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86-626: The I-35W Mississippi River bridge (officially known as Bridge 9340 ) was an eight-lane, steel truss arch bridge that carried Interstate 35W across the Mississippi River one-half mile (875 m) downstream from the Saint Anthony Falls in Minneapolis , Minnesota , United States. The bridge opened in 1967, and was Minnesota's third busiest, carrying 140,000 vehicles daily. After only 39 years in service, it experienced

172-499: A catastrophic failure during the evening rush hour on August 1, 2007, killing 13 people and injuring 145. The National Transportation Safety Board (NTSB) cited a design flaw as the likely cause of the collapse, noting that an excessively thin gusset plate ripped along a line of rivets. Additional weight on the bridge at the time of failure was also cited by the NTSB as a contributing factor. Help came immediately from mutual aid in

258-499: A two-hinged arch . In the Iron Bridge shown below, the structure of each frame emulates the kind of structure that previously had been made of wood . Such a wood structure uses closely fitted beams pinned together, so the members within the frames are not free to move relative to one another, as they are in a pin-jointed truss structure that allows rotation at the pin joint. Such rigid structures (which impose bending stresses upon

344-466: A 2001 study by the civil engineering department of the University of Minnesota , no cracking had been previously discovered in the cross girders at the end of the approach spans. The main trusses connected to these cross girders and resistance to motion at the connection point bearings was leading to unanticipated out-of-plane distortion of the cross girders and subsequent stress cracking. The situation

430-463: A 4% interest rate for up to a 30-year length, from the U.S. Small Business Administration . The agency's disaster declaration for Hennepin and contiguous counties came two days after Pawlenty's request to the SBA on August 20, 2007. Open for business and unsure they could repay loans, owners near the collapse in some cases lost 25% or 50% of their income. Large retailers in a mall of chain stores lost about

516-538: A cantilever, but the completed structure does not act as a cantilever. This is very helpful when temporary supports, or falsework , cannot be used to support the structure while it is being built (e.g., over a busy roadway or river, or in a deep valley). Therefore, some truss arch bridges (see Navajo Bridge ) are built from each side as cantilevers until the spans reach each other and are then jacked apart to stress them in compression before finally joining. Nearly all cable-stayed bridges are built using cantilevers as this

602-500: A cantilever-winged sesquiplane built instead with wooden materials, the Fokker V.1 . In the cantilever wing, one or more strong beams, called spars , run along the span of the wing. The end fixed rigidly to the central fuselage is known as the root and the far end as the tip. In flight, the wings generate lift and the spars carry this load through to the fuselage. To resist horizontal shear stress from either drag or engine thrust,

688-565: A computer model of the bridge at the Turner Fairbank Highway Research Center in McLean, Virginia . NTSB investigators were particularly interested in learning why a part of the bridge's southern end shifted eastward as it collapsed, but this particular phenomenon was not germane to the ultimate cause of the collapse. FHWA advised states to inspect the 700 U.S. bridges of similar construction after identifying

774-628: A dozen years after the Wright Brothers ' initial flights, Junkers endeavored to eliminate virtually all major external bracing members in order to decrease airframe drag in flight. The result of this endeavor was the Junkers J 1 pioneering all-metal monoplane of late 1915, designed from the start with all-metal cantilever wing panels. About a year after the initial success of the Junkers J 1, Reinhold Platz of Fokker also achieved success with

860-602: A facility for storing and processing petroleum products. These uses effectively created a toxic waste site under the bridge, leading to a lawsuit and the removal of the contaminated soil. No relationship has been claimed between these previous uses and the bridge failure. The bridge, officially designated "Bridge 9340", was designed by Sverdrup & Parcel to 1961 AASHTO (American Association of State Highway Officials, now American Association of State Highway and Transportation Officials ) standard specifications. The construction contracts, worth in total more than $ 5.2 million at

946-622: A federal disaster declaration. President Bush pledged support during a visit to the site on August 4 with Minnesota elected officials and announced that United States Secretary of Transportation (USDOT) Mary Peters would lead the rebuilding effort. Rybak and Pawlenty gave the president detailed requests for aid during a closed-door meeting. Local authorities were assisted by the Federal Bureau of Investigation (FBI) evidence team, and by United States Navy divers who began arriving on August 5. Thirteen people were killed. Triage centers at

