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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=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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>
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    <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>Laboratory investigation of strength evolution in organic soils improved by deep mixing method</title>
      <link>https://trid.trb.org/View/2562483</link>
      <description><![CDATA[This study investigates the effectiveness of deep soil mixing (DSM) in enhancing the strength and modulus of organic soils. The research evaluates how varying cement types, binder dosages, water-to-cement (w/c) ratios, and curing durations affect the mechanical properties of two different organic soils that were used; natural soil from the Golden Horn region of Istanbul with 12.4% organic content, and an artificial soil created from a 50/50 mixture of Kaolin clay and Leonardite, which has an acidic pH due to high organic content. The specimens were cured for four durations, ranging from seven days to one year. The testing program included mechanical testing; Unconfined Compression Tests (UCS), Ultrasonic Pulse Velocity (UPV) measurements, and chemical analyses; X-Ray Fluorescence (XRF) and Thermogravimetric analyses (TGA). The UCS tests indicated that higher binder dosages and extended curing durations significantly improved the strength. Higher w/c ratios resulted in decreased strength. Long curing durations resulted in strength values which were four times the 28-day strength values. This amplified effect of strength gain in longer durations was evaluated through “Curing time effect index, (fc)”. The results were presented in terms of cement dosage effect, effect of cement type, effect of total water/cement ratio (wt/c), standard deviation values, E50 values and curing time effect index (fc) values respectively. Results of UPV tests were used to develop correlations between strength and ultrasonic pulse velocities. Quantitative evaluations were made using the results of XRF and TGA analyses and strength. Significant amount of data was produced both in terms of mechanical of chemical analyses.]]></description>
      <pubDate>Fri, 11 Jul 2025 08:42:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2562483</guid>
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      <title>Strength damage analysis on cement-and-fly ash-treated organic soils subjected to freeze–thaw cycles</title>
      <link>https://trid.trb.org/View/2487670</link>
      <description><![CDATA[Organic soil is usually required to be improved/treated before engineering construction, especially in cold regions due to deterioration introduced by freeze–thaw cycle. In this study, cement-and-fly ash is adopted as agents to stabilise the organic soil. A photogrammetric method is proposed to accurately reconstruct the surface of these cement-and-fly ash-treated organic soils and measure the volume before and after freeze–thaw cycles (F–T-C). Meantime, unconfined compression (U-C) test was performed to evaluate the performance of these specimens after different numbers of F–T-C, and the influence of organic content on soil behaviour was also investigated. These results indicated that an increase in the cement content enhanced the resistance of the organic soils against volume change before and after F–T-C. A proper adoption of cement-and-fly ash significantly improves the unconfined compression strength (UCS) of organic soils subjected to different numbers of F–T-C. The strength of treated organic soil continuously decreased with increasing content of organic. A model was also established to predict soil stress–strain curves with consideration of the number of F–T-C and volumetric changes after the F–T-C.]]></description>
      <pubDate>Sat, 15 Feb 2025 17:02:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/2487670</guid>
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    <item>
      <title>Soft Soil Engineering in Central Florida</title>
      <link>https://trid.trb.org/View/2228568</link>
      <description><![CDATA[Florida's limestone bedrock results in numerous active and relic sinkholes. In addition to the typical problems with sinkhole formation, they are also often filled with soft and highly compressible organic silts. Phosphate mining in Florida has also created waste pits filled with very soft materials. Linear projects, such as highways and rail projects commonly encounter these deposits which can result in large and unacceptable settlements and/or global stability problems. Remediation of these sites requires careful consideration during the investigation, design, and construction phases of the project. This paper will review the overall approach to remediation of these sites and present five case histories relevant to the issues.]]></description>
      <pubDate>Sat, 28 Dec 2024 16:17:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2228568</guid>
    </item>
    <item>
      <title>Landfill Construction through Peat and Organic Silt</title>
      <link>https://trid.trb.org/View/2228583</link>
