Scott Jolgen Lifeguard as Lifeguard. Conrad L. Rex Piano. More like this. Watch options. Storyline Edit. When graduate student Greg Chambers encounters the seismic readings, he rushes to tell his professor, Anthony McAlister.
Greg suspects that a massive earthquake is about to give the small island a rude awakening. To make matters worse, the epicenter is right under Pajaro Island's new resort, where Anthony's estranged wife Lynn is working. As they drive to warn Lynn, the quake tears through the small town, damaging downtown and leveling several homes. The bridge connecting the island to the mainland is wiped out. Lynn and three others are trapped underground in the resort's utility tunnels.
When Greg is killed during a rescue attempt, Lynn is forced to rally the survivors to try and save themselves. With aftershocks tearing through the site, the tunnels growing more and more unstable, and each passing minute bringing them closer to failure, the rescuers and survivors must use every resource they have to escape total disaster.
User reviews 6 Review. Top review. Wood and steel have more give than stucco, unreinforced concrete, or masonry, and they are favored materials for building in fault zones. Skyscrapers everywhere must be reinforced to withstand strong forces from high winds, but in quake zones, there are additional considerations. Engineers must design in structures that can absorb the energy of the waves throughout the height of the building.
Floors and walls can be constructed to transfer the shaking energy downward through the building and back to the ground. The joints between supportive parts of a building can be reinforced to tolerate being bent or misshapen by earthquake forces. Perhaps the most visually recognizable seismic safety feature of tall buildings is the truss.
A network of diagonal trusses at its base supports the building against both horizontal and vertical forces. In addition to strengthening a building against earthquake shocks, engineers can actually reduce the force a building is subjected to. They install what are called base isolators , which isolate the base of the building from the earth's movements. Most are one of two forms.
Some are like giant hockey pucks that squish and deform as the building rocks atop them, absorbing some of the energy of the shaking. Others are sets of two horizontal surfaces, plates made frictionless so that they will slide past each other. The building sits on the top plates, the bottom plates rest on the ground. When the earth lurches, only the bottom plates move, sliding back and forth under the top plates.
Location, location, location Sometimes the characteristics of a particular earthquake and the ground a structure is on coincide in just the right or wrong way, and the quake is particularly devastating. Occasionally, a seismic wave hitting a building will have a frequency that just matches that structure's natural sway. In physics terms, the building has the same resonant frequency as the wave. When this happens, multiple waves at the resonant frequency pass through the structure, their effects amplifying each other.
This makes for a very destructive force. The impact of resonance was very apparent after a large quake in Mexico City in Mid-range buildings of stories were in resonance with the seismic waves, causing those buildings to sufer more damage than shorter or taller ones. P and S waves may seem like shaky business, but the waves that really do damage are the ones that occur when the energy of the quake reaches the surface of the earth. Rayleigh waves churn over and under like rolling ocean waves; Love waves shake the earth from side to side.
Love and Rayleigh waves, named after their discovers, are the ones often responsible for making buildings collapse. Imagine yourself trying to remain standing while the earth was going through such contortions!
To make matters worse, these waves can travel at different speeds through different types of rock, bouncing back or changing direction. In places with certain rock compositions, this bouncing will amplify the waves, which will then cause more damage. Now, imagine a building sitting on ground that is going through all these motions at once. You can see how an earthquake could devastate a city.
That leaves architects and engineers with quite a challenge when they have to consider building to withstand the Big One. When the earth shakes, sandy or muddy soils can flow like liquid. These fissures occurred along the Pajaro River near Watsonville in northern California during the Loma Prieta earthquake.
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