C+S August 2023 Vol. 9 Issue 8 (web)

Civil + Structural Engineer is the best source of news and information for the engineering industry. Thank you for reading!


csengineermag.com AUGUST 2023




VOLUME 9 ISSUE 8 csengineermag.com

publisher Chad Clinehens, P.E. | 479.856.6097 | cclinehens@zweiggroup.com media manager Anna Finley | 479.435.6850 | afinley@zweiggroup.com Editor Luke Carothers | lcarothers@zweiggroup.com

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Civil + Structural Engineer (ISSN 23726717) is published monthly by Zweig Group, Fayetteville, AR. Telephone: 800.466.6275. Copyright© 2023, Zweig Group. Articles not be reproduced in whole or in part without the written permission of the publisher. Opinions expressed in this publication are not necessarily those of Zweig Group. Unsolicited manuscripts will not be returned unless accompanied by a stamped, self-addressed envelope. Subscriptions: Annual digital subscription is free. To subscribe or update your subscription information, please visit our website www.csengineermag.com/subscribe/ or call 800.466.6275.

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THE COVER Fort Worth - Demanding Growth CHANNELS

ENVIRONMENTAL + SUSTAINABILITY 13 Gray vs. Green: Spongy Infrastructure 14 Enlisting One of Nature’s Ecosystem Engineers to Assist with Coastal Defense 16 Technology Is the Key to Revolutionizing the Jobsite— and Making it Safer TECH + SOFTWARE 18 Building the road ahead in 3D: the power of digital transformations in road construction 20 Ferrovial and Alamo NEX Create a 3D Digital Twin to Build a Viaduct Road in a Tight Urban Area STRUCTURES + BUILDINGS 22 Quality Over Quantity: Today’s Bridge & Tunnel Inspection TRANSPORTATION + INFRASTRUCTURE 24 Aligning Smart Building Implementation with Performance Expectations 26 Innovative Technology Helps Deliver The Warrenton Southern Interchange Project 30 Making the Grade: Why Lightweight Aggregates may be the Key to Improved Infrastructure 33 Enhancing the I-5 34 Exploring the massive potential for innovative underground construction technologies in the US 36 PERI Formwork Helps Lay Tracks for Massive Commuter Train Expansion technologies in the US 38 Inside Out: Building Resilient Infrastructure to Safeguard Against Natural Disasters 40 Industrial Constructors / Managers, Inc. facilitates improvements to aerospace test facility thanks to ‘on the go’ construction and welding 42 Critical Infrastructure: Successfully Upgrading Airport Facilities Within a 24-7 Environment WATER + STORMWATER 46 Active Wastewater Treatment in Decentralized Applications 50 Trolley Route Flooding Alleviated by Stormwater Management Solutions departments 8 Events Columns LOOKING BACK, MOVING FORWARD 6 Adapt and Overcome: Railroads in Northwest Arkansas Luke Carothers INDUSTRY INSIGHTS 7 Get Ready for the 2023 Yearbook of Engineering Achievement Award Competition 51 Benchmarks 52 Reader Index






The history of railroad construction has no shortage of stunning and defining feats that can be attributed to our insatiable need to expand and conquer new frontiers. During the latter part of the 19th century, this need came to fruition in a massive expansion of railroads, particularly along the Western frontier. Although the “West” is typically portrayed culturally as a product of places like Arizona, Nevada, and Utah, the western border of the United States also represented the western border of Arkansas in 1880. The first railroad didn’t enter Northwest Arkansas until May of 1881 when the first passenger train arrived in Rogers. Part of the St. Louis and San Francisco Railroad (Frisco), the proposed line between Monett, Missouri and Fort Smith, Arkansas would further advance the company’s transcontinental dreams. Construction on this new line began in the last months of 1880, progressing rapidly south into Northwest Arkansas. One month later, in June of 1881, the first train arrived in Fayetteville. It was greeted by throngs of cheering spectators–and even a brass band–at Fayetteville’s Dickson Street Station. For the spectators that day, and for countless others throughout the region, the coming of the railroad represented a new horizon of possibilities. After being devastated by frequent clashes during the American Civil War, Northwest Arkansas lagged behind adjacent regions in terms of its economic and cultural development. Thus, after failed attempts to do so prior, the coming of the Frisco Railroad to Northwest Arkansas generated a shockwave of excitement through the region. This excitement was palpable–after all, estimations were that the line connecting the region to Fort Smith would be finished before the year was out. Railroad and construction officials estimated that trains would be running through Fort Smith and into Texas before the end of 1881. Despite the significant challenges that stood between Fayetteville and Fort Smith, construction company press releases were confident in this timeline, and, as work began on extending the roadbed south of Fayetteville, crews also began carving out a 1,600-foot tunnel beneath the Ozark divide. Challenges in the tunnel’s construction led to the first delay in the project as the end of 1881 would yield little luck for the crews. South of the Ozark divide and the town of Winslow, the Frisco line would run into another engineering challenge that increased construction costs and led to dangerous working conditions. After tunneling 1,600-feet through the Ozark divide, crews would then have to construct three trestle bridges of significant size. The first of these trestle bridges, which sits about a mile south of the Winslow tunnel, sits 117-feet above the stream below. This massive trestle bridge Adapt and Overcome: Railroads in Northwest Arkansas Luke Carothers looking back, moving forward