      <description><![CDATA[This paper addresses design principles and construction practices used to combat soft ground conditions based on an extensive case history covering 3 years of landfill construction. It includes the characterization of the soft ground at the site using a variety of methods, including cone penetrometer testing (CPT), borings, laboratory testing, and landfill history. Conceptual designs evaluated to improve and/or mitigate the soft ground problems are reviewed. And finally, this paper addresses some of the many difficulties encountered in the field and how problems were resolved. Due to the severity of the soft ground problem, the potential impact to neighboring rail lines, and the available construction time frames, various technologies were implemented. For a 250-linear meter (m) section along the rail line where 85,000 cubic meters (m³) of soft soil required excavation and replacement at an accelerated schedule, an internally braced, dual-wall sheet-pile system was selected. Two sheet-pile walls were driven through the soft soil and embedded in underlying stiff clay till. Staged excavation of soft soil between sheet-pile walls then commenced, internal bracing was placed, and replacement clay was compacted in place. Remaining soft soil on the landfill side was 'mud-waved' out during placement of a soil buttress. For another section adjacent to the railroad, a soil preload application was employed. This economical approach was selected because the soft soil thickness was less than 4 m and there would be a 2-year construction schedule. The two case histories demonstrate a wide variety of techniques that may be employed to combat soft ground problems.]]></description>
      <pubDate>Sat, 28 Dec 2024 16:17:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2228583</guid>
    </item>
    <item>
      <title>Efficacy of Crustacean and Protein-Based Biopolymer Inclusion on the Strength Characteristics of Organic Soil</title>
      <link>https://trid.trb.org/View/2422977</link>
      <description><![CDATA[The current study evaluated the potential of crustacean polysaccharide and protein-based biopolymers, namely, chitosan and casein, in ameliorating a low organic soil. The inclusion of these biopolymers will ensure the reusability and recyclability of waste materials derived from the marine industry and dairy industry, respectively. The unconfined compressive strength and consolidated undrained shear parameters were investigated at varying dosages of chitosan and casein (0.5%, 1%, 2%, and 4%) and curing periods (up to 90 days). The compressive strength increased with an increase in the curing period and dosage and led to maximum values of 4.39 and 3.13 MPa for chitosan- and casein-treated soils, respectively, for 4% dosage and 90 days of curing. The effective cohesion (c′) and friction angle (ϕ′) improved after including chitosan and casein. The scanning electron microscopy images revealed that the filler characteristics of chitosan led to strength improvement up to 60 days and developed bond strength via fiber bridging after 60 days of curing at higher dosages. In contrast, the casein–soil mix revealed a higher fibrous structure after a curing period of 28 days, which resulted in strength improvement. This contributed to the highest effective friction angle of 21.57° for the 2% and 60-day-cured casein–soil mix. Casein outperformed chitosan in imparting higher effective shear parameters at 1% and 2% dosages. Fourier transform infrared analysis validated the absence of any new compounds within the soil structure. The research findings on chitosan and casein from the current study recommend the application of these materials for addressing the issues of unstable slopes and pavement subgrade.]]></description>
      <pubDate>Tue, 15 Oct 2024 09:17:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2422977</guid>
    </item>
    <item>
      <title>Stabilisation of organic soils with alkali-activated binders</title>
      <link>https://trid.trb.org/View/2310390</link>
      <description><![CDATA[Peat and organic soils are soft soils with high compressibility and low mechanical strength. Therefore, construction over organic subgrades leads to the road foundation suffering unacceptable settlements. Besides, traditional binders such as Portland cement and lime could not effectively enhance the mechanical properties of the organic soils. Consequently, in most cases, these soils are replaced by high-quality materials. This study investigates the effectiveness of using alkali-activated binders to stabilise organic soils. Industrial by-products such as ground granulated blast furnace slag (GGBFS) and fly ash (FA) were used and activated by 10 M sodium hydroxide and sodium silicate solutions to prepare geopolymer binders. The cured specimens were characterised using compression strength tests, one-dimensional consolidation tests, scanning electron microscopy, and energy-dispersive X-ray spectroscopy tests. The experimental results indicated that utilising alkali-activated binders to stabilise the organic soils successfully improved mechanical strength and decreased settlement. The optimum alkali-activated binders resulting from this study can modify the peat soil consisting of 75.32% organic matter to be employed as the road subgrade material.]]></description>
      <pubDate>Mon, 01 Apr 2024 16:57:22 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310390</guid>
    </item>
    <item>
      <title>Novel hybrid machine learning models including support vector machine with meta-heuristic algorithms in predicting unconfined compressive strength of organic soils stabilised with cement and lime</title>
      <link>https://trid.trb.org/View/2310458</link>
