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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=PHNlYXJjaD48cGFyYW1zPjxwYXJhbSBuYW1lPSJkYXRlaW4iIHZhbHVlPSJhbGwiIC8+PHBhcmFtIG5hbWU9InN1YmplY3Rsb2dpYyIgdmFsdWU9Im9yIiAvPjxwYXJhbSBuYW1lPSJ0ZXJtc2xvZ2ljIiB2YWx1ZT0ib3IiIC8+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMCIgLz48L3BhcmFtcz48ZmlsdGVycz48ZmlsdGVyIGZpZWxkPSJpbmRleHRlcm1zIiB2YWx1ZT0iJnF1b3Q7V2F2ZSBlcXVhdGlvbnMmcXVvdDsiIG9yaWdpbmFsX3ZhbHVlPSImcXVvdDtXYXZlIGVxdWF0aW9ucyZxdW90OyIgLz48L2ZpbHRlcnM+PHJhbmdlcyAvPjxzb3J0cz48c29ydCBmaWVsZD0icHVibGlzaGVkIiBvcmRlcj0iZGVzYyIgLz48L3NvcnRzPjxwZXJzaXN0cz48cGVyc2lzdCBuYW1lPSJyYW5nZXR5cGUiIHZhbHVlPSJwdWJsaXNoZWRkYXRlIiAvPjwvcGVyc2lzdHM+PC9zZWFyY2g+" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <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>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Investigation of Sands Subjected to Dynamic Loading</title>
      <link>https://trid.trb.org/View/2548963</link>
      <description><![CDATA[The broad objective of this project is to fully develop the use of the computer solution of the wave equation so that it may be used to predict driving stresses in piling and to estimate static load bearing capacity of piling from driving resistance records. This report should be considered as a supplement of Research Report No. 33-7. As stated in the preface, Research Report Number 33-7 was considered as an interim report of an exploratory investigation into the dynamic load-deformation properties of sands. This supplement (Research Report No. 33-7A) includes improvements in instrumentation which were made since the interim report was published, and it presents results of final tests on the dynamic properties of three different sands. Peak dynamic and static strengths of saturated sand samples under triaxial confinement are determined experimentally and presented herein. Particular attention is given to the effects of loading velocity, sample density, and intergranular pressure. Experimental results are compared with results predicted by using the rheological model currently in use with the computer solution of the wave equation. A modification of this rheological model is proposed so that it can be used to reproduce experimental data and correctly predict peak dynamic load.]]></description>
      <pubDate>Tue, 27 May 2025 10:12:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2548963</guid>
    </item>
    <item>
      <title>Impact Load-Deformation Properties of Pile Cushioning Materials</title>
      <link>https://trid.trb.org/View/2548962</link>
      <description><![CDATA[The broad objective of this project is to fully develop the use of the computer solution of the wave equation so that it may be used to predict driving stresses in piling and be used to estimate the static load bearing capacity of piling from driving resistance records. This report covers the specific objective of determining the dynamic load-deformation properties of various pile cushion materials. These properties are necessary for the wave equation analysis and have been found to have a most significant effect on the driving stresses and pile penetration during driving.]]></description>
      <pubDate>Tue, 27 May 2025 10:12:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2548962</guid>
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    <item>
      <title>Wave Equation Analysis of Pile Driving WEAP Program: Volume IV - Narrative Presentation</title>
      <link>https://trid.trb.org/View/2213655</link>
      <description><![CDATA[A computer program was written and tested that performs a realistic Wave Equation Analysis of Piles driven by any type of impact hammer. Conventional pile and soil models were used in addition to both a thermodynamic model for diesels and refined mechanical hammer models. The program development was aimed at providing a simple input and both a flexible and extensive output that includes automatic plotting capabilities. Pile Driving Hammer data were prepared and stored in a file for most of the commonly encountered models. The computer language is FORTRAN 4. The program was extensively tested against measured pile top force and velocity data and against measured diesel combustion pressure and stroke. This volume is the fourth in a series.]]></description>
      <pubDate>Tue, 18 Jul 2023 12:53:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2213655</guid>
    </item>
    <item>
      <title>Research on Instability of Dimethyl Ether Jet under Normal and Superheated Conditions</title>
      <link>https://trid.trb.org/View/1816012</link>
