Engineers' Society of Western Pennsylvania


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Wednesday, June 12, 2018

Technical Sessions

Iconic New Bridges Session

Time: 8:00 AM – 12:00 Noon
Session Chair: Ken Wright
Room: Annapolis

IBC 19-48: Innovative Construction Means and Methods for the New Champlain Bridge
Jeff Rogerson, Flatiron Construction Corporation, Ile-de-Sœurs (Verdun), QC Canada

Signature on the Saint Lawrence Construction (SSLC), a consortium comprised of SNC-Lavalin Inc., Flatiron Constructors Canada, Dragados  and EBC, is mandated to build the New Champlain Bridge Corridor Project (NCBCP). Significant challenges include: Construction schedule: The Bridge must be in service by December 2018. The Seaway traffic must be maintained during the main span’s construction. This paper discusses among others, the following innovative construction methods used for the New Champlain Bridge (NCB): A custom-built gantry for the installation of the precast footings/pier starters in the river; The delivery system for the segments to the tip of the deck in the main span. These erection systems were developed and selected to suit the specific challenges of the project, including speed of construction, maintenance of shipping and environmental protection. Durability is also a key design consideration, with a 125-year design life set as design criteria.

IBC 19-49: Owner Objectives and Delivery Method for the New Champlain Bridge Corridor Project
Guy Mailhot, Infrastructure Canada, Montreal, QC Canada

A rapidly deteriorating condition of the existing Champlain Bridge in Montreal, led the Government of Canada to accelerate its replacement and ultimately award a $3.98 billion CDN contract to Signature on the Saint Lawrence Group to deliver a new replacement crossing. Entailing a 3.4 km long structure over the St. Lawrence River with some 193,000 m2 of new deck construction, the works represent one of the largest infrastructure projects currently underway in North America and will produce Canada’s biggest bridge.

The first of six related papers submitted to this conference, this paper explains the need for an accelerated schedule, describes the delivery method used, summarizes the imposed requirements to ensure delivery of a highly durable structure (125-year design life) and key architectural features of the bridge required to endow Montreal with an elegant world-class transportation infrastructure.

IBC 19-50: The New Champlain Bridge – Performance and Design Criteria
Marwan Nader, Ph.D., P.E., T.Y. Lin International, San Francisco, CA

The New Champlain Bridge is one of the highest profile infrastructure projects in North America due to its economic importance to the region, the premature deterioration of the existing structure, and its visibility from throughout the metropolitan area. The NBSL is comprised of three bridges: a 529m signature span comprised of a asymmetric cable-stayed bridge with a main span of 240m; a 762m East Approach with a maximum span of 109m; and 2,044m West Approach with a typical span of 80.4m. This paper discusses the performance criteria of this life-line structure and the development of design criteria to addressing durability design, temperature, wind, vessel, scour, and the area’s seismic conditions.

IBC 19-51: Design of the Cable-Stayed Bridge Signature Span of the New Champlain Bridge
Marwan Nader, Ph.D., P.E., T.Y. Lin International, San Francisco, CA

The cable-stayed bridge of the New Champlain Bridge Project is a signature crossing. The asymmetrical structure features a 124m back span and a 240m main span. The 160m-high, single-pylon consists of a tuning-fork configuration of twin masts. Inclined concrete tower legs and “W”-shaped steel pier caps supporting the deck define the unique aesthetics of this bridge. The focus of this paper is to describe the bridge including a discussion of the superstructure, main span tower, supporting piers and cable-stay system. It also describes the erection techniques used. Working alongside the Contractor, the design team made innovative use of pre-casting, modular segments, and non-traditional erection sequencing to meet the Project’s fast-track schedule of only 42 months, even while faced with the severe winters in Montréal.

IBC 19-52: Technical Challenges in Design of the Approach Viaducts of the New Champlain Bridge
Zachary McGain, SYSTRA – IBT, Laval, QC; Sevak Demirdjian, SNC Lavalin

The New Champlain Bridge is an iconic structure, being delivered on an extremely fast-tracked schedule. Add to that numerous limitations on construction activities arising from the sensitive river environment, difficult climatic conditions, and concerns over existing regional infrastructure. Finally, throw in strict visual quality requirements to achieve a pre-published architectural concept. This paper discusses how the above conditions guided decision making and design concepts for the approach structures and specific design challenges encountered while meeting the expectations of the constructor, concessionaire and the Authority.

