# Structural Engineering Viva Questions and Answers

Contents

## What is structural engineering?

Structural engineering is a branch of civil engineering that deals with the design, analysis, and construction of structures such as buildings, bridges, and tunnels. Structural engineers use mathematical calculations and physics principles to ensure that structures can withstand loads and stresses without collapsing.

## What are the different types of loads on a structure?

Dead load is the weight of the structure itself, including the weight of the walls, floors, and roofs. Live load is the weight of people, furniture, and equipment that are present in the building.

## What is the purpose of a foundation?

The purpose of a foundation is to transfer the load of a structure to the ground and to provide stability to the structure. The foundation must be designed to resist the loads imposed by the structure and the soil conditions at the site.

## What is a shear wall?

A shear wall is a structural element used to resist lateral loads such as wind and earthquakes. Shear walls are typically made of reinforced concrete or masonry and are designed to act as a vertical cantilever beam.

## What is the difference between a beam and a column?

A beam is a structural element that supports loads by resisting bending. A column is a vertical structural element that supports loads by resisting compression.

## What is a moment?

A moment is a force that causes a bending effect on a structure. It is equal to the product of the force and the distance from the point of application of the force to the point of rotation.

## What is the difference between a statically determinate structure and a statically indeterminate structure?

A statically determinate structure is one in which the reactions and internal forces can be determined using statics alone. A statically indeterminate structure is one in which the reactions and internal forces cannot be determined using statics alone.

## What is a truss?

A truss is a structural element made of interconnected members arranged in a triangular pattern. Trusses are commonly used in bridges and buildings to support heavy loads.

## What is the purpose of a brace in a structure?

A brace is a structural element used to resist lateral loads and provide stability to a structure. Braces are typically diagonal members that connect beams or columns and are designed to resist tension and compression forces.

## What is a moment of inertia?

A moment of inertia is a property of a cross-sectional area that measures the resistance of the section to bending. It is a function of the shape and size of the section and is used to determine the stresses and deflections in a beam or column.

What is a cantilever beam?
A cantilever beam is a beam that is supported on only one end and is free to deflect under load. Examples of cantilever beams include diving boards and balconies.

## What is a simply supported beam?

A simply supported beam is a beam that is supported at both ends and is free to deflect under load. Examples of simply supported beams include bridges and roof trusses.

## What is a fixed beam?

A fixed beam is a beam that is supported at both ends and is restrained from rotation or movement. Examples of fixed beams include building frames and retaining walls.

## What is a beam-column?

A beam-column is a structural element that combines the functions of both a beam and a column. It is used to support loads in both the horizontal and vertical directions.

## What is a moment-resisting frame?

A moment-resisting frame is a structural system that is designed to resist lateral loads by using beams and columns that are capable of developing significant bending moments.

## What is a space frame?

A space frame is a three-dimensional structural system composed of interconnected structural elements arranged in a geometric pattern. Space frames are used to span large areas and support heavy loads.

## What is a cable-stayed bridge?

A cable-stayed bridge is a type of bridge in which the deck is supported by cables that are attached to towers. The cables transfer the loads from the deck to the towers, which in turn transfer the loads to the foundation.

## What is a suspension bridge?

A suspension bridge is a type of bridge in which the deck is suspended from cables that are attached to towers. The cables transfer the loads from the deck to the towers, which in turn transfer the loads to the foundation.

## What is a precast concrete element?

A precast concrete element is a structural component that is cast and cured in a factory before being transported to the construction site. Precast concrete elements are used to speed up construction and improve quality control.

## What is post-tensioning?

Post-tensioning is a method of reinforcing concrete by placing steel tendons in the concrete and then stressing the tendons after the concrete has cured. The process can increase the strength and durability of the concrete.

## What is a shear key?

A shear key is a structural element used to connect two concrete elements such as beams or slabs. The shear key is designed to transfer the shear forces between the two elements.

## What is a pile foundation?

A pile foundation is a type of foundation that uses deep, slender columns made of steel, concrete, or wood to transfer the load of a structure to a deeper, more stable layer of soil or rock.

## What is a drilled shaft foundation?

A drilled shaft foundation is a type of foundation that uses a deep, cylindrical hole drilled into the ground to transfer the load of a structure to a deeper, more stable layer of soil or rock.

## What is a mat foundation?

A mat foundation is a type of foundation that spreads the load of a structure over a large area of soil. It is used for structures that have large loads or are located on weak or compressible soils.

## What is a reinforced concrete beam?

A reinforced concrete beam is a structural element made of concrete and reinforced with steel bars. The steel bars, also known as reinforcement, provide additional strength and stiffness to the beam.

