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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>Dynamic Soil Models for Backcalculation of Material Properties from Falling Weight Deflectometer Deflection Data</title>
      <link>https://trid.trb.org/View/1468702</link>
      <description><![CDATA[Falling Weight Deflectometer (FWD) test is one of the most widely used methods for in-situ nondestructive evaluation of pavement/soil properties and examination of the structural condition of in-service pavements. A dynamic half-space model is employed in the present work for backcalculation of engineering soil properties from the FWD data. The advantages, limitations and the reliability of the backcalculation elastic moduli evaluated from dynamic soil model are discussed in this paper. Selected numerical results are presented to portray the influence of governing parameters, for example, the presence of shallow stiff layer and the mass density of soil material on dynamic backcalculation of the soil elastic modulus. The investigation presented in this study provides a better understanding of dynamic backcalculation processes which is essential for the development of dynamic backcalculation program and its applications.]]></description>
      <pubDate>Fri, 23 Jun 2017 14:03:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1468702</guid>
    </item>
    <item>
      <title>Condition Monitoring of Urban Infrastructure : Effects of Ground Movement on Adjacent Structures</title>
      <link>https://trid.trb.org/View/1239147</link>
      <description><![CDATA[This document consists of two thesis papers: "Hypoplastic Constitutive Law Adapted to Simulate Excavations in Chicago Glacial Clays" by Fernando Sarabia submitted June 2012; and "Analysis of Top‐Down Construction at the Block 37 Project in Chicago, Illinois" written by Kristi Sue Kern, 6/6/2011.   Economic considerations drive the more effective use of space in urban areas, promoting the construction of taller buildings with deeper basement structure. The crowded nature of urban environments imposes strict restrictions to the tolerable performance of these new constructions. These restrictions are translated in the need for the development of more precise tools that can be used by engineering practitioners to predict construction induced deformations. Geotechnical finite element simulations are a common technique to estimate construction performance. This methodology can be enhanced by the use of optimization routines to calibrate the constitutive model parameters with existing data. Specifically the finite element simulation strategy adopted in this research incorporated the use of an advanced soil model that is conceptually capable of capturing the nonlinear nature of soil stiffness from the very small to large strain levels. In the second paper, the Block 37 Project in Chicago, Illinois presented a good case study to evaluate the performance of an excavation support system during top-down construction.  Top-down construction is an increasingly popular form of construction being employed by contractors in urban environments because of its apparent ability to minimize adjacent ground movements.  The ground movements observed during the Block 37 excavation were evaluated and compared to previous case studies.  A finite element simulation was produced to recreate the excavation activities to more closely see the effect of specific construction activities on adjacent ground movements.  The creep and shrinkage of the lateral support elements were calculated as a possible explanation for the discrepancy between the observed movements and the calculated movements from the finite element simulation.]]></description>
      <pubDate>Tue, 19 Feb 2013 08:47:52 GMT</pubDate>
      <guid>https://trid.trb.org/View/1239147</guid>
    </item>
    <item>
      <title>Comparison between a Terramechanics Model and a Continuum Soil
Model Implemented within the Absolute Nodal Coordinate 
Formulation</title>
      <link>https://trid.trb.org/View/1222384</link>
      <description><![CDATA[In order to determine the best approach for the modeling of tracked vehicle-terrain interactions, a comparison is made between terramechanics and continuum mechanics plasticity soil models that can be used in vehicle dynamic simulations. The absolute nodal coordinate formulation (ANCF) which can be used in multibody system (MBS) dynamics to model large rotations and large deformations will provide a novel framework for this comparison. First, a brief review of the analytical derivation and implementation of a terramechanics soil model for drawbar pull-slip and pressure-sinkage are presented in order to establish the basic assumptions underlying this model. An assumed shape and mass for the vehicle-terrain interface and an empirically derived constitutive model are two clear assumptions inherent in terramechanics based approaches. The (modified) Bekker soil models are integrated finite element (FE) ANCF interpolations to determine the generalized forces. Continuum mechanics soil models that are suited for tracked vehicle-terrain interaction are identified and integrated into the internal force calculation of ANCF MBS algorithms. The paper discusses important fundamental issues that must be addressed when implementing continuum mechanics-based soil models as well as terramechanics models into MBS algorithms for modeling complex tracked vehicle/soil interactions. The improvement of the vehicle-terrain interface estimation resulting from FE methods can provide a terramechanics approach which may be scalable to differing vehicles and loadings. It is found that the assumed existence, uniqueness, and evolution of the yield surface(s) of continuum soil models play a critical role in predicting the soil behavior while also providing a rational method for improvement of soil constitutive modeling.]]></description>