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1032-477: A major pile-up on the bridge on the northbound side. In February and December 1996, the bridge was identified as the single most treacherous cold-weather spot in the Twin Cities freeway system, because of the almost frictionless thin layer of black ice that regularly formed when temperatures dropped below freezing. The bridge's proximity to Saint Anthony Falls contributed significantly to the icing problem and

1118-436: A portion of the overall $ 250 million, which was given to enable "clean-up and recovery work, including clearing debris and re-routing traffic, as well as for design work on a new bridge". "On behalf of Minnesota, we are grateful for all of this help," Pawlenty said. The National Transportation Safety Board immediately began a comprehensive investigation that was expected to take up to eighteen months. Immediately following

1204-424: A possible design flaw related to large steel sheets called gusset plates , which connect girders in the truss structure. Officials raised questions as to why such a flaw would not have been discovered in over 40 years of inspections. The flaw was first discovered by Wiss, Janney, Elstner Associates, Inc. , an independent consulting firm hired by Mn/DOT to investigate the cause of the collapse. On January 15, 2008,

1290-515: A separate measure, the I-35W bridge was rated "structurally deficient", but was deemed to have met "minimum tolerable limits to be left in place as it is". In December 2006, a steel reinforcement project was planned for the bridge. However, the project was canceled in January 2007 in favor of periodic safety inspections, after engineers realized that drilling for the retrofitting would, in fact, weaken

1376-503: A variation in this parameter indicates the concentration of the analyte . Recently, microcantilevers have been fabricated that are porous, allowing for a much larger surface area for analyte to bind to, increasing sensitivity by raising the ratio of the analyte mass to the device mass. Surface stress on microcantilever, due to receptor-target binding, which produces cantilever deflection can be analyzed using optical methods like laser interferometry. Zhao et al., also showed that by changing

1462-458: A wire-braced design. However, as the speed of the aircraft increases, the drag of the bracing increases sharply, while the wing structure must be strengthened, typically by increasing the strength of the spars and the thickness of the skinning. At speeds of around 200 miles per hour (320 km/h) the drag of the bracing becomes excessive and the wing strong enough to be made a cantilever without excess weight penalty. Increases in engine power through

1548-515: Is a private firm that assisted local authorities. Local businesses donated wireless Internet, ice, drinks and meals for first responders. The Salvation Army canteens served food and water to rescue workers. Teams of officers were sent to hospitals to follow up with the injured, who had been transported to eight different medical facilities. The Minneapolis Police Chaplain Corps Chaplain Director, Dr. Jeffrey Stewart, arrived and

1634-455: Is force and w {\displaystyle w} is the cantilever width. The spring constant is related to the cantilever resonance frequency ω 0 {\displaystyle \omega _{0}} by the usual harmonic oscillator formula ω 0 = k / m equivalent {\displaystyle \omega _{0}={\sqrt {k/m_{\text{equivalent}}}}} . A change in

1720-582: Is one of their chief advantages. Many box girder bridges are built segmentally , or in short pieces. This type of construction lends itself well to balanced cantilever construction where the bridge is built in both directions from a single support. These structures rely heavily on torque and rotational equilibrium for their stability. In an architectural application, Frank Lloyd Wright 's Fallingwater used cantilevers to project large balconies. The East Stand at Elland Road Stadium in Leeds was, when completed,

1806-401: Is the cantilever thickness. Very sensitive optical and capacitive methods have been developed to measure changes in the static deflection of cantilever beams used in dc-coupled sensors. The second is the formula relating the cantilever spring constant k {\displaystyle k} to the cantilever dimensions and material constants: where F {\displaystyle F}

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1892-422: Is the immunosensor based on an antibody layer that interacts selectively with a particular immunogen and reports about its content in a specimen. In the static mode of operation, the sensor response is represented by the beam bending with respect to a reference microcantilever. Alternatively, microcantilever sensors can be operated in the dynamic mode. In this case, the beam vibrates at its resonance frequency and

