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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
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      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>A hybrid physics–Bayesian framework for fatigue design curves under cryogenic conditions with consideration of load ratio and residual stress</title>
      <link>https://trid.trb.org/View/2637877</link>
      <description><![CDATA[Fatigue performance is a critical design consideration for cryogenic structures used in the storage and transport of alternative fuels such as liquefied natural gas (LNG), ammonia, and captured CO₂. However, fatigue crack growth rate (FCGR) testing at cryogenic temperatures is expensive and prone to uncertainty due to complex experimental conditions. This study proposes a physics-informed Bayesian framework to improve the prediction and design of FCGR behaviour without extensive cryogenic testing. Four probabilistic models are developed: two Gaussian process (GP) regressions, a physics-informed Bayesian neural network (PIBNN), and a hybrid physics–GP fusion model. The framework explicitly incorporates temperature-dependent material properties, residual stress, load ratio, and crack closure mechanisms while utilising Bayesian inference to quantify epistemic and aleatory uncertainties. The physics-informed components constrain the model to physically admissible trends, improving extrapolation beyond the training data. Based on these models, Bayesian design curves are constructed to replace the traditional “mean + 2SD” rule, achieving a balanced level of conservatism with quantified confidence intervals. The proposed approach demonstrates reliable prediction of fatigue behaviour under untested cryogenic conditions, offering a data-efficient and mechanistically consistent tool for the design and integrity assessment of cryogenic structures.]]></description>
      <pubDate>Tue, 10 Mar 2026 09:55:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2637877</guid>
    </item>
    <item>
      <title>Impact of Heavy Trucks on Highway Bridges</title>
      <link>https://trid.trb.org/View/2159497</link>
      <description><![CDATA[Dynamic impact of multigirder steel bridges is investigated based on three-dimensional nonlinear truck models derived from actual heavy truck traffic. Truck traffic data are collected by weigh-in-motion (WIM) measurements. Multigirder bridges are treated as grillage beam system. Road surface roughness is generated as transversely correlated random processes. Trucks with significant counts are selected to calculate impact factors, which are obtained based on twenty-time simulations. Dynamic responses are obtained by combining static responses and impact factors. The results from a site on I-75 indicate that the truck traffic with average daily truck traffic (ADTT) of 1,065 causes little fatigue damage on steel girders of Categories A and B. Accumulated fatigue damage due to each truck type is calculated and the trucks causing the most fatigue damage are found.]]></description>
      <pubDate>Sat, 07 Mar 2026 16:05:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/2159497</guid>
    </item>
    <item>
      <title>Multiscale Evaluation of Open-Graded Friction Course (OGFC) Asphalt Mixture Fatigue Damage</title>
      <link>https://trid.trb.org/View/2643352</link>
      <description><![CDATA[Research on the microscopic mechanisms of open-graded friction courses (OGFCs) is still in its early stages, and the specific effects of various factors on the fatigue performance of OGFCs have not been fully explored. This study investigates the effects of oil-stone ratios, void fractions, and maximum nominal particle sizes on the fatigue life of OGFCs at the macroscopic and microscopic scales. At the macroscopic level, indirect tensile fatigue tests were conducted on OGFC specimens. At the microscopic level, a three-dimensional (3D) reconstruction model of OGFC was developed using computed tomography (CT) and image processing techniques. Additionally, a 3D randomized aggregate model was developed using the Monte Carlo method and an aggregate random placement algorithm. Virtual splitting and fatigue tests were conducted to analyse the correlation between virtual and experimental macroscopic tests. The results showed that the splitting strength and fatigue life of the OGFC increased at higher oil-stone ratios but decreased at higher void fractions and larger nominal maximum particle sizes. The variation in the results of the virtual splitting fatigue tests derived from the CT reconstruction model and the experimental results was only 9–11%, indicating a strong correlation between the two approaches.]]></description>
      <pubDate>Wed, 25 Feb 2026 09:05:24 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643352</guid>
    </item>
    <item>
      <title>Fatigue damage evolution process of the slab track considering T-C asymmetric damage energy release rate</title>
      <link>https://trid.trb.org/View/2642534</link>