      <description><![CDATA[Each type of soil has different optimal soil stabilisation additive content. To design the optimal soil stabilisation component, reliable and efficient models are required. The study proposes the Machine Learning (ML) model Support Vector Regression (SVR) to predict the Unconfined Compressive Strength (UCS) of stabilised soil. To be able to deliver optimal performance, five metaheuristic algorithms: Simulated Annealing (SA), Random Restart Hill Climbing (RRHC), Particle swarm optimisation (PSO), Hunger Games Search (HGS) and Slime Mould Algorithm (SMA) are integrated with the SVR model. To explore the effect of the number of inputs on the model’s performance, the data was divided into two scenarios of input variable number. ML models are evaluated by K-Fold and numerical indicators R2, RMSE and MAE. The results show that in Scenario 1, the SVR-HGS model has a higher predictive performance than other predictive models. While in Scenario 2, the SVR-PSO model gives better performance than the remaining predictive models. SHapley Additive exPlanation (SHAP) and Partial Dependence Plots 2D (PDP) were used to gain insight into the effects of variables on UCS, and the effects of cement and lime on the variables. Obtaining variables that have an important influence on the variation of stabilised soil UCS, in which cement is considered the most significant variable. The detection of A-line value is a relatively important predictor of UCS. At a suitable A-line value, it is possible to reduce the content of chemical stabilising agents (cement, lime) while maintaining the UCS value at a relative threshold.]]></description>
      <pubDate>Tue, 12 Mar 2024 11:05:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2310458</guid>
    </item>
    <item>
      <title>Effects of freeze-thaw cycles on high-sulfated organic soil improved by waste of glass raw materials processing factory</title>
      <link>https://trid.trb.org/View/2321752</link>
      <description><![CDATA[Changes in soil performance due to freeze–thaw cycles can lead to subsidence or swelling of asphalt, which will have a significant impact on road safety performance. The present study aims to stabilize sulfated fine-grained soil containing organic matter with waste from glass raw material production factory and to investigate the effects of Freeze–Thaw cycles on soil properties. First, to examine the effect of adding waste to the base soil before applying the F-T cycle, three compounds containing 5, 10, and 15% of waste were investigated. The results revealed that compounds containing 10, 5, and 15% of waste had the highest shear strength and CBR, respectively. Then, to investigate the effect of F-T cycles, UCS, triaxial tests, and CBR were performed for samples containing 5 and 10% waste with 90-day curing. After applying 4 different F-T cycles (3, 6, 9, and 12 cycles), while reducing the shear strength and CBR number of stabilized samples, the axial strain values showed an ascending trend. The resilience modulus was also calculated using the CBR results, indicating that in the stabilized samples, before and after the cycle, the recommended values of the standards were met. Thus, according to the results obtained for compounds containing 10% of waste, it was found that this waste can be used to reduce the amount of traditional stabilizers such as anti-sulfate cement or lime in cold regions to improve sulfated soils containing organic matter.]]></description>
      <pubDate>Tue, 30 Jan 2024 09:25:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2321752</guid>
    </item>
    <item>
      <title>Development of Organoclay Suitable for Applications in Recycled Rubber–Based Asphalt Binders: Montmorillonite Tailored with Quaternary Ammonium Salt</title>
      <link>https://trid.trb.org/View/2055645</link>
      <description><![CDATA[The objective of this study was to obtain insight into the synthesis and structural changes of organo-montmorillonite (OMT) by tailoring montmorillonite (MMT) with the help of a quaternary ammonium salt. The OMT was prepared as a precursor to the development of enhanced asphalt rubber (AR) product. The dimethyldioctadecylammonium chloride (DDAC) provided the required thermodynamic driving force for changing the polarity of hydrophilic MMT to organophilic when both materials were mixed at 80°C under constant stirring for about 12 h. The newly synthesized OMT and base MMT were thoroughly characterized by using particle size analyzer, zeta potential, infrared (IR) spectroscopy, powder X-ray diffraction, and scanning electron microscopy (SEM) with energy-dispersive X-ray (EDX) measurements encompassing 20,936 data points. The SEM images of OMT depicted the grafted fibrils of long-chain aliphatic hydrocarbons. At the same time, EDX indicated the exchange of sodium and magnesium cations with carbon and nitrogen of the DDAC. Comparison of the IR spectra for reactants and OMT powders concluded that water molecules were removed and methyl/methylene functional groups were inserted in the OMT. The 100 basal reflections of OMT were 1.894 nm, while that of untreated MMT was 1.522 nm, which corroborated the intercalation of the long alkyl chains of the DDAC, a cationic surfactant in the OMT. The study established a simple method for the preparation of OMT to be used as an AR modifier for roadway applications supporting the utilization of nanoclay material in resolving storage stability issues and enhancing properties of recycled rubber–based asphalt products.]]></description>
      <pubDate>Thu, 17 Nov 2022 10:15:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2055645</guid>
    </item>
    <item>
      <title>Evaluation of the organic soil compressibility from in-situ and laboratory tests for road application</title>
