By CHRISTY HOPPE - The Dallas Morning News - Fri., Aug. 3, 2007
Texas officials expressed confidence in the state's bridge inspection program Thursday but promised a quick response to the federal government's call to immediately inspect all bridges similar to the Minneapolis span that collapsed into the Mississippi River.
U.S. Transportation Secretary Mary Peters signed off on an advisory that was sent by the Federal Highway Administration urging state transportation departments to conduct inspections of bridges similar to the collapsed steel-deck truss bridge. Officials said there are about 700 such bridges.
Chris Lippincott, a governmental liaison for the Texas Department of Transportation, said late Thursday that there are more than 30 such bridges on major state highways in Texas, and probably more on city and county roads.
Mr. Lippincott said that he was unaware of the federal alert but that Texas would follow such a directive.
"If we receive notification from the Federal Highway Administration to inspect a class of bridges, we will do so as quickly as possible. This will be in addition to our regular and aggressive inspection process," he said.
Before the alert, Texas officials had said they planned no stepped-up inspections, even as governors across the nation ordered their engineers to begin new assessments in light of Wednesday's tragedy in Minnesota.
Mark Cross, spokesman for the Texas Department of Transportation, said Texas, which has more bridges than any other state -- 49,829 as of 2006 -- now inspects all of them at least once every two years. Bridges in more critical condition are checked more often, he said, and because of the recent heavy rains, bridge inspections have been a top priority to ensure their structural soundness.
"We are on top of that," Mr. Cross said.
Top state bridge engineer Randy Cox said that although Texas has bridges of truss design similar to the Minneapolis bridge, there's no inherent additional danger.
In Missouri, Massachusetts and New Jersey, governors ordered new rounds of bridge inspections. Nationally, 12 percent of bridges are categorized as "structurally deficient," meaning they are deteriorating. In Texas, 4 percent of all bridges -- 2,125 -- are so categorized. Of those in Texas, 2 percent, or 483 bridges, are on major thoroughfares.
Last year, Texas issued 178 contracts for major bridge reconstruction and repair, including 17 in the Dallas area. In all, $489 million was spent for replacement and rehabilitation of bridges, according to a 2006 report on the condition of bridges put together by the Texas Department of Transportation.
Mr. Cross said older infrastructure "is a challenge" throughout the state and nation, but Texas has worked hard to identify problems and systematically repair problems.
The Associated Press contributed to this report.
THE STATE OF TEXAS BRIDGES
According to the state's 2006 report on the condition of Texas bridges:
*Texas has 49,829 bridges. That doesn't include private, pedestrian, railroad, utility or federally owned spans. The total is 40 percent more than any other state.
*Roughly 19 percent of all Texas bridges were built before 1950. Thirty-five percent were built from 1950 to 1970.
*As of last September, 2,125 bridges (4 percent of the total) were classified as "structurally deficient," meaning they have been closed or have deteriorated to a point that the load-bearing capacity is below the originally intended maximum.
*Dallas County had 10 state-maintained bridges that were structurally deficient. Collin County had one and Denton County, five. Tarrant County had 36.
*Dallas County had 24 locally-maintained bridges that were structurally deficient. Collin County had seven, Denton County had 32, and Tarrant, 34.
*Rockwall County had no structurally deficient bridges in either category.
*The state's improvement plan is chipping away at the number of deficient bridges. In 2000, the state had 758 deficient, state-maintained bridges; last year there were 483.
*Last fiscal year, the state allotted $50.5 million for bridge maintenance.
ALL ABOUT U.S. BRIDGES
*Last year, at least 73,533 of the nation's 607,363 bridges, or about 12 percent, were classified as "structurally deficient," according to the Federal Highway Administration. These bridges carry a daily average of more than 300 million vehicles.
*Repairing them all would take at least a generation and cost more than $188 billion, according to the American Society of Civil Engineers. That works out to at least $9.4 billion a year over 20 years.
*According to the Federal Highway Administration, 83 percent of the bridges in the U.S. Highway Bridge Inventory are inspected every two years. About 12 percent, those in bad shape, are inspected annually, and 5 percent, those in very good shape, every four years.
*An analysis of 2006 Federal Highway Administration data found that Minnesota bridges were generally in better shape than those in other states. Only about 6 percent of the state's bridges were listed as being structurally deficient. Nearly 27 percent of Oklahoma's bridges were cited by the federal government as being structurally deficient, the nation's highest percentage.
