Discussing current issues in engineering
As the pandemic continues to draw attention to infrastructure shortcomings all over the globe, engineers and city planners must ask themselves how they can contribute equitable and accessible industry decisions to a post-pandemic world. In an effort to confront this question, California’s Los Angeles County hosted a series of five webinars last year at the Los Angeles Headquarters Association, an organization designed to advance economic growth in the county.
The series ran from July to November and featured a long list of influential panelists including an L.A. City planning commissioner, regional non-profit executive, chief design officer at the L.A. mayor’s office, Lyft senior public policy manager, architects, and designers. Panelists addressed pervasive issues made plainer by the pandemic and our country’s present grappling with institutionalized racism and racial inequality.
Because engineering and design professionals have traditionally held a significant role in land use decision-making, panelists placed a focus on the professional’s duty to address the needs of a community. In the past, engineers have been key players in an approach that tells communities what they will receive without addressing (or even seeking out) the concerns of community residents.
Take, for example, the fact that women, specifically women of color and mothers with children, are more likely to ride the bus than men. Yet bus stops all around the country are essentially designed for the use of 30-year-old white men—individuals who may not be threatened by standing in the dark at night, or in the summer sun for twenty minutes. Furthermore, as discussion moderator Katherine Perez points out, community land-use decisions have often unevenly damaged diverse and low-income neighborhoods. Consider decisions regarding landfill or freeway locations—or any other variety of less-desirable infrastructure for that matter.
Webinar discussions highlighted the power that engineers have to address issues of equity through their creativity and influence on project budgets. As panelist Paul Moore, P.E., of the Arup professional services firm states, “[W]hile policymakers and planners can have fantastic ideas and intentions about how to reshape cities, it’s engineers who are often empowered to implement the ideas.”
The Los Angeles Headquarters Association webinars publicized the role of engineers in inclusive infrastructure. Moving forward, engineers around the world are responsible for the creation of equitable and sustainable value accrual practices through their infrastructure and design projects.
To learn more about the L.A. Headquarters Association webinars and panelists, click here.
EnviroRail Embraces Green Railroad Construction and Maintenance Through Partnership with Mechanical Concrete
The Nebraska-based railroad service contractor EnviroRail recently licensed Mechanical Concrete, an industrial strength aggregate confinement technology, marking a first for the future of sustainable railroad construction and maintenance.
All roads require regular maintenance throughout their lifespans. This is due in part to the fact that most road foundations, including railroad foundations, are comprised of compacted stone aggregate which weakens when wet. As pressure is applied to the wet aggregate particles spread out laterally resulting in a loss of road structure. This process yields features like ruts, potholes, and collapsed road edges. Railroads are particularly susceptible to this form of deterioration because of the high pressure loads typically transported by rail.
Samuel G. Bonasso, P.E., the creator of Mechanical Concrete, realized that in order to slow down this cycle of road deterioration and maintenance he needed to address the structural issue associated with loss of road base structure. His solution was simple: to prevent the loss of road structure, prevent aggregate lateral spread. What’s more, Bonasso incorporated a readily-available, oft-discarded industrial waste product into his process, creating a reliable and sustainable materials sourcing practice.
Each year, more than three hundred million waste auto tires are generated in the United States. And while tire recyclers make use of some eighty percent of waste tires through the recycling process, roughly half of those recycled tires are then burned for tire-derived-fuel. Mechanical Concrete is the first large-scale reuse alternative for discarded tires.
Mechanical Concrete uses waste auto tires to contain stone aggregate, thereby preventing the majority of aggregate lateral spread. Waste tires are stripped of their side walls to create a durable rubber cylinder and then filled with a granular aggregate. The resultant product creates a foundation that is stronger and more dependable than aggregate used in isolation.