## What is a composite beam?

A composite beam is a structural element made of two or more different materials, such as concrete and steel. The materials work together to provide increased strength and stiffness compared to a single material beam.

## What is a steel frame?

A steel frame is a structural system that uses steel beams and columns to support loads. Steel frames are commonly used in high-rise buildings and industrial structures.

## What is a moment connection?

A moment connection is a type of connection between steel beams and columns that is capable of transferring significant bending moments. Moment connections are commonly used in steel frames.

## What is a shear connection?

A shear connection is a type of connection between steel beams and columns that is capable of transferring shear forces. Shear connections are commonly used in steel frames.

## What is a bolted connection?

A bolted connection is a type of connection between structural elements that uses bolts to transfer loads. Bolted connections are commonly used in steel frames and other structures.

## What is a welded connection?

A welded connection is a type of connection between structural elements that uses welding to transfer loads. Welded connections are commonly used in steel frames and other structures.

## What is a moment frame?

A moment frame is a structural system that uses beams and columns capable of developing significant bending moments to resist lateral loads. Moment frames are commonly used in high-rise buildings and other structures.

## What is a braced frame?

A braced frame is a structural system that uses diagonal bracing to resist lateral loads. Braced frames are commonly used in high-rise buildings and other structures.

## What is a shear wall?

A shear wall is a structural element made of reinforced concrete or masonry that is used to resist lateral loads. Shear walls are commonly used in high-rise buildings and other structures.

## What is a moment-resisting connection?

A moment-resisting connection is a type of connection between structural elements that is capable of transferring significant bending moments. Moment-resisting connections are commonly used in steel frames and other structures.

## What is a bolted moment-resisting connection?

A bolted moment-resisting connection is a type of connection between steel beams and columns that uses bolts to transfer significant bending moments. Bolted moment-resisting connections are commonly used in steel frames.

## What is a welded moment-resisting connection?

A welded moment-resisting connection is a type of connection between steel beams and columns that uses welding to transfer significant bending moments. Welded moment-resisting connections are commonly used in steel frames.

## What is a precast concrete frame?

A precast concrete frame is a structural system made of precast concrete elements that are connected together to form a complete frame. Precast concrete frames are commonly used in low-rise buildings.

## What is a retaining wall?

A retaining wall is a structure designed to resist the lateral pressure of soil when there is a change in ground elevation. Retaining walls are commonly used in slopes, hillsides, and terraces.

## What is a cantilever retaining wall?

A cantilever retaining wall is a type of retaining wall that uses a horizontal steel or reinforced concrete beam, known as a footing, to resist soil pressure.

## What is a gravity retaining wall?

A gravity retaining wall is a type of retaining wall that uses its weight to resist soil pressure. Gravity retaining walls are commonly made of concrete or stone.

## What is a reinforced earth wall?

A reinforced earth wall is a type of retaining wall that uses layers of geosynthetic materials, such as polyester or polypropylene, to reinforce soil.

## What is a sheet pile wall?

A sheet pile wall is a type of retaining wall that uses interlocking steel or concrete sheets to retain soil.

## What is a diaphragm wall?

A diaphragm wall is a type of retaining wall that uses a reinforced concrete wall to resist soil pressure. Diaphragm walls are commonly used in deep excavation works.

## What is a pile foundation?

A pile foundation is a type of foundation system that uses vertical or inclined structural elements, known as piles, to transfer loads to deeper soil layers.

## What is a driven pile?

A driven pile is a type of pile foundation that is driven into the ground using a pile driver.

## What is a bored pile?

A bored pile is a type of pile foundation that is excavated using a drilling machine and filled with concrete or grout.

## What is a helical pile?

A helical pile is a type of pile foundation that uses helix-shaped steel plates to transfer loads to deeper soil layers.

## What is a raft foundation?

A raft foundation is a type of foundation system that uses a large concrete slab to transfer loads to the soil. Raft foundations are commonly used in low-rise buildings and structures with poor soil conditions.

## What is a mat foundation?

A mat foundation is a type of foundation system that uses a thick concrete slab to transfer loads to the soil. Mat foundations are commonly used in high-rise buildings and structures with poor soil conditions.

## What is a pile cap?

A pile cap is a type of foundation element that is used to distribute loads from a column or wall to a group of piles.

## What is a footing?

A footing is a type of foundation element that is used to distribute loads from a column or wall to the soil. Footings can be shallow or deep, depending on soil conditions.

## What is a deep foundation?

A deep foundation is a type of foundation system that transfers loads to deeper soil layers than shallow foundations.

## What is a shallow foundation?

A shallow foundation is a type of foundation system that transfers loads to the upper layer of soil.

## What is a settlement?

A settlement is a downward movement of a structure or foundation caused by soil compression or consolidation.