      <description><![CDATA[Based on linear stability analysis, this paper derived a dispersion equation which relates the disturbance growth rate to its wave number. Moreover, the dimensionless form and solution procedure of the dispersion equation were obtained. In order to improve the understanding of atomization mechanism of dimethyl ether (DME) jet, the instability of DME jet under normal and superheated conditions were analyzed in detail, and some valuable conclusions were made.]]></description>
      <pubDate>Tue, 23 Aug 2022 09:11:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/1816012</guid>
    </item>
    <item>
      <title>Improved Wave Equation Analysis of Steel H-Piles in Shales Considering LRFD and Economic Impact Studies</title>
      <link>https://trid.trb.org/View/1940615</link>
      <description><![CDATA[Shale is a transition material harder than soil and softer than hard rock. Treating shale as soil-like material in the Wave Equation Analysis Program (WEAP) could result in several construction challenges such as early pile refusal and pile damage. To overcome these limitations, this paper presents the development of improved WEAP methods for steel H-piles driven in shale including load and resistance factor design (LRFD) recommendations. The parametric study reveals a significant effect of damping factors of shale on the bearing graph analysis and the determination of ultimate pile resistance. Using load test data of 32 steel H-test piles driven onto shale in Kansas, a back-calculation procedure was adopted to yield recommended dynamic parameters for shale, which are incorporated into two proposed WEAP methods. A range of damping factors from 0.03 to 0.97 s/m are recommended for two proposed WEAP methods, shale types, and weathering conditions. The accuracy and efficiency of the proposed methods and default WEAP method were validated and compared using 44 dynamic load test results and data of 2 static pile load tests at the end of driving. Furthermore, 49 dynamic test results at the beginning of restrike condition were also used for comparison. The LRFD resistance and efficiency factors were calibrated for the three WEAP methods for analyzing shale pile resistances. An economic study reveals that the three WEAP methods, on average, overpredict the weight of steel pile per load demand ranging from −0.01 to −0.05 kg/kN. Among the three methods, the proposed WEAP-UW-R will yield the least excess steel weight, on average, during construction, which will alleviate construction challenges encountered in the current practice, such as higher construction costs and longer durations.]]></description>
      <pubDate>Tue, 24 May 2022 10:05:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1940615</guid>
    </item>
    <item>
      <title>Drivability of large diameter steel cylinders during hammer-group vibratory installation for the hong kong–zhuhai–macao bridge</title>
      <link>https://trid.trb.org/View/1905347</link>
      <description><![CDATA[The Hong Kong–Zhuhai–Macao Bridge (HZMB) involved the installation of 120 mega-cylinders with a diameter of 22 m, weights up to 513 tonnes, and penetration depths up to 33 m using an eight-vibratory hammer group. Due to the lack of engineering experience on the drivability of large-diameter cylinders under multiple vibratory hammers, predicting the penetration rate and time of steel cylinders is an open challenge that has a considerable impact on the construction control of the HZMB. In this study, the vibratory penetration of large-diameter steel cylinders in the HZMB is investigated based on geological surveys, field monitoring, and drivability analysis. The vibratory penetration rate, installation accuracy, and dynamic responses of the steel cylinders at both the eastern and western artificial islands are analyzed. The dynamic soil resistance has a great influence on the cylinder drivability. However, the current design methods for estimating the vibratory driving soil resistance are proven inaccurate without considering the scale effects. Therefore, a modified method with a normalized effective area ratio A¯[subscript r,eff] is proposed in this study to calculate the vibratory soil resistance for open-ended thin-wall cylinders under unplugged conditions. Considering the scale effects on the vibratory driving soil resistance, the proposed method leads to closer results to the measured data, providing a reference for future engineering practice.]]></description>
      <pubDate>Fri, 25 Feb 2022 08:58:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1905347</guid>
    </item>
    <item>
      <title>Development of Load and Resistance Factor Design Procedures for Driven Piles on Soft Rocks in Wyoming</title>
      <link>https://trid.trb.org/View/1659708</link>