1978-600: The Minnesota Commercial Railway was blocked by the collapse. The Grand Rounds National Scenic Byway bike path was disrupted as well as two roads, West River Parkway and 2nd Street SE. The 10th Avenue Bridge , which parallels this bridge about a block downstream, as well as the Stone Arch Bridge , located upstream, were closed to both vehicle and pedestrian traffic until August 31. The Federal Aviation Administration restricted pilots in

2064-523: The Twin Cities freeway system. When the bridge fell, it was still the most recent river crossing built on a new site in Minneapolis. After the building boom ebbed during the 1970s, infrastructure management shifted toward inspection and maintenance. The bridge's fourteen spans extended 1,907 feet (581 m) long. The three main spans were of deck truss construction while all but two of the eleven approach spans were steel multi-girder construction,

2150-414: The arch bridge . The actual resolution of forces will depend upon the bridge' design . If no horizontal thrusting forces are generated, this becomes an arch-shaped truss which is essentially a bent beam – see moon bridge for an example. If horizontal thrust is generated but the apex of the arch is a pin joint, this is termed as a three-hinged arch . If no hinge exists at the apex, it will normally be

2236-647: The 1960s design work, but in May 2012, the United States Supreme Court turned down its appeal, allowing the state of Minnesota suit to proceed. Jacobs paid $ 8.9 million in November 2012 to settle the suit without admitting wrongdoing. The collapse of the bridge affected river, rail, road, bicycle and pedestrian, and air transit. Pool 1 , created by Ford Dam, was closed to river navigation between mile markers 847 and 854.5. A rail spur switched by

2322-410: The 3-nautical-mile (5.6 km) radius of the rescue and recovery. Thirty-five people lost their jobs when Aggregate Industries of Leicestershire , UK, a company that delivered construction materials by barge, cut production in the area. Small businesses in metropolitan area counties that were harmed by the bridge collapse could apply beginning August 27, 2007 for loans of up to $ 1.5 million, at

2408-520: The Board's investigation is still on-going and no determination of probable cause has been reached, interim findings in the investigation have revealed a safety issue that warrants attention ... During the wreckage recovery, investigators discovered that gusset plates at eight different joint locations in the main center span were fractured. The Board, with assistance from the FHWA, conducted a thorough review of

2494-636: The Cedar Avenue Bridge. Immediately upstream is the Saint Anthony Falls lower lock and dam. The first bridge upstream is the historic Stone Arch Bridge , built for the Great Northern Railway and now used for bicycle and pedestrian traffic. The north foundation pier of the bridge was near a hydroelectric plant that was razed in 1988. The south abutment was in an area polluted by a coal gas processing plant and

2580-684: The Emergency Operations Center established at 6:20 p.m. in Minneapolis City Hall . Recovery of deceased victims took over three weeks. At the request of the NTSB Chairman Mark Rosenker , the U.S. Navy sent 17 divers and a five-person command-and-control element from its Mobile Diving and Salvage Unit Two. The Navy Dive team started diving operations in the river at 2 a.m., within hours of arriving, and conducted operations around

2666-448: The NTSB announced it had determined that the bridge's design specified steel gusset plates that were undersized and inadequate to support the intended load of the bridge, a load that had increased over time. This assertion was based on an interim report that calculated the demand-to-capacity ratio for the gusset plates. The NTSB recommended that similar bridge designs be reviewed for this problem. NTSB Chairman Mark Rosenker said: Although

I-35W Mississippi River bridge - Misplaced Pages Continue

2752-538: The NTSB's final report found that corrosion was not a contributing factor. Since 1993, the bridge was inspected annually by MnDOT , although no inspection report was completed in 2007, due to the construction work. In the years prior to the collapse, several reports cited problems with the bridge structure. In 1990, the federal government gave the I-35W bridge a rating of "structurally deficient", citing significant corrosion in its bearings. Approximately 75,000 other U.S. bridges had this classification in 2007. According to

