5_AMB_EA_April_2016_508_noAppendixes.pdf

National Park Service United States Department of the Interior

Environmental Assessment

The Arlington Memorial Bridge Rehabilitation

April 2016

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ENVIRONMENTAL ASSESSMENT

THE ARLINGTON MEMORIAL BRIDGE

REHABILITATION

April 2016

The Arlington Memorial Bridge Rehabilitation

Washington, DC

PROJECT SUMMARY

INTRODUCTION

Pursuant to Section 101(2)(C) of the National Environmental Policy Act of 1969, as amended, the National Park Service, in cooperation with the Federal Highway Administration, is evaluating the proposed rehabilitation of the Arlington Memorial Bridge. The US Coast Guard and National Capital Planning Commission are acting as cooperating agencies. The historic bridge spans the Potomac River between the National Mall in Washington, DC, and the Arlington National Cemetery in Virginia. The bridge is an important element of the George Washington Memorial Parkway, the regional transportation network, and the monumental core of Washington, DC.

The proposed Arlington Memorial Bridge project includes the rehabilitation or replacement of the steel draw span (technically referred to as the bascule span); repairs to the deteriorated portions of the abutments, piers, and concrete arch spans; replacement of the concrete bridge deck; resurfacing of the travel lanes; replacement of the concrete sidewalks and refitting of granite curbs; repairs to granite bridge railings; repairs to lamp posts; repairs to access panels; installation of an improved drainage system; and other minor nonstructural bridge improvements.

This Environmental Assessment analyzes the potential environmental impacts that would result from the implementation of the proposed action. This Environmental Assessment has been prepared in accordance with the National Environmental Policy Act, the regulations of the Council on Environmental Quality for implementing the National Environmental Policy Act (40 Code of Federal Regulations 1500-1508), and Director’s Order 12: Conservation Planning, Environmental Impact Analysis, and Decision-making (NPS 2011a). Section 106 of the National Historic Preservation Act of 1966, as amended, is being conducted as a separate but parallel process.

PURPOSE OF AND NEED FOR ACTION

The purpose of the project is to restore the structural integrity of the Arlington Memorial Bridge while protecting and preserving, to the extent feasible, its memorial character and significant design elements.

The Arlington Memorial Bridge is more than 80 years old and has never undergone a major rehabilitation. Several temporary repairs have kept it operational to meet the needs of the traveling public. However, like many other older highway bridges across the nation, this bridge needs comprehensive repair to ensure its ability to provide adequate traffic service for decades to come.

The Federal Highway Administration regularly inspects the bridge in accordance with generally recognized structural engineering guidelines and standards. These detailed structural inspections and studies have identified significant amounts of corroded steel and deteriorated concrete. The most critical elements needing repair are the concrete arch spans and the steel bascule (drawbridge) span. Therefore, the project is needed to address the ongoing corrosion of steel structural members i

Arlington Memorial Bridge Rehabilitation Environmental Assessment Project Summary of the bascule span, deterioration of the concrete on the bridge’s concrete arches, and deterioration of the sidewalks and wearing surface.

While the bridge is still considered safe for travel, the superstructure is deteriorating at an accelerated pace. The National Park Service, at the recommendation of the Federal Highway Administration, has posted a 10-ton load limit across the entire length of the bridge. The load restriction, which has eliminated most bus traffic, will remain in effect until the permanent rehabilitation project is completed. As the bridge continues to deteriorate, the National Park Service and the Federal Highway Administration may impose further weight restrictions and/or close the bridge.

OVERVIEW OF THE ALTERNATIVES

This Environmental Assessment analyzes the No-Action Alternative along with four Action Alternatives for rehabilitation of the Arlington Memorial Bridge. The No-Action Alternative provides a basis for comparing the management direction and environmental consequences of the other alternatives. Under all alternatives, including the No-Action Alternative, the trunnion posts would be reinforced with steel columns to provide additional strength in order to protect the integrity of the bascule span.

All Action Alternatives would include repairs to the concrete arch spans, concrete bridge piers, bridge railings and other non-structural bridge components, and replacement of expansion joints, bearings, bridge deck, and sidewalks. Under Alternative 1A the bascule span would be replaced with a new span comprised of precast concrete box girders. Under Alternative 1B the bascule span would be replaced with a new span comprised of variable depth steel girders. Two construction methods are being considered for Alternatives 1A and 1B. Construction Method A would require a temporary full closure of the bridge, sidewalks, and all vehicular travel lanes while the bascule span is replaced.

Construction Method B would use a phased approach to replace the bascule span and would require partial closure of the bridge with the closure of three vehicular travel lanes and one sidewalk. Under Alternative 2 the bascule span would be replaced with a new span comprised of welded steel truss construction. Under Alternative 3 the existing bascule span would be completely rehabilitated in place.

Under all Action Alternatives, several land and river staging areas would be necessary. This Environmental Assessment analyzes two river staging areas which will be located on two temporary barges north and south of the Arlington Memorial Bridge. In addition, the impacts associated with the use of causeways or dock/work platforms have been assessed. Four land staging areas are also analyzed and are located on Memorial Circle, south of Memorial Circle, north of the Lincoln Memorial, and near the Watergate Steps.

The National Park Service, in cooperation with the Federal Highway Administration, has identified Alternative 1B: Replace the Bascule Span with a New Span Comprised of Variable Depth Steel Girders, as the Preferred Alternative for the rehabilitation and repair of the Arlington Memorial Bridge.

