Substructure and superstructure of buildings

Substructure and Superstructure of Buildings

Constructing the Substructure

  • Excavation: The first step of the construction process is excavating the site for the foundations.

  • Groundwork: Setting out occurs after excavation to finalise the building’s position on the site.

  • Foundations: The foundations are made to evenly distribute the building’s load to the ground.

  • Plinth: After the foundation, a plinth is constructed to prevent the surface water from entering the structure.

  • Piling: For larger buildings, piles may be driven deep into the ground to support the weight of the building.

Types of Superstructure

  • Frame Structure: This is a structure system with a combination of column and beam elements, and the building’s load is transferred from roof to the columns.

  • Load Bearing Structure: Also known as ‘wall structure’, where the wall bears the load along with the columns.

Building the Superstructure

  • Columns: These vertical structures transfer the building load from the superstructure to the substructure.

  • Beams: Beams are horizontal structures that transfer the load from the slabs to the columns.

  • Slabs: These are flat, horizontal elements of the building like floors, roofs, ceilings, that take the load from walls.

  • Walls: These vertical elements either bear the load (load-bearing walls) or segregate space (partition walls).

  • Roof: The top element of the building that protects the interior elements from weather conditions.

Connection Between Substructure and Superstructure

  • Transition Structure: This is the transition point between the substructure and the superstructure. This usually involves a load-bearing beam or wall built directly above the foundation.

Factors Influencing Substructure and Superstructure

  • Site conditions: The type of soil, water table level, and seismic activity of the site can determine the type of substructure to use.

  • Building Use: The intended use of the building influences the superstructure’s design and construction material.

  • Budget: Both the substructure and superstructure must be in line with the budget of the project.

  • Legal Requirements: Building codes and regulations can influence the design of both substructure and superstructure.

Understanding Building Loads

  • Dead Load: This is the weight of the building itself, including all permanently attached equipment, walls, columns, etc.

  • Live Load: Variable loads that the building is subjected to during its lifetime, like furniture, people, wind, etc.

  • Environmental Load: Loads caused due to environmental factors like earthquakes, heavy winds, floods etc.

In construction, emphasis should always be laid on the design. A well-designed building efficiently distributes the load throughout the structure. Also, the materials used must always be considered for their strength, weight, durability, and how they respond to different loads.