IBC 19-53: Creation of an Elegant and Iconic New Frederick Douglass Memorial Bridge
Kenneth V. Butler, P.E., AECOM, Glen Allen, VA ; Delmar D. Lytle and Richard W. Kenney, District DOT, Washington, DC ; Eric Hayes, South Capitol Bridgebuilders, Washington, DC

The existing Frederick Douglass Memorial Bridge, one of the District’s busiest commuter gateways, is 70-years old and past its service life. South Capitol Street was a primary corridor in Major Pierre L’Enfant’s 1791 Plan of the City of Washington, which developed South, East and North Capitol streets to extend directly from the U.S. Capitol, and become prominent gateways to the Monumental Core. Underscoring this historic plan, DDOT and the Design Build team were tasked with creating a new bridge design that would last 100-years and transform South Capitol Street into a prominent gateway. The new bridge crossing the Anacostia River uses the ancient structural form of an arch, and marries it to modern technology. In addition to aesthetic challenges, the project includes technical complexities as well. Unlike conventional arch bridges, the three-arch system is designed to allow the superstructure to freely move through the arches with expansion joints only at the beginning and end of the structure. The bridge expands and contracts through the arches, similar to a glider chair. The unusual variable depth “kite” shape of the arch, unbraced parallel arches and internal splice connection details (needed for aesthetics) all added challenges to both design and erection. The design and construction had to consider all of the environmental site constraints as well as creating a signature bridge that the National Capital Planning Commission, US Historic Preservation Office and the US Commission of Fine arts would embrace. The paper will present the major objectives of the project and progress of construction.

IBC 19-54: Design and Erection Analysis of the New Frederick Douglass Memorial Bridge
Nathan M. Porter, P.E. and Eric T. Nelson, AECOM, Glen Allen, VA

This presentation will focus on the technical aspects of designing a signature arch bridge. The 540-feet long multiple arch spans have many challenges technically including: stability of parallel unbraced arches; geometric control of variable depth hexagonal arches 7 to 14 feet deep; thermal movement of 3 sequential arches; critical steel arch base connections into post-tensioned concrete v-piers; use of cable-stay technology to support the superstructure including accommodation of rotation and translation; 1800-ton capacity steel pipe piles; complex substructure shapes and water line footings; and impact avoidance of critical utilities including a 108-inch diameter force main. The presentation will discuss the design approach and methodology as well as the role of the bridge architect versus the designer and contractor. Additionally, the erection of the structure will be discussed in light of loads and stresses imparted on the structure during construction.  Wind tunnel testing; technical provision security requirements; scour analyses; and a 100-year corrosion protection plan will be highlighted.

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Segmental Concrete/Rail/Transit Session

Time: 8:00 AM – 12:00 Noon
Session Chair: Jen Laning
Room: Woodrow Wilson A

This session highlights some of the latest signature projects in segmental concrete bridge design and the latest knowledge and developing expertise for rail structures. Featured are overviews on unique segmental concrete bridge projects from the United States, India and Turkey, as well as discussions of design and preservation challenges for railroad bridge structures that will interest owners, analysts, designers and constructors.

IBC 19-55: Landmark Extradose Bridge on the Ganges River
Morgan Trowland, McElhanney Consulting Services, Vancouver, BC Canada; David Jeakle, McElhanney Consulting Services, Tampa, FL

