips & middle strips Column strip (exterior panel) -Mu x factor Column strip Midspan +Mu x factor Column strip (interior panel) -Mu x factor • Middle strips: the rest of -Mu, +Mu not resisted by column strip18 Dr Vu Thi Thu Thuy 11.9 Chapter 11 Reinforced concrete design I Parttern Loading effect - Applicable limit of DDM is W L2WD no need to check for pattern load effect - Slab & column dimensions should meet the value for min in Table 11.2 Dr Vu Thi Thu Thuy 19 Shear -moment transfer to column supporting flat plates   d    Vc     fc' bo d ;  s   f c' bo d ; f c' bo d   b c   o    - Shear strength c=long side/ short side of column Vc usually