Train depot, Dickson Street, Fayetteville Arkansas, date unknown. Courtesy frisco.org

along with the other two, which are each shorter than the last from North to South, formed a section of railway that sits at an average incline of 113-feet per mile. Despite predictions that the line would be completed by the end of 1881, challenges with tunnel construction and disease soon took their toll. By the last months of 1881, work was faltering on the tunnel, and a decision had to be made about the continuation of the project. In November 1881, the decision was made to double the workforce for the tunnel and construct a temporary “shoofly” railroad. This temporary zigzag railroad was a unique innovation not necessarily in concept, but in the tremendous skill in which it took to create. This treacherous section of railroad took only a few months to complete, and allowed work to continue south of the tunnel where the three massive trestle bridges were being erected. Although challenges in the tunnel’s construction extended the initial deadline, the construction of this temporary railroad minimized the overall impact. Despite persistent challenges in tunneling, the temporary railroad meant that work could continue on the vital structures further south. While the tunnel itself posed unique challenges, the ability to adapt work meant that the three massive trestle bridges were finished at nearly the same time as the tunnel. The Frisco line through Northwest Arkansas was open and running services by August of 1882. Although initial predictions failed to account for the challenges in tunnel construction, the ability to adapt and overcome was a large reason for the continuation of construction. With the Frisco line open, Northwest Arkansas entered into an era of prosperity in which the railroad provided a crucial link in expanding industry and commerce. LUKE CAROTHERS is the Editor for Civil + Structural Engineer Media. If you want us to cover your project or want to feature your own article, he can be reached at lcarothers@zweiggroup.com.


csengineermag.com AUGUST 2023

YAY – or should we say YEA – the time is here; don’t miss your chance to enter this year’s dynamic Yearbook of Engineering Achievement (YEA) competition which opens up on September 1. The competition, in its third year, is hosted by Civil+Structural Engineer Media and will highlight the most outstanding architecture, engineering, and construction projects of 2023. The deadline to enter a project(s) is October 18th. What is YEA? YEA showcases AEC projects that have clearly moved the industry forward through community and environmental impact, innovative technical processes, or groundbreaking vision and execution. Firms from all fields of the AEC industry are invited to submit any project completed, or scheduled to be completed, within the 2023 calendar year that are from any of these five categories: 1. Housing/Residential 2. Transportation/Infrastructure 3. Water/Stormwater/Wastewater 4. Environmental/Sustainability 5. Small Firm (fewer than 50 employees) Project submission(s) must also: • have a positive impact on the communities in which they are built; • use a key technology or strategy to achieve larger goals; and • achieve other outstanding designations pertinent to the AEC industry. There’s no fee to submit a project and firms are encouraged to enter more than one, though only one project per category is permitted. And, the project needs to be completed or scheduled to be completed before the end of 2023. Once a firm has decided what project (s) it would like to enter, the rest is easy. There’s a short information form which asks a few questions about the project and also requests photos/videos. The winning projects from the 2023 YEA competition will be featured in the December issue of Civil+Structural Engineer Magazine and the project that earns the most overall votes will be awarded the 2023 Summit Project. Each of the winning projects will have their own page on the website and the Summit Project will be featured on the cover of Civil+Structural Engineer Magazine ’s December issue. Get Ready for the 2023 Yearbook of Engineering Achievement Award Competition By Liisa Andreassen

Industry Insights

How does it work? As a leading source of business news, thought leadership, and project information for the AEC industry, Civil+Structural Engineer Media is proud to serve the world’s designers. That’s why it leaves the fate of the winners in the hands of a jury of AEC peers and colleagues. After all, these are the boots on the ground people – the experts, professionals, and leaders who work to elevate the AEC industry every day. Last year’s Summit Award winner was from the transportation and infrastructure category – The Sixth Street Viaduct Replacement – submitted by HNTB. The project was the largest and most complex bridge building project in the history of Los Angeles and set a new threshold for seismic safety and expanding the utility of urban bridges. Its submission received over 2,000 votes which was testament to the project’s groundbreaking vision and execution. The submission that garnered the most votes from the water/stormwater/ wastewater category was the Vertex Companies project in the City of Houston. This one involved a major public transit line for America’s fourth most populous city and the project was completed with minimal impact to the city’s population. The social, environmental, and economic impacts of these projects are largely localized and benefit the communities in which they are built. So, no matter the impact – whether improved flood control or transit times – these projects have on the built and natural environment, they have been done in a way that improves the lives of the people who live in that community. And, when you share your projects with others through a competition like 2023 YEA, you become part of something greater than just your firm or community. You’re promoting industry-wide thought leadership and fostering an innovative path into the future by demonstrating just what’s possible when you combine capabilities and ingenuity. The bottom line? You’re helping to elevate the AEC industry. So, are your wheels turning? Do you have some potential contenders in mind? We’d love to see them and invite all of our readers to join us in celebrating the projects that have elevated the AEC industry and set the bar for future endeavors. Entries will be hosted on the C+S website through the contest voting period (October 27-November 10) and website visitors will be encouraged to vote once per day for the project they feel most represents the best of the best in the AEC industry.