The upcoming Sultanganj Bridge will feature the largest extradose spans in India and will form an iconic landmark at a significant cultural site on the revered Ganges River. This $300M crossing will provide much needed transport links to accelerate development in a remote region of Bihar, a north eastern state of India home to over 100 million people. The 2 mile, 30 span structure features 5110ft of extradose spans: a precast segmental superstructure assisted by a single plane of stay cables on central pylons. The typical extradose unit has a total length of 1886ft and comprises spans of 410-533-533-410ft which will be built by balanced cantilevering with segments delivered by barge. The single cell box girder has a typical width of 84ft to accommodate four lanes of vehicular traffic and two footpaths. It features a 28ft wide central box of variable depth with the deck wings supported by inclined struts. In one zone the superstructure is widened to 110ft providing pickup and drop off access to the Dolphin Observatory towers which overlook the navigational channel and are expected to draw many sightseers seeking glimpses of the native Ganges dolphins. The owner, Bihar state government, is procuring the structure through a design-build contact with completion expected in late 2019.

IBC 19-56: Design and Construction of a Modern Concrete Segmental Bridge
John Dvorak, P.E., CBI and Ken Heil, P.E., Figg Bridge Engineers, Inc., Englewood, CO

The new Cline Avenue Bridge over the Indiana Harbor and Ship Canal in East Chicago, Indiana is under construction. The previous bridge was closed in 2009 and removed by Indiana DOT due to deficiencies. The new elevated expressway bridge is being accomplished with 100% private funding and will reconnect the 3.5-mile gap of State Road 912 between Calumet and Michigan Avenues. It is part of the state highway system and provides a vital link to important commercial industries and employment centers along the Lake Michigan shoreline. The project consists of constructing a 6,236’ long precast concrete segmental bridge built in the balanced cantilever method, rehabilitating an existing steel bridge, and resurfacing improvements to the approach roadways. The new bridge incorporates a sustainable concrete design to last over 150 years and eco-friendly LED lighting. It is being built with local materials and local labor, providing labor, training and an economic stimulus to the area both during and after construction. The new, modern Cline Avenue Bridge will use non-stop, all-electronic toll collection using the best technology available when it opens to traffic.

IBC 19-57: Design of Ihsaniye Viaduct of Northern Marmara Motorway
Julien Erdogan, Francois Pissot, Giulio-Maria Scotto, Michal Ambor, and Umut Aldatmaz, Freyssinet, Rueil Malmaison, Veuillez Sélectionner, France

Ihsaniye viaduct is a key link to Istanbul New Airport, one of tomorrow’s megastructure. The viaduct, initially designed as a pre-tensioned I girders bridge, with 45m span, pier heights up to 37m and large foundations, is 860m long. Freyssinet offered an alternative optimized design based on post-tensioned concrete box girder together with incremental launching method (ILM) with 66m span, making this project outstanding in terms of maximum launching span without temporary support. This construction method also facilitates crossing of two existing highways placed along its length. Above one of those obstacles, an 80m span was proposed to avoid the construction of a permanent pier and foundation in the median. Adopted seismic strategy enabled to significantly decrease sizes of foundations. Overall, the reduction of quantities and the advantages of the incremental launching method clearly justified the change of design from multigirder bridge to ILM Bridge.

IBC 19-58: Study of Rail Break Gap on Bridges: Finite Element Analysis, Modification of Gap Formula and Parametric Investigation
Hamid Omran, Ph.D., P.Eng. and Cari Smit, P.Eng., Stantec, Calgary, AB Canada

Design of railway bridges supporting continuously welded rails requires an accurate estimation of the gap at possible rail break. The estimated rail gap shall be smaller than the allowable values to avoid derailment. A literature review revealed the inaccuracy of the existing gap formulas. The authors developed a nonlinear 2D Finite Element (FE) model of the rail structure and validated it against the available analytical approaches for ballast tracks. This study further employed the FE model to estimate the rail break gap on bridges. A comparison between the existing formulas and the developed FE model showed significant differences among the results. The existing formulas accurately predict the gap on ballast tracks beyond the bridge structure. However, the predictions are inaccurate on bridges due to the complex rail-structure interactions. This paper proposes a modified equation for the rail break gap. It also presents a parametric study on the effects of rail fasteners, structure fixity points, and superstructure stiffness on the rail break gap. The outline of this research leads to a better understanding and prediction of the rail break gap.