      <description><![CDATA[Train loading, characterized by high frequency, low amplitude, and high cycle count, induces high-cycle fatigue in slab tracks. This study develops a fatigue damage constitutive model based on tension-compression(T-C) asymmetric damage energy release rate, embedding a self-programmed material subroutine into a refined finite element model to analyze damage and stress field evolution. It investigates effects of train load, prestressing, and debonding on track slab fatigue damage. Results show: 1. A set of material damage parameters was determined via simulations, semi-analytical sensitivity analysis, and experiments (compression: a⁻= 4.0, B⁻= 28.0, m⁻= 8.9, α₁⁻=65.0, α₂⁻= 25.5; tension: α₁⁺= 48.0, α₂⁺= 4.7, a⁺= 4.5, m⁺= 0.1, B⁺= 1.89); 2. The model enables damage accumulation when the material is in the loading phase, better characterizing fatigue evolution; 3. Calculation results show without reinforcement, 2.5 million cycles at 250 kN maximum load induce 2.46 times more damage than at 200 kN; 4. Prestress reduces maximum track slab bottom damage by 0.209 after 2.5 million cycles compared with non-prestressed loadcase; 5. Longer CA mortar debonding exacerbates damage at slab top near debonding roots, while shorter debonding creates a "shear effect" accelerating bottom damage in the same region; 6. For 35–85 kN train loads with 830 mm × 1.0 mm debonding, significant stress redistribution occurs between 1–1.35 million cycles, with maximum stress shifting from slab center to sides.]]></description>
      <pubDate>Tue, 24 Feb 2026 09:01:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2642534</guid>
    </item>
    <item>
      <title>Effects of NiO nanomaterial as a bitumen modifier on asphalt mixtures' performance against fatigue and low-temperature cracking in the presence of de-icer agents</title>
      <link>https://trid.trb.org/View/2663699</link>
      <description><![CDATA[Chloride-based de-icing salts are effective for winter road safety but raise environmental and economic concerns by accelerating asphalt deterioration through runoff, penetration, and chemical erosion. To counteract damage driven by deicer, this study examined nano-nickel oxide (nano-NiO) at 2 % and 4 % by weight as a PG 58–22 and PG 64–16 bitumen additive under moisture exposure caused by three common brine solutions: sodium chloride (NaCl), magnesium chloride (MgCl₂), and calcium chloride (CaCl₂). The experimental program employed semi-circular bending (SCB) tests at low temperatures (-10 and −20 °C), Pull-off tests at intermediate and low temperatures (-20, −10, 15, and 25 °C), and indirect tensile fatigue (ITF) tests at intermediate temperatures (15 and 25 °C). The results demonstrated that moisture conditions induced by de-icing agents significantly worsen the cohesion strength, adhesion resistance, fracture properties, and shorten the fatigue life of asphalt mixtures, with CaCl₂ showing the most detrimental effects. In contrast, incorporating 2 % and 4 % nano-NiO substantially improved these parameters; thus, the nanomaterial enhanced mixture integrity by reinforcing cohesion and adhesion bonds, thereby preventing crack formation and stress concentration. Mixtures modified with nano-NiO demonstrated greater resistance to failure at low temperatures. This was evidenced by an increase in the energy required to create a crack (fracture energy) and an increase in the critical stress intensity at the crack tip required for brittle fracture (fracture toughness). Furthermore, the modified samples showed an increased fatigue life (number of load cycles until final failure). Consequently, modified mixtures exhibited superior fatigue and fracture resistance when exposed to de-icing salts. Based on the statistical analysis, it was determined that bitumen modified with 4 % nano-NiO exhibited the best performance in enhancing bitumen-aggregate adhesion/cohesion at low and intermediate temperatures, improving the mixture's low-temperature fracture properties, and extending its intermediate-temperature fatigue life. Furthermore, the evaluation of the low- and intermediate-temperature performance of the base combinations tested in this study revealed that PG 64–16 bitumen, when used with limestone aggregate, produces a mixture with higher stability against the damaging conditions induced by de-icing chemicals. In summary, the results indicate that HMAs made with PG 64–16 bitumen modified with 4 % nano-NiO and limestone aggregate possess the greatest resistance to fatigue and thermal cracking in corrosive de-icing salt environments.]]></description>
      <pubDate>Thu, 19 Feb 2026 10:53:37 GMT</pubDate>
      <guid>https://trid.trb.org/View/2663699</guid>
    </item>
    <item>
      <title>Calibration of Rutting and Fatigue Cracking Models for Flexible Pavement Design in Louisiana Using AASHTOWare Pavement ME Design</title>
      <link>https://trid.trb.org/View/2632881</link>