For more information about the contest and to submit your entry, visit: https:// csengineermag.com/yea/ . And, if you have any questions about the submission process, please contact Luke Carothers at: lcarothers@zweiggroup.com .




events + virtual Events

September 2023

October 2023 Chief Strategy Officer Roundtable October 11-13 – Fayetteville, AR

M&A next Symposium September 12-13 – Frisco, TX

The CSO Roundtable Retreat is a unique opportunity for AEC firm leaders to engage and interact with industry peers to discuss current issues facing firms today, explore industry trends and next practices, and confront the biggest challenges they face leading their firms. Come prepared to discuss your biggest challenges and successes during this highly interactive session. With you in control of the subject matter, roundtable discussions strike at the heart of what you need to effect change in your organization. https://zweiggroup.com/products/chief-strategy-officer-roundtable

Reserve your seat at this highly interactive event designed to provide M&A education and practical application through interactive roundtable discussions, thought leadership from expert panelists, and focused networking to connect leaders from across the country. You will end the day better informed about the opportunities for M&A as a growth strategy. https://www.zweiggroup.com/products/2023-m-a-next-symposium

ElevateaEC conference & Awards Gala September 13-15 – Frisco, TX

November 2023

Registration is open for the annual in-person conference in Frisco, September 13-15. The 2023 winners of the Hot Firm list, Best Firms To Work For, Marketing Excellence, Excellence in Client Experience, Rising Stars, Top New Ventures, and the Jerry Allen Courage In Leadership Awards will be celebrated at the iconic black-tie awards gala. https://www.zweiggroup.com/pages/annual-elevateaec-conference Business of Automated Mobility Forum: Flight Path to UAM September 27-28 Join SAE and AUVSI, along with industry and government stakeholders, for collaborative discussions to accelerate the evolution to a safe and efficient low-altitude transport system. Engage on the critical topics to realize the potential of UAM, including regulatory outlook, vehicle development and production, operational management, UTM, safety, and security. https://www.auvsi.net/bamforum/home

Minds & Machines: Dominating the Convergence of AI Intelligence and Strategy in AEC November 2-3 – Nashville, TN Zweig Group’s T(AI)SK FORCE will be hosting a two-day symposium to deep dive into AI integration and operations. Our immersive seminars and workshops equip AEC leaders and managers with understanding, insight, and intelligence to identify and act upon AI opportunities within their organizations. We liken AI to a marathon that never ends. No matter if you walk, run, or sprint, this will be your first step to getting in the race. This training provides a high-impact, hands-on learning experience that is designed to help emerging and current leaders be at the forefront of the AI technological revolution. AI is not a trend or fad, it is a fixture. AI is here to stay. https://zweiggroup.com/products/minds-machines This is the unmissable global event for the lifting industry; almost 100 exhibitors, over 1,500 industry professionals attending, two days of knowledge sharing and training, as well as the celebrated LEEA Awards. The annual event hosted by the Lifting Equipment Engineers Association, the leading global representative body for all those involved in the lifting industry worldwide, is your chance to connect with your customers, meet new clients and do business. The show attracts end users from a wide range of vertical markets, including oil and gas, energy, offshore, road & maritime transport, construction, utilities, rail, renewable energy, civil engineering, entertainment and manufacturing, and more. https://liftex.org/liftex-liverpool-2023 LiftEx 2023 November 21-22 – Liverpool

BIBM Congress September 27-29 – Amsterdam

The 24th BIBM Congress will take place in Amsterdam! The congress will be held in the Dutch capital—the “Venice of the North.” The congress will be under the slogan “Green | Digital | Resilient | Precast Concrete Solutions.” Congress language is English. https://bibmcongress.eu/

SEAoT State Conference SEPTEMBER 28 - 29

The Structural Engineers Association of Texas is hosting their annual conference in Houston, TX. This two-day premier structural engineering conference in Texas features world-class speakers and panelists discussing various technical topics, industry challenges, and business practices. Look for Zweig Group's Kristin Kautz as she speaks about The State of Artificial Intelligence (AI) in AEC. https://seaot.org/2023-state-conference/


