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    <title>Transport Research International Documentation (TRID)</title>
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    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Design and Testing of Modular Expansion Joint Noise Mitigation Strategies</title>
      <link>https://trid.trb.org/View/2630562</link>
      <description><![CDATA[This investigation focuses on the design and feasibility of noise mitigation strategies for installation in modular expansion joints (MEJs) on highway bridges. Expansion joints are necessary for effective bridge function but contribute greatly to surrounding noise pollution. The three primary sources of noise from MEJs identified include the resonance of the air within the gaps, the resonance of the beams, and the resonance of the tires. By incorporating engineered chevron support structures into the gaps of the MEJs, the research demonstrates the feasibility of significantly reducing noise emanating from MEJs. The novel chevron design flexes to expand and contract, matching the movement of the roadway but resisting vertical loading from cars driving overhead. The noise reduction treatment was applied to a westbound lane of the east MEJ on the SR 520 floating bridge across Lake Washington, connecting Seattle with the city of Medina, for a 2-month evaluation period. According to energy spectral density data collected from roadside audio recordings, this solution proved to be highly effective. At a distance of 160?ft from the joint, a noise reduction of more than 10?dB in the 500–900?Hz frequency range was recorded. Beyond 500?ft, the distinction between noise from the concrete road surface and from the MEJ diminished to the extent that it became challenging to discern when individual cars traversed the MEJ.]]></description>
      <pubDate>Tue, 02 Dec 2025 09:53:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2630562</guid>
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    <item>
      <title>Hydrodynamic performance of a continuous floating bridge with heave plates</title>
      <link>https://trid.trb.org/View/1764020</link>
      <description><![CDATA[This paper establishes a two-dimensional mathematical model of a continuous floating bridge with heave plates under linear monochromatic waves. Based on linear potential flow theory, the fluid domain is divided into two regions. The analytical equations for the rigid floating bridge considering the heave plate effect are derived from the boundary conditions. The wave force, added mass and damping coefficient, and response amplitude operator (RAO) are calculated via the matched eigenfunction expansion method (MEEM). The influence of the number and size of heave plates on bridge hydrodynamic performance is analyzed, and the New Lacey V. Murrow Memorial Bridge is taken as an example for optimization. The results show that heave plates have a significant impact on the hydrodynamic performance of the floating structure. An increase in the number and length of heave plates makes the roll and roll resonance frequency approach the high-frequency area, while the heave is opposite. Compared with increasing the number of heave plates, the heave response can be maintained at a relatively low level over a wider wavelength range by increasing heave plate length. Heave plate length is a more sensitive parameter during optimization.]]></description>
      <pubDate>Wed, 10 Feb 2021 09:27:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1764020</guid>
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    <item>
      <title>The Fremont Siphon Replacement Project: A Hybrid Approach to Baselining Microtunnel Projects</title>
      <link>https://trid.trb.org/View/1688311</link>
      <description><![CDATA[The Fremont Siphon Replacement Project included twin 2.15-meter (84-inch) diameter, 141-meter (464-foot) long microtunnel bores beneath the Lake Washington Ship Canal in Seattle, Washington. In addition to the microtunnel bores, the project included two secant pile shafts up to 9.8 meters (32 feet) in diameter and up to 24.4 meters (80 feet) deep, two near-surface connections to the existing trunk sewer system, and a new odor control facility. To mitigate microtunnel risk on the project, King County (the project owner) selected a unique baselining approach where baseline geotechnical conditions for the shafts were described in a traditional geotechnical baseline report, while baseline conditions for the microtunnel drives were presented in the project specifications, with values limited to a cobble and boulder strength range, and a maximum boulder size. The baseline also described the ground as highly abrasive, with the number of cobbles and boulders encountered being incidental to tunneling. To facilitate collaboration with the contractor and mitigate the county’s financial risks associated with differing site conditions (DSC) claims, an incentive provision was included in the contract which allowed the contractor to claim a bonus at the completion of each drive as long as a DSC-related claim was not submitted for that drive. In addition, tunnel mining was paid by the hour, with a specified number of hours and minimum unit cost required on the bid form. This innovative approach proved successful, as the contractor completed both microtunnel drives within the allotted time, collecting both incentive payments, despite challenges. This paper details the unique contracting approach used on this project and discusses some of the lessons learned that are being applied to other microtunnel projects in the Seattle area.]]></description>