      <description><![CDATA[Static Analysis methods originally developed for soils are currently used for estimating pile resistances in Intermediate Geomaterials (IGMs), and structural capacity has been considered as the limiting pile capacity on hard rocks. The application of current Load and Resistance Factor Design (LRFD) for piles in IGMs has resulted in relatively high uncertainties in pile resistance estimation during design and the length to which the piles are driven into IGMs during construction. Moreover, the absence of standard criteria to differentiate the geomaterials creates challenges in the design and construction of driven piles in IGMs. The application of a dynamic analysis method using Wave Equation Analysis Program is constrained by geomaterial input for IGMs and rocks. These current challenges have led to conservative pile resistance estimations. Thus, the overall objectives of this study were to determine efficient static analysis methods, dynamic procedures for construction control, pile setup/relaxation, and resistance factors for the estimation of the axial pile resistances in IGMs, ensuring a prescribed level of reliability to meet LRFD philosophy. To accomplish these objectives, classification criteria of geomaterials were first created to establish a standard quantitative delineation between the soils, IGMs, and hard rocks for the design of driven piles. In addition, a catalog of IGM properties was prepared to facilitate the design of piles in IGMs. Secondly, a new set of design equations were developed and validated for IGMs by utilizing the developed geomaterial classification criteria. Thirdly, wave equation analysis procedures for IGMs were recommended for pile construction control. Fourthly, changes in pile resistances in IGMs with respect to time at the end of driving and beginning of restrike were assessed. Finally, probability based resistance factors were calibrated and recommended based on the efficiency factors for the existing and calibrated static analysis methods. To facilitate the implementation of the recommended LRFD procedures, a pile design example is developed.]]></description>
      <pubDate>Thu, 31 Oct 2019 11:40:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1659708</guid>
    </item>
    <item>
      <title>Modelling urban traffic dynamics based upon the variational formulation of kinematic waves</title>
      <link>https://trid.trb.org/View/1509276</link>
      <description><![CDATA[This paper presents a dynamic traffic modelling framework based on the variational formulation of kinematic waves. The authors compare the effectiveness of this relatively recent numerical method with the traditional Godunov-based cell transmission method on various aspects including modelling shocks, dispersion of vehicle platoons, moving bottlenecks, and traffic characteristics with respect to real-world observations made in Central London, UK. The results suggest that the variational method is able to produce high-quality estimates both theoretically and empirically. This study opens up a new research direction in the area of urban traffic modelling and optimisation.]]></description>
      <pubDate>Thu, 17 May 2018 14:46:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1509276</guid>
    </item>
    <item>
      <title>Variable speed limit design based on mode dependent Cell Transmission Model</title>
      <link>https://trid.trb.org/View/1492133</link>
      <description><![CDATA[In this paper a mode dependent variable speed limit (VSL) control strategy is developed for motorway networks. The suggested rolling horizon and coordinated algorithm uses switching mode Cell Transmission Model (CTM) and purports to maximize network throughput.  In this line, first, a VSL signal scheduled piecewise affine switching mode CTM is derived based on the polyhedral description of Godunov fluxes. Second, a two-stage, coordinated, rolling horizon VSL sequence generation procedure is proposed. The set of possible VSL signs is selected by applying input constraints in order to eliminate spatial and temporal VSL oscillations. Then, the set of modes is further reduced according to the stable and adjacent reachable modes of the switching mode CTM. Over the remaining set of input signals, network capacity is maximized with the help of solving a mixed integer optimization problem under the form of reference density tracking objective. The method is implemented in simulation environment to demonstrate its computational efficiency and viability to attenuate shockwaves.]]></description>
      <pubDate>Tue, 02 Jan 2018 10:39:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1492133</guid>
    </item>
    <item>
      <title>Modeling the Dynamic Behavior of the Upper Structure of the Railway Track</title>
      <link>https://trid.trb.org/View/1468699</link>
