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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+PHBhcmFtIG5hbWU9ImxvY2F0aW9uIiB2YWx1ZT0iMCIgLz48L3BhcmFtcz48ZmlsdGVycz48ZmlsdGVyIGZpZWxkPSJpbmRleHRlcm1zIiB2YWx1ZT0iJnF1b3Q7VW5kcmFpbmVkJnF1b3Q7IiBvcmlnaW5hbF92YWx1ZT0iJnF1b3Q7VW5kcmFpbmVkJnF1b3Q7IiAvPjwvZmlsdGVycz48cmFuZ2VzIC8+PHNvcnRzPjxzb3J0IGZpZWxkPSJwdWJsaXNoZWQiIG9yZGVyPSJkZXNjIiAvPjwvc29ydHM+PHBlcnNpc3RzPjxwZXJzaXN0IG5hbWU9InJhbmdldHlwZSIgdmFsdWU9InB1Ymxpc2hlZGRhdGUiIC8+PC9wZXJzaXN0cz48L3NlYXJjaD4=" 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>Cone Penetration Test Correlations for Missouri Soils </title>
      <link>https://trid.trb.org/View/2673279</link>
      <description><![CDATA[The objective of this research is to provide MoDOT with Missouri-specific guidance on the use of cone penetration test (CPT) measurements to estimate geotechnical parameters. This work will focus on two areas: (1) Development of Missouri-specific correlations to estimate undrained strengths of Missouri clays from CPT measurements. and (2) Investigation of inconsistencies between standard penetration test (SPT) and CPT derived values for granular soils in Missouri.]]></description>
      <pubDate>Tue, 24 Feb 2026 15:30:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2673279</guid>
    </item>
    <item>
      <title>Swarm-Based Extreme Gradient Boosting Models for Predicting the Undrained Stability Factor of Twin Circular Tunnels</title>
      <link>https://trid.trb.org/View/2620696</link>
      <description><![CDATA[This study examines the undrained stability of twin circular tunnels in anisotropic and heterogeneous clays using three-dimensional adaptive finite-element limit analysis (3D-AFELA). Four design variables are considered in the study. They are the cover-depth ratio (C/D), the spacing ratio (S/D), the anisotropy ratio (re), and the undrained shear strength gradient ratio (ρD/suTC0). A detailed parametric study, utilizing various design charts and contour plots, is conducted to discuss the impacts of these variables on the stability factor (N) and the failure mechanism. Using the data set from 3D-AFELA, three hybrid machine-learning models are proposed for stability predictions: GWO-XGBoost, WOA-XGBoost, and SHO-XGBoost. These models combine nature-inspired optimization algorithms (gray wolf optimizer, whale optimization algorithm, and sea-horse optimizer) with Extreme Gradient Boosting (XGBoost). Compared to XGBoost's default settings, hybrid approaches can reduce the model's error by nearly 60%. Among these, the SHO-XGBoost model notably lowers computational costs. Additionally, permutation feature importance and the cosine amplitude method are applied in the sensitivity analysis, revealing that ρD/suTC0 is the most important variable. The findings from this study provide a comprehensive and practical approach to addressing the undrained stability of 3D twin circular tunnels in anisotropic and heterogeneous clays.]]></description>
      <pubDate>Mon, 05 Jan 2026 09:52:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/2620696</guid>
    </item>
    <item>
      <title>Study on the shear characteristics of undrained circulation of rubber sand under traffic load</title>
      <link>https://trid.trb.org/View/2577239</link>
      <description><![CDATA[As a lightweight and environmentally friendly granular material, rubber-sand mixtures have been widely utilized in roadbed filling engineering due to their excellent vibration-damping performance. However, systematic and in-depth research on the dynamic response mechanisms of rubber–sand mixtures under traffic loading remains limited. In this study, hollow cylinder torsional shear tests were conducted to investigate the effects of varying rubber contents (0 %, 20 %, 40 %, and 60 %) on the dynamic shear characteristics of rubber sand subjected to traffic loading. Additionally, a three–dimensional discrete element method (DEM)–based undrained hollow cylinder torsional shear model was established to analyze the evolution of particle displacement, particle mechanical coordination number, strong chain percentage, and fabric anisotropy during the torsional shear process. The results indicate that at low and medium rubber contents (20 %, 40 %), liquefaction and reorganization of the particle skeleton trigger abrupt increases in axial strain and suppress the rebound effect. Meanwhile, horizontal shear–band reorientation accelerates axial strain accumulation. Under these conditions, as rubber content increases, the damping ratio rises linearly, while the shear modulus decreases. At the microscopic level, the particle contact network experiences a reduction in the ratio of mechanical coordination numbers and strong force chains, accompanied by an accelerated decay of normal contact forces in the vertical direction. However, when the rubber content reaches 60 %, the elastic continuous phase formed by densely packed rubber particles stabilizes the strain field and suppresses displacement localization, enhancing stiffness. Microscopically, the number of normal contacts increases, the percentage of strong chains stabilizes, and the rate of decay of vertical normal contact forces is significantly reduced.]]></description>