      <pubDate>Fri, 28 Feb 2020 10:11:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1688311</guid>
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    <item>
      <title>Mitigating the Intrusion: Modeling the Effects of Lock Operations on Water Quality in the Lake Washington Ship Canal</title>
      <link>https://trid.trb.org/View/1606263</link>
      <description><![CDATA[The Hiram Chittenden Locks and Dam control the exchange of salt and fresh water between Puget Sound and the Lake Washington Ship Canal (LWSC). During each lockage the denser saltwater from the sound flows from the bottom of the locks into the lighter freshwater in Salmon Bay and proceeds to move upstream through the LWSC toward Lakes Union and Washington. This influx of water improves salmonid habitat near the locks by decreasing temperatures and increasing dissolved oxygen content, however it can have a detrimental effect on the freshwater environment in Lake Washington. Operations at the lock and dam must balance these competing water quality issues while maintaining the navigational ability through the locks. WEST Consultants, Inc. developed a two dimensional (vertical) temperature and salinity model of the LWSC in CE-QUAL-W2. The model simulates the inflows and outflows to the LWSC as well as the exchange of saltwater at the locks for 2014 and 2015. Saltwater exchange at the boundary is parameterized through an exchange coefficient. Modeled temperatures and salinities match observations well under high flow conditions but the model accuracy drops under low flow conditions. The model is most sensitive to the temperature and salinity boundary conditions at the downstream boundary where exchange with Puget Sound water occurs. Lock and dam operations drove the modeled parameters and accurate operational records were required to simulate the observed response.]]></description>
      <pubDate>Fri, 20 Dec 2019 16:23:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1606263</guid>
    </item>
    <item>
      <title>Integration of Light Rail on the I-90 Floating Bridge Across Lake Washington</title>
      <link>https://trid.trb.org/View/1438856</link>
      <description><![CDATA[Installing light rail transit across a floating roadway bridge presents many unique challenges, foremost of which is how to design the multidimensional moving joints at both ends of transition spans between the fixed and floating structures. A technical solution to this technical challenge has been proposed, analyzed, modeled, designed, and prototype tested in the context of the East Link Extension, a light rail transit project being carried out by Central Puget Sound Regional Transit Authority (Sound Transit). Described are the planning, execution, and results of a full-scale prototype testing program of the proposed Curved Element Supported Rail (CESuRa) Track Bridge System, based on the relationship of curved rail supports in two independent planes that adjust in response to the movements of the Interstate 90 (I-90) Bridge. The prototype CESuRa track bridges performed as expected; the information gathered and lessons learned will greatly benefit the final design, the production track-bridge fabrication, and the installation process. Also discussed is the anticipated performance of these track bridges on the I-90 structure in conjunction with the proposed direct fixation track system, fixed rail anchors, and sliding rail expansion joints to be strategically located across the 1.1-mi I-90 Bridge. Built in 1989, the I-90 Bridge is the fifth-longest floating bridge in the world and carries three westbound and two reversible lanes of traffic between Seattle and Mercer Island, Washington. The bridge will be reconfigured to carry four westbound lanes, and the reversible lanes will be converted to light rail transit.]]></description>
      <pubDate>Thu, 30 Mar 2017 14:27:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1438856</guid>
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    <item>
      <title>Crossing Lake Washington</title>
      <link>https://trid.trb.org/View/1416772</link>
      <description><![CDATA[The world's longest floating bridge, SR 520 Evergreen Point Floating Bridge, was opened by the Washington State Department of Transportation in April 2016. The new crossing carries State Route 520 across Lake Washington, near Seattle, as did the structure it replaces. The bridge's transition spans are pinned to the fixed, land-based structures by a built-up steel weldment, and in order to accommodate the bridge's motions, spherical bearings with identical radii form a sphere that acts like a trailer hitch. Immense gravity anchors are used in places where soil conditions permit on the underwater slopes, and due to their size, required special logistical considerations.]]></description>
      <pubDate>Wed, 27 Jul 2016 09:49:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/1416772</guid>
    </item>
    <item>
      <title>Do Bridges Affect Migrating Juvenile Salmon: Tracking Juvenile Salmon and Predator Fish
