Substructure

Definition

• The substructure is the lower portion of the building structure, located below the ground level.
• It primarily serves as the foundation, providing support to the upper structure.
• Substructures are essential in distributing the load evenly across the building site.

Components of a Substructure

• The key components of a substructure are the foundation, footings, and basement levels if they exist.
• Footings are an integral part of the foundation system. They are typically made of concrete, and their purpose is to support the foundation and prevent sinking.
• The foundation ensures that the weight of the building is evenly distributed to the ground and it also protects against moisture, insects, and other potential hazards.
• The basement levels are part of the substructure when they are located below the ground level.

Types of Foundations in Substructures

• Strip foundations are usually used for load-bearing walls. They consist of a continuous strip of concrete that spreads the load from the building across the width of the foundation.
• Pad foundations are another type of foundation in which the weight of the building is supported by isolated pads, generally used for lighter structures or where ground quality is poor.
• Raft foundations, or mat foundations, are large concrete slabs that spread the load across the whole area of the building. They are mostly used when the soil is weak or for large structures in order to distribute the load more effectively.
• Piled foundations are long, slender columns of wood, steel or concrete driven deep into the ground. They are used in situations where the soil at the surface is weak, but gets stronger at greater depth.

Importance of Substructures

• Substructures provide stability and safeguard the structure against shifting or sinking into the ground.
• They isolate the superstructure from dampness, ground movements and help in retaining the earth around the structure.
• The construction of substructures requires careful planning and consideration of ground conditions, as they can greatly influence the building’s durability and longevity.
• They also contribute to managing the transfer of heat between the ground and the building.

Construction Process

• The construction of a substructure begins with site investigation to understand the characteristics of the soil and water table level.
• After the investigation, excavation work takes place to create space for the foundations.
• Next is the installation of the foundations according to the design characteristics.
• The final step in the substructure construction is drainage and waterproofing to prevent water penetration and subsequent damage.

Safety Measures

• Due to the significant risks involved with substructure construction, safe operating procedures and personal protective equipment (PPE) are essential.
• Typical PPE includes hard hats, visibility vests, steel toe-cap boots, and gloves.
• Other safety measures include regular site inspections, proper workstations, and training of construction workers to ensure safe and accurate work execution.