      <description><![CDATA[The present work is devoted to modeling the behavior of railway track under dynamic load of wheel pair in view of elastic, viscoelastic and elastic-plastic properties of the area of interaction between two solids and elastic anisotropic properties of the subgrade, which differ in three main areas: along the rails along the sleepers and vertically downwards. The wave equation railway tracks suggest that the deformation and the permanent way and the mound itself is the field of interaction of bodies takes place in view of the spread of a finite speed of the wave surfaces. The solution methods used methods of asymptotic expansions in the time and space coordinate, the method of matching the expansions obtained for short times in the contact zone and outside it.]]></description>
      <pubDate>Fri, 23 Jun 2017 14:03:03 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468699</guid>
    </item>
    <item>
      <title>Underwater Noise Reduction of Marine Pile Driving Using a Double Pile: Vashon Ferry Terminal Test</title>
      <link>https://trid.trb.org/View/1436910</link>
      <description><![CDATA[Impact pile driving of steel piles in aquatic environments produces extremely high underwater sound levels. To address this problem, a double-walled pile has been developed to decrease the total noise transmitted into the water and substrate. The double-walled pile consists of two concentric steel pipe piles flexibly connected by a special driving shoe, allowing for an air gap between the two tubes. The double-walled pile is driven into the sediment by using traditional equipment that strikes the inner pile only. The air gap between the inner and outer pile and the flexible coupling prevent the radial deformation wave produced by the pile hammer from interacting with the water and the sediment. A second full-scale test of the double-walled pile technology was performed at Vashon Island, Puget Sound, Washington. A potential reduction of the peak pressure in excess of 17 dB was observed for the double pile and of 16 dB for the mandrel pile. Root mean square (RMS) levels and cumulative sound exposure levels (SEL) decreased by 13 dB and 12 dB, respectively. Use of the Washington State Department of Transportation (WSDOT) Geotechnical Design Manual Pile Driving Formula showed that the pile capacity of the novel piles was comparable to that of a control pile with the same outer diameter. PDA (Pile Driving Analyzer) data were also collected from both the inner and outer piles of the mandrel and double piles and will be used to modify current software for predicting drivability and stresses in the piles [WEAP (Wave Equation Analysis of Pile Driving) analysis] and for estimating load capacity after driving [CAPWAP (Case Pile Wave Analysis Program) analysis].]]></description>
      <pubDate>Fri, 16 Dec 2016 11:34:34 GMT</pubDate>
      <guid>https://trid.trb.org/View/1436910</guid>
    </item>
    <item>
      <title>Optimal queue placement in dynamic system optimum solutions for single origin-destination traffic networks</title>
      <link>https://trid.trb.org/View/1425365</link>
      <description><![CDATA[The Dynamic System Optimum (DSO) traffic assignment problem aims to determine a time-dependent routing pattern of travellers in a network such that the given time-dependent origin-destination demands are satisfied and the total travel time is at a minimum, assuming some model for dynamic network loading. The network kinematic wave model is now widely accepted as such a model, given its realism in reproducing phenomena such as transient queues and spillback to upstream links. An attractive solution strategy for DSO based on such a model is to reformulate as a set of side constraints apply a standard solver, and to this end two methods have been previously proposed, one based on the discretisation scheme known as the Cell Transmission Model (CTM), and the other based on the Link Transmission Model (LTM) derived from variational theory. In the present paper the authors aim to combine the advantages of CTM (in tracking time-dependent congestion formation within a link) with those of LTM (avoiding cell discretisation, providing a more computationally attractive with much fewer constraints). The motivation for the authors' work is the previously-reported possibility for DSO to have multiple solutions, which differ in where queues are formed and dissipated in the network. The authors' aim is to find DSO solutions that optimally distribute the congestion over links inside the network which essentially eliminate avoidable queue spillbacks. In order to do so, the authors require more information than the LTM can offer, but wish to avoid the computational burden of CTM for DSO. The authors thus adopt an extension of the LTM called the Two-regime Transmission Model (TTM), which is consistent with LTM at link entries and exits but which is additionally able to accurately track the spatial and temporal formation of the congestion boundary within a link (which the authors later show to be a critical element, relative to LTM). The authors set out the theoretical background necessary for the formulation of the network-level TTM as a set of linear side constraints. Numerical experiments are used to illustrate the application of the method to determine DSO solutions avoiding spillbacks, reduce/eliminate the congestion and to show the distinctive elements of adopting TTM over LTM. Furthermore, in comparison to a fine-level CTM-based DSO method, the authors' formulation is seen to significantly reduce the number of linear constraints while maintaining a reasonable accuracy.]]></description>
