EARTHQUAKE VULNERABILITY OF TRANSPORTATION SYSTEMS IN THE CENTRAL UNITED STATES - PDF

Please download to get full document.

View again

of 25
All materials on our website are shared by users. If you have any questions about copyright issues, please report us to resolve them. We are always happy to assist you.
Information Report
Category:

Instruction manuals

Published:

Views: 5 | Pages: 25

Extension: PDF | Download: 0

Share
Related documents
Description
EARTHQUAKE VULNERABILITY OF TRANSPORTATION SYSTEMS IN THE CENTRAL UNITED STATES Compiled by the Central U.S. Earthquake Consortium with technical support from MS Technology September 1996 Revised August
Transcript
EARTHQUAKE VULNERABILITY OF TRANSPORTATION SYSTEMS IN THE CENTRAL UNITED STATES Compiled by the Central U.S. Earthquake Consortium with technical support from MS Technology September 1996 Revised August 11, 2000 EARTHQUAKE VULNERABILITY OF TRANSPORTATION SYSTEMS IN THE CENTRAL UNITED STATES This monograph was prepared by the Central U.S. Earthquake Consortium with technical support from MS Technology and funding support from the U.S. Department of Transportation, Research and Special Programs Administration, Office of Emergency Transportation September 1996 Reprinted under contract with Office of Emergency Transportation August 11, 2000 Central United States Earthquake Consortium DEPARTMENT OF TRANSPORTATION U NITED STATES OF AMERICA PREFACE Transportation systems in the Central U.S. including highways, bridges, railways, waterways, ports, and airports are vulnerable to the effects of a damaging earthquake in the New Madrid seismic zone. Furthermore, damages to transportation systems may extend to several states, which presents transportation officials in government and the private sector with unique problems and challenges. In an effort to increase awareness of the earthquake risk in the Central U.S., and specifically the vulnerability of transportation systems, The U.S. Department of Transportation collaborated with the Central U.S. Earthquake Consortium to prepare this monograph. The Central U.S. Earthquake Consortium (CUSEC) is a nonprofit organization, funded by the Federal Emergency Management Agency, that is dedicated to reducing deaths, injuries, damage to property and economic losses resulting from earthquakes occurring in the Central United States. Its members are the seven states that are most vulnerable to earthquakes in this region: Arkansas, Illinois, Indiana, Kentucky, Mississippi, Missouri, and Tennessee. Emergency transportation planning is an important element in CUSEC s long-term plan to reduce the earthquake risk in the Central U.S. In this regard, the Consortium has worked closely with the U.S. Department of Transportation on several projects and training activities that address the vulnerability of transportation systems to a New Madrid earthquake, and measures that can be taken to advance mitigation, response and recovery planning. This monograph is a contribution towards this basic effort. 2 CONTENTS 2 Preface 5 Introduction Transportation System Vulnerability 7 The Earthquake Risk Multi-State Impact Recent Earthquakes Probability of Future Damaging Earthquakes Earthquake Induced Hazards Faulting Liquefaction Slope Stability Dam or Levee Failure Hazardous Materials Spills 11 Effects of Earthquakes on the Transportation System Highway Transportation Railroad Transportation Waterway Transportation Ports Air Transportation Liquid Fuel and Transport 20 Reducing the Vulnerability of Transportation Systems: Challenges and Opportunities Vulnerability Assessment Awareness and Education Mitigation Response and Recovery Research and Information Transfer 24 Resources 3 INTRODUCTION The Central United States is vulnerable to a damaging earthquake. With little or no warning, an earthquake in the New Madrid seismic zone could strike seven or more states, causing major physical, social, and economic disruption to a region that is home to forty million people. While most people associate the New Madrid fault with the great earthquakes of which produced four temblors near magnitude 8 and thousands of aftershocks this region continues to have the highest level of seismicity in the United States east of the Rocky Mountains. Earthquakes of estimated magnitude 6.4 and 6.8 occurred in 1843 and 1895 respectively. The potential losses from future earthquakes of magnitude 6 or greater in the New Madrid seismic zone are expected to be significant, for at least three reasons: 1) the population centers, notably Memphis and St. Louis, have thousands of structures that are not designed and constructed to withstand the effects of earthquakes; 2) the region is characterized by poorly consolidated sedimentary rocks, which are poor foundation material; and 3) a New Madrid quake would impact a multi-state region (about 10 times larger than the area impacted by a California earthquake of comparable size). Transportation System Vulnerability The Central U.S. is a major transportation corridor. Indeed, Memphis the home of Federal Express bills itself as America s Distribution Center. 