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    <title>Transport Research International Documentation (TRID)</title>
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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>Self-excited hoisting chain tension measurements for dam spillway gates and identification of uneven hoisting</title>
      <link>https://trid.trb.org/View/2529993</link>
      <description><![CDATA[Tainter gates are critical components of inland navigation systems, as they regulate the flow of water through dams, enabling a navigable depth of waterway. A critical issue with Tainter gates arises when the gates are raised or lowered in a skewed, uneven fashion, which can cause redistribution of stresses and exacerbate fatigue damage. This uneven hoisting of the gate manifests itself as unequal tension in the chains that raise the gate. An opportunity to indirectly measure the tension in hoisting chains arose during field testing of a Tainter gate, where accelerometers were placed on easily accessible locations on the Tainter gate with the goal to perform a modal analysis of the gate. During operation, the hoisting chains of the tested gate would audibly pop, which was clearly identifiable in acceleration records and expected to be the response of the chains themselves, rather than the modal vibrations of the Tainter gate. To support the notion that the recorded vibrations represent the response of the chains, this paper explores the dynamics of the chains to develop the relationship between chain frequency and tension. The developed relationship is validated in a laboratory experiment of a chain cut from a Tainter gate where the natural frequency of the chain is measured for varying tension in the chain. The results of the study show that this approach can be used as a quick and inexpensive method to monitor for uneven hoisting on Tainter gates from easily accessible locations on the gate and with inexpensive sensors.]]></description>
      <pubDate>Tue, 22 Apr 2025 13:17:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/2529993</guid>
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    <item>
      <title>1983 Flow Emergency at Glen Canyon Dam—The Fastest Boat through the Grand Canyon</title>
      <link>https://trid.trb.org/View/1706730</link>
      <description><![CDATA[Colorado River runoff at Glen Canyon Dam in northeast Arizona was 180% of normal in the late spring of 1983. The peak inflow to Lake Powell of 111,500 ft3/s (3,158 m3/s) occurred on June 29th and required operation of both spillways in addition to the powerhouse and outlet works for two months with a maximum release of 92,600 ft3/s (2,623 m3/s) to the Colorado River below Glen Canyon Dam. A large aeration slot was designed, laboratory tested, and installed in the tunnel spillways before the 1984 runoff season. At the time of the high releases, three fearless river guides illegally launched a small dory at Lee’s Ferry for an unforgettable adventure to set a new time record for the 277-mile (446 km) journey through the Grand Canyon. The story of the illegal river runners was juxtaposed in time with the Glen Canyon Dam engineers' race to avoid a spillway catastrophe during the 1983 spring runoff. The dam engineers and operators had different opinions of the dam than that of the river guides—they felt the dam was a living monolith, pulsating with energy and dynamism and the river runners felt the dam was an offense against nature. The 1983 flow emergency at Glen Canyon is a story of success by both groups, but only after overcoming huge challenges. The story will be summarized in this paper.]]></description>
      <pubDate>Tue, 26 May 2020 10:16:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1706730</guid>
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    <item>
      <title>Rock Mechanics and its Effects on Spillway Modification Design</title>
      <link>https://trid.trb.org/View/1692583</link>
      <description><![CDATA[Success Lake is a U.S. Army Corps of Engineers dam and reservoir located about 6 miles upstream of the city of Porterville, CA on the Tule River and provides flood damage risk reduction, agricultural water supply, and recreation. An engineering study was completed in 1999 that proposed to raise the spillway 10 feet and lengthen it across the channel from 200 to 365 feet to provide additional flood risk reduction and irrigation water supply. Following that, a baseline risk assessment was completed that found the main risk drivers to be extreme loading events and confirmed that the proposed raise and widening would further reduce the flood related risks. General site geology consists of moderately fractured diorite, with large bodies of quartzite and metavolcanics with known areas of block failure and sliding. The existing spillway is unlined with a 3 foot-wide x 200 foot-long reinforced concrete sill that is embedded into rock. Modifications will include widening the spillway to the right by blasting and excavating, reassessing the side slope rock stability, and investigating a landslide that occurred in the left abutment during original construction. New structural features include a 10 foot high reinforced concrete ogee weir, a 100 foot wide concrete apron with a downstream concrete headcut cutoff wall, reinforced concrete sidewalls anchored into rock, and relocation of a public access road. Additional geologic site investigations include: geologic mapping, seismic refraction survey (pwave), structural geologic data gathering, subsurface drilling, downhole optical and acoustic televiewer, and lab testing. This data was processed to analyze all potential cut slopes and to design stable slopes based on block stability analyses for, sliding, wedge failure, and toppling. The extensive geologic investigations and kinematic analyses have decreased design and construction risk by reducing the number of onsite unknowns and allowing the design team to proceed forward with increased confidence in slope geometries and less risk of significant differing site conditions during construction.]]></description>