      <pubDate>Fri, 21 Oct 2016 16:32:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1425365</guid>
    </item>
    <item>
      <title>Symmetries in the kinematic wave model and a parameter-free representation of traffic flow</title>
      <link>https://trid.trb.org/View/1411077</link>
      <description><![CDATA[This paper identifies a family of linear transformations where conservation laws are invariant. In the case of a triangular fundamental diagram, it is shown that for a subset of these transformations, flow, total distance traveled and total delay are invariant. This means that for capacity or delay computations one may choose the transformation—i.e., the shape of the triangular diagram—that simplifies the problem the most, which does not require knowing the actual fundamental diagram. This is appealing also for delay-optimizing control problems since they may be solved using an isosceles fundamental diagram, which provides the most efficient numerical methods. Examples are given.]]></description>
      <pubDate>Wed, 27 Jul 2016 09:49:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/1411077</guid>
    </item>
    <item>
      <title>Load and Resistance Factor Design (LRFD) Pile Driving Project–Phase II Study</title>
      <link>https://trid.trb.org/View/1406653</link>
      <description><![CDATA[Driven piles are the most common foundation solution used in bridge construction (Paikowsky et al., 2004). Their safe use requires to reliable verification of their capacity and integrity. Dynamic analyses of driven piles are methods attempting to obtain the static capacity of a pile, utilizing its behavior during driving. Dynamic equations (aka pile driving formulas) are the earliest and simplest forms of dynamic analyses. The development and the examination of such equation tailored for Minnesota Department of Transportation (MnDOT) demands is presented. In phase I of the study reported by Paikowsky et al. (2009), databases were utilized to investigate previous MnDOT (and other) dynamic formulas and use object oriented programming for linear regression to develop a new formula that was then calibrated for Load and Resistance Factor Design (LRFD) methodology and evaluated for its performance. This report presents the findings of phase II of the study in which a comprehensive investigation of the Phase I findings were conducted. The studies lead to the development of dynamic formulae suitable for MnDOT foundation practices, its calibrated resistance factors and its application to concrete and timber piles. Phase II of the study also expanded on related issues associated with Wave Equation analyses and static load tests, assisting the MnDOT in establishing requirements and specifications.]]></description>
      <pubDate>Fri, 20 May 2016 15:47:19 GMT</pubDate>
      <guid>https://trid.trb.org/View/1406653</guid>
    </item>
    <item>
      <title>Pile Driving Formulas Revisited</title>
      <link>https://trid.trb.org/View/1346538</link>
      <description><![CDATA[Energy formulas have historically been used to estimate capacity for driven piles. Some engineers still rely on them today and researchers attempt to refine the safety factors or resistance factors to allow a more economic result. However, energy formulas make broad assumptions about “average hammer performance” that cannot always be properly accounted for during installation and thus leave themselves open to gross inaccuracies on any “individual project”, and therefore significant risk. Additionally, since common energy formulas do not model the driving system or pile or soil, observing hammer stroke and blow count is not sufficient to guarantee a specific capacity has been achieved on an individual project. It has been well documented by measurements that supposedly similarly rated hammers can transfer significantly different energies to the pile. Using the wave equation analysis to model these vastly different hammer system efficiencies, the resulting variance on calculated capacity from commonly used energy formulas is investigated and presented. Set-up assumptions contribute to further inaccuracies.]]></description>
      <pubDate>Wed, 01 Apr 2015 08:51:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/1346538</guid>
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