## What is a subsidence?

A subsidence is a sinking of the ground caused by natural or human-induced factors.

## What is a slope stability analysis?

A slope stability analysis is a process of evaluating the stability of a slope or embankment and predicting potential slope failure.

## What is a seismic analysis?

A seismic analysis is a process of evaluating the response of a structure to earthquake-induced ground motions.

## What is a wind analysis?

A wind analysis is a process of evaluating the response of a structure to wind-induced loads.

## What is a dynamic analysis?

A dynamic analysis is a process of evaluating the response of a structure to dynamic loads, such as those caused by wind, earthquakes, or machinery.

## What is a static analysis?

A static analysis is a process of evaluating the response of a structure to static loads, such as those caused by gravity or applied loads.

## What is a structural analysis?

A structural analysis is a process of evaluating the strength and stability of a structure under various loads and environmental conditions.

## What is a design code?

A design code is a set of guidelines and standards used in the design and construction of structures to ensure safety, reliability, and efficiency.

## What is a factor of safety?

A factor of safety is a numerical value used in design calculations to ensure that the structure can withstand loads that are greater than the expected or maximum loads.

## What is a serviceability limit state?

A serviceability limit state is a condition in which a structure or component is still functioning properly but may exhibit excessive deflections, vibrations, or other deformations.

## What is a ultimate limit state?

An ultimate limit state is a condition in which a structure or component fails or becomes unsafe due to excessive stress, deformation, or other factors.

## What is a moment?

A moment is a measure of the tendency of a force to cause rotation around an axis. Moments are typically measured in units of Newton-meters (Nm) or foot-pounds (ft-lb).

## What is a shear force?

A shear force is a force that is perpendicular to the axis of a structure or component, causing deformation or failure due to the internal stresses.

## What is a deflection?

A deflection is a bending or displacement of a structure or component due to external loads or forces.

## What is a creep?

Creep is a time-dependent deformation of a structure or component under a constant load or stress.

## What is a buckling?

Buckling is a sudden and catastrophic failure of a structure or component due to excessive compressive loads or stresses.

## What is a torsion?

Torsion is a twisting deformation of a structure or component due to a torque or rotational force.

## What is a moment of inertia?

The moment of inertia is a measure of an object’s resistance to changes in rotational motion. It is calculated based on the object’s mass and distribution around an axis.

## What is a centroid?

The centroid is the center of mass or balance point of a structure or object. It is calculated based on the distribution of mass or weight around an axis.

## What is a stress?

Stress is the force per unit area exerted on a structure or component due to external loads or forces.

## What is a strain?

Strain is the deformation per unit length or volume of a structure or component due to external loads or forces.

## What is a modulus of elasticity?

The modulus of elasticity is a measure of a material’s stiffness or ability to resist deformation under stress.

## What is a yield strength?

The yield strength is the maximum stress that a material can withstand before it begins to deform permanently.

## What is a ultimate strength?

The ultimate strength is the maximum stress that a material can withstand before it fails completely.

## What is a ductility?

Ductility is the ability of a material to deform without fracturing or breaking under stress.

## What is a toughness?

Toughness is the ability of a material to absorb energy and deform plastically before fracturing or breaking,

## What is a fatigue failure?

Fatigue failure is a type of failure that occurs over time due to repeated cyclic loading, causing cracks or fractures in a structure or component.

## What is a resonance?

Resonance is the tendency of a structure or component to vibrate at its natural frequency in response to external loads or forces.

## What is a natural frequency?

The natural frequency is the frequency at which a structure or component vibrates when it is excited by an external force.

## What is a damping?

Damping is the dissipation of energy from a vibrating structure or component due to internal friction, causing the amplitude of the vibration to decrease over time.

## What is a seismic design?

Seismic design is the process of designing structures to resist earthquakes and other seismic events by considering the site-specific seismic hazard and ground motion characteristics.

## What is a wind load?

A wind load is the force exerted by wind on a structure or component, causing bending, torsion, or other types of deformation.

A dead load is the weight of a structure or component that is due to its own self-weight or the weight of permanently attached components.

## What is a live load?

A live load is the weight of a structure or component that is due to moving or transient loads, such as people, vehicles, or equipment.

## What is a point load?

A point load is a concentrated load applied to a specific point on a structure or component, such as the weight of a person or an object.

## What is a distributed load?

A distributed load is a load that is evenly distributed over a specific area or length of a structure or component, such as the weight of a roof or a floor.

## What is a pre-stressed concrete?

Pre-stressed concrete is a type of concrete in which high-strength steel wires or tendons are embedded before the concrete is cast, creating a compressive stress in the concrete that counteracts the tensile stress induced by external loads or forces.