Chapter 1 Types of Structures & Loads 1

Chapter 1

Types of Structures

& Loads

Chapter 1 Types of Structures & Loads 2

Introduction

• Structure refers to a system of connected

parts used to support load, such as

Buildings, Bridges, towers, …………….

• Engineers should account for structures

safety, esthetics and serviceability,

economic and environmental issues.

Chapter 1 Types of Structures & Loads 3

Structural Elements

Any structure comprises a

number of elements

• Tie Rods

Chapter 1 Types of Structures & Loads 4

Beams

• Type of Beams

Chapter 1 Types of Structures & Loads 5

Columns

• Columns

Chapter 1 Types of Structures & Loads 6

Type of Structure

• Trusses

Chapter 1 Types of Structures & Loads 7

Cables and Arches

Chapter 1 Types of Structures & Loads 8

Cables and Arches

Chapter 1 Types of Structures & Loads 9

Frames

• Frames members are subjected to axial, shear and

moment

Chapter 1 Types of Structures & Loads 10

Surface Structures

Chapter 1 Types of Structures & Loads 11

Loads

Codes

General Building Codes

Specify the requirement of minimum design load on

structures

1. ASCE

2. UBC

3. IBC

Chapter 1 Types of Structures & Loads 12

Loads

Codes

Design Code

Used to establish the requirement for the actual

structural design

1. ACI

2. AISC

3. AASHTO

Chapter 1 Types of Structures & Loads 13

Dead Load

Consist of the weight of the various structural members

and weight of any object that permanently attached to the

structure

Chapter 1 Types of Structures & Loads 14

Dead Load

Chapter 1 Types of Structures & Loads 15

Live Load

• Building Loads

• Bridge Load

Can vary both in their magnitude and location

Chapter 1 Types of Structures & Loads 16

Wind Load

)(N/m 613.0

22IVKKKq

pressureWind

dztzz

V The velocity of the wind measured 10 m above the ground

I Importance factor depends upon nature of the building

Kz The velocity pressure coefficient which is function of height

Kzt a factor that account for wind speed increases due to hills and

escarpments for flat ground Kzt=1.0

Kd a factor account for direction of wind when subjected to load

combination

Chapter 1 Types of Structures & Loads 17

Wind Load

)(N/m )(

2

pihp GCqqGCp

BuildingEnclosedforpressureWind

Chapter 1 Types of Structures & Loads 18

fph AGCqF

SignsforpressurewindDesign

Wind Load

Chapter 1 Types of Structures & Loads 19

Snow Load

gte IpCCF 7.0

Chapter 1 Types of Structures & Loads 20

Earthquake Load

Chapter 1 Types of Structures & Loads 21

Hydrostatic and Soil

Pressure

Other natural Loads

Chapter 1 Types of Structures & Loads 22

Structural Design

• LRFD (Load and resistance factor design)

Load combination example:

1.4 Dead Load

1.2 Dead Load +1.6 Live Load

1.2 Dead Load +1.6 Live Load + 0.5 Snow

Load

1.2 Dead Load + 1.5 Eq. Load + 0.5 Live Load