      <pubDate>Mon, 08 Sep 2025 14:54:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2577239</guid>
    </item>
    <item>
      <title>Undrained Triaxial Compression Testing of Sand-Low Plastic Silt Mixtures</title>
      <link>https://trid.trb.org/View/2488365</link>
      <description><![CDATA[This study presents some consolidated undrained triaxial compression (CU) tests of sand-low plastic silt (ML) mixtures, with ML contents of 0 %, 10 %, 20 %, 30 %, 40 %, and 50 %. The tests were performed on each mixture at three effective consolidation stresses (ECSs) of 50, 100, and 150 kPa. Triaxial testing equipment equipped with submersible local linear variable differential transformers (LVDTs) was employed to obtain accurate non-linear stiffness responses of the tested specimens over the course of the test. The testing results showed that the minimum and maximum void ratios (emin and emax) of the specimens decreased until 20 % ML additions and then increased. Increasing the ECS of the test increased the deviatoric stress, contractive volumetric response and secant modulus (Eu) of all mixtures. Increasing the ML content at a given ECS decreased the deviatoric stress of the mixtures. The ML additions increased the excess pore water pressure (PWP) of the mixtures. The sand with low ML contents (0, 10, and 20 %) exhibited an initial contractive behaviour, followed by a dilative response. However, sand mixed with 30, 40, and 50 % ML were dominated by contractive response. The Eu values of sand decreased with the ML additions. Consequently, these suggest that sand grains can retain their dilative nature and stability when the ML contents are low (i.e., sand-dominated soil matrix). However, when ML dominates the soil matrix, the mixtures exhibited a dominant contractive response with decreasing mean effective stress in their stress paths.]]></description>
      <pubDate>Tue, 18 Feb 2025 10:56:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/2488365</guid>
    </item>
    <item>
      <title>Changes in undrained shear strength as a function of time under embankments : Final report</title>
      <link>https://trid.trb.org/View/2491302</link>
      <description><![CDATA[A methodology to evaluate the changes of undrained shear strength in the sub-soil as a functionof time under the centreline of an embankment was developed. This is based on modelsimulations, using the instrumented test embankment in Haarajoki, Finland, as a case study.The simulations demonstrate that the evolution of the undrained strength under embankmentloading as a function of time is complicated. Firstly, the evolution of strength is related to bothconsolidation and creep, which are strongly affected by the apparent preconsolidation pressureand the creep parameters. Any significant gains in strength are only possible when the effectivestresses go beyond the normal consolidation surface. Furthermore, the degradation of bondingin sensitive clays may in the short term reduce the undrained shear strength, in particular ifthe preconsolidation pressure is only marginally exceeded. Most importantly, the results alsoidentify gaps in our knowledge, with regards of the role of the evolution and anisotropy andprincipal stress rotation on the evolving undrained shear strength, which affect the strengthmobilisation in most of the failure surface.]]></description>
      <pubDate>Fri, 17 Jan 2025 15:18:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2491302</guid>
    </item>
    <item>
      <title>Prediction of Undrained Shear Strength Utilizing a Hybrid Stacking Model Enhanced by Bayesian Optimization Algorithm</title>
      <link>https://trid.trb.org/View/2437838</link>