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NOTE TO REVIEWERS AND RESPONDENTS

We value and welcome your input on this project. The public comment period closes on May 9, 2016. The preferred system for receiving public comments electronically is through the National Park Service Planning, Environment, and Public Comment (PEPC) website, where the Environmental Assessment is publicly posted on the internet. The PEPC database is a tool used by the National Park Service to manage official correspondence and analyze public comment in the planning process. The website address is http://parkplanning.nps.gov/memorialbridgeea. To complete a comment form online, from the list of projects, click on the Arlington Memorial Bridge Rehabilitation. In the left menu, click Document List, then Environmental Assessment, and Comment on Document.

You can also mail comments to:

Superintendent, George Washington Memorial Parkway c/o Turkey Run Park

McLean, VA 22101

If you wish to comment on the Environmental Assessment, you may submit comments electronically or directly by mail. Before including your address, phone number, e-mail address, or other personal identifying information in your comment, you should be aware that your entire comment – including your personal identifying information – may be made publicly available at any time. While you may request in your comment that your personal identifying information be withheld from public review, we cannot guarantee that we will be able to do so.

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TABLE OF CONTENTS

Chapter 1: Purpose and Need 1

Introduction 1

Purpose of and Need for Action 2

Project Objectives 2

Project Area 3

Description of the Arlington Memorial Bridge 4

Project Background 10

Structural Inspections, Studies and Assessments 11

Temporary Repairs 14

Significance of the Arlington Memorial Bridge 15

Significance of the George Washington Memorial Parkway 16

Relationship to Laws, Executive Orders, Policies and Other Plans 16

Applicable Federal Laws and Regulations 16

Applicable State and Local Laws, Regulations, Policies and Plans 20

Executive Orders and Director’s Orders 21

National Park Service Management Policies 23

Overview of Public Participation 23

Issues and Impact Topics 24

Issues 24

Impact Topics Analyzed in this Environmental Assessment 26

Impact Topics Dismissed from Further Analysis 29

Chapter 2: Alternatives 37

Introduction 37

Description of Alternatives 37

No-Action Alternative 37

Elements Common to the Action Alternatives 38

Alternative 1A: Replace the Bascule Span with a New Span Comprised of Precast Concrete Box Girders (Beams) 40

Alternative 1B: Replace the Bascule Span with a New Span Comprised of Variable Depth Steel Girders 44

Alternative 2: Replace the Bascule Span with a New Span Comprised of Welded Steel Truss Construction 46

Alternative 3: Rehabilitate the Existing Bascule Span in Place 48 v

Environmental Assessment Table of Contents

Temporary Trunnion Shoring 51

Construction Phasing 51

Construction Staging 51

Land-Based Staging Areas 54

River Based Staging Areas 55

Mitigation Measures of the Action Alternatives 58

Alternatives Considered but Dismissed 60

Environmentally Preferable Alternative 62

National Park Service Preferred Alternative 63

How the Alternatives Meet the Objectives 64

Summary of Impacts 67

Chapter 3: Affected Environment 75

Water Quality 75

Riverine 76

Wildlife including Rare, Threatened and Endangered Species 77

Cultural Resources 81

Historic Structures and Districts, Including Cultural Landscapes 84

Visitor Use and Experience 93

Transportation 95

Navigation 99

Chapter 4: Environmental Consequences 107

General Methodology for Assessing Impacts 107

General Analysis Methods 107

Impact Thresholds 108

Cumulative Impacts Analysis Method 108

Water Quality 112

Riverine 123

Wildlife including Rare, Threatened and Endangered Species 133

Cultural Resources 146

Historic Structures and Districts, Including Cultural Landscapes 162

Visitor Use and Experience 162

Transportation 174

Navigation 193 vi

Chapter 5: Consultation and Coordination 201

Agency Coordination 201

Section 7 Consultation 201

Section 106 Consultation 203

Tribal Consultation 204

Section 401/404 and Section 10 Consultation 204

US Coast Guard Consultation 204

Transportation Planning 205

Chapter 6: List of Preparers 207

Glossary and Acronyms 209

References 215

LIST OF FIGURES

Figure 1: View of the Arlington Memorial Bridge, Lincoln Memorial, and Washington Monument from the George Washington Memorial Parkway 1

Figure 2: View of the Arlington Memorial Bridge, Women in Military Service for America Memorial, and Arlington House from the Lincoln Memorial 1

Figure 3: Project Area 3

Figure 4: Arlington Memorial Bridge over the Potomac River 4

Figure 5: View looking to the south at the underpass of Ohio Drive, SW 5

Figure 6: Bridge railings, sidewalks, and lampposts 6

Figure 7: View of Arlington Memorial Bridge’s bascule span 6

Figure 8: Diagrams of machinery used to open the bascule span 8

Figure 9: Diagrams of machinery and operator rooms located inside Abutments 2 and 3, south elevation 9

Figure 10: View of Memorial Avenue and Arlington House from the Arlington Memorial Circle 10

Figure 11: View of severe corrosion of the inner trunnion post of the bascule span 11

Figure 12: View of temporary pedestrian bridge spanning deteriorated sidewalks over the bascule span abutments 14

Figure 13: FEMA floodplains located within a one mile radius of the Arlington Memorial Bridge 31

Figure 14: Conceptual rendering of the concrete box girder replacement structure proposed under Alternative 1A (Underside View) 40 vii

Figure 15: Conceptual rendering of the existing steel facade planned for reuse under all alternatives