2838-578: The area, MFD managed the ground operations, and HCSO was in charge of the water operation. The city provided 75 firefighters and 75 law enforcement units. Rescue of victims stranded on the bridge was complete in three hours. "We had a state bridge, in a county river, between two banks of a city. ... But we didn't have one problem with any of these issues, because we knew who was in charge of the assets," said Rocco Forte, city Emergency Preparedness Director. City, metropolitan area, county and state employees at all levels knew their roles and had practiced them since

2924-395: The behavior of MEMS cantilevers. The first is Stoney's formula , which relates cantilever end deflection δ to applied stress σ: where ν {\displaystyle \nu } is Poisson's ratio , E {\displaystyle E} is Young's modulus , L {\displaystyle L} is the beam length and t {\displaystyle t}

3010-454: The bridge collapse. In August 2010, the last of the lawsuits against URS Corporation were settled for $ 52.4 million to avoid prolonged litigation. The cases were handled via a novel consortium of legal entities that worked on a pro-bono basis. The state of Minnesota brought a lawsuit against Jacobs Engineering Group , the successor of Sverdrup & Parcel , the firm that designed the bridge. Jacobs argued too much time had passed since

3096-399: The bridge with potassium acetate solution to keep the area free of winter black ice. The system came into operation in 2000. Although there were no additional major multi-vehicle collisions after the automated de-icing system was installed, it was raised as a possibility that the potassium acetate may have contributed to the collapse of the bridge by corroding the structural supports, though

3182-503: The bridge. At 6:05 p.m. CDT on August 1, 2007, with rush hour bridge traffic moving slowly through the limited number of lanes, the central span of the bridge suddenly gave way, followed by the adjoining spans. The structure and deck collapsed into the river and onto the riverbanks below, the south part toppling 81 feet (25 m) eastward in the process. A total of 111 vehicles were involved, sending their occupants and 18 construction workers as far as 115 feet (35 m) down to

3268-467: The bridge. In internal Mn/DOT documents, bridge officials talked about the possibility of the bridge collapsing, and worried that they might have to condemn it. The construction taking place in the weeks prior to the collapse included joint work and replacing lighting, concrete and guard rails . At the time of the collapse, four of the eight lanes were closed for resurfacing, and there were 575,000 pounds (261 tonnes) of construction supplies and equipment on

3354-518: The cantilever structure to release it, often with an anisotropic wet or dry etching technique. Without cantilever transducers, atomic force microscopy would not be possible. A large number of research groups are attempting to develop cantilever arrays as biosensors for medical diagnostic applications. MEMS cantilevers are also finding application as radio frequency filters and resonators . The MEMS cantilevers are commonly made as unimorphs or bimorphs . Two equations are key to understanding

3440-533: The cantilevers are usually built as pairs, with each cantilever used to support one end of a central section. The Forth Bridge in Scotland is an example of a cantilever truss bridge . A cantilever in a traditionally timber framed building is called a jetty or forebay . In the southern United States, a historic barn type is the cantilever barn of log construction . Temporary cantilevers are often used in construction. The partially constructed structure creates

3526-399: The cause of the collapse on behalf of FHWA, Mn/DOT and Progressive Construction, Inc. NTSB also interviewed eyewitnesses. Peters announced that USDOT had granted Minnesota $ 5 million the day following the collapse. On August 10, Peters announced an additional $ 5 million "for Minneapolis", or "the state", "to reimburse Minneapolis for increased transit operations to serve commuters in

I-35W Mississippi River bridge - Misplaced Pages Continue

3612-425: The central span and 30 feet (9.1 m) deep at the outer ends of the adjoining spans. At the top of the main trusses were the deck trusses, 12 feet (3.7 m) in depth and integral with the main trusses. The transverse deck beams, part of the deck truss, rested on top of the main trusses. These deck beams supported longitudinal deck stringers 27 inches (69 cm) in depth, and reinforced-concrete pavement. The deck

3698-537: The city received FEMA emergency management training the year following the September 11, 2001 attacks . Their rapid response time is also credited to the Minnesota and United States Department of Homeland Security (DHS) investment in 800 MHz mobile radio communications that were operating in Minneapolis and three of the responding counties, the city of Minneapolis collapsed-structures rescue and dive team, and

