Foundational Concepts in Architectural Structures

Equilibrium

A structure is in equilibrium when the sum of all forces and moments acting on it is zero. This means there is no net force or rotation.

Translational Equilibrium

Forces in both the X and Y directions sum to zero.

Rotational Equilibrium

Moments (torques) around any point sum to zero.

Imbalance in Structures

All successful structures are intentionally designed to be slightly 'imbalanced' to prevent failure by ensuring load distribution.

Diagonal Bracing

Used to prevent lateral movement and stabilize structures. It helps distribute forces and resist twisting or buckling.

Masonry

A material used in constructing walls, foundations, and columns. It provides strength, particularly in compression, and is often used in conjunction with bracing systems.

Foundation

The lower portion of a building structure that connects it to the ground. Its primary purpose is to transfer loads from the structure to the soil.

Shallow Foundations

Spread the load over a large area.

Deep Foundations

Used when surface soil conditions are not suitable. Piles are driven deep into the ground to reach stable soil or rock.

Raft Foundations

Used in areas with weak soil. A large concrete slab spreads the load over a large area, supporting the entire structure.

Subsurface Conditions

Understanding the type of soil and rock beneath the structure is critical. This is determined by geotechnical investigations, which assess the soil's strength, stability, and ability to bear loads.

Geotechnical Reports

These reports evaluate the safety of the proposed construction site by assessing the soil's properties, such as load-bearing capacity, presence of groundwater, and soil compaction.

Buckling

The sudden failure of a structure due to excessive compressive forces. It typically happens in columns or slender structures.

Elastic Buckling

Occurs when a column or beam is compressed beyond its elastic limit.

Inelastic Buckling

Happens when material yield occurs before buckling.

Critical Load

The load at which buckling occurs is calculated using Euler's formula: Pcr = (π² E I) / (L²), where Pcr = Critical load, E = Modulus of elasticity, I = Moment of inertia, L = Effective length of the column.

Beam

A horizontal structural element that supports loads and transfers them to supports such as columns or walls.

Simply Supported Beam

A beam that rests on two supports.

Continuous Beam

A beam that extends over more than two supports.

Cantilever Beam

A beam that is supported at one end only.

Shear and Bending

Beams experience shear forces and bending moments due to loads. These forces must be calculated to ensure the beam's design is adequate for the loads.

Free Body Diagram (FBD)

A visual representation of a structure or part of a structure, showing all external forces and moments acting on it.

Purpose of Free Body Diagram

Helps in calculating reactions, forces, and moments to analyze structural integrity.

Simple Span Beam

A beam supported at both ends, without any intermediate supports.

Construction Joints

A joint between two segments of a structure that are constructed at different times, necessary for allowing safe load transfer during construction phases.