Composite Structures & Prestressed Concrete

Reduces pore water pressure in the rock

Precast segments are pushed into position during construction to reduce environmental impact.

Provide lateral stability in structures, handling in-plane and out-of-plane forces.

Structures vibrate at a certain frequency. Matching a structure's natural frequency to an external load can cause problems.

Rubber bearings reduce earthquake energy transmission to the structure.

Structures combining different materials (e.g., steel and concrete) to share load.

Concrete with pre-stressed steel tendons to resist tensile forces and increase strength.

Design factors (L/D) influencing beam/slab length and height for proper load bearing.

Ensuring structural frequency does not resonate with applied loads.

Structures to hold back earth, including concrete, gabion, and secant pile walls.

Spray-applied concrete for stabilizing loose rock in tunnels.

Metal anchors used to stabilize rock in tunnels by connecting unstable and stable rock zones.

Bridge construction method, building segments outward for balanced and symmetric loads.

Using composite systems can reduce material usage, allow for larger spans with less deflection, and enhance structural efficiency.

Vibrations are a concern for serviceability in composite floors.

Solutions for excessive vibrations in composite floors include increasing slab thickness or using damping materials like viscoelastic layers.

The design factors (L/D) influencing the length and height of beams and slabs for proper load bearing.

Prestressed concrete generally resists dynamic loading better, reducing natural frequency issues that lead to vibrations.

Strong and durable retaining walls that need proper drainage systems (weep holes) to prevent water buildup.

Flexible retaining walls made from wire cages filled with rocks, allowing drainage but unsuitable for high walls.

Retaining walls made from overlapping piles, suitable for deep excavations, providing both soil retention and water-tightness.

Possible failures for retaining walls include overturning (rotation), sliding (lack of friction), and structural failure (inadequate reinforcement or design).

Drainage systems in retaining walls prevent hydrostatic pressure buildup behind the wall by using geotextile layers and perforated pipes.

Bridge vibrations occur when the natural frequency of the bridge matches the frequency of applied loads, such as wind or traffic.

Patterns of deflection in structures during dynamic loading that depict how the structure vibrates.

Composite beams, combining steel and concrete, are used to reduce material usage and handle dynamic loads effectively in long-span bridges.

Drainage systems in tunnels reduce pore water pressure in the rock, preventing water buildup and potential problems.

Shrinkage in shotcrete is caused by water evaporation and can lead to cracks. Adding fibers can prevent shrinkage.

Creep is a long-term deformation of tunnel structures caused by constant pressure.

Rock bolts can corrode in tunnels, especially in corrosive environments. Galvanized bolts are used to prevent corrosion.

Bridge construction technique involving precast segments pushed into position, minimizing environmental impact.

Expansion joints are incorporated into bridge decks to allow for thermal expansion and contraction, preventing cracking and stress buildup.

Atriums in buildings allow for buoyancy-driven airflow (stack effect), drawing air upwards due to heat differences.

Cross ventilation is a ventilation strategy that utilizes two openings to create air flow across a space, effectively cooling the area.

Double-skin façades in buildings provide a layer of insulation and natural daylight, contributing to energy efficiency and daylighting.

Fire Resistance Periods (FRPs) are defined time periods that structures are designed to withstand fire, ensuring safe evacuation.

Shear walls are crucial for lateral stability in earthquake-prone structures, resisting both in-plane and out-of-plane forces.

Base isolation is a method used to reduce earthquake energy transmission to structures by using rubber bearings that absorb vibrations.