      <description><![CDATA[Undrained shear strength serves as one of the crucial indicators for analyzing the strength and assessing the stability of clay. To enhance the predictive capability of undrained shear strength, we introduced a hybrid stacking model, the KSMRX, which leverages the Bayesian optimization algorithm. Comparative analyses against base models revealed that the KSMRX model significantly enhanced prediction accuracy, elevating it from 51.3% to 72.5%. This substantial improvement underscored the efficacy of our approach in predicting drained shear strength. Moreover, when compared with the prediction accuracies of 15 other hybrid models, the KSMRX hybrid stacking model consistently demonstrated superior performance. Therefore, this study not only presents a novel and more convenient computational approach, facilitating the acquisition of highly accurate geotechnical parameters, but also serves as a reference for the implementation of geotechnical engineering projects.]]></description>
      <pubDate>Tue, 08 Oct 2024 16:31:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2437838</guid>
    </item>
    <item>
      <title>Combined bearing capacity of bucket foundations in soft-over-stiff clay</title>
      <link>https://trid.trb.org/View/2005353</link>
      <description><![CDATA[In this study, a series of three-dimensional small-strain analyses are carried out to explore the combined capacity of bucket foundations in soft-over-stiff clay under general loading. It aims to provide a supplement to existing design codes. Numerical models are generated and validated with existing data in open literature, where good agreements are obtained. The effects of the layered deposit are explored, including the thickness of the upper soft clay, the length of skirt, the magnitude of the vertical load, and soil properties. Due to the presence of soft clay, the uniaxial bearing capacities reduce significantly, reaching as low as 25% reduction compared to the caisson in uniform stiff clay. In the V-H, V-M and V-H-M spaces, the failure envelopes are normalized in unique shapes according to the geometry of the bucket. Based on the numerical results, an empirical design procedure is proposed to evaluate the failure envelopes of bucket foundations subjected to complex loading conditions in soft-over-stiff clay.]]></description>
      <pubDate>Fri, 26 Aug 2022 16:49:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/2005353</guid>
    </item>
    <item>
      <title>Undrained Shear Strength of Plastic Silt Subject to Blast-induced Excess Pore Pressures</title>
      <link>https://trid.trb.org/View/1895787</link>
      <description><![CDATA[This research report evaluates the undrained shear strength of plastic silts soils subject to raised excess pore pressures such as those resulting from strong ground motion. The knowledge of the possible reduction in undrained shear strength of soils is useful for planning and executing construction of transportation infrastructure subject to earthquake shaking. The results of this study showed that for excess pore pressures equal to 12.6 to 17.5% of the in situ vertical effective overburden stress, the plastic silt deposit forming the subject of this investigation resulted in a loss of undrained shear strength ranging from 44 to 50%. The post-blasting undrained shear strength associated with the raised excess pore pressure field was determined equal to the initial, residual undrained shear strength as observed using the vane shear test.]]></description>
      <pubDate>Thu, 16 Dec 2021 16:08:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/1895787</guid>
    </item>
    <item>
      <title>Characteristic zones for initial state of sand under undrained shearing</title>
      <link>https://trid.trb.org/View/1890431</link>
      <description><![CDATA[A new line for characterising the initial state of sand in the e-lnp plane is firstly introduced in this note, which is defined as the normal compression line (NCL) for sand. Together with a series of existing characteristic state lines, four characteristic zones are subsequently established in the e-lnp plane, namely, liquefaction zone; strain softening zone; quasi-steady state zone and strain hardening zone. Under undrained shearing, saturated sands with the initial state located at the same zone can exhibit similar type of stress-strain relation denoted by the name of zone. A good agreement has been found between the proposed zones and existing experimental results, revealing the ability of proposed zones in characterising the initial state of sand. Finally, the significance of the proposed characteristic zones is demonstrated in the applications associated with sand.]]></description>
      <pubDate>Tue, 30 Nov 2021 10:23:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1890431</guid>
    </item>