      <pubDate>Thu, 02 Apr 2020 09:42:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1692583</guid>
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    <item>
      <title>Storage for One More Century</title>
      <link>https://trid.trb.org/View/1665594</link>
      <description><![CDATA[Since its completion more than a century ago by a previous owner, Denver Water's Antero Dam has experienced seepage problems, forcing the utility to limit the storage capacity of the associated reservoir. After the completion of a carefully planned four-phase dam and spillway rehabilitation project, the newly revamped Antero Dam is expected to operate safely for another 100 years.]]></description>
      <pubDate>Thu, 14 Nov 2019 09:30:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1665594</guid>
    </item>
    <item>
      <title>Expansions with Different Origins in a Concrete Dam with Bridge over Spillway</title>
      <link>https://trid.trb.org/View/1502268</link>
      <description><![CDATA[Concrete dams with expansions from different origins are rare and scarcely documented in the literature, therefore their study gains special interest. This study presents the case of a 62-year-old concrete dam with signs of deterioration due to expansive reactions. Several tests performed on the samples extracted from the dam such as X-ray diffraction, scanning electron microscope with energy dispersive spectroscopy mode and petrography suggest that the expansions are due to a delayed ettringite formation and a subsequent alkali-silica reaction. Thermal and mechanical models developed in the study support this diagnosis.]]></description>
      <pubDate>Wed, 25 Apr 2018 11:15:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1502268</guid>
    </item>
    <item>
      <title>Soil Structure Interactions of Retaining Walls</title>
      <link>https://trid.trb.org/View/1397740</link>
      <description><![CDATA[Structural stiffness of a retaining wall, properties of the foundation soils, and the construction sequence, including order of placement of fill in front and back of the wall, affect movements and hence the development of active and passive earth pressures. Retaining walls considered in this paper are the traditional reinforced concrete type usually constructed along highways and dam spillway structures – the highway wall is a simple cantilever and the spillway wall in an earth dam is a counterfort. Another type of earth retaining structure considered is an unconventional type, which was used during construction of a second large-diameter reinforced concrete siphon alongside an existing siphon of similar proportions for water conveyance on a hydro project. Results of numerical modeling for the highway retaining wall are compared with measured data. For the spillway and the siphon structures, only numerical analyses are included, as these structures were not instrumented. Practical significance of the information included in the paper are: (a) both the structure and the soil on which it is founded form an integrated system that needs to be analyzed as such for meaningful results; (b) interfaces between the soil and structure, where separation and slip can occur, should be included in numerical modeling; and (c) sequence of construction starting with the initial excavation, and construction sequence including placement of the fill in lifts, should be simulated.]]></description>
      <pubDate>Thu, 26 May 2016 14:49:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/1397740</guid>
    </item>
    <item>
      <title>Glen Elder Dam and Fort Randall Dam Spillway Repairs</title>
      <link>https://trid.trb.org/View/1356887</link>
      <description><![CDATA[Two dams in the Missouri River Basin have recently undergone unique repair work. The concrete slabs of the spillway of the Glen Elder Dam on the Solomon River were deteriorating. The spillway of the Fort Randall Dam on the Missouri River was damaged by record-breaking water flow due to flooding. Both dams were repaired with the use of hydrodemolition to remove deteriorating concrete. In both cases, hydrodemolition was shown to be an effective solution. In addition, low-shrinkage concrete mixtures were used to replace the damaged concrete, which has helped mitigate cracking.]]></description>
      <pubDate>Fri, 26 Jun 2015 13:45:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1356887</guid>
    </item>
    <item>
      <title>Use of Photogrammetric Measurements in a Concrete Damage Survey: Guernsey Dam South Spillway</title>
      <link>https://trid.trb.org/View/1275322</link>