csengineermag.com AUGUST 2023

2023 SE3 National Symposium: Engagement and Equity in the Structural Engineering Profession NOVEMBER 7 – ANAHEIM, CA This half-day program is the second Structural Engineering Engagement and Equity (SE3) Symposium to be held in conjunction with a national engineering conference since the 2019 NCSEA Summit. The event welcomes engineers of all levels, business owners, human resource managers, and anyone within the AEC industry who is interested in promoting dialogue on engagement and equity in the structural engineering profession. As part of this program, attendees will participate in five separate sessions focused on various aspects of engagement, retention, diversity and inclusion. They will learn about SE3 initiatives and activities, hear from industry panelists on the state of our profession, and acquire practical strategies and best practices for improving retention within their organizations. Look for Zweig Group's Director of Learning and ElevateHER, Shirley Che, as she delivers one of the main stage sessions: ElevateHER, A Path to a More Engaged & Sustainable AEC Workforce. https://www.ncseasummit.com/special-program/ preconferencesymposium2023 Meet the National Council of Structural Engineers Associations in the happiest place on earth to network and learn with the happiest engineers around. Interact with and learn from leaders in the field, curious problem solvers, and expert speakers. Stay current on advancements and best practices in structural engineering and building and design codes—in education sessions and in the Exhibit Hall. Discuss technical, business, and industry challenges—and work toward solutions in a collaborative community. Look for Zweig Group's Kyle Ahern and Shirley Che at their breakout session: A modern day AEC professional's guide to Employee Experience (EX). https://www.ncseasummit.com/ NCSEA Summit NOVEMBER 7-10 – ANAHEIM, CA




Fort Worth - Demanding Growth

By Riley Seahorn

Of the top 30 most populous cities , Fort Worth is the fastest growing, at 4.1 percent population growth since 2020 and the largest numeric population gain of any US city in 2022, according to the US Census Bureau. With that, there are many City of Fort Worth, TxDOT and developer-driven projects under way to meet population demands and improve the city’s infrastructure. Located on the Northside of Fort Worth, Alliance Town Center, a new shopping, entertainment, and residential development, is an example of the outward expansion spurred by the population boom. This growth created the need for expanded infrastructure and was the driver behind the 2018 City Bond for Streets and Mobility Improvements. In order to handle the expected traffic flow in the rapidly growing Alliance Town Center area, the City determined that the two mile span of Harmon Road (a main thoroughfare in the vicinity) between US287 and Golden Triangle Blvd needed to be expanded from a two-lane roadway to a four-lane road with turn lanes and three integral roundabouts at major intersections with 10-foot-wide shared use sidewalks. Initially, the project was intended to be a public hard bid traditional selection, however after partnering with McCarthy Building Companies on a major infrastructure project (Hemphill Street Connector) near downtown that successfully demonstrated the benefits of Construction Manager at Risk (CMAR) delivery method, the City decided to use CMAR for the Harmon Road project procurement – awarding the work to McCarthy Building Companies’ Southern Region Civil Business Unit.

Stakeholder and Construction CMAR delivery enables the owner, contractor, and engineer to align and work in partnership from early engagement through construction delivery, providing the best outcome for the client, community, and stakeholders. The first significant challenge of the project was sequencing construction to best fit the project constraints while taking into consideration stakeholders along the project corridor (developers, residents, businesses) as well as City Council directives on closing major and minor intersections. The main planning focal points were the phasing of roundabouts at Presidio Vista, Heritage Trace, and Golden Triangle intersections along with two water main tie-ins during the low demand season. The team worked together to prepare their approach to the critical intersections and tie-ins for key stakeholder and City Council approval–providing numerous phasing options with timelines and cost analysis for performing the roundabouts in complete closures, half closures, and quarters. Each sequence ranged from three months out to more than nine months. Stakeholders advised the team to proceed with a variety of closures subject to traffic detour impacts. Presidio Vista was to be constructed in halves, Heritage Trace in thirds (the west half as a full roadway closure and the east half split into two quarter closures) and lastly Golden Triangle in halves. Knowing the sequence required for each roundabout, the team created a detailed eight-phased plan. The existing roadway alignment provided a unique obstacle to the eight phases. The roadway from




US287 to Heritage Trace existed on the future southbound lanes and the roadway from Heritage Trace north to Golden Triangle was on the future northbound lanes, causing a switch over at the Heritage Trace intersection. The crews had green fields alongside the existing roadways to begin construction without impacting normal traffic flows. Working both northbound and southbound lanes simultaneously, the project was able to progress the critical path through the roundabouts and utility tie-ins. With each roundabout being completed in its own phase, Golden Triangle Boulevard brought the team the second substantial challenge in overall sequencing and planning - two main transmission waterlines servicing countless residents would need to be tied-in under a 48-hour shutdown window. Construction started March of 2021 and was to be completed by early summer of 2023 – leaving the team with one low demand season, December 1st to March 1st. Shortly after the notice to proceed was issued in March of 2021, three winter snowstorms within a two-week period crippled Texas roadways and electricity grid, shutting down supplier businesses and deliveries which multiplied pandemic-related supply issues. The storm caused unexpected timeline delays, greatly increasing lead times on various materials. The critical path of the project started in Phase 1 which was driven by the installation of various large storm drainage box culverts. Due to the storm impacts, the original material delivery was pushed out by a minimum of 11 weeks. The project team was able to mitigate critical impacts to the overall project schedule by shifting phases and working on the Heritage roundabout which had minimal storm piping. This allowed the overall sequencing to change but still maintain the optimal window for the Golden Triangle utility tie-in. Water Works The construction of Golden Triangle’s two main water transmission lines - Water Line A (24-inch water main) and Water Line B (36-inch water main) was a critical operation due to the complexities presented by the intersection itself. The two water mains had to be connected by a 36-inch butterfly valve inside a cast-in-place concrete vault - in the middle of an active intersection. Due to the Project’s phasing constraints, the operation was broken into two subparts to ensure traffic continued to flow smoothly along Harmon Road. Phase A constructed the Water Line A segment along Harmon Road from north to south splitting the existing intersection in half at the vault. Sequentially, Phase B constructed Water Line B from the vault westbound along Golden Triangle Boulevard. The team excavated, laid pipe, and constructed the vault for Phase A over a month starting in September of 2022. Quickly, the team swapped traffic control to construct the Phase B segment. It was critical that both phases be completed for the low-demand season due to one 48-hour window being allotted for the tie-in of both mainlines. Due to Water Line A tie-in point to Line B laying under existing pavement higher than the future roadway cut, the team had to excavate from existing ground 19-feet down to make the tie-in at the center of the future roundabout. This alone added a safety challenge and