In demonstrations hosted by West Virginia University’s School of Engineering, Mechanical Concrete proved three times stronger than traditional road foundations, and ultimately required seventy-five percent less maintenance. The recent contract between EnviroRail, as a nationwide railroad services contractor, and Mechanical Concrete provides encouraging evidence for a new era of railroad maintenance and sustainability.
Click here to learn more about EnviroRail’s contract with Mechanical Concrete. For more information on Mechanical Concrete, visit the company site.
Hospitals have struggled to make space for influxes of COVID-19 patients since early in the pandemic. In counties around the country, continued surges of the virus now affect medical services for any individual who may need care, regardless of whether the individual suffers from COVID-19. Health districts have been forced to respond to diminished ICU bed capacities with creative measures. For New York State’s Long Island region, as for many other areas around the country, these measures have taken the form of temporary field hospitals.
The placid, wooded campuses of Long Island’s Stony Brook University (SBU) and SUNY College at Westbury host two of these temporary hospitals. The structures are hulking, frame-supported tents that add a combined 2,060 beds to the area’s medical network. Each tent is comprised of heavy-gauge vinyl panels that are individually tensioned and bolted to a metal framework.
Prior to construction, engineers faced the difficult task of securing a stormwater control system for projects with two major flooding factors stacked against them. Firstly, the tents would be constructed on poorly drained turf fields and thereby posed a flood risk in the presence of a medium rainfall event. Secondly, the heavy-gauge vinyl material that would ensure a leak-proof final product also made rain cascade faster down the roofs of the tents—in this case, engineers anticipated a maximum rate of 1,230 gallons a minute. If left unchecked, this could accelerate damage to foundations or result in seeping from a structure’s base.
A conventional frame-supported tent utilizes gutters and downspouts to catch and route stormwater. Project engineers needed to take this approach one step further by redirecting stormwater far away from the vulnerable turf. They selected 12-inch double-walled corrugated pipe for its flexibility and local availability. The pipe’s light weight allowed single workers to manipulate and secure large sections at a time, while its flexibility enabled ninety-degree connections aboveground.
Beginning at the field hospital gutter systems, the corrugated pipe bends down and around the tent structures, passing underneath ambulance roadways and eventually into underground swales designed to contain large quantities of runoff and facilitate its percolation. The use of corrugated pipe enabled SBU and SUNY field hospital project engineers to confront flooding factors without sacrificing construction speed or versatility. In both cases, the whole construction process took about three weeks. The hospitals were ready to accept patients in April 2020.
To learn more about stormwater drainage for SBU and SUNY field hospitals, click here. To learn more about the temporary fabric structures frequently used in field hospital designs, click here.
The City of Hampton, Virginia, recently joined a short list of U.S. communities spearheading green infrastructure investment through the use of Environmental Impact Bonds (EIBs).
First developed by D.C.-based social investment firm Quantified Ventures, EIBs are a financing tool that encourages investment in green infrastructure by linking financial returns to measurable performance outcomes. Public utilities issue the bonds alongside performance targets and timeframes, and independent parties assess project success through the achievement of said targets. EIBs can be used to fund pilot approaches to sustainable infrastructure or to scale up lab-tested environmental projects.
The EIB’s outcomes-based financing approach helps to stabilize green infrastructure investments, which can be risky due to the varying efficacies of individual green projects, and thereby increases venture capital opportunities for communities interested in going green. For the City of Hampton, this EIB will equate to approximately $12 million in stormwater-related infrastructure projects with the end goals of reducing pollution and enhancing the city’s resilience to flooding events.
Hampton is bisected by Newmarket Creek, a tributary of the two-mile-long Back River that eventually feeds into the Chesapeake Bay. In recent years, severe weather events and sea level rise have led to the increased flooding of Newmarket Creek. Hampton’s planned green infrastructure projects would combine to expand the stormwater storage capacity of the Newmarket Creek watershed by an excess of 8.6 million gallons. With sea levels and the occurrence of severe weather predicted to continue rising, these projects will provide valuable security against future flooding events while also creating neighborhood assets for Hampton residents.