      <description><![CDATA[The Bureau of Reclamation (Reclamation) uses close-range digital photogrammetry to obtain three-dimensional (3D) digital measurements. The rapid acquisition of photographs and the effectiveness of the photogrammetry software has revolutionized the evaluation of issues that are affected by these measurements. These methods have improved both the quality and quantity of data obtained and enhanced the ability to visualize complex geometry and evaluate related issues. Reclamation has applied photogrammetric measurement technology to obtain geologic and topographic mapping of exposed abutments and excavated foundation surfaces, to measure joint surface roughness, and to monitor rock erosion, concrete spalls, and changes to sediment beds of scale hydraulic models as they are exposed to various stream flow conditions. This paper presents an example of concrete spall measurements at Guernsey Dam's south spillway. The spillway tunnel was being evaluated for possible use after being unused for many years. Initial judgments indicated a need to replace a significant portion of the tunnel lining after years of freeze thaw damage. The damaged area and depth were not well-defined, and the high cost associated with replacing a significant portion of the tunnel lining justified additional study to quantify the extent of the damage and evaluate the need for repairs. Photogrammetric methods were used to develop an accurate, scaled 3D model of the tunnel lining. This resulted in a better evaluation and, more specifically, quantified the areas needing repair, leading to a much less expensive solution.]]></description>
      <pubDate>Mon, 23 Dec 2013 07:52:46 GMT</pubDate>
      <guid>https://trid.trb.org/View/1275322</guid>
    </item>
    <item>
      <title>Photogrammetric Methods and Geologic Discontinuity Mapping for Spillway Modifications, Pathfinder Dam, Wyoming</title>
      <link>https://trid.trb.org/View/1275321</link>
      <description><![CDATA[This paper provides an illustration of recent photogrammetry methods used in support of geologic mapping for the design of a new spillway at Pathfinder Dam, located in the central portion of Wyoming. Terrestrial-based photogrammetry was successfully used in conjunction with field geologic mapping. The collection methods included the collection of topographic data and the measurement of both joint and shear orientations in order to develop a comprehensive three-dimensional (3-D) model for analysis, foundation documentation, and acceptance purposes. The photogrammetric work performed consisted of rapid data collection using an off-the-shelf digital camera. Collection of field digital photographs was accomplished by the use of a camera mounted atop a 12-foot-long survey staff and a wireless shutter trigger system. The new spillway foundation was approximately 750 feet in length and 20 feet in width. The geology of the foundation consisted primarily of granitic bedrock that was cut by several prominent, generally continuous, joint sets, local joint sets, and shear zones. The software available to construct 3-D models using ordinary digital images is being developed and improving at a rapid rate. Processing methods used Adam Technologies 3DM Mine Mapping Suite software to construct this project's photogrammetric model. Processing was performed in a reasonable timeframe, constructing approximately 150 Digital Terrain Models (DTM) pairs, and included statistical analysis of joint sets and presentation of stereoscopic pole plots. Lessons learned regarding the processing challenges of specific field conditions, including scaling and lighting variations, will be discussed.]]></description>
      <pubDate>Mon, 23 Dec 2013 07:52:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1275321</guid>
    </item>
    <item>
      <title>Selection of Wall Rock Thickness for Thermal Stress Analysis of Circular Tunnel Concrete Lining</title>
      <link>https://trid.trb.org/View/1252977</link>
      <description><![CDATA[When the thermal stress in the concrete lining of a spillway tunnel is computed using the finite-element method, the wall rock in the numerical model is generally taken to be a finite size. The selection of the thickness of the wall rock has a significant impact on the computational results for the thermal deformation and thermal stress in the concrete lining. The current study investigated the effect of the wall rock thickness on the thermal deformation and thermal stress in the concrete lining. A formula was derived for calculating the thermal displacement in an infinitely long, thick-walled cylinder, with the displacement being used as the outer boundary condition and the stress as the inner boundary condition. A formula was also derived for calculating the thermal displacement at the interface between the concrete lining and the wall rock of the circular tunnel. To reduce the influence of the wall rock thickness on the calculation accuracy, a method was developed for selecting the outer radius b of the wall rock. This method is useful when analyzing the thermal stress in the concrete lining of a circular spillway tunnel using the finite-element method.]]></description>
      <pubDate>Thu, 20 Jun 2013 16:38:57 GMT</pubDate>
      <guid>https://trid.trb.org/View/1252977</guid>
    </item>
    <item>
      <title>The reincarnation of Lake Townsend Dam</title>
      <link>https://trid.trb.org/View/1249876</link>
      <description><![CDATA[When asked to rehabilitate a 45-year-old dam that provides the city of Greensboro, North Carolina, with most of its drinking water, engineers responded with an innovative plan that called for using the dam as an upstream cofferdam and diversion control structure while the dam's crumbling spillway was replaced. Various spillway configuration - including labyrinth, gated, and combination control sections - were evaluated for each of the four options. Modeling verified the discharge capacity of the labyrinth and was used to evaluate the effectiveness of the stepped downstream slabs and apron stream transition.]]></description>
      <pubDate>Wed, 08 May 2013 11:30:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1249876</guid>