      <description><![CDATA[This paper presents the experience of local calibration of rutting and fatigue cracking coefficients in AASHTOWare pavement ME design (PMED) for asphalt concrete (AC) pavement, examining various methods tailored to different pavement types and their specific transfer functions. Three types of AC pavements were studied: new AC, semirigid, and AC overlay. The AASHTOWare Calibration Assistance Tool was employed throughout the study. The study identifies that an artificial neural network training-based method is advantageous for considering multiple coefficient interactions. For new AC fatigue cracking, the solver method proves efficient with a fixed damage index but is unsuitable for AC overlay cracking due to variable damage increments. The trial-and-error method is effective when dealing with one or two noninterfering coefficients. When predicted distress shows low sensitivity to coefficients, adjusting material parameters becomes essential. The study highlights the high sensitivity of fatigue cracking in semirigid pavements to modulus of rupture. Emphasizing the role of engineering judgment, the study recommends reducing the number of coefficients based on their physical meaning. Overall, this research underscores the importance of selecting appropriate calibration methods based on transfer function characteristics and coefficient interactions, offering a framework for effective calibration in PMED. The findings are grounded in the current editions of PMED, with a recognition that future changes in equations may necessitate different methods.]]></description>
      <pubDate>Wed, 18 Feb 2026 13:22:47 GMT</pubDate>
      <guid>https://trid.trb.org/View/2632881</guid>
    </item>
    <item>
      <title>Using rheology to study the effect of aging on fatigue performance of asphalt binder</title>
      <link>https://trid.trb.org/View/2618007</link>
      <description><![CDATA[The primary objective of this paper is to select a suitable index to characterise the change law of asphalt binder fatigue performance. Four asphalt binders were subjected to RTFOT and PAV. Frequency sweep (FS) test, Linear Amplitude Sweep (LAS) test, Pure Linear Amplitude Sweep (PLAS) test were performed on aged asphalt binder to obtain Glower-Rowe (𝘎-R) parameter, fatigue life (𝘕բ), fatigue resistance energy index (FREI). For the LAS test, three methods (Dissipated Energy(𝘎*·sinδ), Complex Modulus (𝘎*), Pseudo Strain Energy (PSE)) and four failure criteria (35% 𝘎*·sinδ initial, Peak Stress Strain, Peak Stress Pseudo-Strain, Max Storage PSE) were used to obtain the 𝘕բ. The results showed that the G-R parameter is more sensitive to aging. At high strain levels (>20%), the 𝘕բ obtained based on the 35% 𝘎*·sinδ initial decreased with increasing aging time, while the 𝘕բ obtained based on the rest of the failure criteria showed fluctuations. The FREI of the four asphalt binders showed the multi-stage linear decrease with increasing aging time and the decrease rate of each stage was significantly different, which was similar to the cracking path of conventional materials and is favourable for determining the location of the inflection points.]]></description>
      <pubDate>Mon, 09 Feb 2026 13:55:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2618007</guid>
    </item>
    <item>
      <title>Establishing asphalt layer rutting–fatigue cracking performance thresholds for balanced mix design based on viscoelastic properties</title>
      <link>https://trid.trb.org/View/2643692</link>
      <description><![CDATA[This study presented a methodological framework for establishing performance thresholds for rutting and fatigue cracking of asphalt layers by integrating viscoelastic properties and finite element (FE) modeling for potential balanced mix design (BMD) applications. Using dynamic modulus (DM) master curves derived from the asphalt layers of 55 Long-Term Pavement Performance sections, critical stress-strain responses were computed and applied within a mechanistic-empirical (M-E) framework to predict performance under varying field conditions with new M-E coefficients determined through iterative calibrations. The methodological approach incorporated newly-developed material-performance parameters including viscoelastic rutting index (VERindex) and viscoelastic cracking index (VECindex) as quantitative indicators of mixture performance. Subsequent M-E modeling using diverse asphalt mixtures and a typical pavement structure were utilized to propose the VERindex-VECindex thresholds and verify their capability to predict performance under multiple levels of environmental, traffic loading, and structural conditions. Overall, the results suggested that the proposed VERindex-VECindex thresholds may potentially support the BMD approach by providing a robust criterion for material screening and selection based on the viscoelastic properties as well as consideration of the pavement structure and field conditions. Nonetheless, further studies are recommended to substantiate the proposed VERindex-VECindex thresholds and validate their applicability under different pavement structures and field conditions.]]></description>
      <pubDate>Thu, 29 Jan 2026 17:02:25 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643692</guid>