3784-459: The clock for the next three weeks, until the recovery portion of the mission was completed. The FBI teams had planned to search with an unmanned submarine, but had to abandon this plan after they found it was too big to maneuver in the debris field and cloudy water. Minneapolis Police Captain Mike Martin stated that, "The public safety divers are trained up to a level where they can kind of pick

3870-466: The collapse) Governor Tim Pawlenty stated that the bridge had been scheduled to be replaced in 2020. The I-35W bridge ranked near the bottom of federal inspection ratings nationwide. Bridge inspectors use a sufficiency rating that ranges from the highest score, 100, to the lowest score, zero. In 2005, they rated the bridge at 50, indicating that replacement may have been in order. Out of over 100,000 heavily used bridges, only about 4% scored below 50. On

3956-495: The collapse, Governor Pawlenty and Mn/DOT announced that the Illinois-based engineering firm of Wiss, Janney, Elstner Associates, Inc. had also been selected to provide essential analysis that would parallel the investigation being conducted by the NTSB. One week after the collapse, workers were just beginning to move debris and vehicles to further the process of recovering victims. Cameras and motion detectors were added to

4042-436: The concrete. Structural steel was then disassembled by cranes, and the concrete piers were removed by excavators. National Transportation Safety Board (NTSB) officials asked demolition crews to use extreme care in removing the bridge remnants to preserve as much of the bridge materials as possible for later analysis. By the end of October 2007, the demolition operation was substantially complete, enabling construction to begin on

4128-415: The design of the bridge, with an emphasis on the design of the gusset plates. This review discovered that the original design process of the I-35W bridge led to a serious error in sizing some of the gusset plates in the main truss. On March 17, 2008, the NTSB announced an update on the investigation relating to load capacity, design issues, computer analysis and modeling, digital image analysis and analysis of

4214-499: The divers. After the last person's remains were removed from the wreckage on August 21, the company's crews began dismantling the bridge's remnants. Crews first removed the vehicles stranded on the bridge. By August 18, 80 of the 88 stranded cars and trucks had been moved to the MPD impound lot where owners could claim their vehicles. Then workers shifted to removing the bridge deck using cranes and excavators equipped with hoe rams to break

4300-665: The elements) were further developed in the 20th century as the Vierendeel truss . This article about a specific type of bridge is a stub . You can help Misplaced Pages by expanding it . Cantilever When subjected to a structural load at its far, unsupported end, the cantilever carries the load to the support where it applies a shear stress and a bending moment . Cantilever construction allows overhanging structures without additional support. Cantilevers are widely found in construction, notably in cantilever bridges and balconies (see corbel ). In cantilever bridges,

4386-774: The ends of the bridge routed 50 victims to area hospitals, some in trucks, as ambulances were in short supply. Many of the injured had blunt trauma injuries. Those near the south end were taken to Hennepin County Medical Center (HCMC) — those near the north end, to the Fairview University Medical Center and other hospitals. At least 22 children were injured. Thirteen children were treated at Children's Hospitals and Clinics of Minnesota , five at HCMC and four or five at North Memorial Medical Center in Robbinsdale, Minnesota . During

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4472-438: The first 40 hours, 11 area hospitals treated 98 victims. Only a few of the vehicles were submerged, but many people were stranded on the collapsed sections of the bridge. Several vehicles caught fire, including a semi-trailer truck , from which the driver's body was later recovered. When fire crews arrived, they had to route hoses from several blocks away. A school bus carrying 63 children ended up resting precariously against

4558-581: The force applied to a cantilever can shift the resonance frequency. The frequency shift can be measured with exquisite accuracy using heterodyne techniques and is the basis of ac-coupled cantilever sensors. The principal advantage of MEMS cantilevers is their cheapness and ease of fabrication in large arrays. The challenge for their practical application lies in the square and cubic dependences of cantilever performance specifications on dimensions. These superlinear dependences mean that cantilevers are quite sensitive to variation in process parameters, particularly

