SLAB, FOUNDATION, & COLUMN Flashcards
- Main beam supports floor joists; floor joists support planks
- We don’t use this in the Philippines because of termite infestation and problem with DNR
- Soft wood – easily decays and infested with termites
- For ease of installation and less initial costs
- Western countries use this because of insulation; they can insulate between the floor joists
Timber Floor Framing
- Not done in housing
- Used in temporary structures like bunker houses for construction workers
- Easy to do and less initial cost
- Lightweight compared to concrete; can transfer to one place to another
Metal Floor Framing
slab not lying on a support like the soil or the ground; there are a lot of rebars to ensure that it can carry weight; not necessary for 2nd and 3rd floors; can be used for basements, so long as it is supported by beams or other structural elements
- Suspended slab –
on top of natural grade line (elevation of soil) or filling material (soil)
- Slab on grade or slab on fill –
- Your ground floor should be higher than the road; when the natural grade level is low so you have to increase the height by putting in filling materials
- (Not as much reinforcement) There is not as much rebars for slab on grade or fill because the roads are thick enough to carry vibrating elements like vehicles; only rely on two: make it thick or if you want it thin, provide rebars to ensure it is sturdy enough to prevent it from cracking
Concrete Slab
- For Engr. Damuag’s case, there should be a placement of at least ___ of rebars; use ___ – smallest structural rebars being used; place it with a distance of 0.60 meters both ways
60 millimeters
10 millimeters
a/b ≤ 0.5 (short span/long span)
OR LONGER SPAN/SHORTER SPAN >= 2
o One Way Slab
refers to the orientation of your reinforcement; only one side has reinforcements because it is rectangular in shape
one way reinforcement –
a/b > 0.5 (short span/long span)
OR LONGER SPAN/SHORTER SPAN < 2
o Two Way Slab
rebars in two directions; square in shape
two way reinforcement –
- While a typical slab has beam, ___ has drop panel and capital
Flat Slab (Form)
- It looks like an inverted beam; you thicken the part closest to the column (part most vulnerable when it comes to punching)
Flat Slab (Form)
- Commonly used for areas wherein there is limited head room space (floor to ceiling height)
Flat Slab (Form)
- With this kind of configuration, you can directly place your pipes underneath; there is no beams that will block the pipes from going which way
Flat Slab (Form)
- Usually being used as floor systems for housing developments
- Ceiling for the ground floor
- With this kind of configuration, your formworks is already your steel deck
- Add little rebars
Steel Decking (Materials)
- Ease of fill; ease of construction
- No formworks needed underneath it
Prefabricated Slab (Materials)
- Provide a slab that is tied together
- Like a beam; there are holes filled with cables (reinforcement)
Prestressed Slab (Materials)
- It is circular, square or rectangular slab of uniform thickness. Sometimes, it is stepped or haunched to spread the load over a large area.
Spread Footing
- Spread out the bottommost part of the column
- Thickness depends on (punching) load; shorter side is carrying more bending stress than the longer side
Spread Footing
When spread footing is provided to support an individual column, it is called “___” as shown.
isolated footing
- A kind of footing where it is necessary for you to provide a strap beam
Strap Footing
- It consists of two isolated footings connected with a structural strap or a lever. The strap connects the two footings such that they behave as one unit. The strap is designed as a rigid beam.
Strap Footing
A ___ is more economical than a combined footing when the allowable soil pressure is relatively high and the distance between the columns is large.
strap footing
● It is used when the two columns are so close to each other that their individual footings would overlap.
Combined Footing
also provided when the property line is so close to one column that a spread footing would be eccentrically loaded when kept entirely within the property line. By combining it with that of an interior column, the load is evenly distributed.
Combined Footing
A ___ may be rectangular or trapezoidal in plan. ___ is provided when the load on one of the columns is larger than the other column.
combined footing
Trapezoidal footing
- Three or more columns
- Follows the length and direction of the wall
- Useful if columns are very close to each other or if soil pressure is non-homogeneous
Strip/continuous Footing
- A ___ is provided for a load-bearing wall. A ___ is also provided for a row of columns which are so closely spaced that their spread footings overlap or nearly touch each other.
strip footing
In such a case, it is more economical to provide a ___ than to provide a number of spread footings in one line. A ___ is also known as continuous footing.
strip footing
- There is footing all throughout the construction
- Useful for areas with low soil pressure or non-homogeneous soil
Mat or Raft footings
- It is a large slab supporting a number of columns and walls under the entire structure or a large part of the structure. A ___ is required when the allowable soil pressure is low or where the columns and walls are so close that individual footings would overlap or nearly touch each other. ___ are useful in reducing the differential settlements on non-homogeneous soils or where there is a large variation in the loads on individual columns.
mat
Mat foundations
- There are many reasons that a geotechnical engineer would recommend a deep foundation over a shallow foundation, such as for a skyscraper. Some of the common reasons are very large design loads, a poor soil at shallow depth, or site constraints like property lines. There are different terms used to describe different types of deep foundations including the ___ (which is analogous to a pole), the ___ (which is analogous to a column), drilled shafts, and caissons.
pile
pier
- Common for soft soil; it will strengthen soil and make it dense
PILES/PIERS
- Classification of Piles on the basis of Load Transfer: pile dependent on high density soil
o End/Point Bearing Piles
- Classification of Piles on the basis of Load Transfer: dependent of friction
o Friction Piles
- Classification of Piles on the basis of Load Transfer: combination of end/point bearing piles and friction piles
o Friction cum End Bearing Piles
- Types of Piles Based on Materials
o Timber Piles
o Steel Piles (most common; tendency is that it might rust due to subjection of moisture)
o Concrete Piles
o Composite Piles (combination of steel and concrete)
- Classification of Piles according to the Method of Installation of piles
o Driven Piles - hammered
o Bored Piles - drilled
Also called caissons, drilled shafts, drilled piers, Cast-in-drilled-hole piles (CIDH piles) or Cast-in-Situ piles. Rotary boring techniques allow larger diameter piles than any other piling method and permit pile construction through particularly dense or hard strata. Construction methods depend on the geology of the site; in particular, whether boring is to be undertaken in ‘dry’ ground conditions or through water-saturated strata – i.e. ‘wet boring’.
o Bored Piles
extensively used for earth retention and excavation support.
Sheet Piling
is an economic, in situ method of reinforcing and increasing the overall shear strength of unsupported or unstable soil/rock excavations or slopes. The technique involves the installation of closely spaced reinforcing bars (nails) in the face of the excavation or slope.
Soil Nailing
- A ___ in architecture and structural engineering is a structural element that transmits, through compression, the weight of the structure above to other structural elements below.
column or pillar
a column is a ___ member.
compression
if the column height divided by the smallest cross sectional dimension is less than 12
○ Short Column -
if the column height divided by the smallest cross sectional dimension is greater than 12
○ Long Column -
Types of Column (Material):
* Necessary if you have a composite column
* For ___, you need a baseplate
Timber
Types of Column (Material):
* Welded into the baseplate
Steel Members
Types of Column (Material):
* Fabricated off site
Precast Column
Types of Column (Material):
* Most common in the Philippines
Reinforced Concrete Column
- Parts of Reinforced Concrete Column: for bending
○ Vertical bars
- Parts of Reinforced Concrete Column: for column core confinement
○ Lateral Ties
- Type of Reinforced Concrete Column:
○ Tied Column
○ Spiral Column
is a structural member where in it is seated on top of a non axial bearing member like Slabs or beams to be able to answer the structural needs and requirements without sacrificing interior and architectural design
Planted Column