    </item>
    <item>
      <title>Experimental Determination of Crack Growth in Rails Subjected to Long-Term Cyclic Fatigue Loading</title>
      <link>https://trid.trb.org/View/2657010</link>
      <description><![CDATA[It is well known that one of the most significant causes of train derailments within the U.S. is due to rail fracture [FRA 2023]. Despite this fact, a reliable model for predicting fatigue fracture in rails has not yet been deployed within the U.S. We have recently been developing a multiscale computational algorithm for predicting crack evolution in ductile solids subjected to long-term cyclic loading [Souza et al., 2008, Souza et al., 2009, Souza and Allen, 2009, Souza and Allen, 2012, Allen et al., 2017a,b,c, Little et al., 2018]. In this University Transportation Center for Railway Safety (UTCRS)  funded project, we performed intricate experiments on rails with internal cracks as a means of both obtaining material properties and validating an advanced computational model under development in our companion proposal entitled Computational Model for Predicting Fracture in Rails Subjected to Long-Term Cyclic Fatigue Loading. Furthermore, with funding provided by MxV Rail, we have recently completed cyclic crack growth experiments on seven bi-axially loaded rails with internal cracks that had previously been in service [Whetstone et al, 2023]. We are, therefore, in this research developing the ability to: a) characterize fracture parameters for deploying our advanced fracture mechanics model; b) utilize these parameters to predict crack growth due to cyclic fatigue in rails; and c) utilize our experimental results obtained over the previous decade of testing to validate our computational predictive methodology. Should this model development prove to be useful, it is our ultimate intention to utilize this new advanced technology as a tool for determining how long rails in which flaws have been detected can be safely retained in service.]]></description>
      <pubDate>Wed, 28 Jan 2026 14:42:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2657010</guid>
    </item>
    <item>
      <title>Computational Model for Predicting Fracture in Rails Subjected to Long-Term Cyclic Fatigue Loading</title>
      <link>https://trid.trb.org/View/2657009</link>
      <description><![CDATA[Subsurface fatigue crack growth within railheads can lead to catastrophic failures in rails and is currently one of the major concerns of the rail industry, as they pose a significant safety concern accompanied by critical rail maintenance costs. It is necessary to better assess and predict crack growth within rails, especially when an internal defect is detected, to establish timelier and more cost-effective railway operation protocols. The method most commonly used for predicting the fatigue life of railheads is based on the Paris-Erdogan law, which has limitations in addressing diverse, realistic situations affected by geometric characteristics (e.g. size, orientation, location) of internal flaws (or cracks). This study proposes a nonlinear cohesive zone (NCZ) model capable of accounting for the geometric characteristics of internal defects and inelastic nonlinear fatigue fracture growth in railheads. This study shows that the model effectively simulates fatigue crack growth in rails. The parametric analysis conducted within this study indicates that key NCZ parameters are effective indicators of rail fatigue life. Application of this model would enable appropriate fracture characterization that can be used for predicting fatigue crack growth rate and fatigue life of railheads that contain pre-existing flaws. Simulations of sub-surface crack growth, leveraged by experimental observations from fatigue testing of railheads, demonstrate the potential for the NCZ model to properly characterize fatigue fracture growth in railheads. This fatigue characterization serves as an effective tool for predicting the remaining life of rail sections, which can facilitate proactive maintenance.]]></description>
      <pubDate>Wed, 28 Jan 2026 14:42:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2657009</guid>
    </item>
    <item>
      <title>Comparative fatigue crack analysis of yaw bearings in floating offshore wind turbines to turbulent wind</title>
      <link>https://trid.trb.org/View/2627104</link>
      <description><![CDATA[Wind turbines play a crucial role in renewable energy generation. The yaw bearing, as the largest bearing component in a wind turbine, supports the rotational motion of the nacelle. Compared to fixed onshore and offshore turbines, floating offshore wind turbines (FOWTs) are subjected to more complex environmental loads, increasing the susceptibility of their yaw bearings to fatigue cracks. This study proposes a systematic methodology for fatigue crack assessment in yaw bearings of FOWTs and benchmarks the results against those from fixed turbines operating under various turbulent wind conditions. A modified submodel technique, coupled with the extended finite element method (XFEM), is employed to simulate crack propagation at critical locations. The computed stress intensity factor (SIF) and maximum tangential stress (MTS) direction reveal that both environmental loads and foundation types significantly affect bearing fatigue life. A parameterized study on initial crack depth and inclination is conducted. The results show that at an initial crack depth of 3 mm, cracks propagate simultaneously toward the bearing interior and the raceway surface through a mixed Mode I and II mechanism, leading to spalling and through-crack failures. For a 30° inclination, surface spalling is predominant, whereas at 90°, through-crack failure is more likely to occur.]]></description>