    </item>
    <item>
      <title>Three-Dimensional Hydromechanical Sectional Analysis of Cracked Nonprismatic Concrete Spillway Piers</title>
      <link>https://trid.trb.org/View/1237001</link>
      <description><![CDATA[Several concrete hydraulic structures, such as spillway piers, must be considered three-dimensional (3D) components subjected to 3D loads. A very convenient approach to perform stability analysis of concrete dams is the so-called gravity method, leading to the solution of a PMM problem (axial force P and biaxial bending moments Mx, My) assuming linear normal stress distribution. If cracking takes place, water penetrates into the cracks, inducing the development of full uplift pressures (UPs). Sliding safety factors (SSFs) are computed using shear force resultants Vx, Vy, and a Mohr-Coulomb failure criterion while ignoring torsion T (VVT). This paper presents a 3D extension of the gravity method for cracked planar concrete sections of arbitrary geometry subjected to arbitrary loads (PMM-VVT). To compute the shear stress distribution, a VVT sectional analysis algorithm has been developed based on the theory of elasticity (TE), including Saint-Venant and warping torsional components combined with triangular 2D finite elements (FEs). Afterward, the SSF on the failure plane is computed from the integration of normal stresses on the remaining uncracked area where the Mohr-Coulomb criterion (considering the shear stresses from the VVT solution) has not been locally exceeded. Two validation examples and a case study of an actual pier are presented to illustrate the accuracy and efficiency of the proposed approach compared with full 3D FE analyses.]]></description>
      <pubDate>Wed, 13 Feb 2013 10:18:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1237001</guid>
    </item>
    <item>
      <title>Managing Dams: Challenges in a Time of Change</title>
      <link>https://trid.trb.org/View/1138551</link>
      <description><![CDATA[This book contains the proceedings of the 16th Biennial Conference of the British Dam Society, Managing dams: Challenges in a Time of Change, covering a wide range of topics of direct relevance to all who are involved in the engineering and management of dams and reservoirs. A major challenge in the United Kingdom (UK) is to ensure that the nation’s stock of existing dams is properly managed to ensure both their safety and continued functionality. Recent improvements in the knowledge of factors influential in dam failure are presented, along with papers on remedial work for existing dams and how risk can be assessed and managed. There are several papers on the upgrade of spillways that were needed following risk analyses. New dams for water supply or hydroelectricity overseas and for flood alleviation purposes in the UK are also considered, with a range of dam types and sizes discussed.]]></description>
      <pubDate>Wed, 16 May 2012 15:08:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1138551</guid>
    </item>
    <item>
      <title>Energy Dissipation down a Stepped Spillway with Nonuniform Step Heights</title>
      <link>https://trid.trb.org/View/1124890</link>
      <description><![CDATA[Although most stepped spillway–design guidelines were developed for uniform step heights, a nonuniform stepped design might be a practical alternative in some cases. A physical study was conducted in a moderate slope-stepped chute (1V:2H) and five stepped configurations were tested for 0.7<dc/h<1.9. Detailed air-water flow measurements were performed for each configuration and the results were compared in terms of flow patterns, energy dissipation, and flow resistance. The basic findings showed minor differences between all configurations and indicated that the rate of energy dissipation was about the same for uniform and nonuniform stepped configurations. But the observations suggested that the nonuniform stepped configurations might induce some flow instabilities for smaller flow rates.]]></description>
      <pubDate>Wed, 25 Jan 2012 14:23:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1124890</guid>
    </item>
    <item>
      <title>Chute Aerators: Preaerated Approach Flow</title>
      <link>https://trid.trb.org/View/1124881</link>
      <description><![CDATA[Long spillways often include more than one chute aerator to assure an appropriate cavitation protection. The first aerator guarantees sufficient bottom air concentration along a limited streamwise distance attributed to deaeration. Further downstream, the air concentration may be insufficient to protect the chute from cavitation damage. There, a second aerator is required whose operation is affected by preaerated approach flow. The present investigation systematically model-tested typical chute aerators with various approach flow features including preaeration. The resulting air entrainment coefficient as the ratio of air discharge entrained into the flow by the water discharge remains practically unaffected. The jet length is also not affected. Downstream of these aerators, the streamwise development of the average and the bottom air concentrations was affected by preaeration: the average value increased, whereas the bottom value marginally decreased. The effect of preaeration was found to be only relevant for average approach flow concentrations exceeding some 20% of the corresponding uniform flow concentration.]]></description>
      <pubDate>Wed, 25 Jan 2012 14:23:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1124881</guid>
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