Moving traffic through the Presidio Vista Roundabout

encompassed daily verification that the excavation remained sound, verification of elevations at the current roadway, and addition of concrete traffic barriers (CTB) and asphalt to allow the public to commute past the work area with a buffer layer. At the time of the tie-in, all locations were excavated and ready to go once the city shut down the valves. Three different crews rotated between each tie-in location cutting, laying, and welding in the new pipe. The lines were pressurized and active under the 48-hour window, making this a pivotal moment for the Harmon Road Project’s overall success.


AUGUST 2023 csengineermag.com

Throughout the project, the construction team was able to work through ambiguities and challenges because of the teams collaboration and risk mitigation strategies within CMAR delivery method: • coordinating multiple stakeholders, businesses, and residents • mitigating unknown and/or unforeseen conditions • maneuvering through a highly phased project • leading the success of both public and private development alongside franchise utility relocations adjacent to the work • supporting the community through ongoing communication efforts • McCarthy mitigating risks via allowances and contingencies and led as a partner and advocate to City of Fort Worth due to the project conditions • continual communication efforts with the client and engineering team. While ove rcoming the many unique challenges of this project, the team completed it on schedule with over half a million dollars in shared savings and unspent budgets.

CMAR - A Group Effort for Best Outcomes As the project progressed over the next year, the crowded corridor continued to acquire new stakeholders and third-party developments performing their own construction work alongside the Harmon Road Project. Numerous developments–fire stations, expansions of apartment complexes, fast food franchises, and more–began construction and or entered a design phase while the Harmon Road Project pushed onward towards substantial completion. Coordination with franchise utilities became essential to ensure the project was able to continue without impacting the critical path. The entire team had a part in the coordination from synchronizing designs with new developers, to working with utility franchises to ensure no damage was done to the newly constructed roadway, along with working together to sequence their scopes prior to placing final pavement. Each party had a unique approach to accommodate what best worked for their project–from site walks to weekly calls for status updates, to helping excavate or holding back a pour to ensure the teams–both Harmon Road and the third parties could perform the necessary work needed to sustain the growth occurring along the roadway.

Riley Seahorn, Assoc. DBIA , is a project manager with McCarthy Building Companies Southern Region.

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Environmental + Sustainability

Gray vs. Green: Spongy Infrastructure By Luke Carothers

More and more frequently in recent years, cities across the world have had to contend with increased flooding coming as a result of climate change. Traditional flood mitigation techniques involving concrete infrastructure have been deployed to handle excess rainwater and runoff to varying degrees of effect, but many experts believe the solution to these challenges lies not in concrete infrastructure but in green infrastructure. Rather than relying on concrete infrastructure solutions to manage water, cities can harness the natural processes of grass, trees, leaves, lakes, and ponds as green infrastructure. These natural processes present a sustainable way of responding to climate change. This concept of a city’s ability to absorb and manage rainwater through its green infrastructure is often described as its “sponginess"–a term that has been around for almost two decades. This concept of a “spongy” city is not only a sustainable solution in responding to climate change, it is also a powerful metaphor that resonates strongly with the public. Vincent Lee, Civil and Water Lead at Arup, says that the concept of spongy cities has been around for the last twenty years, although the name varies from place to place. Lee says that this shift from traditional ways of managing water like concrete channels and pipes to leveraging nature-based solutions has been global as cities are seeing the benefits of small-scale adoption. Using a new machine learning land-use tool, Arup tested the ability of ten diverse global cities to naturally absorb rainwater–otherwise known as sponginess–in order to highlight the importance of cities moving beyond concrete infrastructure, encouraging them to look to nature for solutions to climate change-related challenges such as increased flooding. According to the report website, Arup’s goal in creating the Global Sponge Cities Snapshot is to get people talking about green infrastructure. According to Lee, there were ultimately two driving factors behind Arup’s development of the Global Sponge Cities Snapshot with the first being the movement for cities to harness the power of nature and leverage nature-based solutions and biodiversity for water management. Lee believes there is a strong desire amongst cities to leverage these natural solutions. The second factor behind the development of the Global Sponge Cities Snapshot is the evolution of data and technology. With the availability of open source data, processes can become more consistent across different parts of the world. Furthermore, technological advancements have increased the speed at which these sorts of analyses can be performed. Charles Ormsby, Climate and Sustainability services leader for Arup in Canada, says that this sort of analysis is a powerful tool for fields like civil engineering. For Ormsby, this is a product of the great spirit of innovation within the group. Still more, he believes that, even though he carries the perspective of a civil engineer, more and more disciplines and groups of professionals are thinking about these concepts perhaps through a different lens. As these disciplines and groups are applying their own needs and goals onto the concepts, Ormsby believes these

