Accelerated Arrogance: The FIU Pedestrian Bridge Collapse

in 2018, when the rush to install the FIU

pedestrian

bridge

, inadequate project calculations, the crisis in meeting urgent deadlines, and gross neglect of blatant warning signs led to a clearly avoidable tragedy that claimed innocent lives, breaking down the murder, it was a busy afternoon in March 2018 at the intersection of Southwest. 8th and East Campus Circle in Miami Florida Southwest 8th Street is an eight-lane road on the north side of FIU or the main campus of Florida International University, this particular area was slightly congested in recent weeks due to the construction of the new crossing FIU and Sweetwater

pedestrian

elevated

bridge

that would link the campus and the suburb of Sweetwater near three main parking lots on the FIU side that connect near the University City off-campus housing under construction, also recently implemented, just on the FIU side North, the pedestrian bridge would allow B campus students to cross eight lanes of traffic and the nearby Canal safely and with relative ease.

It was also evident that this overpass would be a significant source of pride for FIU Sweetwater and its partners, evident by its truly unique design, artistic influences and bold promotional campaigns, and especially because the university is home to the acclaimed school of construction engineering and specifically FIU's

accelerated

bridge construction or ABC program under construction but not completely impeding traffic on Southwest 8th, FIU's pedestrian bridge project had reached a point where only two lanes needed to be closed to continue your work on Thursday, March 15. 2018, although at approximately 1:45 p.m. The bridge suddenly

collapse

d along with the eight vehicles that hit it.

A small group of workers were present at the top of the structure and this catastrophe injured 10 and claimed the lives of six, five of whom were in occupied vehicles below and one of the workers. Ultimately designed to be an asymmetrical cable state supported by a concrete truss or suspension bridge in appearance, the idea itself saw many ups and downs over the years due to budget issues. The suburban city of Sweetwater is home to much of FIU's off-campus housing and is flanked by university locations. the location of the College of Engineering to the east northeast the main campus directly to the south the southwest 8th lane 8th Street cuts right between the two and is actually the old Highway 41 the main surface The road that directly enters and exits the center of Miami's volume of pedestrians needing the crossing has been a well-known safety hazard for years, including 18-year-old Alexis Dale, who moved from San Diego this summer to attend college, unfortunately one day before the start of the school was fatally struck while crossing 8th Street at Southwest 109th.

Avenue early Sunday morning through a partnership between FIU, the city of Sweetwater Fig Group and Mania Construction Management or MCM, design control and approval would ultimately rest with the Florida Department of Transportation or, if bridge was to be a two-span uncovered bridge. - Redundant concrete frame in its load-bearing structure with a decorative tower on top that reaches to the roof with ornamental braces of steel tubes that emulate the appearance of a cable-stayed or suspension bridge. Asymmetrical and complex designs, although load-bearing structures like these are challenging and require the most. engineering professionalism and calculations at a cost of approximately $12 million, a total length of 320 feet including stairs and landings at each end, the main span would weigh 950 tons and be 175 feet long to accommodate the 5 eastbound lanes and all three heading west.

Lanes with a proposed walkway for a separate rear addition leading directly to the pg4 red parking lot on the FIU side, was previously 11 feet shorter, a design review requested in October 2016 by fot brought it to this length, requiring to accommodate a future eastbound bus lane as Well, the second span over the canal would be 99 feet long and the tower would be located 109 feet directly above the burma between the canal and Southwest 8th Mania construction management or MCM would be the main contractor on site for the construction work which is now important to note. This is the only thing that this was all about and it's not just an opinion: this was overt and intentional in the design of the Bridge, while concrete box girders have become increasingly common until recent years.

The Concrete or Composite Truss Bridge was extremely rare, as the trusses were composed almost exclusively of steel, the only non-redundant centered line of girders along with such a heavy canopy, were also somewhat unique; However, it was the fake State Tower cable as decoration that attracted the most attention in the architecture and engineering communities, as it would be a huge amount. of additional static loading just for the sake of aesthetics, something virtually unheard of in the world of engineering bridges of this magnitude for purely aesthetic purposes, is not impossible, but again it is very complex and requires the utmost professionalism in planning and design.

In fact, fig group makes this the pillar of their work, something that has attracted so many clients in bridges as art, they call it, the concrete would be composed of the promising self-washing composite material that we are seeing more and more lately, along with the reinforcement of rebar, this self-washing material is intended to keep the bridge looking fresh and new by preventing it from taking on the typical dirty gray color seen on so many older bridges, as the loading was entirely up to the members of the concrete trust. , this new self-washing composite would be the main structural element helped only by reinforcing bars. and would no doubt be put to the test here, eventually the main span would be assembled and transported into place under the

accelerated

bridge construction program or ABC, a program that FIU is proud of even to this day, this meant through This revolutionary ABC program and its Innovations: process would seek to minimize traffic disruption by building new bridges.