Project designs include a series of manmade wetlands and detention ponds that combine to form a “stormwater park,” extensive vegetation installations, and an increase in elevation for a major city road. You can learn more about the City of Hampton’s Environmental Impact Bond and green infrastructure projects here.
Research into a new bridge design offers potential relief for the expensive and dangerous threats posed to bridges by seismic events.
Contemporary bridge designs follow a monolithic model: forms are constructed then concrete is poured over the forms, yielding a final structure. These traditional monolithic bridges are strong enough to support their own weight plus additional loads such as traffic but are often damaged by unexpected seismic events like earthquakes.
Restoration to a bridge damaged by seismic activity is a lengthy and expensive process, and the damage itself can result in injuries and loss of life. In recent months, researchers at the University of Colorado Boulder and Texas A&M University set out to evaluate a theoretical bridge design, called the hybrid sliding-rocking (HSR) bridge, that aims to mitigate the issues plaguing traditional bridges as a result of seismic events.
Where a monolithic bridge emphasizes unyielding concrete, an HSR bridge offers columns containing limb-inspired joints that slide and rock to diffuse seismic energy as it travels through the ground. Not only is an HSR bridge more capable of energy dispersal—the uniquely complex sliding-rocking interaction also allows HSR bridges to self-center amidst seismic activity, almost like the adjustments to joint movement made by a person who has achieved “sea legs.”
Researchers at CU Boulder and Texas A&M conducted earthquake simulations on experimental HSR columns and found that the HSR columns sustained less damage when compared to practical evaluations of conventionally designed columns. Damages sustained by the HSR columns also proved relatively quick to fix with common restoration materials.
Although HSR bridge design remains theoretical, with no practical implementation into real world bridges at this time, findings from this latest research study generate optimism for the future of bridge safety and durability amidst seismic activity. You can learn more about the research study conducted by CU Boulder and Texas A&M here.
The American Society of Civil Engineers (ASCE) just released their first-ever Report Card for West Virginia’s infrastructure, giving the state an overall grade of “D”. This grade indicates the state’s infrastructure is in poor condition with new construction and repair efforts unable to keep up with the state’s needs. The report card was also broken down into infrastructure categories giving grades for bridges (D+), dams (D), drinking water (D), roads (D+), and wastewater (D).
The report found that of West Virginia’s 7,291 bridges, 21% are structurally deficient, which is significantly greater than the national average of 7%. Of the 38,854 miles of public roads in West Virginia, 31% are in poor condition compared to 21% nationally. As a result, the ASCE report estimates that it costs $723 per motorist per year from driving on roads in need of repair in West Virginia.
Dams in West Virginia were also rated as poor with 75% of the state’s dams classified as high-hazard potential, indicating failure would result in significant economic loss and loss of life. The state would reportedly need more than $900 million in funding to continue operation, maintenance, and repair of high hazard dams.
Lastly, an estimated $1.39 billion is needed in drinking water infrastructure over the next 20 years with West Virginia currently losing more than 50% of their treated water due to leaks in infrastructure. Significant portions of West Virginia’s wastewater systems have also deteriorated with 59 combined sewer systems needing $1.2 billion in funds to address state and federal requirements.
Some encouraging prospects, however, include the establishment of the West Virginia Roads to Prosperity Program in 2017 that will ultimately invest $2.8 billion in more than 700 road and bridge projects and create over 48,000 jobs. In addition, inter-agency collaborations are expanding access to resources to upgrade drinking water and wastewater infrastructure to meet new quality standards. And overall, it’s important to note that West Virginia’s “D” infrastructure grade is on par with the nation’s overall D+ grade from the most recent 2017 infrastructure report card for the United States. You can read West Virginia’s full ASCE infrastructure report card here.
