In 2000, hoan bridge failure in milwaukee, wisconsin, exposed the. There was also no evidence of fatigue crack development in this region from surface or internal discontinuities. Uhm laminates have been shown to be effective to prevent fatigue crack initiation in steel members. In december 2000, two of the three major girders supporting the hoan bridge in milwaukee failed. Arresting cracks in steel bridges amazon web services. It focuses on the causes of and factors associated with this phenomenon as it has been responsible for the failure of several bridges in the last dozen years. Approachspan failure of the hoan bridge as a case study. The objective of this study was to develop a simplified method of predicting the fatigue reliability of steel bridge details with preexisting cracks. Inspecting steel bridges for fatigue pdf when cracks are discovered on bridges in service, fatigue is usually the cause.
The cracks allowed a portion of the concrete deck to sag down 4 ft. Failure of steel bridges due to constraint induced fracture. Required project showing for proposed bridge rehabilitation of rte. Hoan bridge failure investigation federal highway administration. When fatigue cracks reach a critical size, brittle fracture could result usually on a cold night. Chapter 3 findings and application fracturecritical.
The joint connecting the lower lateral bracing to the web is clearly the initiation site of failure in the hoan. To determine the fatigue service life and the accumulated damage of the investigated bridge, the first step was related to the determination of the stress ranges that occurred at the bridge. Students apply prerequisite statistics knowledge and concepts learned in an associated lesson to a realworld stateoftheart research problem that asks them to quantitatively analyze the effectiveness of different cracked steel repair methods. Fatigue cracks are still a cause for concern because they will continue to grow and eventually reach a size where brittle fracture will occur. For example, in 1967, the point pleasant bridge over the ohio. However, diagonal cracks are also sometimes present but tend to be restricted to the bridge ends.
Bridge collapse in minneapolis page 2 motorcycle forum. Nov 16, 2007 when inspectors find bridge components in need of attention, traffic, age and weather are the most common contributing factors. Eventually, the growth of one or a few crack of the larger cracks will dominate over the rest of the cracks. Changes in traffic patterns, volume, and any degradation of structural components can influence the fatigue life of the bridge. Task 387, maintenance actions to address fatigue cracking in steel bridge. The ae technique can be used to identify active fatigue cracks and to monitor their growth under heavy axle loads in steel bridges.
Typical fatigue crack across a repaired flange butt weld in a welded igirder test specimen. Brittle fracture can occur at high constraint details with little or no warning impending fracture fhwa, 20 6. Fracture mechanics calculations were performed and indicated that effectively infinite fatigue life can be expected, and that the flange of the girder can tolerate a large greater than 2 inches fatigue crack before fracturing. Using acoustic emission to monitor fatigue cracks on the. Prediction of fatigue life of reinforced concrete bridges. Following the events of september 11th, 2001, there has been considerable. Inspection and management of bridges with fracturecritical details explores the inspection and maintenance of bridges with fracturecritical members fcms, as defined in the american association of state highway and transportation officials load and resistance factor design lrfd bridge design specifications. Inspecting steel bridges for fatigue currently required by indot for complex and fracturecritical bridge inspection qualification. This paper discusses issues related to the failure of steel bridge structures attributable to a certain type of fracture called constraint induced fracture cif. The damaged part of the bridge was located about 200 ft. To assess this condition a series of experimental test were conducted to examine the fatigue susceptibility of intersecting weld details commonly used in indiana. Depending on bridge age, poor details heighten the potential for fatigue cracks and increase the possibility of multimember fractures during a fracture event.
Fatigue safety of reinforced concrete bridge decks includes a fatigue safety check of the rebars, and existing knowledge in fatigue behaviour of steel structures can be adopted. Some considerations in the design of long span bridges against progressive collapse theodore p. Therefore, the bridge deck section should be one of the main parts of the fatigue analysis for a bridge. Often several types of fatigue cracks have developed in a single bridge because different details existed on. Surface appearance of fatigue crack is smooth and silky. Horizontal stiffener fatigue crack ky 117 over i 24 in 1987. February 2014 research project final report 201409.
Fatigue strength of steel bridge members with intersecting. The strength aspects of the cif phenomenon are analyzed using the example. The hoan bridge also know as the milwaukee harbor bridge, opened to traffic in 1974, is located on interstate highway 794 over the milwaukee river in the city of milwaukee,i wisconsin. A fatigue life evaluation, reflecting the actual conditions, has value to bridge owners. Western bridge preservation partnership san diego ca. Lichtenstein performed a longterm retrofit design for the hoan bridge that addressed the identified causes for the sudden brittle fracture and eliminated all fractureprone details. This paper discusses issues related to the failure of steel bridge structures attributable to a. There was also no evidence of fatigue crack development in this region. Although construction on the bridge lasted briefly from 1970. Hill said, the biggest thing that causes fatigue on pavement or bridges is heavy commercial trucks.