The ABC process uses materials and planning design methods to reduce construction time on site. It's safe to say that with the volume and frequency of pedestrians crossing such a busy street it's a must. The question is why this has not generally been a priority for local municipalities here, since in most disasters of this type it is rare that a single cause or a single party is to blame and this particular

collapse

served as made as a clear example in Chain of Failures. and the

arrogance

of the group thinks Modern Times And the current year's argument is no exception and provides no immunity to this fallacy, initial construction would take place in an assembly yard parallel to Southwest 8 on the FIU side of the highway, the two main pairs of the Bridge that would support each end and this main span would receive the highest priority for assembly and commissioning, the goal is to close the road as little as possible and the ABC process is what drives most of an operation like this , close assembly and false worker instead of stretches along the road obstructing traffic and then transports the main span, in this case placing it in place with the use of self-propelled modular transporters or spmts, as is the case with many aspects of bridge construction, although this is obviously much easier in concept than in practice.

The process of moving an assembled structure as heavy as a single unit, even a few feet, let alone rotating its orientation, changing lifting points, leveling the plane on which it sits, etc., is time-consuming and exerts a strain. great pressure on it even under the best conditions. In these circumstances, the goal once the concrete sets on a bridge like this and in this portion in particular is to have all of the load-bearing members under what is known as compression. Concrete is notoriously weak under tension but much stronger under compression. Using rebar helps mitigate this a bit, but to oversimplify, think about placing a rectangular step at its end and stacking something on top of it instead of placing this step flat like a bridge across two supports at the ends. and then doing the same with concrete now under tension, it is much more prone to cracking. and give, the same applies to pulling on concrete, another form of tension, like pulling on a spring rather than compressing it, this is known as the tensile strength of concrete and although they are much lower than its compressive strength , these factors still need to be calculated and well understood even though their primary purpose will be to undergo compression for most of their life as assembly and casting were nearing completion in the yard at the top, the fake work Since the expected compression and tension were not in balance along with the rebar skeleton within each concrete member, each truss also contained what are known as post-tensioning rods, these rods allow teams to increase or release tension. in each of them, bringing them to the desired condition for the application.

In this case, each compression member is the target with each trust member and their respective joints or nodes balanced on top. to a false job or now was the time to lift the structure onto the spmt, the kinematics of these new forces meant that balance would be lost again, the bridge being raised over the transports from a different position meant that the post-tensioned, returning them to a state of compression. The internal design tolerances trans report would be carried out quickly although, in fact, although the ABC process has gained popularity in the last decade, the FIU bridge was to be an example of how this part was carried out at an apparently time record, the bridge in Georgia took several months to build, then around 60 hours to put into position, the one in Florida took only 6 hours while it gains popularity and slowly becomes commonplace, especially to replace the most interstate bridges. old ones reaching the end of their accelerated useful life.

Bridge construction has incredibly nuances and forces. It should be noted that it is quite possible that this would never have been considered in the past when building a bridge: fixing it in place with the spmt in position, it was time to lower the main span over the bridge. Drill, however, the pillars would also be fitted with shims. spacers essentially to temporarily hold it a little higher than placing it directly on top of the pairs with this structure now out of balance again post tensioning would be carried out to bring all the members back into compression, cracks had appeared, although they caused a loud sound and distinctive heard by workers. at node 1112 The joint where trust members 11 and 12 intersect during assembly on top of the fake work 19 days before this, on February 24, these cracks continued to spread and visibly worsened, closely documented by several parties involved in management until during further tensioning operations on the top of the canopy the concrete at node 1112 completely exploded, the first point of failure was followed almost simultaneously by failure points 2 and three and the subsequent collapse Instant on the road below.

However, these events began long before the assembly yard, and to understand this, we will need to dig deeper. and go back 16 months to the drawing board so to speak, we have already communicated to the developer that accelerating the bridge is called accelerated bridge construction or ABC for short accelerated bridge construction accelerated bridge construction some call it instantaneous bridge acceleration the bridge and the concern for the streets and plaza later, now keep in mind that this sequence of cause and effect was only achieved after a thorough 19-month official investigation by the NTSB and its partners, which even then dragged on beyond this due to complications with the main parties involved in the bridge attempting to effectively absolve themselves of any wrongdoing at all times.

This summary here, for example, from the NTSB was published in February 2021, a follow-up report to the official har 1902 report from October 2019. When designs of this nature are produced, it is common practice for them to undergo review by independent peers, essentially third-party consultants in the field certified to evaluate calculations, load capacities, and other related engineering verifications to ensure that drawings and plans meet specifications and requirements for the planned use. fig Bridge Group, the registered engineering company, would engage LS Burger and Associates for this quality control process; However, investigators discovered that the Lewis Burger company was notqualified by the Florida Department of Transportation for this type of complex Bridge certification and was the last word.

On a project like this, Fot should have independently verified this information before signing. A similar process is also carried out when construction begins and external engineering consultants will be present on the job site to manage. Monitor and inspect as construction progresses. Mania Construction Management. The company hired. by FIU for construction work on the site would hire Bolton Perez and Associates Consulting Engineers for this task. The Bridge group designs were non-redundant and provided only a single load path, meaning that essentially, if one member fails, a total collapse would likely not occur. Completely unusual in the world of structural engineering, however, Fig was creating this design based entirely and almost unbelievably on the fact that they mistakenly considered this structure to actually be redundant and had created their calculations and load capacity needs on based on this false redundancy factor.

