ABASOLO, PRINCE GABRIEL U. CE497- R4
1. What is Steel Design?
Steel design is the process of analyzing and detailing structural members made of structural steel to ensure
they can safely carry applied loads. In the Philippines, this is governed by the NSCP (National Structural Code
of the Philippines), which adapts from AISC (American Institute of Steel Construction) standards. It
considers:
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Tension and compression members
Beams and girders
Steel connections (bolted/welded)
Stability (buckling, lateral torsional buckling)
2. What is Timber Design?
Timber design deals with the use of wood as a structural material, applying engineering principles to
account for its anisotropic (direction-dependent) and variable strength properties. In the Philippines, timber
design follows the NSCP (adapted from the NDS – National Design Specification for Wood Construction,
USA). It covers:
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Allowable stresses in bending, tension, compression, shear
Duration of load factors
Moisture and termite considerations (very important in PH climate) •
nails, and shear plates
Connections using bolts,
3. Difference between Steel and Timber Design (per PH codes)
Aspect Steel Design (NSCP – AISC-based)
Material
Timber Design (NSCP – NDS-based)
Homogeneous, isotropic, predictable
Non-homogeneous, anisotropic, variable
Strength Basis High strength, ductile
Lower strength, brittle in some cases
Design
LRFD & ASD
Method
Durability
ASD (allowable stress design) with load duration
factors
Corrosion (needs protection)
Susceptible to decay, termites, moisture
Connections
Bolts, welds, rivets
Bolts, nails, screws, shear plates
Local Use
span
Skyscrapers, bridges, largestructures
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Vernacular houses, churches, resorts, small-span
structures
4. Examples of Structures in the Philippines
Famous Steel Structures in the Philippines
1. SM Mall of Asia Arena (Pasay City) – iconic steel dome structure.
2. San Juanico Bridge (Leyte-Samar) – longest bridge in PH, steel truss design.
3. Mactan-Cebu International Airport Terminal 2 (Cebu) – steel frame system with long spans.
Famous Timber Structures in the Philippines
1. San Agustin Church (Intramuros, Manila) – interiors use massive narra and molave timber elements.
2. Las Casas Filipinas de Acuzar (Bataan) – heritage houses rebuilt with traditional timber structures.
3. Dapitan Heritage Houses (Zamboanga del Norte) – preserved ancestral homes showcasing timber
design
ABASOLO, PRINCE GABRIEL U. CE497- R4
1. Types of Loading
In structural engineering, loads are the external forces or actions applied to a structure. The main types are:
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Dead Load (DL)
Permanent/static loads like self-weight of structural members, finishes, fixed equipment, etc.
Live Load (LL)
Variable/transient loads such as people, furniture, vehicles, and movable objects.
Environmental Loads o Wind Load (W) – force of wind pressure/suction.
o Seismic Load (E) – inertial forces due to earthquakes. o
Snow Load (S) –
(not common in PH, but still in NSCP).
o Rain Load (R) – ponding water on flat roofs.
Other Loads (when applicable) o
Soil/Lateral Earth Pressure o Hydrostatic
Pressure o
Construction Load (CL)
2. Loading Combinations in the Philippines (NSCP)
The NSCP adopts load combinations similar to ASD (Allowable Stress Design) and LRFD (Load and
Resistance Factor Design).
basic factored load combinations (LRFD) per NSCP 2015, Sec. 203:
1. 1.4 DL
2. 1.2 DL + 1.6 LL + 0.5 (Lr or R or S)
3. 1.2 DL + 1.6 (Lr or R or S) + (0.5 LL or 0.8 W)
4. 1.2 DL + 1.0 W + LL + 0.5 (Lr or R or S)
5. 1.2 DL + 1.0 E + LL
6. 0.9 DL + 1.0 W
7. 0.9 DL + 1.0 E
Where:
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DL = Dead Load
LL = Live Load
Lr = Roof Live Load
R = Rain Load
S = Snow Load
W = Wind Load
E = Seismic Load