*Of the 10 worst-off counties for bridges, seven are in Oklahoma or Nebraska. On the other end of the scale, at least 10 counties with a significant number of bridges have none that are structurally deficient, according to the latest government statistics. Six of those are in Texas.
Associated Press
Showing posts with label Texas bridges. Show all posts
Showing posts with label Texas bridges. Show all posts
Sunday, August 5, 2007
Saturday, August 4, 2007
Flaws found in many bridges
By Gordon Dickson, Anthony Spangler and Jeff Claassen - Star-Telegram staff writers - Fri, Aug. 03, 2007
Twenty-three bridges in Tarrant County fared worse in their most recent inspections than the bridge that collapsed Wednesday in Minneapolis, a Star-Telegram review of federal records shows.
A few have been repaired or replaced since the inspections. The low scores for the others don't necessarily mean the bridges are in danger of crumbling, officials cautioned.
"Texas bridges are safe," Randy Cox, director of the Texas Department of Transportation's bridge division, said Thursday. "If it gets to the point where we find a bridge can no longer safely handle a load, we close that bridge."
Nonetheless, inspectors hired by the state to conduct routine examinations of the bridges found an assortment of potential problems, including damage to piers, footings, railings and decks.
Some of the bridges are along busy commuting corridors, including:
The Texas 10 bridge over Northeast Loop 820 in Hurst, where motorists headed toward Hurst Boulevard or Baker Boulevard often feel the pavement shaking as big rigs roll by.
The historical Main Street bridge over the Trinity River near downtown Fort Worth, one of the region's oldest transportation landmarks.
The reports are included on a National Bridge Inventory database kept by the Federal Highway Administration. They include details of the most recent safety inspections, from 2004 to 2006. The database may not reflect current conditions.
The data show that 12.4 percent of the nation's nearly 600,000 bridges were rated "structurally deficient." In Texas, 4.5 percent of the nearly 50,000 bridges were deemed structurally deficient, as were 2.7 percent of Tarrant County's roughly 2,700 bridges.
The state Transportation Department declined to comment on specifics about the Tarrant County bridges. Agency officials said they have asked the state attorney general's office for an opinion as to whether bridge inspection records must be made public under freedom of information laws. The reports contain information that might help terrorists, a spokeswoman said.
Some of the bridges have been repaired, including a Keller Smithfield Road bridge in Keller and a Pipeline Road bridge in Hurst. At least one, the Duncan Perry Road bridge over Interstate 30 in Arlington, has been rebuilt.
Each bridge receives a sufficiency rating -- computed by a formula that considers dozens of factors noted during an inspection -- with scores from zero to 100. A score of 80 or less indicates some rehabilitation may be needed; a 50 or less indicates replacement may be in order. The Minneapolis bridge had a sufficiency rating of 50, according to federal bridge inventory data.
The data also rate a bridge's components on a scale of 0 to 9. A zero represents a failure, and a 9 is excellent; 6 is satisfactory; 5 is fair; 4 is poor; and 2 is critical.
Inspection ratings
The Minneapolis bridge was inspected in 2005 and scored a 4 for its structural members -- typically the support system between the pavement and the piers or footings.
It received a rating of 6 for its substructure, which includes "piers, abutments, piles, fenders, footings or other components," according to federal documentation. The deck -- or pavement, sidewalks and rails -- was rated 5.
The Star-Telegram reviewed records of more than 1,000 bridges in Tarrant County and found that 23 were considered structurally deficient and had earned sufficiency ratings lower than the Minneapolis bridge.
The Main Street bridge across the Trinity River in downtown Fort Worth has a sufficiency rating of 33.8, according to a March 2005 inspection. The deck and substructure were rated satisfactory, but the superstructure was rated poor.
The scouring, or effect of erosion on the bridge's foundation, was not inspected, according to the federal inventory data.
About 14,000 cars cross the bridge, which was built in 1914, each day, according to 2004 estimates included in the inspection records.
Fort Worth last repaired the bridge in the late 1980s and took X-rays of the entire structure, said George Behmanesh, the city's assistant director of transportation and public works.
"Although the rating is low, that bridge is safe because it is way overdesigned," he said. "It has huge columns. If it were a standard modern bridge, we would be concerned about it."
The Seventh Street bridge over the Trinity and Forest Park Boulevard scored even lower -- 33.2 -- and its deck and substructure were rated fair. Its superstructure received a poor rating, which can include "advanced section loss, deterioration, spalling or scour," federal records show.