4644-490: The foreseeable future, regular inspection, structural health monitoring , and use of strain gauges had been suggested. In 2005, the bridge was again rated as "structurally deficient" and in possible need of replacement, according to the U.S. Department of Transportation's National Bridge Inventory database. Problems were noted in two subsequent inspection reports. The inspection carried out June 15, 2006 found problems of cracking and fatigue. On August 2, 2007 (the day after

4730-574: The guardrail of the collapsed structure, near the burning semi-trailer truck. The children were returning from a field trip to a water park as part of the Waite House Neighborhood Center Day Camp based in the Phillips community . Jeremy Hernandez, a 20-year-old staff member on the bus, assisted many of the children by kicking out the rear emergency exit and escorting or carrying them to safety. One youth worker

4816-612: The help of Hennepin County Medical Center (HCMC), North Memorial and Allina paramedics. By the next morning, they had shifted their focus to the recovery of bodies, with several vehicles known to be trapped under the debris and several people still unaccounted for. Twenty divers organized by the Hennepin County Sheriff's Office (HCSO) used side-scan sonar to locate vehicles submerged in the murky water. Their efforts were hampered by debris and challenging currents. The United States Army Corps of Engineers (USACE) lowered

4902-417: The initial rescue, Mn/DOT retained Carl Bolander & Sons, an earthworks and demolition contractor of Saint Paul, Minnesota , to remove the collapsed bridge and demolish the remaining spans that did not fall. Divers left the water briefly on August 18 while the company's crew used cranes , excavation drills and cutting torches to remove parts of the bridge deck, beams and girders, hoping to improve access for

4988-693: The largest cantilever stand in the world holding 17,000 spectators. The roof built over the stands at Old Trafford uses a cantilever so that no supports will block views of the field. The old (now demolished) Miami Stadium had a similar roof over the spectator area. The largest cantilevered roof in Europe is located at St James' Park in Newcastle-Upon-Tyne , the home stadium of Newcastle United F.C. Less obvious examples of cantilevers are free-standing (vertical) radio towers without guy-wires , and chimneys , which resist being blown over by

5074-503: The last week of November, announced a "$ 1 million plan" for the victims. State law has limits that may restrict awards to below that amount. No legislative action was needed for this step. "The administration wanted approval from the Joint House–Senate Subcommittee on Claims as a sign of bipartisan support"—which it received. On May 2, 2008, the state of Minnesota reached a $ 38 million agreement to compensate victims of

5160-485: The late 1920s and early 1930s raised speeds through this zone and by the late 1930s cantilever wings had almost wholly superseded braced ones. Other changes such as enclosed cockpits, retractable undercarriage, landing flaps and stressed-skin construction furthered the design revolution, with the pivotal moment widely acknowledged to be the MacRobertson England-Australia air race of 1934, which

5246-403: The low-hanging fruit. They can do the stuff that's easy. The bodies that are in the areas where they can sweep shore to shore, the vehicles that they can get into and search that weren't crushed. They were able to remove some of those. Now what we're looking at is the vehicles that are under the bridge deck and the structural pieces." Seventy-five local, state and federal agencies were involved in

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5332-595: The new I-35W bridge on November 1, 2007. Much of the bridge debris was temporarily stored at the nearby Bohemian Flats as part of the ongoing investigation of the collapse; it was removed to a storage facility in Afton, Minnesota , in fall 2010. Federal officials planned to bring some of the bridge steel and concrete to the NTSB Material Laboratory in Washington, D.C. , for analysis toward determining

5418-625: The rescue and recovery including emergency personnel and volunteers from the counties of Anoka , Carver , Dakota , Hennepin , Olmsted , Ramsey , Scott , Washington , Winona , and Wright in Minnesota; and St. Croix County, Wisconsin , St. Croix EMS & Rescue Dive Team, and others standing by. Federal assistance came from the United States Department of Defense , DHS, USACE and the United States Coast Guard . Adventure Divers of Minot, North Dakota ,

5504-651: The river level by two feet (61 cm) downriver at Ford Dam to allow easier access to vehicles in the water. The Minneapolis Fire Department (MFD) created the National Incident Management System command center in the parking lot of the American Red Cross and an adjacent printing company on the west bank. The Minneapolis Police Department (MPD), Minnesota State Patrol and the University of Minnesota Police secured

