An-Najah National University Faculty of Engineering Civil Engineering Department Design of Al-Ahd Building Prepared by: - Osama Raddad - MusabEleyan -Abd Al-haleemyahya -RamiAssaf - Ahmad Abu Mwais Supervisor : Wael Abu Asab
Outline: • Introduction • Loads • Preliminary Design • Static Design • Wind and Earthquake load • Slab and Beam • Footing
General Introduction • AL-Ahdbuilding is twenty four stories of reinforced concrete building located in Bethlehem city. • the average elevation of each story 3m, ground floor of 3.75 m height to be used for commercial goods and basement floor of 3 m height to be used for garage and storage.
General introduction, cont. • In this project we study the building from mainly structural, architectural points of view. • The structural design of the project will consist of 3 parts: • Static Design Analysis of the structural elements under gravity loads • Dynamic Design analysis of the structural elements under dynamic loads • Structural Modeling • the process at which the physical structure is represented by mathematical model
Project Description • Design codes • Materials • Structural system • Slab system • Loading • Computer programs • Loads combination
Design codes • “ACI -2011” (American Concrete Institute Code 2011) • “IBC -2009” (International Building Code 2009) • ASCE for design loads • Jordanian code
Materials • Concrete compressive strength, • Steel yield strength, fy = 420 MPa. • Modulus of elasticity • reinforced concrete with weight per unit volume = 25 kN/m3 that is equivalent to density = 2.5 ton/m3
Structural System Shear Wall • shear wall system this type is easy to construct, and the material that use in this system is available, but this type is a very difficult to open a window and door in the wall so it is not provides adequate ventilation and lighting.
Slab system The slab systems to be used is two way solid slab.
Design Loads • Vertical loads : Dead and Live loads • Lateral loads : Wind and Earthquake loads
Computer programs • In analysis and design: SAP2000 (v14.2.2) program
Loads combination • The load combinations are: according to ACI 318-11 9.2.1: Wu= 1.4D.L Wu= 1.2D.L+ 1.6L.L Service load = 1.0 D.L + 1.0 L.L
Loads • Dead load and superimposed dead load: Dead load: A constant load in a structure that is due to the weight of the members superimposed dead load: is defined as any applied load other than dead load like: Plastering, tiles, paint, …etc
Live Load • Live loads are the weights of people, furniture, supplies, machines, stores, … • In order to find the live loads there two ways: 1- Codes like IBC’s table 2- Experience
Wind Load • Building and other structures, including the main Wind - force Resisting System , shall be designed to resist wind load. • Uplift load • Shear load • Lateral Load
Earthquake Loads • Earthquake loads are dynamic loads, which acting on the whole structure, and may occur in any direction.
Structural system for shear resistance • 1.Rigid Structural Frame • Rigid frame structures provide more stability. This type of frame structures resists the shear, moment, and torsion more effectively than any other type of frame structures
Structural system for shear resistance, cont. • 2. Braced Structural Frames • It use to the resistance against the lateral forces and sideways forces due to applied load
Structural system for shear resistance, cont. • 3. Shear walls: shear walls can be used to provide stability of the building frame.
Preliminary Design • There are many structural systems that may be used this building structure • The following diagram shows slab systems classification based on load path and type of section:
Floor Structural system • The structural systems that was chosen for this building, A two way solid slab with dropped beams
Preliminary Design • Slab thicknesses For two way slab systems, we will specify the minimum slab thickness based on deflection criteria h min= 220 mm
Preliminary Design, cont. • Beams: The depth of internal beams = 60 cm The depth of external beams = 40 cm • Columns : The dimension of columns is to be assumed as 50 ×50 cm
4. Static Design • Final Dimensions
Verification of SAP model • 1-Compatibility:
2-Equilibrium: • - Sap result : • - manual Calculation
3. Stress- strain relationship: • This item include verification the values of moment on middle strip, column strip
After achieving compatibility, equilibrium and stress strain relationship, we are confident that the model works well and we can start static design.
5. Wind & Earthquake load • By calculating the Wind load and Earthquake load The following results was obtained
Calculation of wind load: • Equation that use in this calculation qz = 0.613*kz*kzt*kd*v2*I • where : kz will find by using table 6.3 in code ASCE kzt can be assume 1 kd with value of 0.85 I for tower equal 2
For Slab: Because the type of slab is two way in the project, more than one strip is taken in each direction as frame and the value of moment in each frame shown as follow: