Facebook Social Icon Instagram Icon Twitter Social Icon You Tube Social Icon
 
 
 
 
 
 
 
 
 
 

Why does my house shake?

When explosives are detonated the rock is fractured by the release of large amounts of energy. 

Unfortunately, not all of the energy is used and some will be transmitted to the surrounding environment. Blasting can account for approximately 25% of the operating cost of a quarry. Any ground vibration that is transmitted to surrounding areas, homes, etc. is essentially wasted energy and, in the eyes of the quarry, wasted money. 

During blasting, energy waves are transmitted through the ground as vibrations, and through the air as air blast.

As the ground vibration affects a house, the structure will begin to respond or shake. Unless a person inside a house is expecting a blast to occur, it is usually startling when the vibration reaches the structure. How a person perceives a blast will vary. Humans are more sensitive to blasts than structural components. The perception a person has as to the intensity of the blast cannot be directly translated to the sensitivity of any structural components.

In reference to airblast, Johnson County enforces a maximum decibel (dB) level of 134, depending on the type of seismograph used to record the blasts. Airblast is usually what a person hears and feels. Although an individual might find a blast to be intrusive or loud once again, it cannot be directly translated to the sensitivity of any structural components. Based on studies conducted by the U.S. Bureau of Mines, windows would be one of the first things to break as a result of blasting damage. Studies have found as a general rule it takes approximately 171 dB for windows to break. Other structural damage is possible at 180 dB. Once again the maximum limit for airblast enforced by Johnson County is 134 dB.