Figure 16: Conceptual rendering of the variable depth steel girder replacement structure proposed under Alternative 1B (Underside View) 44

Figure 17: Conceptual rendering of the welded steel truss replacement structure proposed under Alternative 2 (Underside View) 46

Figure 18: Conceptual rendering of the rehabilitated bascule span proposed under Alternative 3 (Underside View) 48

Figure 19: Proposed construction staging area locations 53

Figure 20. Construction Staging Area A 54

Figure 21. Construction Staging Area B 54

Figure 22. Construction Staging Area C 55

Figure 23. Construction Staging Area D 55

Figure 24. Example of Temporary Construction Causeway 56

Figure 25. Example of a Dock/Work Platform 56

Figure 26. View of Barge Staging Area 1 (Looking south from the Arlington Memorial Bridge) 57

Figure 27. View of Barge Staging Area 2 (Looking north from the Arlington Memorial Bridge) 57

Figure 28: Conceptual rendering of the concrete arch replacement structure proposed under a dismissed alternative 61

Figure 29: Conceptual rendering of the concrete arch replacement structure proposed under a dismissed alternative (Underside View) 61

Figure 30: Wetlands near the Arlington Memorial Bridge 78

Figure 31: Submerged Aquatic Vegetation near the Arlington Memorial Bridge 79

Figure 32: Atlantic sturgeon (Acipenser oxyrhynchus) 80

Figure 33: Shortnose sturgeon (Acipenser brevirostrum) 80

Figure 34: Area of Potential Effect 83

Figure 35: Northeastern view of the Arlington Memorial Bridge from the Mount Vernon Trail 84

Figure 36: View of the bascule span, south side of the Arlington Memorial Bridge 84

Figure 37: Eastern view of the Memorial Avenue Corridor from the entrance to the Arlington National Cemetery 85

Figure 38: View of the underpass for the George Washington Memorial Parkway and Mount Vernon Trail 86

Figure 39: View of the Navy-Marine Memorial 87

Figure 40: View of the Arlington Memorial Bridge from the Mount Vernon Trail 87

Figure 41: View of Arlington House: The Robert E. Lee Memorial 88

Figure 42: View of the Kennedy Center from the Arlington Memorial Bridge 91

Figure 43: View of the Lincoln Memorial from the eastern end of the Arlington Memorial Bridge viii

Figure 44: Traffic pattern along the roadways and ramps at the western approach to the Arlington

Memorial Bridge 95

Figure 45: Traffic pattern along the roadways and ramps at the eastern approach to the Arlington Memorial Bridge 96

Figure 46: Long delay corridors in the vicinity of the Arlington Memorial Bridge 98

Figure 47: Emergency evacuation routes in Washington DC 99

Figure 48: Federal Navigation Channel 101

Figure 49: Navigational restrictions along the Potomac River 102

Figure 50: NOAA Navigation map showing the Arlington Memorial Bridge as a fixed span bridge

Figure 51: Recreational boaters near the Arlington Memorial Bridge 104

Figure 52: Marinas along the Potomac River 105

Figure 53: Non-Motorized Boat Navigation 106

Figure 54: Cumulative Projects 110

Figure 55: Typical Installation Layout of Floating Turbidity Barriers 114

Figure 56: Barge Staging Areas 1 and 2 122

Figure 57: Barge Staging Areas and Associated Dredging with Submerged Aquatic Vegetation 132

Figure 58: Conceptual rendering of the concrete box girder replacement structure proposed under Alternative 1A (Underside View) 150

Figure 59: View of the Arlington Memorial Bridge from the Navy-Marine Memorial 151

Figure 60: Conceptual rendering of the variable depth steel girder replacement structure proposed under Alternative 1B (Underside View) 154

Figure 61: Conceptual rendering of the welded steel truss replacement structure proposed under Alternative 2 (Underside View) 155

Figure 62: Steel truss bascule span that would be rehabilitated in place under Alternative 3 157

Figure 63: Example of steel truss under sidewalk with severe corrosion that may require replacement

Figure 64: Full Closure Scenario - Changes in Traffic Volumes 180

Figure 65: Three-Lane Closure Scenario A - Changes in Traffic Volumes 181

Figure 66: Three-Lane Closure Scenario B - Changes in Traffic Volumes 182

Figure 67: Pedestrian/bicycle detour route between the Lincoln Memorial and the Arlington National Cemetery 184 ix

LIST OF TABLES

Table 1: Inspections, Studies and Assessments to ate 12

Table 2: Summary of Action Alternatives 50

Table 3: How the Alternatives Meet the Project Objectives 65

Table 4: Summary of Environmental Consequences 67

Table 5: Special Events Utilizing the Arlington Memorial Bridge 94

Table 6: Daily Traffic- Potomac River Crossings 96

Table 7: Navigational Clearances of Bridges along the Potomac River 102

Table 8: Cumulative Impact Projects or Actions 111

Table 9: Forecasted Daily Volumes over the Potomac River (Year 2017) 178

Table 10: Congestion Levels (Vehicle Hours of Delay) in the Study Area (Year 2017) 179

APPENDIXES

Appendix A: Consultation Letters

Appendix B: Wetland Statement of Findings x

CHAPTER 1: PURPOSE AND NEED

INTRODUCTION

Pursuant to Section 101(2)(C) of the National Environmental Policy Act (NEPA) of 1969, as amended, the National Park Service, in cooperation with the Federal Highway Administration, is evaluating the proposed rehabilitation of the Arlington Memorial Bridge. The US Coast Guard (USCG) and the National Capital Planning Commission are acting as cooperating agencies. The historic bridge spans the Potomac River between the National Mall in Washington, DC and the Arlington National Cemetery in Virginia. The bridge is an important element of the George Washington Memorial Parkway, the regional transportation network, and the monumental core of Washington, DC. The Arlington Memorial Bridge is shown in Figure 1 and Figure 2 along with other memorials and monuments surrounding the bridge.

