Now's the time to prepare and develop emergency response plans.
Earthquakes have no season, can occur almost anywhere and cannot be predicted with any certainty. Worldwide, more than 55,000 earthquakes of a magnitude greater than 3.0 on the Richter Scale are felt annually. And the cost of earthquake-triggered damage to buildings and other property can be astronomical.
The Northridge, Calif., USA, earthquake in 1994 and the Kobe, Japan, earthquake in 1995, are two good examples of costly events. The Northridge earthquake, a magnitude 6.7 event, is considered the most destructive and costly earthquake to hit the United States since 1906. Causing massive losses, the earthquake exceeded US$20 billion in direct damage-related costs, including US$12.5 billion in insured losses. More devastating still was the Kobe earthquake. The magnitude 6.9 earthquake produced total loss costs estimated at US$200 billion.
Fortunately, preventive action can greatly reduce the amount of damage sustained in the event of a major earth movement. With careful advance planning, proper design and protection of buildings and equipment, and training of employees, the potential physical damage and business interruption associated with a devastating earthquake can be greatly reduced.
The most obvious way to significantly reduce or eliminate exposure to earthquake loss is by selecting locations outside seismic areas or in low earthquake hazard zones. Where this is not possible, avoid the most earthquake-vulnerable sites, including those located:
- on or very near a known seismic fault;
- on terrain subject to landslide; or
- in an area of poor soil or organic landfill subject to large settlement, liquefaction, lateral spreading, etc.
If operating in earthquake-hazard zones cannot be avoided, there are steps they can take to prepare for and mitigate the impact of earthquake.
Securing Equipment and Storage
A major concern in earthquake loss prevention is securing large items including storage racks and valuable pieces of equipment. Contents can be displaced if they are not anchored, in some cases, moving several feet. For low-profile objects that slide, shake damage can be minimal, but losses may increase when equipment must be realigned or interconnections repaired. Because forces are magnified at higher points in a building, taller objects are more likely to overturn than those at ground level. Securing equipment and rack storage can minimize loss in these events.
For some facilities, the cost of anchoring every piece of equipment can be high. In such cases, it is best to prioritize the need for anchoring based on whether movement would result in significant damage. Consider starting by anchoring objects that are high in value, critical to maintaining production continuity, or hazardous if damaged.
Sprinkler System Bracing
If a sprinkler system is compromised during an earthquake, it will dramatically affect the ability to combat a fire. Unfortunately, the period after an earthquake also is a time when the risk of fire could be significantly higher than normal. Sprinkler systems can be protected from most seismic damage by systematically providing bracing, flexibility and clearance. Bracing prevents differential movement from occurring between the sprinkler piping and the building, resulting in the major sections of the sprinkler system moving as a unit.
In addition, flexibility can be built into the sprinkler system by installing flexible couplings in areas that can move in different directions during an earthquake. Finally, clearance is necessary around sprinkler piping whenever it penetrates non-frangible walls or floors as well as when the piping is near other equipment or piping.
Ignitable Liquid and Gas
Earthquake shaking can result in the release of ignitable liquid and other combustible materials, which can come in contact with ignition sources, particularly electrical arcing from damaged electrical systems. Preventing the release of ignitable liquid and gas from equipment and piping is the most practical way to significantly reduce the risk of fire following an earthquake. This risk can be mitigated by installing affordable seismic gas shutoff valves, effective earthquake-actuated shutoff valves that stop the flow of ignitable materials.
Emergency Response Plan
The above steps will certainly help reduce the loss potential from an earthquake. Nevertheless, one of the most important items is our clients' Emergency Response Plans (ERP). Among other things, these plans should identify the gas shut off valves, water shut off valves (in case there are leaks); a method of securing the building to prevent looting; a list of contractors to help restore operations; data backup plans; and an alternate location to establish operations. For more information on earthquake loss prevention engineering, take a look at our earthquake-related resources in the AFM Natural Hazard Toolkit or contact your account engineer.