IBC 19-59: Design of a Concrete Tied-Arch Bridge for California High-Speed Rail Requirements: Use of Vertical Hangers vs Inclined Hangers
Ebadollah Honarvar, Ph.D., P.E., Martin Kendall, P.E., and Suhail Albhaisi, Ph.D., P.E., Jacobs, New York, NY

When use of steel is unfavorable, a concrete tied arch bridge is a feasible and cost-effective structural system to support high-speed rails spanning a relatively long distance over existing features on the ground while providing minimum horizontal and vertical clearance requirements. In this paper, a systematic study was carried out to optimize the structural performance and design of a complex 236 ft long single span concrete tied arch bridge by investigating the effect of hanger configuration on the bridge behavior. Using both inclined hangers (network tied arch) and vertical hangers (Langer configuration), the bridge response was evaluated for static loads in addition to track-structure interaction and seismic requirements specified by the California High-Speed Rail project. As a part of this evaluation, the main structural member sizes, including the reinforced concrete knuckles, posttensioned concrete tie beams, reinforced concrete arches, and steel hangers were refined. A detailed 3D finite-element model of the bridge was developed to complete rail-structure interaction, static, dynamic, seismic, and construction stage analysis, given consideration to geometry, material, and boundary nonlinearities. Generally, the analytical results indicated that the network tied arch alternative is more beneficial than vertical hanger system by reducing the main member sizes, without compromising the structural performance and intended functionality of the bridge. It was also found that the sag effects, and thus the geometry nonlinearity in a network tied arch bridge are negligible due to short length of the hangers. Using the analytical results, design recommendations are also provided to satisfactorily design concrete tied-arch bridges.

IBC 19-60: Myrtle Avenue Bridge: The Accelerated Replacement of the New York City Transit Bridge
Arjuna Ranasinghe, Ph.D., P.E., SE, Mohamad Feteha, P.E. and Lauren Weber, P.E., Jacobs Engineering, New York, NY

The Myrtle Avenue Bridge replacement is the first ever such undertaking by the New York City Transit in its history. The existing bridge consisted of three – 52’ span through-girders and carried two tracks of the MTA Subway M Line over a rail maintenance yard. This was replaced with a bridge having three – 67’ span through-girders. The existing bridge had gravity abutments. The new stub abutments are founded on drilled micropiles. Limited interruptions were allowed below the bridge and that combined with a gas main in front of the south abutment dictated the construction of new abutments behind the existing ones. This also required the protection of the existing tracks below the bridge. Retaining the existing abutment walls limited the construction under the bridge and allowed the construction of stub abutments behind them reducing the cost. Micropiles used limited the vibration that could have adversely affected the gas main and the existing abutment walls if driven piles were used. Realignment of the tracks was not possible. This limited the available space for the middle through-girder and special measures had to be taken for the design of its knee braces. It was required to maintain and protect the utilities attached to the bridge. Temporary poles were provided with high-tension cables for temporary utility support. The bridge owner required the entire bridge to be designed with bolts and no welding was allowed in order to alleviate any fatigue concerns.

Paper discusses the design and construction challenges and solutions for the project.

IBC 19-61: Behavior of Eyebars on a 110-year Old Truss Railroad Bridge
David Jacobs, P.E., F.ASCE and Ramesh Malla, Ph.D., University of Connecticut, Storrs, CT

From the mid-1800s until the early 1900s, eyebars were commonly used as tension members in steel truss railroad bridges. Eyebar members were favored by structural designers of the period because they a) were easy to fabricate, b) faster to erect than other shapes, and c) minimized secondary stresses by allowing freer rotation at joints. The objective of this research was to gain a better understanding of the effects of excessive wear on the eyebars and connecting pins due to age of very old truss railroad bridges. To study the behavior of eyebars on a 110-year-old railroad bridge, field testing of eyebar responses to live loads (moving trains) was performed. Strain and accelerometer readings were recorded on many of the eyebars used as diagonal counters and as bottom chord members. Readings were taken from four different types of passenger trains with speeds ranging from approximately 8.05 to 64.36 km/h (5 to 40 mph). Results indicate that as bars are loaded, frequently they are neither loaded simultaneously nor equally, as they were designed, resulting in overstress in one or more bars. This behavior is due to wear at both the pins and the contact surfaces of the eyebar holes. Also studied and analyzed are methods used by North American railroads for repairing eyebars exhibiting this excessive wear. This research provides bridge engineers with a better basis for determining which eyebars in a set may require shortening, better choice of possible remedial measures; both resulting in extending the life cycle of old bridges.