The proposed Arlington Memorial Bridge project includes the rehabilitation or replacement of the steel draw span (technically referred to as the bascule span); repairs to the deteriorated portions of the abutments, piers, and concrete arch spans; replacement of the concrete bridge deck; resurfacing of the travel lanes; replacement of the concrete sidewalks and refitting of granite curbs; repairs to granite bridge railings; repairs to lamp posts; repairs to access panels; installation of an improved drainage system; and other minor nonstructural bridge improvements.

This Environmental Assessment analyzes the potential environmental impacts that would result from the implementation of the proposed action. This Environmental Assessment has been prepared in accordance with the National Environmental Policy Act, the regulations of the Council on Environmental Quality for implementing National Environmental Policy Act (40 Code of Federal

Figure 1: View of the Arlington Memorial Bridge, Lincoln Memorial, and Washington Monument from the George Washington Memorial Parkway

Figure 2: View of the Arlington Memorial Bridge, Women in Military Service for America Memorial, and Arlington House from the Lincoln Memorial

Environmental Assessment Purpose and Need

Regulations 1500-1508), and Director’s Order 12: Conservation Planning, Environmental Impact Analysis, and Decision-making (NPS 2011a). Consultation regarding Section 106 of the National Historic Preservation Act of 1966, as amended, is being conducted as a separate but parallel process.

PURPOSE OF AND NEED FOR ACTION

The purpose of the project is to restore the structural integrity of the Arlington Memorial Bridge while protecting and preserving, to the extent feasible, its memorial character and significant design elements.

The Arlington Memorial Bridge is more than 80 years old and has never undergone a major rehabilitation. Several temporary repairs have kept it operational to meet the needs of the traveling public. However, like many other older highway bridges across the nation, this bridge needs comprehensive repair to ensure its ability to provide adequate traffic service for decades to come.

The Federal Highway Administration regularly inspects the bridge in accordance with generally recognized structural engineering guidelines and standards. These detailed structural inspections and studies have identified significant amounts of corroded steel and deteriorated concrete. The most critical elements needing repair are the concrete arch spans and the steel bascule (drawbridge) span. Therefore, the project is needed to address the ongoing corrosion of steel structural members of the bascule span, deterioration of the concrete on the bridge’s concrete arch spans, and deterioration of the sidewalks and wearing surface.

While the bridge is still considered safe for travel, the superstructure is deteriorating at an accelerated pace. The National Park Service, at the recommendation of the Federal Highway Administration has posted a 10-ton load limit across the entire length of the bridge. The load restriction, which has eliminated most bus traffic, will remain in effect until the permanent rehabilitation project is complete. As the bridge continues to deteriorate, the National Park Service and the Federal Highway Administration may impose further weight restrictions and/or close the bridge.

PROJECT OBJECTIVES

Objectives are generally defined as “what must be achieved to a large degree for the action to be considered a success” (NPS 2011a) and represent more specific statements of purpose and need. All alternatives selected for detailed analysis must meet all objectives to a large degree and must substantially address the purpose of and need for action. The following objectives were identified by the planning team for this project:

1. Address the structural deterioration of the bridge while preserving the Memorial’s historic integrity to the extent feasible;

2. Minimize extent and duration of full bridge and /or partial lane closures and overall disruption to traffic during construction;

3. Avoid disruptions to utilities during construction; and

4. Minimize future maintenance requirements and associated costs.

PROJECT AREA

The Arlington Memorial Bridge spans the Potomac River, connecting Lincoln Memorial Circle with the Memorial Circle on Columbia Island (officially renamed Lady Bird Johnson Park in 1968) in Washington, DC. Further west, the bridge provides access to Memorial Avenue and the ceremonial entrance to Arlington National Cemetery within the Commonwealth of Virginia. The project area for the proposed rehabilitation of the Arlington Memorial Bridge consists of the bridge and surrounding roadways, construction staging areas in the vicinity of the bridge, and the Potomac River channel and shorelines, approximately 1,400 feet upstream and 2,100 feet downstream of the bridge (Figure 3).

Figure 3: Project Area

DESCRIPTION OF THE ARLINGTON MEMORIAL BRIDGE

The Arlington Memorial Bridge serves as a memorial to the reconciliation between the Union and Confederacy following the Civil War. As the western link in the chain of monuments that starts at the Capitol building, the Arlington Memorial Bridge connects the National Mall in Washington, DC with Arlington National Cemetery in Virginia (Nolin 1988). The Memorial Bridge was designed by William Mitchell Kendall while employed by McKim, Mead & White, a prominent architectural firm based in New York City. The bridge reflects the original intention of the McMillan Commission, whose charge was to guide the development of the monumental core and the park system of Washington, DC by building a memorial bridge on this site which would join the North and South (Figure 4).

The bridge provides a physical and symbolic link between the North and the South, and was designed as an entryway and a grand approach to the monumental core of our nation’s capital. The bridge and its associated architectural, engineering, sculptural, and landscape features are significant as important elements in the neoclassical urban design of the National Capital as it evolved during the first third of the 20th century. Specifically, the bridge’s bascule span is recognized as an innovative engineering achievement.