5 During the twentieth century, the U.S. has witnessed an explosion in the growth of transportation systems, population, and wealth. In 1900, our nation s transportation system was comprised of three elements: unpaved highway, railroad, and waterway, which accounted for 78 percent of all commodity transport. Generally speaking, the consequences of failure in a transportation system due to an earthquake or other natural disaster can involve: Direct loss of life due to collapse or structural failure of the lifeline. Indirect loss of life due to an inability to respond to secondary catastrophes, such as fires, and/or provide emergency medical aid. Delayed recovery operations. Release of hazardous products (e.g., losses from tank cars derailed by track failure, gas leaks from ruptured utility lines) and environmental impacts. Direct loss of property and utility service (e.g., the collapse of a bridge carrying utilities). Losses due to interruption of access (e.g., export losses due to port damage). Disruption of economic activity across the region and nation as well as in the community directly affected. Nearly a century later, 90 percent of all travel measured in passenger miles is by the highway system. Air travel during this period increased dramatically, accounting for 9 percent of passenger miles. The remaining 1 percent is by rail, water, and local transit. Our nation s economy, then, is inextricably tied to our transportation infrastructure. To put this into perspective, in 1992, the U.S. Gross Domestic Product was over $6 trillion, of which $728 billion, or 12.1%, was attributable to transportation demand. In addition, over 11 million employees support today s transportation systems. In essence, the Central U.S. is a major transportation corridor whose infrastructure roads, bridges, runways, port facilities, rail lines, tunnels rests atop a landscape that is vulnerable to the effects of earthquakes, including ground shaking and liquefaction (quicksand effect resulting from soil failure). The consequences from a major New Madrid earthquake would be substantial, estimated from $60 to $100 billion. The destruction to the transportation system would make up a significant portion of those losses. This monograph is organized into three sections. The first part examines the unique nature of the earthquake risk in the Central U.S. The second section discusses the effects of earthquakes on each component of our nation s transportation system, and how this will affect response and recovery efforts. The final section of the monograph looks ahead to the challenges and opportunities for transportation officials, emergency managers and others in developing a comprehensive approach to reducing the vulnerability of our transportation system to earthquakes in the Central U.S. Date 1838/06/ /01/ /10/ /08/ /09/ /10/ /04/ /11/ /08/ /05/ /07/ /09/ /04/ /11/27.. History Magnitude THE EARTHQUAKE RISK T he potential for a destructive earthquake is a real threat to the Central United States. In the winter of , the central Mississippi Valley was struck by three of the most powerful earthquakes in the U.S. history. On December 16, 1811, the residents of the town of New Madrid, Missouri were abruptly awakened by violent shaking from the first of three magnitude 8 earthquakes in the region. Thousands of aftershocks were to rock the region during that winter. The earthquakes of that memorable winter were not freak events. On the contrary, scientists have learned that strong earthquakes in the central Mississippi Valley have occurred repeatedly in the geologic past. The area of major earthquake activity also has frequent minor shocks and is known as the New Madrid seismic zone. of Damaging Earthquakes in the Central U.S. Location Date Magnitude Location Southern Illinois Marked Tree, Arkansas Southern Illinois Southern Missouri Southern Illinois Charleston, Missouri Vincennes, Indiana Southeastern Missouri Mississippi Valley Illinois Illinois Indiana-Illinois border Eastern Missouri Illinois 1925/04/ /05/ /12/ /02/ /03/ /10/ /11/ /01/ /03/ /01/ /06/ /09/ /05/ /09/ Indiana-Illinois border Northeastern Arkansas Northern Mississippi New Madrid, Missouri Southern Missouri Eastern Missouri South-central Illinois Central Arkansas Eastern Arkansas North-central Arkansas Southeastern Illinois Southeastern Missouri Southeastern Missouri Ohio/Pennsylvania border 7 Multi-State Impact Earthquakes in the central or eastern United States affect much larger areas than earthquakes of similar magnitude in the western United States. For example, the San Francisco, California earthquake of 1906 (magnitude 7.8) was felt 350 miles away in the middle of Nevada, whereas the New Madrid earthquake of December 1811 (magnitude 8.0) rang church bells in Richmond, Virginia, 1,000 miles away. Differences in geology east and west of the Rocky Mountains contribute to this significant contrast. Recent Earthquakes in Central U.S. Moderate earthquakes in the magnitude 5.8 to 6.9 range occur with more frequency in the Central U.S. than larger, potentially catastrophic earthquakes. Furthermore, the loss of life and destruction in recent earthquakes of only moderate magnitude dramatically illustrate the need for earthquake preparedness programs in the Central U.S. (for example, 33 lives and $20 billion in the 1994 Northridge, California earthquake and 5,500 lives and $100 billion in the 1995 magnitude 6.9 Kobe, Japan, earthquake) Magnitude Magnitude MILES Shaking felt, but little damage to objects Minor to major damage to buildings and their contents Reference: Schweig, Eugene et al., U.S. Geological Survey Fact Sheet The multi-state impact of a New Madrid earthquake is the primary reason that the Central U.S. Earthquake Consortium was established in 1983 to coordinate member state planning efforts. Earthquakes in the moderate range occur on the average of every fifty years in the New Madrid seismic zone. The last earthquake in this magnitude range was a 6.8 quake in 1895, so statistically speaking, the region is due for a moderate, but damaging earthquake. 