    <item>
      <title>Consequences-Based Analysis of Undrained Shear Behavior of Soils and Liquefaction Hazards, Phase 1: Filling the Data Gaps</title>
      <link>https://trid.trb.org/View/1879802</link>
      <description><![CDATA[The overall objective of this multi-year, multi-phase effort is to create a true performance-based model to evaluate the consequences of undrained response in all soils, including consequences resulting from earthquake-induced liquefaction and cyclic softening. Through this overall project, a more robust method for estimating field performance of soils during undrained events (including earthquakes) will be developed and tested. Due to the ability of the CPT to collect nearly continuous profiles of data in most soil types, for these studies we will focus initially on using CPT data for analyzing undrained shear behavior and liquefaction hazards. The framework is intended to be adaptable to other methods such as Standard Penetration Test (SPT), laboratory testing and analysis, and shear wave velocity (Vs) data.  The objective of this Phase 1 study is to fill critical data gaps to document the undrained shear behavior of sands, silts, and clays for both static and dynamic loadings, and to provide a preliminary set of predictive models for the undrained shear response of soils. We anticipate that several state DOTs would be interested in participating in this initial pooled fund study.  Later, in separate pooled fund studies, Phase 2 would focus on additional development of the models for consequences-based analysis of the undrained shear behavior of soils, and Phase 3 would focus on testing and validation of the models.]]></description>
      <pubDate>Thu, 23 Sep 2021 10:51:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/1879802</guid>
    </item>
    <item>
      <title>Upper and lower bounds for three-dimensional undrained stability of shallow tunnels</title>
      <link>https://trid.trb.org/View/1763514</link>
      <description><![CDATA[This paper deals with the determination of upper and lower bounds for the three-dimensional undrained stability of shallow tunnels. The tunnel is circular and a distance between its face and its lining is considered. The soil shear strength is modeled using the Tresca criterion. Results of the upper and lower bounds of the stability number are presented, for several geometrical and resistance configurations and their comparison with previous results is made, showing the clear improvement obtained. Finally, equations approaching the stability number are proposed.]]></description>
      <pubDate>Mon, 22 Feb 2021 10:21:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1763514</guid>
    </item>
    <item>
      <title>Influence of the Spatial Variability of Soil Shear Strength on Deep Excavation: A Case Study of a Bangkok Underground MRT Station</title>
      <link>https://trid.trb.org/View/1753178</link>
      <description><![CDATA[This paper investigates the effects that the spatial variability of a soil's undrained shear strength has on lateral wall movements and ground surface settlements when performing a deep excavation stability analysis. A random finite-element method is employed to statistically assess a deep excavation. A case study based on an actual deep excavation project in Bangkok's subsoils was used to validate the methodology. The two-dimensional spatial variability of the undrained shear strength in the clay layers of Bangkok's subsoil is simulated using the random field theory and Monte Carlo simulation. The Mohr–Coulomb model is used to predict lateral wall movements and ground surface settlements, while the stability analysis of the deep excavation is evaluated by the factor of safety using the strength reduction approach. The results show that spatial variability highly affects the distribution of lateral wall movements and ground surface settlements, as well as the scatter of the factor of safety corresponding to progressing stages of excavation.]]></description>
      <pubDate>Tue, 24 Nov 2020 15:58:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/1753178</guid>
    </item>
    <item>
      <title>Investigation of the Atterberg limits and undrained fall-cone shear strength variation with water content of some peat soils</title>
      <link>https://trid.trb.org/View/1628147</link>