In this paper bonded cfrp laminates were used for strengthening, however, the method can be applied for other retrofit elements such as unbonded laminates, bolted steel plates and prestressed steel tendons. The fracture of a solid usually occurs due to the development of certain displacement discontinuity surfaces within the solid. The forensic investigation concluded that the cracking was due to brittle fracture and not related to fatigue. Estimating fatigue life of patroon island bridge using strain. Cracks are most commonly found near the pier location. The article also described how cracks detected in december 2000 in all three girders of an approach span of the hoan bridge in milwaukee prompted officials to shut the 1970sera bridge. As if they are civil engineers, students statistically analyze and compare 12 sets of experimental data from seven research centers around the world. Chapter 2 research approach fracturecritical system.
Failure analysis of the us 422 girder fracture eric j. New video was just released of a deadly crash on the hoan bridge. To assess this condition a series of experimental test were conducted to examine the fatigue susceptibility of intersecting weld details commonly used in. Fisher atlss engineering research center, lehigh university, bethlehem, pa 18015, usa civil and environmental engineering, lehigh university, bethlehem, pa 18015, usa abstract fatigue cracks and fractures that develop at the intersection of transverse connection plates and gusset plates. As the cracks were not removable by coring, cover plates were bolted to provide alternative load paths. The greatest portion of the fatigue life is spent nucleating and growing a fatigue crack to a length at which it can be detected the range of effective stress intensity factor, that is, the idea of crack closure allows the growth of fatigue cracks to be rationalized the behavior of small cracks is in many respects quite different from long. Hoan bridge investigation steel structures bridges. Fatigue analysis and life prediction of bridges with. During the 1990s, later inspections found fatigue cracks and corrosion in the steel around the bridge s joints. Fatigue is usually associated with tensile stresses but fatigue cracks have been reported due to compressive loads. The daniel hoan memorial bridge is a tiedarch bridge that connects interstate 794 in downtown milwaukee, wisconsin, to the lake freeway across the milwaukee river inlet. Definitions hoan bridge fracture northridge moment frame fractures charpy test and notch toughness cvn kline problem other infamous brittle fractures in structures highcycle fatigue definition. Formation of a crack due to cyclic elastic loading below design stress levels.
You start to see more stresses in the structural components due to accumulated fatigue over time. Inspecting steel bridges for fatigue pdf course brochure hosted at your location. Months later, investigators questioned the engineering design of the bridge. Drilling crackarrest holes is a simple technique, commonly used by bridge owners to control andor repair fatigue cracks in steel bridges. Fhwa structures lab investigates milwaukee bridge collapse. If a displacement develops perpendicular to the surface of displacement, it is called a normal tensile crack or simply a crack.
Pdf composite steelconcrete highway bridge fatigue. Fatigue failure does not occur unless part of the stress cycle involves. Cracks exist in both steel girder bridges and prestressed concrete girder bridges. Bridge deck sections are constructed by connecting many plates, beams and bars by welding, rivets or some other way. These can cause immediate loss of part or all of the capacity of the structure and in the worst case will cause collapse. Inspecting steel bridges for fatigue cai purdue university. Aug 02, 2007 during the 1990s, later inspections found fatigue cracks and corrosion in the steel around the bridge s joints. The bridge was built 32 in 1980s and fatigue cracks were identified in some of the diaphragm connection welds. The bridge was adequately designed and fabricated according to existing code specifications.
Fatigue cracks monitored during 1999 and 2000 on the bridge at the facility for accelerated service testing using the acoustic emission ae technique will provide information to assist bridge engineers in prioritizing repairs and, in many cases, extending the life of steel railroad bridges. Apr 04, 2018 for in situ case studies on both a railway and a highway bridge, measured fatigue stress range spectra indicated that the bonding and bolting steel plate methods significantly enhance local rigidity and decrease local stresses. Strainbased fatigue crack monitoring of steel bridges. Trbs national cooperative highway research program nchrp synthesis 354. The bridge is a 31 singlespan structure of a span length of 46. The hoan bridge case is unique in that there was no evidence of fatigue prior to failure. Two of the three girders had a fracture propagate completely through the 3. The results of the application of the three pouring sequence scenarios to the hoan bridge were similar to those previously reported for the neville island bridge. We include the joint design that connected the lower lateral bracing to the web plates of the girders in this discussion. Failure analysis of the us 422 girder fracture lehigh preserve. Steel denies hoan bridge tie milwaukee business journal.
The greater the applied stress range, the shorter the life. Split sleeve cold expansion overview onesided process. The design fatigue life of a bridge component is based on the stress spectrum the component experiences and the fatigue durability. Fatigue failure of the steel is described in the crack initiation period, which includes crack nucleation and micro crack growth, fol. Retrofit of the hoan bridge to prevent brittle fracture. Extending service life through preemptive retrofits. It is possible that an intersecting weld detail with less constraint than the hoan bridge detail may lead to fatigue crack initiation earlier than otherwise anticipated. Currently required by indot for complex and fracturecritical bridge inspection qualification. Potential for fracture to occur in iowa dot steel girder. With fatigue, the most important stress parameter is the magnitude of the cyclic variation. Abstracton the morning of december, 2000, all three steel girders in a threegirder approach span of the hoan bridge in milwaukee. Extending the service life of steel bridges through field instrumentation robert j. Curtis schroeder joined wje in march 2019 with a background in inspection and evaluation of steel bridges.