8 Faulting An earthquake occurs when a fracture, commonly known as a fault, ruptures due to stresses that have built up in the crust. Fault ruptures are more common in the western U.S. Probability of Future Damaging Earthquakes The probability of a moderate earthquake occurring in the New Madrid seismic zone in the near future is high. Scientists estimate that the probability of a magnitude 6 to 7 earthquake occurring in this seismic zone within the next 50 years is higher than 90 percent. Tremendous surface displacements did occur during the 1811 and 1812 New Madrid earthquakes, when land rose and fell as much as 10 feet. Several lakes were created during these great earthquakes, including Reelfoot Lake in northwest Tennessee. Earthquake Induced Hazards A central question becomes, how can earthquakes affect transportation systems? When earthquakes occur, there are a number of ways in which transportation systems can be affected. Typically, one thinks of the ground shaking hazard that causes major damage or failures. However, there are other earthquake related hazards that can affect transportation systems. These hazards are: (1) faulting, which results in rupture of the earth s surface; (2) ground failures, which can result in liquefaction, slope instability, and subsidence; and (3) induced physical damages, such as flooding, dam or levee failures, landslides, fires and hazardous materials releases. 9 Reelfoot Lake Liquefaction Liquefaction typically occurs in layers of sandy soil that are located in the upper 30 feet of the soil strata where a high water table exists. This phenomena is caused by ground shaking, which rearranges soil particles in such a fashion that a quicksand effect results. When liquefaction occurs, two conditions can result: (1) loss of bearing strength needed to support the foundations of roads, bridges, and buildings; (2) lateral spreading where a layer of stable soil can slide over the top of a liquefied layer. Another type of earthquake induced liquefaction soil failure is a sand blow. As the soil particles lose their ability to provide bearing strength, the weight of the soil above causes pressure in the liquefied layer to build up. This can cause sand and water of the liquefied layer to be jettisoned to the surface through weak points in the overlaying soil. Sand blows were extensive in the New Madrid earthquakes of , and can still be seen today. Slope Stability Slope stability failures, or landslides, occur when unstable slopes lose their cohesive stability during ground shaking. One of the largest rock slides occurred during the 1959 Hebgen, Montana, earthquake, when a complete mountain side was dislodged causing 80 million tons of rock mass and debris to end up at the bottom of the mountain. Slope stability can be a major problem in hilly areas in the Central U.S., and lead to serious problems with road and railway embankment failure. Dam or Levee Failure The Central U.S. has historically been susceptible to flooding. The 1993 Midwest Floods clearly illustrate the consequences of widespread flooding, and the key role that dams and levees play in flood protection in this part of the country. Earthen dam failure, Morgan Hill, CA 10 These same levees and dams are vulnerable to ground shaking. Given the large number of dams and the extensive network of reservoirs and levees along the region s river systems, significant flooding from earthquake induced breaks in dams and levees should be expected at high water periods. Roads and bridges would also be damaged, compounding response and recovery efforts. Hazardous materials releases and spills are a major earthquake induced hazard, one that will have a regional impact. The transportation system that we depend on to move hazardous materials products is clearly vulnerable to earthquakes, as reflected in the following section. Hazardous Materials Spills Hazardous materials are a by-product of the economy of the Central U.S. As a major transportation corridor, tremendous volumes of hazardous materials pass through this region by rail, highway, and river. Oil and natural gas pipelines also crisscross near or through the New Madrid seismic zone, transporting 4 million barrels per day of crude oil, petroleum products and natural gas. As metropolitan areas in the Central U.S. continue to grow, more and more people live and work near industrial and commercial facilities that process or store hazardous materials. EFFECTS OF EARTHQUAKES ON THE TRANSPORTATION SYSTEM Recent earthquakes, including the Northridge, California event (1994), show quite dramatically the damages that earthquakes can inflict on roads, bridges, and other components of our nation s transportation system. 