      <pubDate>Thu, 15 Nov 2012 14:01:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/1222384</guid>
    </item>
    <item>
      <title>Hypoplastic Constitutive Law Adapted to Simulate Excavations in Chicago Glacial Clays</title>
      <link>https://trid.trb.org/View/1222553</link>
      <description><![CDATA[Economic considerations drive the more effective use of space in urban areas, promoting the construction of taller buildings with deeper basement structures. The crowded nature of urban environments imposes strict restrictions to the tolerable performance of these new constructions. These restrictions are translated in the need for the development of more precise tools that can be used by engineering practitioners to predict construction induced deformations. Geotechnical finite element simulations are a common technique to estimate construction performance. This methodology can be enhanced by the use of optimization routines to calibrate the constitutive model parameters with existing data. This thesis introduces enhancements to existing techniques that improve the agreement between model predictions and both laboratory test data and field performance observations. Specifically, the finite element simulation strategy adopted in this research incorporated the use of an advanced soil model that is conceptually capable of capturing the nonlinear nature of soil stiffness from the very small to large strain levels. The techniques incorporated in this research were developed to be used for the prediction of deformations of deep excavations in the Chicago area. The parameters of the selected model were either directly estimated from existing laboratory test data or computed using optimization techniques that used sophisticated triaxial test results as target observations. The procedures used to estimate the model parameters incorporated techniques to account for natural variation in degree of soil plasticity, density and degree of overconsolidation of the different Chicago glacial till layers.]]></description>
      <pubDate>Mon, 12 Nov 2012 15:08:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1222553</guid>
    </item>
    <item>
      <title>Nonlinear, Effective-Stress Ground Motion Response Analyses Following AASHTO Specifications for Load and Resistance Factor Design Seismic Bridge Design</title>
      <link>https://trid.trb.org/View/1092246</link>
      <description><![CDATA[Nonlinear, effective-stress ground motion response analyses were conducted for a bridge site north of Seattle, Washington. This site was characterized by silt and sand layers in the upper 90 ft (27.4 m) of the soil profile that were expected to liquefy during a 975-year seismic event. Procedures described in the 2009 "AASHTO Guide Specifications for LRFD Seismic Bridge Design" were followed when site-specific analyses of ground motion response were conducted. Two one-dimensional, nonlinear effective-stress computer programs, D-MOD2000 and PSNL, were used to perform the analyses. Field and laboratory tests were conducted to define soil parameters for the nonlinear soil models. Results of the analyses were used to identify soil layers that were likely to liquefy as well as changes in design response spectra that could result from liquefaction. These results demonstrated important differences in site-response prediction from subtle changes in soil modeling, including the potential for shielding of upper liquefiable soil layers and the importance of soil dilation when lower layers liquefy. This paper provides a summary of the analyses and discusses observations made from comparison of the two sets of analyses. The paper also highlights uncertainties that can occur when nonlinear, analyses of effective-stress ground motion response are conducted.]]></description>
      <pubDate>Mon, 21 Mar 2011 14:13:41 GMT</pubDate>
      <guid>https://trid.trb.org/View/1092246</guid>
    </item>
    <item>
      <title>Linear Regression Models for Predicting Liquefaction during Cyclic Triaxial Testing</title>
      <link>https://trid.trb.org/View/894640</link>
      <description><![CDATA[Cyclic triaxial tests are commonly used in research and engineering practice to evaluate soil liquefaction potential and the factors that influence it. During testing it is necessary to estimate the level of loading to be applied to the specimen. This can be a difficult task unless the engineer has previously acquired a reasonable amount of experience with this type of testing. In order to provide guidance in selecting an appropriate level of loading, a series of 4 linear regression models have been developed to predict liquefaction in sands and soils with nonplastic silts. The models were separated by soil type and the method of specimen preparation. These models were developed using data from over 750 tests collected from the author's files and the literature. The validity of each model was assessed by examining the statistical parameters of the model, an analysis of residuals, and predictions made using additional data obtained from the literature.]]></description>
      <pubDate>Tue, 21 Jul 2009 08:13:06 GMT</pubDate>
      <guid>https://trid.trb.org/View/894640</guid>