      <pubDate>Mon, 26 Jan 2026 14:44:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2627104</guid>
    </item>
    <item>
      <title>Characterisation and comparative study of fatigue performance of epoxy recycled asphalt under a controlled-strain fatigue load</title>
      <link>https://trid.trb.org/View/2643723</link>
      <description><![CDATA[The aged asphalt binder contained in the reclaimed asphalt pavement (RAP) holds significant economic value, and its recycling is a primary way of pavement regeneration. Epoxy resin has become a new material for recycling aged asphalt due to its strong bonding performance and diffusion ability. To study the effects of strain levels and epoxy contents on the fatigue performance of epoxy recycled asphalt (ERA) binders, the time sweep tests and strain sweep tests were carried out using the dynamic shear rheometer (DSR). The fatigue cracking density of epoxy asphalt binder under a controlled strain loading cycle was calculated using energy balance theory and torque balance theory, and the fatigue performance was evaluated using Pseudo J-Integral Paris’ law. The results show that the fatigue crack density of epoxy asphalt binder presents two stages of crack initiation and crack propagation, different from that of traditional asphalt, and the crack initiation stage is shortened with the increase of epoxy content. The higher the strain level, the faster the fatigue crack propagation of ERA binder. Compared with the virgin epoxy asphalt (EA) binder, the ERA binder shows a lower fatigue crack density evolution rate in the stable stage. A new index E was established to quantify the rate of fatigue extension, with lower values of E denoting enhanced fatigue resistance. ERA and EA have optimal performance at 30% epoxy content. Compared with the epoxy asphalt binder, the ERA binder exhibits a lower index E at the optimal epoxy content (30%), confirming its better fatigue performance. Besides, the Paris’ parameters (A and n) are greatly affected by the epoxy content, which can be used to predict the crack propagation of asphalt binders under different epoxy contents. The fatigue characterisation method provides a feasible method for determining epoxy contents based on the life cycle assessment.]]></description>
      <pubDate>Mon, 26 Jan 2026 08:41:43 GMT</pubDate>
      <guid>https://trid.trb.org/View/2643723</guid>
    </item>
    <item>
      <title>Fatigue behaviour of the reinforced concrete slab-track</title>
      <link>https://trid.trb.org/View/2653121</link>
      <description><![CDATA[This study quantifies the static and high-cycle fatigue performance of non-prestressed reinforced concrete slab-track panels developed as locally optimized variants of the CRTS III system for high-speed rail. Two full-scale designs were tested: NC1, a uniform 250 mm slab with a tensile reinforcement ratio of 1.584%, and NC2, a tapered 210–250 mm slab with a reinforcement ratio of 1.453%. Three-point bending tests with up to 2×106 sinusoidal load cycles, digital image correlation, and embedded strain measurements were used to monitor crack initiation, stiffness degradation, and deflection. NC1 retained higher stiffness, smaller stabilized crack widths, and lower mid-span deflections, while NC2 developed a more uniform but wider crack pattern and higher curvature. Both designs showed early crack acceleration, and flexural behavior governed failure after fatigue. A calibrated 3D nonlinear finite element model with a plasticity–fracture formulation reproduced load–deflection responses, crack localization, and fatigue degradation with minor post-peak deviations. The results demonstrate a trade-off: thicker, higher-reinforcement slabs improve fatigue resilience and serviceability, whereas tapered, lower-reinforcement slabs reduce material use but require stricter crack-width control.]]></description>
      <pubDate>Tue, 20 Jan 2026 10:13:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2653121</guid>
    </item>
    <item>
      <title>Fatigue Assessment of Bridge Members Based on In-Service Stresses-Interim Report No. 2: Data Acquisition System for Strain Measurements</title>
      <link>https://trid.trb.org/View/2635934</link>