5590-496: The river or onto its banks. Northern sections fell into a rail yard , landing on three unoccupied and stationary freight cars . Sequential images of the collapse were taken by an outdoor security camera located at the parking lot entrance of the control facility for the Lower Saint Anthony Falls Lock and Dam. The immediate aftermath of the collapse was also captured by a Mn/DOT traffic camera that

5676-410: The river. The center span was connected to the north and south approaches by shorter spans formed by the same main trusses. Each was 266 feet (81 m) in length, and was connected to the approach spans by a 38-foot (12 m) cantilever . The two main trusses, one on either side, ranged in depth from 60 feet (18 m) above their pier and concrete pylon supports, to 36 feet (11 m) at midspan on

5762-514: The road surface over the years, increasing the static load by 20%. Another factor was the extraordinary weight of construction equipment and material resting on the bridge just above its weakest point at the time of the collapse. That load was estimated at 578,000 pounds (262 tonnes), consisting of sand, water and vehicles. The NTSB determined that corrosion was not a significant contributor, but that inspectors did not routinely check that safety features were functional. Pawlenty and his office, during

5848-403: The same. As of early January 2008, at least one business closed, one announced it was closing, seven of eight SBA applications had not been approved and merchants continued to explain how they are unable to shoulder more debt. Seventy percent of the traffic served by the bridge was downtown-bound. Truss arch bridge A truss arch bridge combines the elements of the truss bridge and

5934-574: The seven-county Minneapolis–Saint Paul metropolitan area and emergency response personnel, charities, and volunteers. Within a few days of the collapse, the Minnesota Department of Transportation (MnDOT) planned its replacement with the I-35W Saint Anthony Falls Bridge . The construction of the replacement bridge was completed quickly, and the new bridge officially opened on September 18, 2008. The bridge

6020-479: The site around the bridge to ward off intruders who, officials said, were hindering the investigation. Hennepin County Sheriff Richard W. Stanek stated, "We are treating this as a crime scene at this point. There's no indication there was any foul play involved, [but] it's a crime scene until we can determine what was the cause of the collapse." The Federal Highway Administration (FHWA) built

6106-399: The site was noted for frequent spinouts and collisions. By January 1999, Minnesota DOT began testing magnesium chloride solutions and a mixture of magnesium chloride and a corn-processing byproduct to see whether either would reduce the black ice that appeared on the bridge during the winter months. In October 1999, the state embedded temperature-activated nozzles in the bridge deck to spray

6192-399: The thickness as this is generally difficult to accurately measure. However, it has been shown that microcantilever thicknesses can be precisely measured and that this variation can be quantified. Controlling residual stress can also be difficult. A chemical sensor can be obtained by coating a recognition receptor layer over the upper side of a microcantilever beam. A typical application

6278-443: The time, were initially offered to HurCon Inc. and Industrial Construction Company. HurCon expressed concern about the project, reporting that one portion of the bridge, Pier 6, could not be built as planned. After failed discussions with MnDOT, HurCon backed out of the project altogether. Construction on the bridge began in 1964 and the structure was completed and opened to traffic in 1967 during an era of large-scale projects to build

6364-411: The two exceptions being concrete slab construction. The piers were not built in the navigation channel; instead, the center span of the bridge consisted of a single 458-foot (140 m) steel arched truss over the 390-foot (120 m) channel. The two support piers for the main trusses, each with two load-bearing concrete pylons at either side of the center main span, were located on opposite banks of

6450-450: The undersized and corroded gusset plates. The investigation revealed that photos from a June 2003 inspection of the bridge showed gusset-plate bowing. On November 13, 2008, the NTSB released the findings of its investigation. The primary cause of the collapse was the undersized gusset plates, at 0.5 inches (13 mm) thick. Contributing to that design or construction error was the fact that 2 inches (51 mm) of concrete had been added to

6536-562: The victim families, assisting them in locating family members, and providing a calm presence. On August 20, the last victim was recovered from the river. A Mayo Clinic transport helicopter was standing by at Flying Cloud Airport . The Minnesota National Guard launched a MEDEVAC helicopter and had up to 10,000 guard members ready to help. As of August 8, 2007, more than 500 Red Cross volunteers and staff persons counseled 2,000 people with grief, trauma, missing persons, and medical issues, and served 7,000 meals to first responders. Following