    </item>
    <item>
      <title>Development of Modulus-Soil Moisture Model for Subgrade Soils Using Suction Control Testing System</title>
      <link>https://trid.trb.org/View/794794</link>
      <description><![CDATA[In a pavement structure, moisture is an environmentally driven variable that can significantly affect the resilient modulus of subgrade soils.  In this study, the variations of deformational modulus with post compaction moisture content were investigated for three subgrade soils using suction control resonant column and torsional shear (RC/TS) tests.  A series of tests were performed to evaluate the modulus values using specimens compacted at various moisture contents and compared to the results obtained by post compaction method by suction controlling.  Applicability of existing models which relate the modulus and soil moisture was assessed using test results, and a model which relates the modulus and soil suction was newly proposed.]]></description>
      <pubDate>Fri, 29 Dec 2006 11:08:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/794794</guid>
    </item>
    <item>
      <title>Performance Assessment of a Precast-Concrete, Buried, Small Arch Bridge</title>
      <link>https://trid.trb.org/View/786736</link>
      <description><![CDATA[Experimental field load-test and finite-element analysis were carried out for the performance assessment of a precast-concrete, modular, three-sided, low-profile, buried, arch bridge system. Finite-element analysis incorporated soil modeling and soil–structure interaction at service and limit load levels. The analytical study simulates step-by-step incremental phases of construction and service loads. The finite-element model was calibrated based on the experimental field assessment, to provide a better correlation between the analytically predicted behavior and the actual response of the structure. The study validates the incorporation of various soil models and soil–structure interaction characteristics, to allow a more cost-effective bridge design.]]></description>
      <pubDate>Mon, 31 Jul 2006 07:48:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/786736</guid>
    </item>
    <item>
      <title>Evaluation of Shear Modulus and Damping in Dynamic Centrifuge Tests</title>
      <link>https://trid.trb.org/View/771689</link>
      <description><![CDATA[Correct evaluation of shear modulus and damping characteristics in soils under dynamic loading is key to both the fundamental understanding of soil behavior and the practical application of soil modeling programs. Dynamic centrifuge tests can contribute significant information about soil behavior, but great care must be taken over the signal processing techniques involved, and the test conditions are different from the laboratory experiments that form the database of existing knowledge. This paper outlines several factors that require careful consideration when deriving stiffness and damping parameters from centrifuge data. Shear modulus and damping degradation curves for a dry sand, saturated sand, soft clay and a model waste are then evaluated to explore some of the factors that are introduced during centrifuge tests. Stiffness is seen to be a more reliable parameter than damping ratio. Damping during centrifuge tests for certain materials appeared to differ from the expected values.]]></description>
      <pubDate>Mon, 13 Feb 2006 11:52:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/771689</guid>
    </item>
    <item>
      <title>Genetic Algorithms for the Calibration of Constitutive Models for Soils</title>
      <link>https://trid.trb.org/View/760021</link>
      <description><![CDATA[This paper presents a study that uses an innovative numerical method called the "genetic algorithm" for material parameter optimization in constitutive modeling. The paper introduces a new scheme, a fitness function, to estimate the error of predicted behavior due to a given set of material parameters. Optimization efficiency of the proposed fitness function is analyzed by changing the selected genetic algorithm parameters. The genetic algorithm and the new fitness function were found to be capable of optimizing material parameters of complex constitutive models.]]></description>
      <pubDate>Tue, 20 Sep 2005 07:13:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/760021</guid>
    </item>
    <item>
      <title>ANALYZING DYNAMIC BEHAVIOR OF GEOSYNTHETIC-REINFORCED SOIL RETAINING WALLS</title>
      <link>https://trid.trb.org/View/705559</link>
      <description><![CDATA[An advanced generalized plasticity soil model and bounding surface geosynthetic model, in conjunction with a dynamic finite element procedure, are used to analyze behavior of geosynthetic reinforced soil retaining walls. The construction behavior of a full-scale wall is first analyzed followed by a series of 5 shaking table tests conducted in a centrifuge. The parameters for the sandy backfill soils are calibrated through the results of monotonic and cyclic triaxial tests. The wall facing deformations, strains in the geogrid reinforcement layers, lateral earth pressures acting at the facing blocks, and vertical stresses at the foundation are presented. In the centrifugal shaking table tests, the response of the walls subject to 20 cycles of sinusoidal wave having a frequency of 2 Hz and of acceleration amplitude of 0.2g are compared with the results of analysis. The acceleration in the backfill, strain in the geogrid layers, and facing deformation are computed and compared to the test results. The results of analysis for both static and dynamic tests compared reasonably well with the experimental results.]]></description>