This is unique, with a single row of girders, not even girders on either side like most bridges, which path the load had to take if a member broke. The level of incompetence here is also infuriating and just as crucial to the chain of failures of the Lewis Berser firm. It was discovered that he had not performed any condition assessments other than the completed, fully assembled version of the bridge. The engineer at Lewis Burger told the researchers that my model was for the structure, since a structure that performed a construction sequence analysis was not part of our scope and again such an analysis requires much more time than we agreed upon.

When referring to the Fig Bridge group in an interview after the collapse, engineer Lewis Berser stated at the beginning. I suggested doing this type of analysis to analyze the connections. I am talking about the nodes or joints to analyze the connections, however the budget and time to do this was not actually agreed upon with the designer. The university says it followed all processes and procedures. The fiu president confirmed on thursday that testing was conducted on the bridge. I have not spoken directly to Mania Construction, but I am satisfied that the testing being carried out was consistent with best practice.

Munia Construction Management, a Miami-based family business based in Miami, partnered with false bridge engineering and a secondary engineering company Lewis Berger group we follow all processes competitive bidding two-phase process an independent engineering company that is fully certified by the state that recommended us fot, so the tolerance had not been taken into account for the atypical stress exerted on any of these parts during the ABC process, in addition to this, since the Fig designs were inadequate, even assigned from factoring in the ABC process, it should have been obvious for a company like Lewis Berer to grasp at least this poorly designed end. design, as that is the purpose of said peer review process, since Fig's calculations were very flawed and the future forces remain so underestimated that nodes 1 2 and 1112 would be pathetically poorly designed and contain non-structural voids, essentially empty, wasted space within the concrete and insufficient reinforcing bars.

It was inevitable that cracking would occur almost immediately once the concrete had set in the Ard assembly and this is exactly what happened at node 1112 as frustrating as this cracking was closely monitored and well documented over a period of 2 to 3 weeks February 24 A loud, distinctive cracking sound is heard from node 1112 as tensioning is completed and the false work removal process begins. On March 10, the SPMs begin to move the main span and over the next few days, during the movement, it is de-tensioned and placed on the bridge piers, the cracks evolve. significantly from what originally seemed concerning to Beyond Alarming on March 13, reaching a depth of 2 to 3 inches now and spreading rapidly throughout Joint Region 1112, this could and should have been easily identified by those in the industry as the joint beginning 1112. to completely dislocate from the bridge deck Denny Pate, the one shown with the seal of approval on the drawings, the principal engineer of record and vice president of the Fig group, was instrumental in bringing the narrative to all the parts that these cracks do not represent any problem.

Hi Tom, I'm Denny Pay. With the engineers on the big bridge, obviously there will be some repairs that will have to be done or whatever, but from a safety perspective we don't see there being any problems there. Pate then headed to Miami and on March 15, the day of the collapse, just hours before, after seeing the cracks in person at 8:00 a.m. He would hold a meeting at 9: a.m. with FIU F do MCM Bolton Perez and the rest to assure them that there was nothing to worry about, at which point neither party expressed any desire to stop work or close On the road below the 950 ton section now being collapsing, the decision was made to send workers to the deck in an attempt to tension member 11 using the post-tensioning rods.

This decision was, of course, feudal and those responsible clung to their straws when the cracking from the beginning to an engineer who gives a dam should have been a message a warning to the bridge shouting that it was already condemned to give way the collapse occurred that same afternoon during the lifting procedure initial frustrations on the part of the ntsb in putting together this puzzle along with the mentalities that cause the collapse, this narrative did not even stop when groupthink collapsed in a group the tendency of individuals to uncritically accept any decision due to conformism groupthink is based on a common desire not to upset the balance of For a group of people, it seems that the same mentality was at play here in all organizations (Fig.

Lewis Berger MCM BPA and finally FIU). It also appears that all organizations absolved themselves of responsibility by rationalizing that if the registered engineer says he is fine, it must be so. okay, and if something bad happens, it's his fault, MCM was eventually forced to restructure and, along with Bolton Perez, were both fined, albeit minimally, the fig group was fed to a greater extent and ended up excluded, eliminated and not allowed from future Federal Highway Administration projects, which as far as I can find they are continuing to appeal in court, were also recently removed from the Houston Ship Channel project, a project they featured heavily on their website and, as far as I can find, updates on their site stopped around this time and the Mark website copyright even shows 2020.

Still, a $13 million settlement was shared with the families of the 10 injured and six missing by the vice president of NTSB, Bruce Lansburg, despite the public's anger, anguish and disappointment, none of the organizations responsible had any intention for this tragic event to occur or cause any injury. or loss of life unfortunately good intentions are not enough for competence and diligence, once the crack became evident, none of the organizations involved were willing to take the essential and unpopular step of stopping and closing the path to the failure human that affects everyone. For us it is complacency, it is not a term the NTSB uses often, but in my opinion it is present in almost all accidents and collisions.

It is my fervent hope that the organizations involved will take the NTSB recommendations seriously and implement them quickly. deserves at least that