An estimated 19,000 cars cross the bridge daily, according to 2004 figures.
Repairs planned
Fort Worth is negotiating with Transportation Department officials to repair the Main Street bridge and replace the Seventh Street bridge, Behmanesh said.
"Both of those bridges were designed and built during a time when they poured an excessive amount of concrete," he said. "There is some erosion and cracks, but because of the size of the columns, we are in good shape. That's what saving our necks."
Behmanesh said the city recently closed a bridge in far north Fort Worth in Denton County. He said the Litsey Road bridge, which crosses Henrietta Creek, was closed because of its poor condition.
"We are willing to close a bridge if we feel it is unsafe," he said.
The Texas 10 bridge over Northeast Loop 820 in Hurst carries more than 11,000 cars daily. It scored 48.8, just below the rating of the Minneapolis bridge.
The inspection data did not include counts for the nine lanes of traffic beneath the Texas 10 bridge -- which, if it collapsed, could cause numerous fatalities and create a rush-hour nightmare comparable to what happened in Minneapolis.
Th Texas 10 bridge, built in 1963, received a poor rating for its deck and a fair rating for its substructure.
Inspection intervals
The Transportation Department hires contractors to inspect bridges at least every 24 months, and that work is supervised by a professional engineer, Cox said. Texas has far more bridges than any other state.
Bridges over bodies of water at least 4 feet deep are also inspected at least once every five years by a specially trained dive team, he said.
In June, state officials announced that they would transfer more than $6 billion from the new-construction fund to the maintenance fund to get more life out of the aging highway system, including bridges.
"The challenge for Texas is that, as our system ages, demand is increasing," agency spokesman Chris Lippincott said.
An outside expert reiterated the state's assertion that Texas bridges are safe.
Most bridges frequented by Texas motorists have redundant support and likely would remain standing even after severe damage.
Therefore, bridges that fare poorly in inspections are probably not a public danger, said Todd Helwig, who is researching ways to strengthen bridges at the University of Texas at Austin.
"I know people are going to be worried whether they should drive across a bridge, but I don't bat an eyelash," he said.
By the numbers
49,829 Number of bridges in Texas as of September.
2 Number of years between bridge inspections; some are evaluated more often.
5 Years between inspections of underwater foundations and columns.
2011 Year by which Texas hopes to have 80 percent of its bridges in good condition or better.
288 Bridges a year that need to be improved to meet the goal.
Read more
Twenty-three bridges in Tarrant County fared worse in their most recent inspections than the bridge that collapsed Wednesday in Minneapolis, a Star-Telegram review of federal records shows.
A few have been repaired or replaced since the inspections. The low scores for the others don't necessarily mean the bridges are in danger of crumbling, officials cautioned.
"Texas bridges are safe," Randy Cox, director of the Texas Department of Transportation's bridge division, said Thursday. "If it gets to the point where we find a bridge can no longer safely handle a load, we close that bridge."
Nonetheless, inspectors hired by the state to conduct routine examinations of the bridges found an assortment of potential problems, including damage to piers, footings, railings and decks.
Some of the bridges are along busy commuting corridors, including:
The Texas 10 bridge over Northeast Loop 820 in Hurst, where motorists headed toward Hurst Boulevard or Baker Boulevard often feel the pavement shaking as big rigs roll by.
The historical Main Street bridge over the Trinity River near downtown Fort Worth, one of the region's oldest transportation landmarks.
The reports are included on a National Bridge Inventory database kept by the Federal Highway Administration. They include details of the most recent safety inspections, from 2004 to 2006. The database may not reflect current conditions.
The data show that 12.4 percent of the nation's nearly 600,000 bridges were rated "structurally deficient." In Texas, 4.5 percent of the nearly 50,000 bridges were deemed structurally deficient, as were 2.7 percent of Tarrant County's roughly 2,700 bridges.
The state Transportation Department declined to comment on specifics about the Tarrant County bridges. Agency officials said they have asked the state attorney general's office for an opinion as to whether bridge inspection records must be made public under freedom of information laws. The reports contain information that might help terrorists, a spokeswoman said.
Some of the bridges have been repaired, including a Keller Smithfield Road bridge in Keller and a Pipeline Road bridge in Hurst. At least one, the Duncan Perry Road bridge over Interstate 30 in Arlington, has been rebuilt.