Fatiguefracture failure of bridges typical progression of. Hoan bridge demolition rescheduled the daily reporter. Intended to bend instead of break, bridge components failed to withstand frigid midwestern winter temperatures and heavy commercial truck traffic. After derailing due to metal fatigue in one of its metal tyres, the hanoverbound intercityexpress high speed train collided with a road bridge, causing it to collapse onto part of the train. Arresting cracks in steel bridges using proven aerospace technology len reid, vice president technology. The hoan bridge is a rare example of the worstcase scenario. A number of localized failures have developed in welded steel bridge components because of fatigue crack propagation, which in some instances has led to brittle fracture. For example, in 1967, the point pleasant bridge over the ohio river in west. This course begins with an overview of the unique construction history of the daniel webster hoan memorial bridge. Manual for repair and retrofit of fatigue cracks in steel bridges. Cold reinforcement and evaluation of steel bridges with. Westbound i80 bridge over the cedar river, bridge engineering center, february 8, 2010 also verified that fatigue crack development was not probable as the stress range cycles were below the fatigue limit. The federal highway administration s fhwa structures lab became a forensic research center this past year, as fhwa led a team in investigating the partial collapse of a 66m 72yd section of milwaukees hoan bridge last december.
Evaluated stress ranges at the fatigue crack locations on i64. As mentioned earlier, the hoan bridge fracture involved a severe triaxial constraint condition due to intersecting welds. Fatigue cracks in a bridge are likely to appear at the location of these connections. This booklet has been prepared as a to the general problem of bridge faljue and to a is. Rupture in tension or rapid extension of a crack leading to gross deformation, loss of function or serviceability, or complete separation of the component. On the bridge at fast, a vertical crack at the flange exhibit 1 became dormant, whereas a crack at one of the welds exhibit 1 remained active in both directions. Fatigue crack definition of fatigue crack by the free. Originally called the harbor bridge, it was renamed after daniel hoan, one of the longest serving mayors of milwaukee. Learn vocabulary, terms, and more with flashcards, games, and other study tools. One of those motorists called 911 to report the problem to the milwaukee county sheriffs office. On the very cold, early morning of december, 2000, a section of a northbound approach span of the hoan bridge began to buckle and crack as motorists were driving over the structure.
Although wellestablished relationships exist for sizing the diameter of crackarrest holes for inplane fatigue loading, the effectiveness of such holes in preventing reinitiation of outofplane distortioninduced fatigue cracks is not well understood. Rettner, primary author american engineering testing, inc. International journal of engineering applied sciences and. Brittle fracture can occur at high constraint details with little or no warning impending fracture. Nondestructive evaluation of cracking on steel bridges and. There are many known cases of fatigue cracking from this type of detail, but this is the first known case of brittle fracture.
The milwaukee business journal features local business news about milwaukee. Validated the proposed methodology through analysis of hoan bridge and twin tub girder bridge tested at ut austin in abaqus. It really depends on when we can do a day and a half of work, including cutting to place the explosives and placing the explosives, said don rhodes, dot communications manager. The fatigue phenomenon is the result of the cumulative process consisting of crack initiation, propagation and the final fracture of a structural component. On the morning of december, 2000, all three steel girders in a threegirder approach span of the hoan bridge in milwaukee, wisconsin, fractured.
Figure 11, figure 12, and figure show the longitudinal normal stress along the center of the bottom flange of girder d, girder e, and girder f, respectively, for the three scenarios. We then discuss the hoan bridges tiedarch span design and approach span design. Extending the service life of steel bridges through field. Some of the common factors that often contribute to a brittle fracture include the use of low fracture toughness steel. The future of fracture critical kansas state university. Increases in the number of trucks and allowable weights has led to a rapid accu mulation of loading cycles. Mar 15, 2001 wisconsin winter wages war on hoan bridge. Effectiveness of crackarrest holes under distortioninduced. Maintenance actions to address fatigue cracking in steel bridge. Fatigue strength of steel bridge members with increasing welds introduction a number of factors can be responsible for the development of a brittle fracture in steel girder highway bridge structures. Fatigue strength of steel bridge members with intersecting welds. Originally called the harbor bridge, it was renamed after daniel hoan, one of the longest serving mayors of mil.
Fatigue cracks were found to originate at large lack of fusion areas in the lateral. The expected life of a steel highway bridge subjected to random, variableamplitude traffic cycles is highly dependent upon damage accumulation caused by various fatigue mechanisms. In the second stage of fatigue, some of the tiny microcracks join together and begin to propagate through the material in a direction that is perpendicular to the maximum tensile stress. In general, the cracks formed parallel to the primary tension from the. In this context, welded joints are well known as the weakest points in bridges, since they are prone to stress concentrations leading to initiation of fatigue cracks being in current design codes. Numerical fracture mechanics results reveal fatigue stresses at the crack tip below the threshold of crack propagation. The hoan bridge failure was attributed to brittle fracture without the. Approachspan failure of the hoan bridge as a case study for. A strengthening theory to prevent fatigue crack initiation in.