Converting an Old 178-acre Golf Course for Stormwater Management Near the Texas Coast Completes Phase Two
One of the largest urban stormwater initiatives ever undertaken in the state of Texas recently completed phase two of the five phase project involving the conversion of a 178-acre golf course into detention ponds, natural habitat areas, and recreational trails for the protection of thousands of homes from flooding events.
Located just outside of Houston in Clear Lake City, TX, an out-of-use 178-acre golf course and country club were purchased by Harris County for the purpose of converting the property into a series of five stormwater detention ponds that will protect approximately 2,000 – 3,000 homes from 100-year flood events. Named “Exploration Green” the project completed phase one in 2018 with the construction of a 23.7-acre detention pond, 15.2 acres of natural habitat, and 1.25 miles of recreational trails. When Hurricane Harvey hit in 2018, 80% of the first phase was completed and the detention area held enough stormwater runoff that houses that typically flooded with just 5 to 10 inches of water from storms had no flooding with the 45 inches of rain from Harvey.
With the recent completion of phase two, the project added an additional 26.2-acre detention pond, 18 acres of natural habitat, and 1.3 miles of recreational trails. Together the two ponds provide a 250 acre-ft. storage capacity for flooding with natural areas comprising nearly 3 acres of wetlands, a small island providing bird habitat, and almost 15 acres of planted native grasses. In 2018 the project received an Excellence in Green Infrastructure Award from the U.S. Environmental Protection Agency and National Association of Flood and Stormwater Management Agencies and in 2020 the project was awarded the Engineering Excellence National Recognition Award from the American Council of Engineering Companies.
Ultimately, Exploration Green will consist of 5 detention ponds and 40 acres of wetlands designed to hold 500 million gallons of stormwater and clean the runoff from 95% of the storms that occur in the community. All five phases are expected to be completed by 2022.
ENR’s 2020 MidAtlantic Project of the Year Awarded to a Washington D.C. Innovative Highway Land-Use Project
Engineering News-Record (ENR) announced the 2020 MidAtlantic Best Project of the year was awarded to a project that constructed a seven-acre platform above highway I-395 in northwest Washington D.C., providing 2.2 million sq. ft. of commercial, retail, and open public space, while also creating a new 700,000 sq. ft. below-grade parking garage spanning three city blocks.
The $263.3 million project, “Capitol Crossing”, returned a three-block section of D.C. back into the city’s historic traffic grid by reestablishing an area between E. Street and Massachusetts Avenue near Capitol Hill. The original traffic grid, established by Pierre L’Enfant in 1791, was disrupted by the construction of highway I-395 in the 1960’s, which divided the East End and Capital Hill neighborhoods. I-395 however, was constructed below street level elevation and the contractors for Capital Crossing devised a plan to cover the existing highway with a massive seven-acre platform and restore street-level space.
The project was first awarded Best Project in the highway/bridge category, placing it as a finalist for the overall MidAtlantic Best Project award. Two panels of industry judges reviewed nearly 100 projects based on criteria including the project’s ability to overcome challenges, contribute to the industry and community, safety and construction measures, and design quality. Ultimately, Capitol Crossing was selected the winning project of the year for the MidAtlantic region.
Capital Crossing not only innovatively utilized space, but the project required extensive relocation of utilities including the installation of a new 138-kV high voltage transmission line, relocating a 36-inch water transmission line, excavating 30 ft. below the water table, and using a lift system with hydraulic jacks to move an 1876 Jewish Historical Society synagogue twice.
In addition, the team had to coordinate extensively with the District’s Department of Transportation, the Federal Highway Administration, and other local and federal authorities for the maintenance and evaluation of affected traffic. The project developed a six-phase traffic control plan including a 24-hour traffic simulation model to help evaluate weekday and weekend construction activities.
Overall, the Capitol Crossing team innovatively utilized available land space while improving traffic flow, reviving the historic vision of D.C., and providing commercial, retail, and pedestrian friendly promenade space. You can view complete building plans and layouts of Capitol Crossing at the official website here.