Movements and Habitat Use Near the SR 520 Bridge in Lake Washington</title>
      <link>https://trid.trb.org/View/1346318</link>
      <description><![CDATA[Large anthropogenic infrastructure such as major bridges in and near waterways can influence the ecological dynamics of the nearby aquatic environment. These influences may affect behavior, habitat use, fitness, and survival of fishes. Chinook salmon (Oncoryhnchus tshawytscha) spawning in tributaries to Lake Washington typically spend three to five months rearing in Lake Washington before travelling through the Lake Washington Ship Canal to Puget Sound. Most salmon smolts in Lake Washington must pass beneath the SR520 Bridge en route to Puget Sound. Plans to replace the existing bridge have sparked interest in how smolts and potential predators behave around and use the bridge. To address this interest, the authors tracked Chinook smolts, smallmouth bass and northern pikeminnow in a 17.2 ha area along a 560 m stretch of the SR520 bridge during June-July 2007 and 2008 using fine-scale acoustic tracking. During the 2007 tracking season a total of 171 smolts were released in three June release groups and 162 were successfully tracked in the study area. Repeating the study design in 2008, 181 smolts were released and 133 were successfully tracked in the study area during a total of four release groups occurring in June and July. Although this study focused on the SR 520 bridge, many fish were also observed at a downstream tracking station approximately 2-miles downstream allowing the author to evaluate movements within and between sites. Different release groups appear to exhibit different behaviors, some release groups rapidly migrated through the SR 520 tracking area in < 3 h (“migrating”), while other release groups were often detected ≥ 2 days (“holding”). The bridge appeared to delay some migrating smolts. These delays were typically short in duration as salmon would move along the bridge–typically towards the shoreline–prior to migrating past the bridge. Many holding smolts used areas near the bridge extensively. Timing of migrational cues, physiological smolt status, water temperature and clarity, and macrophytes may have influenced movement timing and habitat use. During the same study periods small numbers of northern pikeminnow and smallmouth bass were also tracked. Bass preferred habitats under overwater structures, including the bridge–particularly near bridge columns. Pikeminnow preferred macrophytes and overwater structures other than the bridge. Predator diets and abundance were also evaluated in and near the study area. These results suggest that the bridge in its current form may affect the movements of some Chinook smolts and may be preferred habitats for some salmon predators. The SR 520 Bridge Replacement Project is continuing to evaluate these results to help inform design of the proposed bridge replacement.]]></description>
      <pubDate>Tue, 31 Mar 2015 09:06:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1346318</guid>
    </item>
    <item>
      <title>Unprecedented connections</title>
      <link>https://trid.trb.org/View/1312769</link>
      <description><![CDATA[Sound Transit's plan to operate light-rail vehicles on one of the longest floating bridges in the world has no precedent. But that did not stop an intrepid team of designers from developing and testing a novel system for ensuring the safe passage of light-rail vehicles across Lake Washington on the movable joints of the 5,700 ft long Homer M. Hadley Memorial Bridge.]]></description>
      <pubDate>Fri, 20 Jun 2014 09:20:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1312769</guid>
    </item>
    <item>
      <title>Structural Design of Deep Water Pontoon Mooring Anchors</title>
      <link>https://trid.trb.org/View/1302914</link>
      <description><![CDATA[After nearly half a century of service, the world's longest floating bridge is now clogged by traffic, showing its age, and in need of replacement. The Washington State Department of Transportation (WSDOT) is building a new State Route (SR) 520 floating bridge capable of withstanding heavier windstorms and moving significantly more people and goods. Much like a large floating marine dock, the new bridge will consist of concrete pontoons moored to 58 deep water anchors by 8 miles of steel cables. The bathymetry and subsurface conditions of Lake Washington pose unique challenges for the moorage of floating pontoons. The water depths at the anchor locations vary from 30 feet to 210 feet, and subsurface conditions range from very dense to very soft and include soils with unique engineering properties. These conditions necessitated the use of three anchor types: drilled shaft, gravity, and fluke.]]></description>
      <pubDate>Mon, 05 May 2014 07:51:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1302914</guid>
    </item>
    <item>
      <title>Blocks of time</title>
      <link>https://trid.trb.org/View/1131462</link>
      <description><![CDATA[In order to withstand the turbulent waves of Lake Washington adjacent to the city of Seattle, the bridge carrying S.R. 520 over it had to be replaced using an optical mix design balancing flowability and strength in order to eliminate cracking. This article details the methods of pontoon construction that were used to carry out this project.]]></description>