layers build on top of one another to show a “better picture of the intersection of different realities when it comes to urban systems.” From such a layered analysis of urban systems emerge trends that define the impact of these systems on our most vulnerable populations. For example, a snapshot that provides data as to the density of trees and vegetation identifies areas that are most at risk when it comes to things like heat island effect. This, in turn, helps identify groups that are most at risk for mortality when it comes to extreme heat events. Ormsby says that the Global Sponge Cities Snapshot gives a “good sense of the lay of the land” when it comes to green infrastructure and gets the ball rolling in terms of furthering the conversations within different groups. Lee extends this, noting that the Global Sponge Cities Snapshot is a powerful tool for engaging with different stakeholders about leveraging water management while also thinking about aspects like land use, equity, and city planning. As a tool for communicating concepts of green infrastructure with groups outside of the AEC profession, the concept of sponge cities brings a number of different people around a common table. Recently, Arup brought together a group of academic, university professors, community organizations, non-profits, property developers, government officials, municipal officers, and students as well as design professionals, architects, landscape architects, and engineers, assembling at the United Nations Biodiversity Conference (COP-15) in Montreal. With this assembled group, Arup unveiled the Snapshot data for the host city. Working together with the data provided, this group began to discuss how a particular neighborhood could be improved by leveraging greenery and achieving biodiversity regeneration. This generated conversations about ideas like connecting corridors that are historically habitat and rectifying historical inequity issues. Arup’s Global Sponge Cities Snapshot is unique in that it presents concepts that occupy the same space of understanding between the AEC industry and the communities in which our projects exist. As cities across the globe are responding to the effects of climate change, tools like this Snapshot will be instrumental in expanding the use of green infrastructure solutions.

LUKE CAROTHERS is the Editor of Civil + Structural Engineer Magazine. If you want us to cover your project or feature an article, he can be reached at lcarothers@zweiggroup.com.


AUGUST 2023 csengineermag.com

Environmental + Sustainability

Oyster habitat restoration could make a lasting difference in the protection of the vulnerable Gulf Coast shoreline. Enlisting One of Nature’s Ecosystem Engineers to Assist with Coastal Defense

By Kathleen Saal

Oysters receive a lot of attention along the United States Gulf Coast, a region that produces a majority of the country’s commercially harvested bivalve mollusk. But oysters are highly regarded for much more than their economic value. The key role they play in creating and maintaining healthy coastal and estuarine environments makes them an essential part of this important ecosystem. A current study, funded by the Defense Advanced Research Projects Agency (DARPA), is taking a deeper dive into innovative methods that would enable oysters to better protect coastal shorelines. The project, “Reefense: A Mosaic Oyster Habitat for Coastal Defense,” is exploring the development of self-healing, hybrid biological, and ecologically engineered reef-mimicking structures to achieve two main goals — increasing wave attenuation to reduce damaging coastal impacts and erosion, and promoting the development and growth of healthy, self-sustaining oyster populations.

Rutgers University is leading the 18-month project during its first phase, with options that could extend out to a total of five years. The three main areas of study include: • design of the macro structure itself, • selectively breeding oysters that grow faster and are more disease resistant, and • protecting oysters from being eaten by predators. The development of novel materials and reef design is aimed at enabling the use of low-cost, interlocking reef modules that are adaptable to different conditions and can be arranged to minimize any wave energy reaching the shoreline. In locations where wave attenuation is less important, the modular design would protect against erosion from daily currents, while also providing additional habitat value. “We don’t have a module in the water yet, but, from the perspective of progress towards overall project goals, the work has been moving — either on target or earlier than expected,” said Nigel Temple, a coastal restoration specialist with WSP USA and professor at the University of South Alabama. “We are doing wave flume testing and we’ve coalesced around a general design for the modules.”