Dedicated as a National Historic Civil Engineering Landmark in Rockfish Gap, VA, the Claudius Crozet Blue Ridge Tunnel conservation project is almost complete after 18 years of restoration efforts.
The Blue Ridge Tunnel was the longest railroad tunnel in North America at the time of its completion in 1858, traversing nearly one mile through the Afton Mountain connecting Nelson and Augusta county. The tunnel was originally built using only hand drills and black powder and allowed efficient travel Westward from the Eastern United States.
With restoration funding provided by state grants and Federal transportation funds, the tunnel will offer 6,000 feet of pedestrian trails for hikers, walkers, and bicyclists while also linking into existing trail systems. Woolpert architecture, engineering, and geospatial firm was contracted in 2006 to provide planning, engineering, and construction plans for the design of the trails and restoration of the tunnel.
Overall, the tunnel is 16 feet wide and 20 feet high with an exposed rock interior and located 500 feet beneath the Rockfish Gap ridge of the Blue Ridge Mountains. In October the restoration of the tunnel won a Construction and Design award by the Coalition for Recreational Trails and in 2015 the project also won the Central Virginia Chapter of WTS International’s Innovative Transportation Solutions Award.
In September, the tunnel was officially dedicated by Virginia Gov. Ralph Northam and while the tunnel and trails are still under active construction, the public can expect the Blue Ridge Tunnel to open at the end of 2020. To learn more about the Claudius Crozet Blue Ridge Tunnel you can visit the Blue Ridge Tunnel Foundation’s website here.
Rapid snowmelt events have the potential to contribute to hazardous flooding in the United States and researchers are hoping to improve the design of infrastructure to withstand increased flooding levels from unseasonable snowmelt.
While snow usually melts gradually as seasons move from winter into spring, unseasonably warm temperatures and rain falls onto snow packs can lead to severe flooding events. This is putting newfound pressures on infrastructure designed to withstand rain precipitation and not additional water from snowmelt. Researchers from NASA’s Goddard Space Flight Center and the University of New Hampshire are hoping to improve current flooding estimates for civil engineers by incorporating snowmelt estimates into precipitation estimates for regions across the United States.
The national standards that civil engineers use to design flood resistant infrastructure (NOAA Atlas 14) exclusively uses liquid precipitation estimates and not water from snowmelt. In order to improve this standard, Eunsang Cho, a postdoctoral researcher at NASA’s Goddard Space Flight Center, and Jennifer Jacobs, a civil engineering professor at the University of New Hampshire, created a map that incorporates snowmelt into current precipitation maps for the continental United States.
Cho and Jacobs developed an estimate of snow water equivalent (SWE) that measures the amount of water contained in snowpack. They combined the SWE measure with NOAA’s precipitation data to provide a more accurate picture of NOAA’s current standard precipitation values.
They discovered that in snow-dominant regions, the incorporation of snowmelt increased total precipitation estimates up to 7.52 inches and nearly 17 inches for 25- and 100- year flood estimates respectively. They also found that 23% of the 44 states for which NOAA provides precipitation data, had higher precipitation values than those provided by NOAA.
Brian Henn, a scientist working on global climate models at Vulcan highlighted the fact that some of the most extreme snow melting events have occurred within the last 10 years, indicating that flooding events from snowmelt are becoming increasingly hazardous, especially when older infrastructure is not designed to withstand increasing flooding events due to precipitation from snow melts.
It is important to note, however, that NOAA Atlas 14 still works for most regions of the country where snowmelt is not a significant concern. But for mountainous regions of the western U.S. that contain heavy snowpack, NOAA values are becoming inadequate for estimating realistic precipitation amounts. Cho and Jacobs hope that their findings can improve current guidelines and further inform civil engineers so they can incorporate larger flooding events into the design of infrastructure. For more info you can read Cho and Jacobs’ complete published research article here.
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