Unimap Module

Introduction
*Structures refer to a system of connected parts used to support a load
*Factors to consider
- Safety
- Esthetics
- Serviceability
- Economic & environmental constraints

Classification of Structures
*Structural elements
- Tie rods
- Beams
- Columns
*Types of structures
- Trusses
- Cables & Arches
- Surface Structures



Loads
*Design loading for a structure is often specified in codes
- General building codes
- Design codes
*Table 1.1 lists some of the important codes used in practice



*Types of load
- Dead loads
> Weights of various structural members
> Weights of any objects that are permanently attached to the structure
> The densities of typical building materials are listed in Table 1.2 & 1.3




Example
*The floor beam in Fig 1.8 is used to support the 1.83m width of lightweight plain
concrete slab having a thickness of 102mm
*The slab serves as a portion of the ceiling for the floor below & its bottom coated
with plaster
*A 2.44m high, 305mm thick lightweight solid concrete block wall is directly over the
top flange of the beam
*Determine the loading on the beam measured per m length of the beam

Example


Solution
Using the data in Table 1.2 & 1.3:


Loads
*Live loads
- Varies in magnitude & location
- Building loads
> Depends on the purpose for which the building is designed
> These loadings are generally tabulated in local, state or national code
> A sample is shown in Table 1.4

Table 1.4



*Live loads
- Building Loads
> Uniform, concentrated loads
> For buildings having very large floor areas, many codes allow a reduction in
the uniform live load for a floor as it is unlikely the prescribed live load
will occur simultaneously
> ASCE 7-02 allows a reduction of live load on a member having an influence area
(KLL AT) of 37.2 m2 or more


*Live loads
- Building Loads





Example

* A 2-storey office building has interior columns that are spaced 6.71m apart in 2
perpendicular directions (see Fig 1.9)
* If the (flat) roof loading is 0.96kN/m2, determine the reduced live load supported
by a typical interior column located at ground level


Fig 1.9


From Fig 1.9,