2. 2.1 Introduction:
Deadloads:
Dead loads are loads of constant magnitude that remain in one position. They consist of
the Structural frame’s own weight and other loads that are permanently attached to the frame, for
a reinforced concrete building, some dead loads are the frame. Walls, floor, roof, plumbing, and
fixtures.
Live loads:
Live loads are loads that may change in position and magnitude. Simply stated, all loads
that are not dead loads are live loads.
Live loads that move under their own power are said to be
moving loads ,such as trucks ,people ,and cranes, whereas those loads that may be moved ,such
as furniture, warehouse materials, and snow. Other live loads include those caused by
construction operation, wind, rain, earthquake, blast, and temperature changes.
Lateral loads:
Many kinds of lateral loads can act on the building structure like wind, earthquake, water
or soil and oceans waves. While any or all of these may be significant, wind and earthquake
loads are generally more common.
Wind loads:
Wind is the general term used to describe air, which is in motion due to natural causes.
In addition to normal wind, some regions are subjected to especially strong winds, such as hurricanes or
tornadoes. By virtue of its mass and velocity, moving air has kinetic energy.
3. When moving air stopped or deflected by an obstacle such as building, some or all of its kinetic
energy is transformed into potential energy of pressure.
Wind pressure on any particular structure is proportional to the square of the wind velocity, and
total wind force on a structure depends also on the drag characteristics of the structure, air density, and
other factors.
Earthquake loads:
Earthquake can cause local soil failure and surface ruptures. Though hazardous to the building,
these are not discussed further here.
The most significant earthquake effects on buildings usually result from the seismic waves,which
propagate outward in all directions from the earthquake focus. These waves are of severaldifferent types,
and can cause significant ground motion up to severalhundred miles from the source of a strong
earthquake.
When the base of the building move while the upper part tend to remain at rest due to its inertial
resistance,the resulting dynamic response cause time varying member action which must be considered
in design. It is currently impossible to do more than estimate , in general terms, the intensity, sequence,
duration and frequency content of the earthquake induced ground motion to which a structure may be
subjected during its lifetime. For the design purposes, ground motion is described by the history of
hypothesized group acceleration near the structure, and is most commonly expressed in terms of the
response spectrum derived from that history.
5. One way slab
One way table is used to predict slab thickness. Two way slab thickness will be checked
when analyzing by using PROKON software. Slab long term deflection must not exceed the
allowable deflection.
MINIMUM THECKNESS OF NONPRESTRESS BEAM OR ONE WAY SLABS UNLESS
DEFLICTION ARE CLCULATED:
Minimum thickness, h
Simply
supported
One end continuous Both end continuous Cantilever
Member Member not supporting or attached to partitions or other construction
likely to be damaged by large deflections.
Solid one
way slabs
20/l 24/l 28/l 10/l
Beam or
Ribbed one way
slabs
16/l 5.18/l 21/l 8/l
2.2.1 Rib 4:
The panel is a one end continuous with ribbed one way slabs, so
h=
5.18
l
l= 4400mm
h=
5.18
4400
= 237.8mm
The panel is a both end continuous with a Ribbed one way slabs, so
h=
21
l
l= 5800mm
h=
21
5800
= 276.1mm
6. Take h = 300 mm using a 240mm height ribbed slab with
60mm top mat for all the panels
2.2 Dead load calculation:
The slab system used in this building is a one way and tow way ribbed slab system.
All specific weights (ɣ) of the materials used in the load calculations are obtained from the
Jordanian Code for loads and forces 6/2006.
Density of tile 26KN/m3
Density of mortar 22KN/m 3
Density of fill 14.5KN/m3
Density of reinforced concrete 25KN/m3
Partition weight 2.36kN/m2
Weight of hollow block used for ribbed slab
(block size 200 x 400 x 320 mm-)
0. 15KN
Total slab thickness (h) 0.30m
7. 2.2.1 Calculate the weight due to one way ribbed slab:
Dead load is calculated per one meter of rib
Weight of tiles 0.02 x 26 x0.55 = 0.286 KN/m/rib
Weight of Mortar 0.03 x 22 x0.55 = 0.363 KN/m/rib
Weight of Fill 0.10x 14.5x0.55 = 1.02 KN/m/rib
Weight of top slab 0.06 x 25 x 0.55 = 0.78 KN/m/rib
Weight of Rib
(0.12+0.16)
2
x 0.24 x 25 = 1.02 KN/m/rib
Wt. of hollow block 5 x 0.15 =0.75 KN/m/rib
Partition wall 2 × 0.55 =1.10 KN/m/rib
Plaster on ceiling 0.030 x 22 x0.55 =0.363 KN/m/rib
Dead load / m 2 =5.682/ 0.55 = 10.33KN/m2
Live load is taken as = 2kN/m2 = 2× 0.55 = 1.1 𝑘𝑁
𝑟𝑖𝑏⁄