      <description><![CDATA[Road construction in peatlands is challenging. The ability to make rapid estimates of the response of construction soils derived from natural peats to changes in water content is useful for pavement and geotechnical engineers. This paper details some laboratory test results on peat soils sourced from two sites in the South-west of England. The samples were sieved and the roots and natural fibres removed prior to laboratory testing. Water contents on the natural specimens were determined. The percentage of roots in the samples was determined. The thread rolling test was used to estimate the plastic limit of the peat soil material. A series of fall cone tests were conducted at varying moisture contents to determine the liquid limit of the peat soil as well as study the variation of fall cone undrained shear strength with the liquidity index, logarithmic liquidity index and the water content ratio. Both the liquidity index and logarithmic liquidity index are able to predict the fall cone undrained strength to within ± 40% around 90% of the time. When using the water content ratio to predict the fall cone undrained shear strength an accuracy of ± 40% is achieved around 85% of the time. The study concludes that the liquidity index and logarithmic liquidity index are better predictors of fall cone undrained shear strength but the water content ratio approach may be preferred if the engineer is less confident in plastic limit determination for peat soils.]]></description>
      <pubDate>Wed, 14 Aug 2019 14:31:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1628147</guid>
    </item>
    <item>
      <title>Evaluation of Undrained Shear Strength from Cone Penetration Test</title>
      <link>https://trid.trb.org/View/1573258</link>
      <description><![CDATA[The in-situ cone and piezocone penetration tests (CPT, PCPT) have been widely used for the past three decades by the geotechnical engineering community for subsurface soil characterization, soil classification, and for evaluation of many engineering soil properties, such as undrained shear strength (su), constrained modulus (M), coefficient of consolidation (cv), stress history (OCR), etc. The purpose of this paper is to estimate the undrained shear strength (su) of clayey soils using CPT/PCPT data, in addition to some soil boring log data. For this purpose, 70 CPT data collected from different sites at 14 different parishes in Louisiana were analyzed. In each site, both laboratory and CPT tests were performed at the some specific location in order to evaluate the cone and soil parameters (i.e., corrected cone tip resistance, qt; sleeve friction, fs; total overburden pressure, svo; plasticity index, Ip; liquid limit, LL; moisture content, MC). The su of individual soil layers were determined from laboratory unconsolidated undrained (UU) triaxial tests. Both linear and non-linear statistical regression models were developed and verified using the measured soil parameters to estimate su for individual clayey soil layers. Several good su models were developed. However, the su model that contains qt, fs, sv0 parameters was found to be the best model as it satisfies all statistical criteria, in which the estimated values of su from CPT data are very close to the measured values from laboratory UU tests. ).]]></description>
      <pubDate>Fri, 01 Mar 2019 15:51:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1573258</guid>
    </item>
    <item>
      <title>Undrained Cavity-Contraction Analysis for Prediction of Soil Behavior around Tunnels</title>
      <link>https://trid.trb.org/View/1425945</link>
      <description><![CDATA[The cavity-contraction method has been used for decades for the design of tunneling and prediction of ground settlement by modeling the cavity-unloading process from an in situ stress state. Analytical solutions of undrained cavity contraction in a unified state-parameter model for clay and sand (CASM) are developed in this paper to predict soil behavior around tunnels. The overall behavior of clay and sand under both drained and undrained loading conditions could be properly captured by CASM, and the large-strain and effective-stress analyses of cavity contraction provide the distributions of stress/strain within the elastic, plastic, and critical-state regions around a tunnel. The effects of ground condition and soil model parameters are investigated from the results of stress paths and cavity-contraction curves. Comparisons of the ground-reaction curve and the excess pore pressure are also provided between the predicted and measured behavior of tunneling by using data of centrifuge tunnel tests in clay.]]></description>
      <pubDate>Tue, 25 Oct 2016 10:00:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1425945</guid>
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