The area between the southern terminus of the Rock Creek and Potomac Parkway and the bridge is the Watergate, a broad flight of steps leading to the water that represents a ceremonial river entrance to the District of Columbia. At its western end, the Arlington Memorial Bridge complex includes Memorial Circle and its surrounding landscapes, the circular plaza on Columbia Island; the Boundary Channel Bridge, which connects Columbia Island (now Lady Bird Johnson Park) with the Virginia shore; and Memorial Avenue and Hemicycle, the ceremonial entrance to Arlington Cemetery.

A bridge spanning the Potomac River in the location of the Arlington Memorial Bridge was first conceived in the 1830s. In 1832, Congress passed an act that funded the purchase of land for the bridge’s approaches. In 1836, Congress passed an act to build a bridge across the Potomac; however, the bridge was never constructed.

Figure 4: Arlington Memorial Bridge over the Potomac River

Following a major flood in 1881, Congress appropriated funds to raise the tidal flat on the eastern side of the Potomac River. The US Army Corps of Engineers oversaw the dredging of the river to improve navigation while using the dredge spoils to reclaim the tidal flats. The reclaimed land was set aside for a public park and now includes Potomac Park and the western portion of the National Mall. The land on which the bridge abutments of the Arlington Memorial Bridge sit was also created during this time.

The Senate Park Commission, commonly known as the McMillan Commission, was formed in 1901 to study the conditions of the District’s parks. The Commission ultimately developed the Senate Park Commission Plan of 1901 and included a memorial bridge in the location that the Arlington Memorial Bridge was ultimately constructed. The Arlington Memorial Bridge Commission was established in 1913 to oversee the planning and construction of the bridge. Plans were considered for the next decade, but Congress did not allocate any funds for the construction of the bridge until 1922. With the dedication of the Lincoln Memorial in 1922, the logic of a bridge connecting the Lincoln Memorial with the Arlington National Cemetery was evident. However, debate continued over the location and type of span that should be constructed. On December 18, 1922, a joint meeting of the Commission of Fine Arts and the Arlington Memorial Bridge Commission decided in favor of “a low bridge on the line connecting the Lincoln Memorial and Arlington House.”

Architects McKim, Mead & White were selected in early 1923 to design the bridge. William Mitchell Kendall, the lead architect, designed the bridge in the neoclassical style. The Arlington Memorial Bridge is 2,163 feet long and 94 feet wide. The bridge consists of 10 reinforced concrete arch spans and a double leaf bascule span at the bridge’s center. Eight of the 10 concrete arch spans are situated over the Potomac River, while two smaller concrete arches span the George Washington Memorial Parkway and Ohio Drive, SW at each end of the bridge (Figure 5). The bridge has sidewalks on each side measuring 14 feet each, and the roadway measures 60 feet from curb to curb, providing six 10-foot-wide vehicle travel lanes. The bridge is supported by an abutment on each shore, six piers—three per side—and two abutments between the masonry and bascule spans.

The concrete arches are dressed with granite ashlar from the Mount Airy Quarry in North Carolina.

Each side of each of the piers and central abutments feature sculpted granite, bas-relief eagle and fasces ornamentation designed by sculptor C. Paul Jennewein. The keystone of each concrete arch is decorated with an approximately 6-foot-tall bison head sculpted by Alexander Phimister Proctor, a renowned American western artist.

Figure 5: View looking to the south at the underpass of Ohio Drive, SW

Two gilded-bronze equestrian statues entitled The Arts of War: Sacrifice and Valor, by American sculptor Leo Friedlander, are mounted on matching pedestals that flank the Washington entrance.

These statues, along with the adjacent Rock Creek and Potomac Parkway terminus and the Watergate steps, join with the bridge in constituting a formal western terminus of the National Mall at the edge of the Potomac River.

The bridge’s railing is comprised of ornate, granite balusters and railings. For structural reasons, the bascule span’s railing consists of aluminum balusters, bases, and railings shaped to match those of granite on the fixed spans. The roadway and sidewalks are illuminated at night by 40 electric street lamps, four on each river span and two on each roadway span. The current lampposts are replicas of the original ones, which were a standard design by Francis D. Millet that is extensively used throughout Washington, DC (Figure 6).

The decision to include a draw span on the bridge was one of the most controversial aspects of the bridge design. Despite continual decreases in the amount of large ships navigating upriver to Georgetown and despite the fact that the US Army Corps of Engineers wanted to construct a higher bridge to allow large ships to pass without the need to open the bridge, the Arlington Memorial Bridge Commission decided that a draw span was necessary to maintain the bridge’s aesthetics while allowing for the passage of ships.

Following a design competition, the Arlington Memorial Bridge Commission selected the Strauss Engineering Company (formerly the J.B. Strauss Bascule Bridge Company) to design the bascule span with the Phoenix Bridge Company as the builder.

The Arlington Memorial Bridge’s bascule span, or draw span, is a movable steel truss span with two leafs that meet centrally over the navigation channel. The bascule span is faced with pressed ornamental molybdenum steel and painted to blend with the concrete arch spans (Figure 7). At 216 feet, it was once the longest draw

Figure 7: View of Arlington Memorial Bridge’s bascule span

Figure 6: Bridge railings, sidewalks, and lampposts span in the world, as well as the heaviest and the fastest. Counterweights, each weighing 2,400 tons and consisting of concrete, iron ore, and steel punchings, are concealed in the abutments under the bridge. When the bascule span was operable, the counterweights were used to pivot each leaf upward. Each leaf consists of two main steel trusses that are supported by an axle, or trunnion, that rests on trunnion posts, which carry the load of the bridge down to the bridge abutments (Figure 8).