      <pubDate>Thu, 12 Aug 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/705559</guid>
    </item>
    <item>
      <title>EXPERIMENTAL INSPIRATION FOR KINEMATIC HARDENING SOIL MODELS</title>
      <link>https://trid.trb.org/View/703717</link>
      <description><![CDATA[Traditional techniques for identifying yielding of soils in the context of classical elastic-plastic soil models are criticized. However, extended use of such procedures starts to reveal the kinematic nature of plastic behavior of soils. It is suggested that experimental determination of stress response envelopes can provide an objective route toward the collection of stress-strain behavior for soils. Stress response envelopes are presented for true triaxial tests on clay and sand: these clearly reveal the kinematic nature of the soil behavior. Response envelopes are presented for different magnitudes of strain probes. As the magnitude of a strain probe increases, the kinematic element of the response decays and the memory for the increasingly distant history is swept out.]]></description>
      <pubDate>Tue, 08 Jun 2004 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/703717</guid>
    </item>
    <item>
      <title>LATERAL EXTRUSION ANALYSIS OF SANDWICHED WEAK SOIL IN SLURRY TRENCH</title>
      <link>https://trid.trb.org/View/542601</link>
      <description><![CDATA[This paper presents a method to analyze the problem of lateral extrusion of sandwiched weak soil in a slurry trench.  This problem is modeled as weak material compressed between rough plates.  Theoretical solutions are derived on the basis of the limiting plasticity theory.  The arching effect attributed to the finite length of the trench is taken into account in the computation of vertical pressure being exerted upon the weak soil.  The weak soil is evaluated using a factor of stability that represents a measurement of the effectiveness of slurry pressure on preventing weak soil from lateral extrusion.  This factor is defined as a ratio of slurry pressure to lateral extrusion pressure at the level of weak soil.  Validity of the proposed method is examined using a field case study.]]></description>
      <pubDate>Sun, 10 Jan 1999 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/542601</guid>
    </item>
    <item>
      <title>IN SITU DETERMINATION OF SOIL STIFFNESS AND DAMPING</title>
      <link>https://trid.trb.org/View/635879</link>
      <description><![CDATA[Determination of in situ dynamic soil properties is fundamental to the prediction of the seismic behavior of foundations and soil embankment structures.  Both elastic (stiffness) and inelastic (damping) values are required for computational analysis.  To be of value to engineers, the geophysical inversion should employ the same soil model as used in the dynamic analysis software. Current engineering practice employs a Kelvin-Voigt model (spring in parallel with dashpot).  The relevant wave equation is a third-order partial differential equation.  This paper demonstrates how to collect in situ field data and solve for stiffness (scaled shear) and damping values by a method consistent with this constitutive model.  Measurements of seismic wave amplitude decay and velocity dispersion are simultaneously inverted for the required stiffness and damping values.  These in situ stiffness and damping values are directly comparable to those obtained by resonant column measurements in the laboratory. Furthermore, the results may be directly input into currently available engineering software to provide values of stiffness and viscous damping.  This paper includes both synthetic (finite difference) and field data examples that illustrate the method.]]></description>
      <pubDate>Fri, 18 Sep 1998 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/635879</guid>
    </item>
    <item>
      <title>OVERVIEW OF STATE-OF-THE-PRACTICE MODELING OF OVERCONSOLIDATED SOILS</title>
      <link>https://trid.trb.org/View/451785</link>
      <description><![CDATA[Numerical methods currently used in practice to predict the behavior of overconsolidated clays are described.  The paper is not intended to be a state-of-the-art report but rather a state-of-the-practice report on techniques that have been used in practice.  The discussion focuses on the Modified Cam Clay (MCC) model, which is widely accepted because of its practicality and simplicity.  However, there are instances when more sophisticated overconsolidated soil models have been used. The paper presents an overview of the developments of soil elasto-plasticity followed by a detailed description of the MCC model and derivation of its incremental formulation.  In addition, an example describing the calibration of the MCC parameters is presented.  Step-by-step procedures are developed for drained and undrained predictions.  A generalized form of the MCC model is described in which a third stress invariant is included in the formulation.  A constitutive driver code is then implemented to allow for the numerical simulation of three-dimensional stress states.  Finally, a brief description of the implementation of a constitutive driver into a finite element formulation is presented.]]></description>
      <pubDate>Thu, 02 Nov 1995 00:00:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/451785</guid>
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