Temple is serving as the firm’s main liaison with the project and research team. “Our engineers will need to sign off on these designs before they are put in the water and, for them to do that, they have to be convinced that these structures are stable and will hold up in this environment,” he said. The selective breeding of native oysters that are shown to grow faster and be more resistant to disease is another key and ongoing focus for the research teams. Researchers at Auburn University and Louisiana State University are working in collaboration with Rutgers to breed oysters, through phenotypic and genomic selection, for faster growth and tolerance to dermo disease (Perkinsus marinus), which can easily spread among oysters and is associated with extensive oyster mortalities. This part of the project involves maintaining broodstock, managing the spawning and rearing of oysters, and field testing the resulting offspring. After that, researchers are challenged with preventing dermo disease, as part of the selection process led by Rutgers. Oyster lines that make it through this phase are then field tested at three locations in the Gulf of Mexico: St. Andrews Bay, Florida; Grand Bay, Alabama; and Grand Isle, Louisiana. Why Oysters? As a popular seafood, oysters have a tremendous economic impact on the Gulf region. But perhaps lesser known is the outsized and beneficial role they play within their own habitats and natural environment — not least of which are the many benefits they provide other species within the same ecosystem. Oysters are regarded as both “Keystone Species” and “Ecosystem Engineers.” The reefs where they live are made of hard substrate and the ecosystem they create accommodates microhabitats for other species that would not otherwise exist. Conversely, without oysters, ecological communities in brackish and salty waters would be dramatically different. Oyster reefs protect marsh habitat that benefit from wave attenuation and support several other coastal species including fishes and other invertebrates which forage and take shelter from larger predators among these habitats. On top of that, oysters also feed on phytoplankton (tiny plants floating in the water), acting as a natural filter to clean the waters. This enables light to reach the bottom, where seagrasses grow, and help to remove an overabundance of nutrients that would otherwise pollute the waters. The oyster population in the region took a serious hit in 2010 following the Deepwater Horizon oil spill, which is estimated to have killed more than eight billion oysters in the Gulf of Mexico. A long-term goal of the Reefense project is to create methods and technology that will help restore that population so it can protect shorelines. The overall mission of the Reefense project is to create a mosaic of habitats that work together to provide resilience as they support multiple species, while simultaneously promoting self-sustaining oyster populations and helping diminish wave intensity. The magnitude of wave attenuation would be governed by physical

characteristics, like water depth, reef crest elevation and overall structure width and depth, which are typically used to design non-living wave-breaking structures. Work began in May 2022 and will be completed in three phases. WSP will manage the eventual reef construction and is currently working in bay waters off the Florida panhandle to characterize the site and monitor seasonal changes. The firm is also monitoring selectively bred native oysters to evaluate performance and collecting native oysters (under Florida Fish and Wildlife Conservation Commission special activity license number SAL-22-2391-SR), which are shipped to Rutgers for disease testing. Other tasks include deploying and retrieving wave gauges and other sensors, which collect data that will be used to compare before-and- after measurements, following installation of the engineered reefs. WSP is also collaborating on predator exclusion experiments aimed at finding an effective microstructural design to reduce the threat of gastropod predators such as oyster drills and crown conchs. “Gastropods are snails and they have various mechanisms for eating oysters,” Temple said. “For example, the oyster drill, as its name implies, drills a hole in the oyster shell while crown conchs get to the oyster by prying the shell open. They are one of the biggest influences on the decline of oysters in a lot of ecosystems.” This Gulf study is one of three DARPA-funded projects currently being conducted independently of each other. The other two are coral reef studies — one in Florida and the other in Hawaii. Although the teams are not collaborating directly, they are connected through federal permitting. While the individual state permits are proceeding independently, the federal permits are being grouped together and led by the US Navy. In addition to WSP and Rutgers University, the full research team for the Reefense project includes Auburn University, Louisiana State University, Mississippi State University, the University of Arizona, the University of Central Florida, the University of Melbourne, the University of Western Australia, Reef Design Lab and the Partnership for Delaware Estuary. WSP has been involved in a variety of coastal restoration projects using engineered oyster reefs, including the Franklin-98 Living Shoreline, where 20 acres of oyster reefs and 30 acres of salt marshes are being created to protect routinely eroded areas of the Apalachicola Bay shoreline along Highway 98 in Franklin County, Florida. WSP also is monitoring the development of oyster reefs in Pensacola Bay, Florida, and is supporting the Living Breakwaters project off the coast of Staten Island, New York.


AUGUST 2023 csengineermag.com

Tech & Software

Technology is the key to revolutionizing the jobsite — and making it safer

By Troy Dahlin

So many people talk about how technology is reimagining the jobsite. Whether drones, reality capture, or machine control, there’s little debate about technology’s role in the modern jobsite in enabling efficiencies in time, materials, and resources. The discussion, however, should also center on the larger role technology should play to keep the jobsite—and everyone on it—safe. The industry is at a turning point as the next generation of workers takes leadership roles within companies. Undoubtedly, younger generations have a different relationship with technology — we see the conversation in our daily lives; civil and structural engineers need to proactively bring that same discussion into their professional lives. The tendency in any profession is to rely on what’s worked previously, rather than rocking the boat. While approaching the jobsite “the way it’s always been done” works to a point, civil and structural engineers have an opportunity to reimagine the job site and make it safer for everyone in the process. The only certainty is uncertainty. Whether it’s the shortage of skilled workers or the onset of new technologies, a new job site has emerged over the past few years. These changes have led to some level of uncertainty. That sentiment is borne out in the latest data from The Civil Quarterly (TCQ) from Dodge Construction Network, produced in partnership with Infotech and Hexagon. Respondents identified various factors contributing to feelings of uncertainty, including shortages of skilled workers and increased regulations.

