But if these designs haven't been implemented in the real world, predicting how they can be damaged and what repair strategies should be implemented remain unresolved. The researchers said the expert feedback method offers a unique and robust technique for evaluating the feasibility of bridge designs that are still at an early research and development phase. But now the question is what kind of repairs should be used for different types and levels of damage, what will be the cost of these repairs and how long will the repairs take -- these are all unknowns for new bridge designs," said Dr.
Most bridges are monolithic systems made of concrete poured over forms that give the bridges their shape. These bridges are strong enough to support their own weight and other loads, such as traffic. However, Sideris said if there is an unexpected occurrence of seismic activity, these structures could crack, and remedying the damage would be exorbitantly expensive.
To overcome these shortcomings, Sideris and his team have developed a new design called a hybrid sliding-rocking bridge. Instead of a monolithic design, these bridges are made of columns containing limb-inspired joints and segments.
Hence, in the event of an earthquake, the joints allow some of the energy from the ground motion to diffuse while the segments move slightly, sliding over one another rather than bending or cracking.
Search search. Home News. Email Print Share. Research News New way for bridges to withstand earthquakes: support column design. Structural damage in conventional columns, usually caused by a natural disaster, result in cracking damage that would force a bridge to close until repairs are completed.
On the other hand, bridges with HSR columns are able to withstand large earthquakes with minimal damage and require only minor repairs, likely without bridge closures. Such infrastructure not only increases community quality of life, but can also save thousands in taxpayer dollars.
This accessibility will further help the affected communities to recover faster. The taller a structure, the more flexible it is. The more flexible it is, the less energy is required to keep it from toppling or collapsing when the earth's shaking makes it sway. You can feel this same phenomenon while you're riding a bus or subway.
It requires less effort to remain standing if you flex your body and flow with the bumps and jolts than if you stiffly try to defy them. Because shorter buildings are stiffer than taller ones, a three-story apartment house is considered more vulnerable to earthquake damage than a story skyscraper.
When planning the seismic safety of a building, structural engineers must design the support elements of shorter buildings to withstand greater forces than those of taller buildings. Of course, the materials a building is constructed from also determine its strength, and again, flexibility is important. 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.
0コメント