      <pubDate>Fri, 17 Feb 2012 08:30:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/1131462</guid>
    </item>
    <item>
      <title>Toll rates for Washington bridge will depend on time of day</title>
      <link>https://trid.trb.org/View/1085747</link>
      <description><![CDATA[]]></description>
      <pubDate>Thu, 30 Dec 2010 10:24:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1085747</guid>
    </item>
    <item>
      <title>MEASUREMENT AND EVALUATION OF MOORING CABLE FORCES DURING STORM EVENTS ON THE EVERGREEN POINT FLOATING BRIDGE: LAKE WASHINGTON, WASHINGTON STATE</title>
      <link>https://trid.trb.org/View/683490</link>
      <description><![CDATA[On January 20, 1993, the Evergreen Point Floating Bridge incurred structural damage at two mooring cables and at various other locations during a storm event of approximately the 20-year return period magnitude.  The two mooring cables damaged were the shorter and stiffer cables located at the ends of the bridge and were likely damaged because of load attraction issues.  To improve the performance of the floating bridge during storms, special replacement cables were installed after the 1993 storm near the areas where cable distress was noted. Measurements of cable forces were made during the winter season of 2001-2002 to evaluate the effectiveness of the replacement mooring cables.  From the experimental measurements, it was found that the special replacement mooring cables have reduced the load attraction at the shorter end cables with respect to cable tension values reported for the pre-retrofit analysis.  However, the measurements indicate that the replacement cables continue to attract loads between 65% and 80% higher than those measured at the longer and more flexible cables located near the midspan of the floating bridge during storm events of approximately the 1-year return period magnitude.]]></description>
      <pubDate>Wed, 03 Dec 2003 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/683490</guid>
    </item>
    <item>
      <title>REFLECTED WAVES IN LAKE WASHINGTON</title>
      <link>https://trid.trb.org/View/98879</link>
      <description><![CDATA[SOME PHENOMENA ON THE SHORELINE OF LAKE WASHINGTON HAVE BEEN REPORTED TO BE CAUSED BY WAVES REFLECTED FROM THE EVERGREEN POINT /FLOATING/ BRIDGE. AN EXPLORATORY OR PHASE I STUDY WAS UNDERTAKEN TO ASCERTAIN THE LIMITS OF REFLECTED WAVES AND THEIR FREQUENCY AS RELATED TO WIND SPEED AND DIRECTION. WIND DATA FROM THREE OFFICIAL RECORDING STATIONS WERE UTILIZED TO DETERMINE PROBABLE WIND-WAVE CONDITIONS. FOUR SETS OF AERIAL PHOTOGRAPHS WERE TAKEN UNDER DIFFERENT WIND CONDITIONS FOR THE PURPOSES OF OBTAINING WAVE LENGTHS AND GENERAL PATTERNS. A PORTABLE SENSING UNIT WAS USED TO MEASURE WAVE HEIGHT AND FREQUENCY FROM PIERS EXTENDING INTO THE LAKE FROM SELECTED SHORE LOCATIONS. THESE MEASUREMENTS WERE FOUND TO AGREE FAVORABLY WITH PREDICTIONS FROM STANDARD TECHNIQUES. A 16-MM. MOTION PICTURE FILM WAS TAKEN UNDER A MODERATE WIND CONDITION TO SHOW SOME OF THE TYPICAL PHENOMENA ADJACENT TO THE BRIDGE AND THE SHORELINE. AN ANALYSIS WAS DEVELOPED TO DESCRIBE THE ADVANCE OF A WAVE TRAIN AGAINST A WIND. PREDICTIONS OF THE DECAY WITH DISTANCE OF SUCH A WAVE BASED ON THIS ANALYSIS FIT FIELD OBSERVATIONS QUITE REALISTICALLY. GENERALIZED INTERPRETATIONS WERE MADE FOR THE INTERACTION OF THE REFLECTED WAVES WITH THE SHORELINE AND SHORELINE STRUCTURES. THE POSSIBILITIES OF APPLYING A PNEUMATIC OR HYDRAULIC BREAKWATER TO DISSIPATE THE WAVES AT THE BRIDGE WERE INVESTIGATED IN CONSIDERABLE DETAIL. THE SCARCITY OF KNOWN EXPERIMENTAL DATA FOR THE DEEP WATER WAVES ENCOUNTERED, PRECLUDED A POSITIVE CONCLUSION ON REQUIRED DIMENSIONS WITHOUT TEST DATA. /AUTHOR/]]></description>
      <pubDate>Thu, 01 Dec 1994 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/98879</guid>
    </item>
    <item>
      <title>A SEATTLE MEANDER.</title>
      <link>https://trid.trb.org/View/526760</link>
      <description><![CDATA[8 ASUBTITLE: THE CHITTENDEN LOCKS COMPLEX COMBINES COMMERCE AND CARNIVAL.]]></description>
      <pubDate>Wed, 15 Sep 1993 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/526760</guid>
    </item>
    <item>
      <title>A SURVEY OF MASS TRANSIT ALTERNATIVES TO INTERSTATE 90</title>
      <link>https://trid.trb.org/View/51052</link>
      <description><![CDATA[Attempts to complete the Interstate Highway 90 (I-90) project across Lake Washington have been frustrated by legal and public controversy. The 1973 Federal-Aid Highway act added a new policy for local officials: To withdraw an interstate segment from the nationwide Interstate System and substitute a mass transit project in the same urbanized area. The report deals with mass transit substitution alternatives to I-90. Its purpose is to respond to the desire of local officials to learn more about the available transit opportunities to assist them in a decision to withdraw and substitute, or not. This report describes five alternative concepts for transit investments to serve the region with specific project options within each alternative.]]></description>
      <pubDate>Wed, 20 Sep 1978 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/51052</guid>
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