The Arlington Memorial Bridge was the first of its kind to have all of the components of the bascule span that allowed it to rise concealed under the bridge and in the span’s abutments.

Two machinery rooms, one for each leaf, are located on the lowest floor of the bascule span abutments (Nolin 1988) (Figure 9). The control room is adjacent to the east side machinery room, rather than in a tower above the deck as is the case in many other bascule spans, which was an innovation created specifically for the Arlington Memorial Bridge. From this control room, the bascule span operator managed the machinery that raised and lowered the bridge. Because the operator was underneath the bridge, he had to rely on two other persons, known as an overseer and a guard, who were stationed in small cabins, integrated into the north balustrade and recessed approximately 3 feet below the sidewalk level, much like a baseball dugout, in order to operate the span. Two small, bronze-framed windows in each cabin furnished a limited view up the river and across the roadway in the downstream direction. When operable, the bascule span was able to open in 60 to 120 seconds.

Rather than the typical gates with flashing lights on top of the bridge to stop traffic, the Arlington Memorial Bridge employed 12 lights mounted atop pickets that rose out of the pavement in the center of each lane on both sides of the bascule span. When the bascule span was in the closed position, the only visible parts were small iron disks flush with the roadway surface. In addition to these warning lights, a pair of fixed red lights and a gong were mounted on a lamppost on the sidewalk adjacent to on-coming traffic. When preparing to raise the bascule span, the overseer would raise the pickets 3 feet and two red lamps at the top of each one would alternately flash to warn motorists that the draw span was about to be opened. These warning lights are no longer present within the bascule span deck.

During its period of active operation between 1932 and 1961, the bascule span was opened to provide access for large ships to the Georgetown waterfront. Due to decreased shipping traffic on the Potomac River and the later downstream construction of a fixed, low-clearance bridge (currently the 14th Street Bridge Complex), the bascule span was permanently fastened in the closed position in 1965 (KressCox Associates, P.C. 1986). The USCG permit on file for the existing structure authorized a drawbridge at this site. Before 1966, the agency responsible for drawbridge operation regulations was the US Army Corps of Engineers. In July 1962, the Army Corps of Engineers published that the draw bridge need not open for the passage of vessels. The Coast Guard re-affirmed this authorization in 1968.

Figure 8: Diagrams of machinery used to open the bascule span

Figure 9: Diagrams of machinery and operator rooms located inside Abutments 2 and 3, south elevation (note – north elevation is mirror image; e.g. the motor-generator room in Abutment 3 is on the north side of the abutment)

The axis of the bridge, which is angled southwesterly from the east-west Mall axis, is carried on Memorial Avenue across the Boundary Channel Bridge to the Virginia shore where it terminates at the grand renaissance gateway to Arlington National Cemetery and now the location of the Women in Military Service for America Memorial (Figure 10). Several memorials such as the United Spanish War Veterans Memorial and the Seabees Memorial are situated along Memorial Avenue in proximity to the bridge. In addition, the Arlington National Cemetery and Arlington House, the Robert E. Lee Memorial, can be seen from the bridge. The bridge also crosses the Mount Vernon Trail and the George Washington Memorial Parkway on Columbia Island between the Potomac River and the Boundary Channel, which marks the boundary between the District of Columbia and the Commonwealth of Virginia.

The Arlington Memorial Bridge and Related Features (including the Watergate, Rock Creek and Potomac Parkway Terminus, Memorial Circle and its surrounding landscapes, Boundary Channel Bridge, the Arts of Peace, the Arts of War, and Memorial Avenue and Hemicycle) were listed in the DC Inventory of Historic Sites on November 8, 1964, and in the National Register of Historic Places on April 4, 1980 (NPS 1980).

The bridge continues to provide access across the Potomac River for vehicular travel with connections to several heavily traveled roadways in the area, including the George Washington Memorial Parkway. The bridge also provides a crossing for pedestrians and bicyclists on the bridge’s wide sidewalks, provides access to the Mount Vernon Trail, and has been used for many large scale events throughout the years such as parades, marathons, and funeral processions. Ferries, water taxis, dinner cruises, tour boats, private recreational watercraft, and rowers on the Potomac River pass under the bridge to access areas upstream and downstream. In 2007, approximately 72,000 motor vehicles were carried across the Arlington Memorial Bridge each day. In 2011, an average of 54,212 vehicles per day traveled across the bridge. The variation in traffic volumes may be due to motorists avoiding construction activities on other Potomac River bridges.

PROJECT BACKGROUND

The Arlington Memorial Bridge is administered and maintained by the George Washington Memorial Parkway, a unit of the National Park Service. The Federal Highway Administration has performed scheduled routine inspections on the Arlington Memorial Bridge, including underwater

Figure 10: View of Memorial Avenue and Arlington House from the Arlington Memorial Circle inspections on the bridge piers, since 1978. The full bridge is inspected every two years and the bascule span is inspected every year. Given the current condition of the bridge, additional inspections are being conducted including 6-month interim inspections on areas of concern on the bascule span and 6-month interim inspections of the underside of the concrete bridge deck over the concrete arch spans.