6622-419: The wake of last week's bridge collapse". U.S. Congress removed the $ 100 million per-incident cap on emergency appropriations. The United States House of Representatives and United States Senate each voted unanimously for $ 250 million in emergency funding for Minnesota that President Bush signed into law on August 6. On August 10, 2007, Peters announced $ 50 million in immediate emergency relief,

6708-424: The wind through cantilever action at their base. The cantilever is commonly used in the wings of fixed-wing aircraft . Early aircraft had light structures which were braced with wires and struts . However, these introduced aerodynamic drag which limited performance. While it is heavier, the cantilever avoids this issue and allows the plane to fly faster. Hugo Junkers pioneered the cantilever wing in 1915. Only

6794-453: The wing must also form a stiff cantilever in the horizontal plane. A single-spar design will usually be fitted with a second smaller drag-spar nearer the trailing edge , braced to the main spar via additional internal members or a stressed skin. The wing must also resist twisting forces, achieved by cross-bracing or otherwise stiffening the main structure. Cantilever wings require much stronger and heavier spars than would otherwise be needed in

6880-399: Was 113 ft 4 in (34.54 m) in breadth and was split longitudinally. It had transverse expansion joints at the centers and ends of each of the three main spans. The roadway deck was approximately 115 feet (35 m) above the water level. On December 19, 1985, the temperature reached −30 °F (−34 °C). Vehicles coming across the bridge experienced black ice and there was

6966-451: Was addressed prior to the study by drilling the cracks to prevent further propagation and adding support struts to the cross girder to prevent further distortion. The report also noted a concern about lack of redundancy in the main truss system, which meant the bridge had a greater risk of collapse in the event of any single structural failure. Although the report concluded that the bridge should not have any problems with fatigue cracking in

7052-777: Was asked to set up and manage a Family Assistance Center (FAC) for the victims' families. He coordinated site location and staffing arrangements with the city's Department of Health and Family support and relevant Hennepin County offices. When Chaplain Supervisor John LeMay and Lead Chaplain Linda Koelman arrived on the scene, they assisted in setting up the FAC at the Holiday Inn by 8 p.m. As additional Minneapolis Police Chaplains arrived, they began providing services to

7138-572: Was facing away from the bridge during the collapse itself. Mayor R. T. Rybak and Governor Tim Pawlenty declared a state of emergency for the city of Minneapolis and for the State of Minnesota on August 2. Rybak's declaration was approved and extended indefinitely by the Minneapolis City Council the next day. As of the morning following the collapse, according to White House Press Secretary Tony Snow , Minnesota had not requested

7224-487: Was located in Minneapolis, Minnesota's largest city, and connected the neighborhoods of Downtown East and Marcy-Holmes . The south abutment was northeast of the Hubert H. Humphrey Metrodome , and the north abutment was northwest of the University of Minnesota East Bank campus. The bridge was the southeastern boundary of the "Mississippi Mile" downtown riverfront parkland. Downstream is the 10th Avenue Bridge , once known as

7310-403: Was severely injured. Civilians immediately took part in the rescue efforts. Minneapolis and Hennepin County received mutual aid from neighboring cities and counties throughout the metropolitan area. The Minneapolis Fire Department (MFD) arrived in six minutes and responded quickly, helping people who were trapped in their vehicles. They took 81 minutes to triage and transport 145 patients with

7396-677: Was won by a de Havilland DH.88 Comet . Currently, cantilever wings are almost universal with bracing only being used for some slower aircraft where a lighter weight is prioritized over speed, such as in the ultralight class. Cantilevered beams are the most ubiquitous structures in the field of microelectromechanical systems (MEMS). An early example of a MEMS cantilever is the Resonistor, an electromechanical monolithic resonator. MEMS cantilevers are commonly fabricated from silicon (Si), silicon nitride (Si 3 N 4 ), or polymers . The fabrication process typically involves undercutting

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