To tackle these concerns, roughly half of the civil contractors and civil engineers surveyed said they would allocate more resources toward recruitment. However, only a small proportion mentioned investing in technology. The widespread deployment of technology on the jobsite can fundamentally change operations for the better — and in the process, make the jobsite safer. While there are multiple ways to achieve a safer jobsite, having technology as the enabler allows teams to chart the solutions they want to deploy on the jobsite. Addressing safety today doesn’t only mean physical safety; it’s expanded to include mental health. The seen and the unseen. Numbers from the Centers for Disease Control and Prevention (CDC) reveal an often-overlooked threat facing the industries: suicide and, by extension, declining mental health. CDC numbers reveal the construction industry’s suicide rate is one of the highest of any industry. However, the official numbers may not fully capture the scope of the crisis. In 2016, the suicide rate of 49.4 per 100,000 for men in the “construction and extraction occupations” was roughly double the suicide rate for civilian working men between 16 and 64 years old in 32 states (27.4/100,000). It was also five times more than the construction industry’s fatal work-related injuries rate of 9.5/100,000 in 2018. It is difficult to say what is causing the elevated suicide rate, and the CDC suggested additional research to understand why the rate is higher




for construction workers. Anecdotal evidence points to job strain, long work hours and other “psychological risk factors,” including depression and stress, contributing to the rate. What is happening on the jobsite today? Reshaping the jobsite requires reexamining every aspect of the construction process, starting with site preparation. On the modern jobsite, companies must look at site prep as more than moving dirt because the success of a project starts before the first shovel turns any dirt. Historically, many people in the industry start working before they perform the checks to ensure the job site is safe. Unfortunately, these operators function based on what they know and what they have done their entire careers. What happens is that crews often find discrepancies or errors after they’ve started to move dirt. That means rework, and companies start losing money. Technology is the game-changer that can help improve safety, and it starts with focusing on the root causes. If job strain and long work hours are among the leading causes of worker suicide, firms should look at solutions that reduce those factors. Solutions like machine control and total stations help teams easily capture jobsite intelligence and complete tasks quicker, allowing them to spend less time on the job site. Additionally, performing utility detection checks before starting excavation work can lead to a safer jobsite, while potentially saving millions of dollars. While site preparation teams often focus on avoiding costly mistakes, the costliest mistake a company can make on the job site is not taking safety seriously. Data collection will help companies track the risks. The true benefit of technology is the opportunity it gives companies to know everything happening on the jobsite. For that knowledge to be useful, companies must maintain it in a format they can easily reference and guide their operations. A growing use to improve operations is the collection and analysis of safety data. However, Dodge data revealed that companies aren’t harnessing the power of data-driven safety. The report confirmed that large companies are collecting safety data, but not enough are using technology to accelerate the data collection process, minimize human error, and derive analysis from the data collected. According to the Dodge data, most civil contractors (93 percent) gather safety data by manually filling out forms. The percentage holds true for small, mid-size and large companies. Paper forms manually completed must be entered into a system to allow for impactful analysis, opening the door to potential mistakes. Not enough companies opt for solutions like wearable sensors or site access technology to ensure the data they collect is accurate.

About half (47 percent) of civil contractors think collecting and analyzing jobsite safety data is too time-consuming, the Dodge data revealed, which is not surprising given the common use of manual processes. Shockingly, 10 percent of civil contractors aren’t collecting any safety data. Technology augments a company’s biggest investment: its people. Often the most important investment isn’t a piece of equipment or technology. Instead, people are the most significant investment and what truly powers an organization. Engineering firms often don’t realize how much technology can help improve their operations until they meet with a provider and test solutions. For a company to be successful, it is important to prioritize the well-being and safety of its employees. Deploying these solutions will help avoid those mistakes and help save money, but the most significant savings are realized with a focus on the team. Earlier data from The Civil Quarterly (TCQ) showed that only about a third of contractor respondents (34 percent) said their companies have “good access to resources that help address mental health issues.” When asked about their organization’s state of mind/mental health compared with five years ago, twice as many civil contractors (36 percent) report improvements than worsening conditions (15 percent). While this survey is specific to civil contractors, it’s likely indicative of the entire construction industry. The uptick could result from the relatively high levels of job security or even the increasing attention to mental health since the COVID-19 pandemic. Still, more work is needed. Technology cannot remove all risks from the jobsite or guarantee a worker’s safety. However, it can potentially make the jobsite safer by removing at least some of its risks. Contractors cannot afford to stand idly by and watch the industry’s changes. They are not observers of these changes; they are actively involved in them. It’s time to embrace the current technology today and lay the foundation for the industry of tomorrow. Only then can we start to make the jobsite safer.

Troy Dahlin is vice president, heavy construction segment, US/CAN of Leica Geosystems, part of Hexagon. For more information, please visit www. leica-geosystems.com .


AUGUST 2023 csengineermag.com

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