Each bridge receives a sufficiency rating -- computed by a formula that considers dozens of factors noted during an inspection -- with scores from zero to 100. A score of 80 or less indicates some rehabilitation may be needed; a 50 or less indicates replacement may be in order. The Minneapolis bridge had a sufficiency rating of 50, according to federal bridge inventory data.
The data also rate a bridge's components on a scale of 0 to 9. A zero represents a failure, and a 9 is excellent; 6 is satisfactory; 5 is fair; 4 is poor; and 2 is critical.
Inspection ratings
The Minneapolis bridge was inspected in 2005 and scored a 4 for its structural members -- typically the support system between the pavement and the piers or footings.
It received a rating of 6 for its substructure, which includes "piers, abutments, piles, fenders, footings or other components," according to federal documentation. The deck -- or pavement, sidewalks and rails -- was rated 5.
The Star-Telegram reviewed records of more than 1,000 bridges in Tarrant County and found that 23 were considered structurally deficient and had earned sufficiency ratings lower than the Minneapolis bridge.
The Main Street bridge across the Trinity River in downtown Fort Worth has a sufficiency rating of 33.8, according to a March 2005 inspection. The deck and substructure were rated satisfactory, but the superstructure was rated poor.
The scouring, or effect of erosion on the bridge's foundation, was not inspected, according to the federal inventory data.
About 14,000 cars cross the bridge, which was built in 1914, each day, according to 2004 estimates included in the inspection records.
Fort Worth last repaired the bridge in the late 1980s and took X-rays of the entire structure, said George Behmanesh, the city's assistant director of transportation and public works.
"Although the rating is low, that bridge is safe because it is way overdesigned," he said. "It has huge columns. If it were a standard modern bridge, we would be concerned about it."
The Seventh Street bridge over the Trinity and Forest Park Boulevard scored even lower -- 33.2 -- and its deck and substructure were rated fair. Its superstructure received a poor rating, which can include "advanced section loss, deterioration, spalling or scour," federal records show.
An estimated 19,000 cars cross the bridge daily, according to 2004 figures.
Repairs planned
Fort Worth is negotiating with Transportation Department officials to repair the Main Street bridge and replace the Seventh Street bridge, Behmanesh said.
"Both of those bridges were designed and built during a time when they poured an excessive amount of concrete," he said. "There is some erosion and cracks, but because of the size of the columns, we are in good shape. That's what saving our necks."
Behmanesh said the city recently closed a bridge in far north Fort Worth in Denton County. He said the Litsey Road bridge, which crosses Henrietta Creek, was closed because of its poor condition.
"We are willing to close a bridge if we feel it is unsafe," he said.
The Texas 10 bridge over Northeast Loop 820 in Hurst carries more than 11,000 cars daily. It scored 48.8, just below the rating of the Minneapolis bridge.
The inspection data did not include counts for the nine lanes of traffic beneath the Texas 10 bridge -- which, if it collapsed, could cause numerous fatalities and create a rush-hour nightmare comparable to what happened in Minneapolis.
Th Texas 10 bridge, built in 1963, received a poor rating for its deck and a fair rating for its substructure.
Inspection intervals
The Transportation Department hires contractors to inspect bridges at least every 24 months, and that work is supervised by a professional engineer, Cox said. Texas has far more bridges than any other state.
Bridges over bodies of water at least 4 feet deep are also inspected at least once every five years by a specially trained dive team, he said.
In June, state officials announced that they would transfer more than $6 billion from the new-construction fund to the maintenance fund to get more life out of the aging highway system, including bridges.
"The challenge for Texas is that, as our system ages, demand is increasing," agency spokesman Chris Lippincott said.
An outside expert reiterated the state's assertion that Texas bridges are safe.
Most bridges frequented by Texas motorists have redundant support and likely would remain standing even after severe damage.
Therefore, bridges that fare poorly in inspections are probably not a public danger, said Todd Helwig, who is researching ways to strengthen bridges at the University of Texas at Austin.
"I know people are going to be worried whether they should drive across a bridge, but I don't bat an eyelash," he said.
By the numbers
49,829 Number of bridges in Texas as of September.
2 Number of years between bridge inspections; some are evaluated more often.
5 Years between inspections of underwater foundations and columns.
2011 Year by which Texas hopes to have 80 percent of its bridges in good condition or better.
288 Bridges a year that need to be improved to meet the goal.
Read more
Subscribe to:
Posts (Atom)