The most recent bridge inspection, performed in April 2015, determined that overall the Arlington Memorial Bridge is in poor condition with isolated areas of severe deterioration. The framing for the sidewalks over the bascule piers is significantly deteriorated but not posing any safety concerns to pedestrians at present due to temporary bridges constructed over the affected areas. The trunnion posts continue to exhibit significant and increased deterioration (Figure 11). The report makes several recommendations of actions that would slow the rate of deterioration while a major rehabilitation is planned. These actions include sealing the trunnion posts or diverting roadway drainage to prevent further deterioration;

removing the debris from the base of the trunnion posts; reconfiguring the roadway/curb interface to address runoff draining under the curb and onto the superstructure;

and cleaning and sealing the joints below the granite curb to help prevent drainage on the steel fascia truss below.

The progressive deterioration of steel and concrete structural components of the concrete arch spans has reduced the bridge’s vehicle load carrying capacity. As a result of this deterioration, the National Park Service, at the recommendation of the Federal Highway Administration, has posted a 10-ton load limit across the entire length of the bridge. The load restriction, which has eliminated most bus traffic, will remain in effect until the permanent rehabilitation project is completed. As the bridge continues to deteriorate, the National Park Service and the Federal Highway Administration may impose further weight restrictions and/or close the bridge.

Structural Inspections, Studies, and Assessments

In addition to routine scheduled inspections, numerous other inspections, studies, and assessments have been conducted on the Arlington Memorial Bridge to further evaluate its structural integrity.

These evaluations are listed and summarized in Table 1.

Figure 11: View of severe corrosion of the inner trunnion post of the bascule span

TABLE 1. INSPECTIONS, STUDIES AND ASSESSMENTS TO DATE

Inspection Type

Date Performed

Purpose Findings

Utility Survey

February

Identify utilities on and surrounding bridge

Utilities mapped.

September

To assess the condition of the concrete deck

Core samples indicated moderate deterioration throughout the bridge deck with fracturing and water intrusion evident at various depths within the original concrete.

June 2010

To assess the condition of the concrete deck

Core samples indicated moderate deterioration of the bridge deck concrete with fracturing, spalling, crumbling, and water intrusion evident.

Bridge Deck Study

February

Condition assessment of the bridge deck using a robotic system

The assessment was conducted using the RABITTM Bridge Inspection Tool, a fully automated robotic system, as well as several other evaluation technologies such as ground-penetrating radar, impact echo, and ultrasonic surface wave testing. Results of the surveys indicated a high degree of deterioration, including severe delamination over the majority of the bridge deck.

March 2015

Condition assessment of the bridge deck using a robotic system

The deck is in poor condition and is mostly delaminated or debonded.

October 2009

Identify areas of deterioration and section loss throughout the bascule span

The sidewalks of this structure have widespread deterioration, including delamination and spalling of the concrete surface and displacement of the granite curbs. Additionally, there are issues which present a hazard for pedestrians on this highly traveled structure including misaligned sliding plate expansion joint covers and access hatches with severely corroded support framing.

Bascule Span

April 2011

Monitor deterioration and identify and map area of section loss or other deterioration throughout the superstructure of the bascule span

The inspection indicated that the superstructure of the bascule span was in fair condition overall with isolated areas of severe deterioration. These isolated areas include the framing for the fixed portions of the sidewalks over the bascule abutments, the bearing seats for the fixed stringers along the back of both bascule abutments, and the curb stringers on the south side of the west bascule leaf.

Type

Date Performed

Purpose Findings

April 2014

Monitor deterioration and identify and map area of section loss or other deterioration throughout the superstructure of the bascule span

Overall the superstructure of the bascule span was in fair to poor condition with isolated areas of severe deterioration. The deterioration of the structure continues to progress at a rapid pace.

September

Special inspection of catwalk system inside bascule span

The most severe deterioration was located in the areas adjacent to the inner trunnion posts in both leafs, where leakage occurs through the roadway/curb interface.

April 2015

Foundation investigation of bascule span abutments

Concluded that the bascule span abutments are adequate to support the bascule span.

Trunnion Posts

February

Obtain data to evaluate current condition of trunnion posts

Significant amount of visible corrosion was identified on the inner trunnion members as well as spalled concrete and poor drainage conditions at each trunnion post. Ultrasonic testing indicated severe section loss of the steel plates that make up the inner trunnion posts.

January 2014

More in-depth study to evaluate current condition of trunnion posts

Findings from the 2011 were confirmed.

Additional debris was cleaned from access points which indicate continuing deterioration.

Underwater inspection

December

Examination of bridge substructure from waterline to channel bottom

Inspected substructures were found to be in fair condition. Several piers were observed to have vertical cracking, section loss mostly along construction joints, spalling, scaling, and impending mortar patch failure. Serious structural deficiencies observed included scour pockets, tremie seal undercutting and exposure at multiple piers and abutments, and larger than hairline cracks (greater than 1/8") on at least one abutment.

In-depth Inspection

April 2013 In-depth assessment of all portions of the bridge

Bridge is in poor condition overall. Interior trunnion posts exhibit significant corrosion.

Sidewalks have widespread deterioration.

Widespread deterioration of the superstructure and substructure concrete continues to be a problem and there are widespread areas of patching and rutting throughout the asphalt road surface.

Type

Date Performed

Purpose Findings

April 2015 In-depth assessment of all portions of the bridge

Bridge is in poor condition overall. Framing for sidewalks is severely deteriorated as are the inner trunnion posts. Several recommendations are made in order to slow the rate of deterioration.