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Special Interest Session

Time: 8:00 AM – 12:00 Noon
Session Chair: John Dietrick
Room: Woodrow Wilson B/C/D

This session will deal with a variety of special topics related to bridge design, construction and rehabilitation. The presentations will include discussions of unique bridge types ranging from covered bridges to cable-supported extradosed bridges. Presentations will also discuss new approaches to evaluating extreme loading conditions such as seismic loads and vessel impact, as well as unique solutions including accelerated bridge techniques to address difficult construction challenges.

IBC 19-62: Low-Cycle Fatigue Cracking of DelDOT BR 1-501: A Case Study
James Bellenoit, P.E., AECOM, Mechanicsburg, PA

Major rehabilitation of the multi-span Newport Viaduct (DelDOT BR 1-501) was initiated in 2010 and substantially complete in 2015. Phased construction was used to maintain two lanes of traffic northbound and southbound at all times. Throughout the various stages, traffic was temporarily shifted onto the outside shoulders of the structure to facilitate construction across the width of the bridge. Normal traffic patterns were restored on the bridge in the summer of 2014. During an NBIS inspection in March 2015, several new cracks were discovered in the diaphragms of the steel tub girders at interior piers of the continuous span units. All cracks occurred in the fascia girders only. Cracks were observed at the tops of the internal plate diaphragms and external connection plates. A metallurgical examination indicated the cracks were due to fatigue and propagated at high growth rates (da/dN) indicative of high amplitude stress cycles. Light-moderate corrosion product was also found which suggested the cracks were relatively recent. Historical traffic data indicated an estimated 24 million trucks crossed the structure between 1978 and 2010, well beyond the number of cycles where noticeable fatigue cracking in web gaps from out-of-plane displacements would be expected. Since cracking was not observed until 2015, normal traffic patterns would not have generated sufficiently large stress cycles to have caused the cracking. Therefore, it was considered more probable that recent shifts in the traffic patterns were responsible. This condition was investigated and determined to have played a key role in the crack development.

IBC 19-63: Implementation for Design of Bridges to Resist Dynamic Barge Impact Loads
Michael Davidson, Ph.D., P.E., Henry Bollmann, and Gary Consolazio, Univerisity of Florida, Gainesville, FL

Bridges spanning navigable waterways are designed to resist vessel collision loading, including loads generated during barge impact events. While design provisions have promoted improved assessments of bridge structures (e.g., risk assessment, computation of nonlinear response), the existing design approach involves static characterizations of vessel collision load and bridge response. However, 15 years of Florida Department of Transportation research on barge-bridge impacts have shown that: (1) impact load and bridge response are dynamic; and, (2) incorporating dynamic effects can lead to advantageous bridge designs. Implementation of automated analysis features for quantifying dynamic risk for barge impact loads is needed to bring about improved uniformity of safety. The objective of this research is to establish an implementation of bridge design for resisting dynamic barge impact loads. Presented herein is the dynamic design implementation itself and resources for practicing engineers to refer to when making use of the implementation. As demonstration of the methodology, two unique bridges are considered, where the dynamic barge collision risk assessment procedure is illustrated for each case. Additionally, major modeling steps for conducting dynamic vessel collision analysis (using currently available bridge finite element analysis software) are identified to exemplify selection of bridge structural configurations that help to minimize design loads.