11 Although transportation system disruption or failure is not considered a major risk to life safety, the socioeconomic consequences can be particularly devastating to the general public. These include the primary impacts that flow directly from impeded access to hospitals, evacuation areas, emergency relief centers, and fire departments, and the secondary impacts due to closed mass-transit facilities and the inability to get to or from work for an extended period of time. A recurring theme of this monograph is that our nation s transportation network should be viewed as an interdependent system of components (e.g., roads, bridges, tracks, retaining walls, tunnels, embankments, etc.), and the failure of any one component can cause problems or even failure in other parts of the system. The following section examines in more detail the effects of earthquakes on key components of the transportation system, with implications for pre-disaster mitigation (steps that can be taken to minimize damages), and response and recovery planning. Highway Transportation The major components of the highway transportation system are pavements, bridges, overpasses, viaducts or elevated expressways, tunnels, embankments, slopes, avalanche and rock shelters, retaining walls, and maintenance facilities. Roadways and bridges are of primary concern, since their loss of function will have the greatest impact on the ability to move people and equipment after the earthquake. Collapsed Interstate 880, Loma Prieta 1989 Roadways will sustain damages in a New Madrid earthquake, primarily from surface displacements, liquefaction, slope instability and earthquake induced flooding from broken levees during high water events. Pavements will crack in a damaging New Madrid earthquake, principally due to ground failure (such as liquefaction). Critical links in the interstate system, including Interstate 55 and Interstate 40, would in all likelihood be closed due to failures to approaches to bridges, and damage to the pavement itself. Bridges and overpasses are the most vulnerable component of the transportation system, as evidenced in recent earthquakes in California and elsewhere. In 1964, nearly every bridge along the partially completed Cooper River Highway in Alaska was seriously 12 damaged or destroyed. Seven years later, the San Fernando earthquake damaged more than 60 bridges on the Golden State Freeway in California. It is estimated that it cost the state approximately $100 million to repair and replace these bridges, including the indirect costs due to bridge closures. In 1989, the Loma Prieta earthquake damaged more than 80 bridges and overpasses, and in the Northridge earthquake (1994), 163 bridges and overpasses were damaged, six of which collapsed. Bridges and overpasses in a New Madrid earthquake would sustain major damages. A Scenario for a 7.6 Earthquake in Charleston, Missouri, prepared by the Federal Emergency Management Agency (FEMA), determined that approximately 1500 bridges in a five state region would be nonfunctional immediately after a 7.6 earthquake, with an estimated 500 of these bridges remaining nonfunctional one month after the event. Collapsed Bridge, 1964 Japan Earthquake The vulnerability of bridges and overpasses in the Central U.S. to a damaging earthquake has major implications for post-disaster response, and long term recovery efforts. Access to disaster sites is critical to effective response operations. The failure of bridges and overpasses will seriously impede response efforts, both interstate and intrastate. Memphis and St. Louis will face major problems of their own. A FEMA loss estimation study (An Assessment of Damage and Casualties for Six Cities in the Central U.S. Resulting from Earthquakes in the New Madrid Seismic Zone, 1985), determined that in a 7.6 earthquake, almost all bridges and overpasses in the city of Memphis and Shelby County would experience major to destructive damage. A companion study (Estimated Future Earthquake Losses for St. Louis City and County, 1990) of a magnitude 7.6 earthquake concluded that St. Louis City and County would lose serviceability to 50 percent of the long span bridges. Other bridges would experience 26 to 88 percent loss of serviceability. Thousands of bridges will need to be inspected before they can be used, which means that priority must be given to the formation and coordination of State and federal bridge inspection teams. The repair of bridges will have a direct impact on the pace of long-term economic recovery, which will be a function in large part of the ability to move goods and services across the region. Finally, the large area of damages will complicate the abilit
Recommended
View more...
We Need Your Support
Thank you for visiting our website and your interest in our free products and services. We are nonprofit website to share and download documents. To the running of this website, we need your help to support us.

Thanks to everyone for your continued support.

No, Thanks