Earthquake Engineering
Earthquakes are vibrations felt at the surface of the earth which are caused by disturbances of the energy in the earth's interior. These vibrations are known as seismic waves. (Skinner Robinson McVerry 1) There are different type sof seisimc waves such as Primary (P) waves, whcih travel the fastest, Secondary (S) waves which cause the earth to vibrate vertically, Surface (L) waves. P and S waves are "affected by changes in the density and the rigidity of the materials through which they pass." (Columbia Encyclopedia) Earthquakes vary in their intensity and duration. Often times they are strong enough to cause massive destriction. Tall buildings often suffer as a result of these natural disasters. In recent years this has become a larger and larger threat with both the number of large buildings, and their number of occupants increasing. In an effort to try to minimize the damage caused by earthquakes many some engineers focus primarily on designing and constructing earthquake resistant buildings. Earthquake engineers have gathered much of their information from analyzing past earthquakes, and learning which buildings can and can't withstand the tremors. The goals of these engineers is to design buildings that can withstand moderate earthquakes and obtain minimal damage, and that the buildings will not collapse lowering the probability of human deaths.
Authorities have attempted to implement codes or regulations, but that has proved to be very difficult tasks becasue there are many variables that effect the dynamic response of buildings. One way to try to avoid disaster is to evaluate seismic risk is to look at a buildings hazards, exposure, vulnerability, and location. Hazards are, for example, landslides ad soil type. Exposure is a building's occupancy and function. Vulnerability is the expected performance of a building's system, and location is how often earthquakes occur in the area. (Lagorio)
Some other things that have become evident are that geometric simplicity and symmetry are key to constructing an earthquake resistant building. Simplicity often leads to symmetry, and in turn symmetry tends to decrease the likelihood of a concentration of mass. This idea of lighter buildings being safer can be explained mathematically using the formula F=MA. To understand how this formula works it is pertinent to recognize that earthquakes alone do not cause damage because all they provide is an acceleration.
An earthquake felt throughout the Midwest on June 18 was a shaky reminder that earthquakes can occur anywhere.
On Earthquakes An earthquake is a shaking or trembling of the crust of the earth caused by underground volcanic action or by the breaking and shifting of rock beneath the surface. The volcanic action and shifting rocks create strain which continues to build to a sudden release of pressure resulting in a shock wave. The vibrations produced in the crust can vary from barely noticeable to enormously destructive. Shock waves can be classified into two broad categories. Waves that send particles oscillating back and forth in the same direction as the waves are traveling are called primary.
producing a earthquake safe environment. In a nuclear facility that in itself is a danger, an honest
The Physical and Human Factors Which Affect the Location and the Impact of the Earthquake Hazard
Mr. Adams describes the San Francisco earthquake as his most profound human suffering experience because the horror of shaking floors, parts of his mom’s house collapse to the floor, and got a broken nose from stumbling into a brick wall (Ansel Adams & The 1906 Earthquake 2008). Earthquakes are part of natural disasters of the earth and normally caused by shaking ground and rapid movement of one block of rock slipping past another a long fractures in the earth crust called faults. Faults that are usually locked excluding abrupt movements, which slippage creates an earthquake (Lutgens, F. & Tarbuck, E.
Fire extinguisher. Check. Working flashlight. Check. Canned food. Check. These emergency necessities were part of the apartment supplies during one of the most traumatizing, memorable, and scary part of my life. Little did I know that a copy of “Surviving earthquakes for dummies” should have been part of this inventory as well. I was only six years old when this personal and natural disaster happened. We lived in a small, mildly sturdy seven-story apartment made of bricks.
Skyscrapers are amazing! Architectural defeats. Wonders of the world. How are they able to withstand even the strongest of winds and earthquakes?
The New Madrid Earthquake is referred to the area that exposed to the robust earthquakes in the United States of America. The area is located in Southeastern Missouri, Northeastern Arkansas, Western Tennessee, Western Kentucky and Southern Illinois, which is the most active seismic in the USA east of the Rocky Mountains. Historically, in 1811-1812, the New Madrid seismic zone suffered a sequence of earthquakes that included three very large earthquakes estimated to be between magnitude 7 and 8, which led to destroy most of the buildings. Therefore, the man-mad infrastructures were a main cause of injuries and deaths among population (United States Geological Survey, 2016).
To determine how the fire prevention systems in a structure weather an earthquake, a test was conducted at the University of California, San Diego, in 2012. The test was preformed outside on a 5 story building, located on an
There are many factors that affect the damages to a building during and after an earthquake, such as the ground beneath the building (fault line, landfills, bedrock) as well as different the types of building material (wood, steel, brick/masonry) and how it behaves during an earthquake. For example, the wood used for framing in smaller structures (i.e. houses), as well as the steel framing used in larger structures like skyscrapers.
2. Watches for the structures response to the earthquakes and have control against the earthquake.
Because Yuhu is located in an earthquake zone, the capability to resist earthquake is highly concerned for the local buildings. In tradition houses, the main structure is hold by wood frames and stones are mounted on the exterior. During the 1996 level 7 earthquake, most of the exterior stone walls were collapsed but wood frame structures well remained. In the design of this project, Li adopted this traditional structure system and added new technologies to improve its resistance to earthquake. In traditional house construction, stones are mounted to the exterior walls and are likely to collapse during earthquake. In this project, vertical steel bars are inserted in the stone walls at a set interval. Horizontal meshes are also installed in layers to prevent lateral force during frequent earthquakes. Traditional stone wall con...
In general, building design usually considers environmental or external loads that a building must have the strength to resist. These loads are gravity, wind and earthquake loads. Leading a high rise building to collapse, the key failure is the failure of transferring load from the building above the failure point to the foundation. There are numbers of reasons to cause the failure of load transfer, such as poor inspection before construction and foundation failure.
Taher, R. (2011). General recommendations for improved building practices in earthquake and hurricane prone areas. San Francisco, CA: Architecture for Humanity Retrieved from
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).