IBC 19-64: Bridge Foundations: Constructability Considerations in the Design and Selection Process
Steve Fung, P.E., Schnabel Engineering, Baltimore, MD

Bridge foundations are designed based on the AASHTO LRFD Design Specifications, 7th Edition, 2014. The specifications provide design guidelines for the design of different foundation elements, however, the selection of the appropriate foundation type for support of the bridge structure is ultimately the responsibility of the designer. The selection of the appropriate foundation type is typically based on one or more of the following factors: The magnitude and type of foundation loads, The subsurface conditions at the site, Cost of the foundation type, Special design considerations such as scour and downdrag loads, Availability of technology and local practice, and Constructability. For designers to fully incorporate constructability into their design, the designers must have a thorough knowledge of the construction process; experience in the construction planning process and field operations; and knowledge of the available technology and resources, to achieve the overall project objectives. While constructability is already practiced to some extent by most designers, some designers do not have this level of knowledge, therefore, some aspects of constructability is sometimes overlooked in the design and selection process of foundations – which could lead to project delays, cost overruns, or even litigation. This presentation provides an overview of some of the constructability issues related to shallow foundations, driven piles and drilled shafts, and discusses some of the constructability issues that the designer should evaluate when selecting foundations in the following environments: Urban fill, High groundwater, Soft compressible soils, Available space/Site constraints, Karst/Sinkholes, and Scour.

IBC 19-65: Poplar Street Bridge Slide
Gregory Kuntz, P.E., HDR, St. Louis, MO; Stacy McMillian, P.E., Missouri DOT – Bridge Division, Jefferson City, MO

The Poplar Street Bridge is a five span (300’-500’-600’-500’-265’) 2165’ long structure which carries I-64, I-55 and I-70 over the Mississippi River in downtown St. Louis and connects Missouri and Illinois. The bridge is actually twin Eastbound and Westbound Structures carrying 4 lanes of traffic each and consisting of two variable depth steel box girders (25’ max. depth) with an orthotropic steel deck on a shared substructure.  The Missouri Department of Transportation hired HDR to provide the following improvements to the Poplar Street Bridge: 1) Increase lane capacity of the EB Bridge from 4 to 5 lanes in conjunction with improving interchange ramp structures on the Missouri side, 2) Rehabilitate the superstructure and substructure and 3) Provide a new and improved wearing surface. The project is currently under construction with a completion date of December 2018. The two unique aspects of the project the presentation will focus on are the new wearing surface and the bridge slide. The new wearing surface consists of a fiber reinforced lightweight concrete overlay mechanically connected to the steel deck through shear studs. In lieu of a traditional widening, the EB superstructure was successfully slid 9’ to the south onto widened piers on March 31, 2018 over the course of 2.5 hours and was widely reported as the 2nd longest bridge slide ever in the by length.  The WB & EB superstructures were then connected together.

IBC 19-66: Bringing the Past to Life: Historic Glendale Bridge Restored and Repurposed
Tony Steffee, P.E., Mead & Hunt, Inc., Lexington, SC

By rehabilitating its framework and restoring the bridge to its historical charm, Mead & Hunt gave the Glendale steel truss pedestrian bridge new life and provided safe, reliable access over Lawson’s Fork Creek. The existing 292-foot-long, three-span steel truss bridge was constructed in the 1930s and taken out of vehicular service in 1978 and given to Spartanburg County, after which, it was left to decay. Though this structure serves as a focal point in the counties trails system, the existing bridge had deteriorated to the point that it was becoming unsafe for pedestrian use. Mead & Hunt started with a detailed inspection of the entire structure to obtain field measurements of member sizes and determine the extent of the deterioration. All three trusses, including truss built-up members, stringers, floor beams, overhang brackets and gusset plates, were then load rated for the final loading requirements to determine which members would be overstressed and needed to be strengthened. Finally, the team worked on the details which replaced the existing asphalt deck with three-inch timber decking, the railings were upgraded to pedestrian standards and lighting was added. Coordination during construction also ensured that the work proceeded safely with no environmental impacts. The rehabilitated bridge blends in seamlessly with its picturesque surroundings, displays a scenic view over the historic mill dam and shoals, and now serves as a beacon of opportunity to the county. For pedestrian and bicycle traffic, to public and private functions, the Glendale Bridge is once again safely serving its community.