      <description><![CDATA[When a bridge is designed, conservative assumptions are made with regard to load distribution and structural continuity. Simple support is assumed when rotational restraint exists, deck girders are assumed noncomposite when significant shear transfer occurs at service loads, haunch is ignored, and elements such as railing are treated as nonstructural dead load rather than as stiffening elements. As a result of these and other conservative assumptions, stresses calculated for design may be well above stresses computed on the basis of strains measured while the bridge is in service. The magnitude of the stress fluctuations under service load determines the fatigue life of the bridge. The accuracy of remaining fatigue life estimates can be improved if these estimates can be based on measured rather than computed strains, typically resulting in a significant increase in projected bridge life. A more accurate fatigue life estimate leads to fewer negative fatigue life computations for operating, undamaged bridges. The result is an overall reduction in retrofit and replacement costs. To take advantage of this cost savings, a data acquisition system has been constructed for use by the Oklahoma Department of Transportation in measuring strains on in-service bridges. Construction of the system involved the development of hardware and software to facilitate interaction with a general-purpose commercial datalogger. Application of the system requires the user to install strain gages on the structure of interest, extend leadwires from the gages to a junction box containing bridge completion circuitry, connect the junction box to a battery-powered datalogger, and connect the datalogger to an on-site computer. The computer is loaded with software to assist the user in setting up the datalogger and downloading collected data. This report contains information regarding construction of the data acquisition system which may be useful for system maintenance and operation. This report also contains a set of general guidelines for conducting a bridge test and applying the test results. It is recommended that a complete bridge evaluation include a thorough visual inspection, an analysis of the structure, and a load test. The load test should include both a series of short-term tests in which stresses are recorded as a truck of known weight passes over the bridge, and at least one long-term test in which the number and magnitude of stress cycles are recorded under normal traffic. Data collected using the data acquisition system can be used to estimate remaining fatigue life and set inspection intervals. The recommended procedure for estimating remaining fatigue life follows NCHRP Report 299, taking full advantage of the fact that stresses are measured rather than computed. The procedure for setting inspection intervals is based on a fracture mechanics estimate of the time required for a crack of an assumed initial length to grow to a critical length when driven by the measured stress cycles.]]></description>
      <pubDate>Tue, 20 Jan 2026 09:42:18 GMT</pubDate>
      <guid>https://trid.trb.org/View/2635934</guid>
    </item>
    <item>
      <title>An Integrated Design Approach for Stabilized Soil Subbase to Prevent Macroscopic Fatigue Cracking</title>
      <link>https://trid.trb.org/View/2630949</link>
      <description><![CDATA[Stabilized soil is widely utilized in pavement engineering to address the disposal of engineering muck, but its fatigue resistance remains a significant challenge. In this study, an integrated design approach for stabilized soil subbases was proposed to prevent macroscopic fatigue cracking and achieve long-lasting, high-toughness pavements. First, a dual-parameter failure criterion was established based on damage density and J-integral thresholds derived from fatigue failure points, informed by indirect tensile fatigue tests on multiple stabilized soil materials. Finite element analysis was subsequently applied, utilizing damage evolution modeling, to quantify and predict the progression of damage within the pavement subbase structure. To overcome computational limitations in high-cycle loading analyses, a hybrid approach was implemented, integrating model simplification and damage density master curves. Finally, simulated damage indicators were compared against the predefined failure criteria. Through iterative adjustments to material damage model parameters and structural layer thickness, damage predictions were constrained within the threshold for preventing macroscopic fatigue cracks. According to the COMSOL simulation results, as the thickness of the stabilized soil subbase decreased, both the tensile stress at the critical location at the bottom of the base and subbase layers increased, and damage followed a similar trend. This systematic methodology integrates the fatigue properties of stabilized soil materials and the fatigue behavior of the structure with stabilized subbase, providing a theoretical foundation and technical guidance for their engineering applications in pavement infrastructure.]]></description>
      <pubDate>Tue, 20 Jan 2026 09:09:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/2630949</guid>
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