November

Assess quality and monitor deterioration of other arches and underpasses of bridge

One of two cores was found to have inadequate compressive strength.

Other Bridge Components

August 2013 Assess quality and monitor deterioration of west abutment of bascule span

Compressive strength of core was acceptable.

February

Assess quality and monitor deterioration of east abutment wall of bascule span and abutment 1 - channel side

Two of five cores were found to have inadequate compressive strength.

Temporary Repairs

Recent emergency repairs include the construction of temporary bridges spanning over the deteriorated sidewalks areas in the fixed portion of the bascule span (Figure 12). Additional temporary repairs have been recently performed to the concrete bearing seats along the back edge of each bascule abutment, the stringers and truss members under the curbs, the steel columns that support the counterweights, and roadway and sidewalk decks. Emergency repair work is ongoing to shore corroded steel members within the bascule span.

Figure 12: View of temporary pedestrian bridge spanning deteriorated sidewalks over the bascule span abutments

Significance of the Arlington Memorial Bridge

The Arlington Memorial Bridge spans the Potomac River connecting Lincoln Memorial Circle with Memorial Circle on Columbia Island, providing access to Memorial Avenue and the ceremonial entrance to Arlington National Cemetery. An important element in the neoclassical urban design of the National Capital as it evolved during the early 20th century, the Arlington Memorial Bridge has been defined as the final link in the chain of monuments that begins at the Capitol building, and connects the National Mall in Washington, DC with Arlington National Cemetery in Virginia. The bridge was designed to connect, both physically and symbolically, the North and the South on the axis between the Lincoln Memorial and Arlington House, the Robert E. Lee Memorial.

The Arlington Memorial Bridge was designed by William Mitchell Kendall during the 1920s while employed by McKim, Mead & White, a prominent architectural firm based in New York City. The bridge is part of the larger McKim, Mead & White design for the Memorial Avenue corridor, which also includes the Watergate Steps, Columbia Island road connections, and Memorial Avenue. The bridge was intentionally designed in the neoclassical style to complement the other monumental buildings in Washington, DC such as the White House, the Lincoln Memorial, and the Jefferson Memorial and to preserve views to the Lincoln Memorial from the Virginia shore of the Potomac River. The uniquely disguised bascule span hid the working mechanisms of the draw span for aesthetic reasons, increasing cost, and making it one of the most controversial features of the bridge design.

Constructed between 1926 and 1932 by H.P Converse & Company (substructure), Hunkin-Conkey Construction Company (superstructure), and Phoenix Bridge Company (bascule span), the Arlington Memorial Bridge was once one of the longest (216 feet), heaviest (7,600 tons), and fastest (one minute) draw spans in the world and included design innovations developed by the Strauss Engineering Company such as concrete counterweights, a hinged counterweight arrangement, and center nose locks. No longer in operation, the average passerby is now unaware that the bridge was meant to open, which is exactly what its designers intended. The bridge was listed in the National Register of Historic Places in 1980 for its architectural characteristics and innovative engineering achievements, including the bascule span.

In addition to its significance as a memorial, the bridge is a vital link in the regional transportation network. Not only does it provide access across the Potomac River for approximately 55,000 vehicles each day, it also provides connections to several heavily traveled roadways by way of the George Washington Memorial Parkway. On its wide sidewalks, the bridge provides a crossing for pedestrians and bicyclists and access to the Mount Vernon Trail. The Arlington Memorial Bridge is used for many events including parades and marathons and is a dramatic and somber approach to Arlington Cemetery for funeral processions. Ferries, water taxis, dinner cruises, boats and rowers using the Potomac River routinely pass under the bridge.

Significance of the George Washington Memorial Parkway

The George Washington Memorial Parkway was developed as a scenic parkway to help preserve the Potomac River Gorge and shoreline while serving as a memorial to the first president of the United States, George Washington. The first section, called the Mount Vernon Memorial Highway, was authorized by legislation signed by President Calvin Coolidge on May 23, 1928, and was completed in 1932 to commemorate the bicentennial of George Washington’s birth on February 22, 1732. As the Mount Vernon Memorial Highway was under construction, President Herbert Hoover signed what became known as the Capper-Cramton Act on May 29, 1930. This Act authorized appropriations for the George Washington Memorial Parkway, which was “to include the shores of the Potomac, and adjacent lands, from Mount Vernon to a point above the Great Falls on the Virginia side including the protection and preservation of the natural scenery of the Gorge and the Great Falls of the Potomac, the preservation of the historic Patowmack Canal, and the acquisition of that portion of the Chesapeake and Ohio Canal below Point of Rocks” (Public Law 71-284, as found in Mackintosh 1996). The Capper-Cramton Act included the Mount Vernon Memorial Highway as a part of the George Washington Memorial Parkway and proposed the protection of the northern and southern shores of the Potomac River. The George Washington Memorial Parkway was designated a National Park Unit in 1933.

Today, the Parkway extends from the Capital Beltway (I-495) to the north to the Mount Vernon estate to the south. The George Washington Memorial Parkway park unit administers the Parkway and a number of additional sites along the Potomac including Great Falls Park, Turkey Run Park, the U.S. Marine Corps War Memorial, Dyke Marsh Wildlife Preserve and others. Sites along the Parkway provide recreational and educational experiences to more than nine million people annually. The original section of the Parkway, the Mount Vernon Memorial Highway, was listed in the National Register of Historic Places in 1981 under criterion B for its commemoration of George Washington and under criterion C for landscape architecture (NPS 1981).