IBC 19-67: Application of the Endurance Time Method to Seismic-Induced Pounding Analysis for Long-Span Extradosed Cable-Stayed Bridges considering Wave Passage Effects
Yu Shen and Professor JianZhong Li, Tongji University, Shanghai, Shanghai China

The endurance time method (ET) is a novel dynamic analysis procedure in which artificially intensifying accelerograms are used as loading inputs. In this method, various dynamic responses under corresponding seismic intensity levels are estimated with a reduced simulation effort. In this paper, the accuracy and effectiveness of ET method in predicting the pounding responses of long-span extradosed cable-stayed bridges with wave-passage effects have been presented. A typical extradosed cable-stayed bridge with two-sides abutments in the valley were selected as the analyzed target, and the incremental dynamic analysis (IDA) results with 22 earthquake records were employed as a basis of comparison for the observations of the validation. Base on the validation results, the wave-passage effect analyses with different velocities were carried out using the ET method. The results indicate that ET method is an alternative implemented method to predict and evaluate seismic-induced pounding response of the long-span extradosed cable-stayed bridges, with the inclusion of wave-passage effects.

IBC 19-68: Village Covered Bridge (Friendship Bridge) Adaptive Reuse
James Hall, Jr., P.E. and Robert Durfee, P.E., Dubios and King, Bedford, NH

In 2014, the NHDOT advised the Town of Wentworth that the pedestrian crossing (1909 steel truss bridge) over the Baker River in the Village of Wentworth was beyond rehabilitation and would be closed to pedestrian use and removed. The closure required school children to travel on an unprotected shoulder to the bus stop on a 0.5-mile detour. The existing truss bridge had provided protected pedestrian access from the Historic Village to the school bus stop. The NHDOT estimated the cost of rehabilitating the historic state-owned at $800,000, stated that funds were not available for the rehabilitation and indicated its intent to demolish and remove the bridge. Concurrently, the Goffes Mill Covered Bridge at Bedford’s Wayfarer Inn was to be demolished along with the Inn facilities to make way for re-development. DuBois & King/3G Construction partnered with the team to organize a plan of action with the Wayfarer Inn and the NHDOT. The project rehabilitated the superstructure and substructure; served as a catalyst to encourage redevelopment of local recreation amenities and reinstalled a covered bridge at a site historically served by a covered bridge. D&K made design directives to transport the bridge intact from another contractor’s demolition site to a site designed for a shorter span bridge. Creative measures included redesign of abutments to accommodate the longer superstructure, removal of legacy structural elements concurrent to additional dead weight removal activities, and employing a metal roof to reduce dead weight and snow load.


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W-10: International Workshop on Emerging Bridge Technologies

Time: 8:00 AM – 12:00 Noon

The main objective of this workshop is to invite speakers from the U.S., China and other Countries to share their experiences with emerging bridge technologies in innovative bridge design, construction, inspection, maintenance and preservation for improving the safety, durability, and economy of highway/railway bridges and tunnels. There will be time for attendees to ask questions after each presentation. After all the presentations are completed, there will be an “Open Forum” for general discussion of topics presented and other issues of interest to the participants. Attendees of this IBC workshop will be able to gain broad understanding of emerging bridge technologies that will positively impact bridges of tomorrow.

Speakers: Myint Lwin, P.E., S.E., Consultant, Olympia, WA; Thomas G. Leech, P.E., S.E., Gannett Fleming, Inc. Pittsburgh, PA; Ronald D. Medlock, P.E., High Steel Structures, Lancaster, PA

W-11: FHWA Bridge Security Design Manual: Overview, Application, and Beyond

Time: 8:00 AM – 12:00 Noon

Physical security of highway bridges is a critical national issue that is not consistently addressed in industry. The U.S. Federal Highway Administration (FHWA) recently teamed with industry and academia to develop the FHWA Bridge Security Design Manual (Manual).  During this workshop, the Manual authors and FHWA personnel will provide an overview of the Manual as well as state-of-the-practice in bridge security, industry best practices, resiliency-based design strategies, and future R&D needs.

Speaker: Eric Sammarco, Ph.D., P.E., Protection Engineering Consultants, LLC, Austin, TX