      <link>https://trid.trb.org/View/1864341</link>
      <description><![CDATA[Organic soil is characterised by high compressibility and should be improved so that it can be used for construction. The use of every method of soil improvement requires knowledge of the compressibility parameters. One of these parameters is the constrained modulus. The constrained modulus can be determined using laboratory or in-situ tests. In this study, the constrained modulus of organic soil was determined using oedometer and piezocone tests (CPTU). The author analysed subsoil under an approximately 250 m section of a designed road in north-eastern Poland. The constrained modulus of organic soil sampled from four different depths was determined in oedometer tests. Piezocone tests were conducted at 18 points located every 15 m along the length of the section concerned. To determine the constrained modulus based on the cone resistance from CPTU tests, the knowledge of the a and aM coefficients is needed. For the tested soil, the optimal range of the a coefficient from 0.4 to 0.7 was determined. The aM coefficient ranged from 0.4 to 0.8. The value of the constrained modulus of organic soil obtained from the oedometer tests, depending on the effective stress, ranged from approximately 100 kPa to 400 kPa. The constrained modulus of the tested soil decreased with depth, which both research methods proved.]]></description>
      <pubDate>Fri, 27 Aug 2021 14:54:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1864341</guid>
    </item>
    <item>
      <title>Application of Microbial Induced Calcite Precipitation to Stabilize Florida High-Organic Matter Soils for Roadway Construction</title>
      <link>https://trid.trb.org/View/1630043</link>
      <description><![CDATA[Microbially induced calcite precipitation (MICP) was used to treat Ottawa 50-70 sand and organic soil (from Polk County,FL, with 50% organic content) in the lab via injection at the bottom of spe cimens. Results showed that the technique was effective in sands, although calcification was variable and not uniform over the height of each specimen, which resulted in variability in the laboratory strength tests. In an effort to create specimens with uniform calcification, a pre-mixing treatment methodology was developed. Results from pre-mixing showed that more-uniform specimens were created. Both injection and pre-mixing MICP techniques were used to treat the organic soil. Results showed that very little calcite was created using either treatment technique. However, the pre-mixing technique was slightly more effective for specimens with lower organic content (10%). Exopolysaccharide (EPS) formation and the role it plays in MICP was investigated. EPS was observed in samples of MICP-treated Ottawa sand and appears to be a necessary component in the process for successful calcification. The inability to calcify in the organic soil may be due to the lack of EPS, which suggests its formation is inhibited by organic matter. A preliminary study was conducted to assess the feasibility of using biostimulation (stimulating native soil microbes) to induce calcite formation in Florida soils. While results showed that the treatment was ineffective, this was expected based upon results from bio-augmented treatments. In an attempt to induce calcification in the organic soil, sodium dodecyl sulfate (SDS) was added to the MICP recipe. While preliminary results were very promising, further investigation showed that specimens treated with SDS-MICP were dissolvable. In addition, results showed an unintended formation of a calcium dodecyl sulfate (CDS) complex that when stoichiometrically balanced, yielded specimens that were very strong and insoluble. This new, unstudied, non-traditional soil treatment technique has been dubbed surfactant-induced soil stabilization (SISS). The SISS method was further investigated as a viable means for treating Florida soils, although a thorough investigation of this soil treatment technique was outside the scope of this project. Preliminary results of SISS-treated specimens are very promising and warrant further investigation.]]></description>
      <pubDate>Tue, 25 Jun 2019 09:17:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1630043</guid>
    </item>
    <item>
      <title>Primary and Post-Surcharge Secondary Settlements of a Highway Embankment Constructed over Highly Organic Soils: A Case History</title>
      <link>https://trid.trb.org/View/1593879</link>
      <description><![CDATA[A new segment of U.S. Highway 14 was constructed over highly organic clay near Nicollet, Minnesota, by using prefabricated vertical drains and surcharging in 2016. The highly compressible soils were predicted to settle 3 feet at the maximum fill area over the duration of 2 to 3 years. During the design phase, coefficient of consolidation (cv) values obtained from 1-D consolidation tests were used to estimate the time-rate of settlement curve. The estimated primary settlement (Sp) of the embankment was about 37 inches after 6 months of surcharging. Nonetheless, a back-analysis using permeability change index (Ck), which has the advantage of representing decrease in permeability due to decrease in void ratio, was performed to model the primary settlement response of the highly organic soils. The computed settlement and pore water pressure show a good agreement with the field data. After the removal of surcharge, the post-surcharge settlement behavior, including rebound and compression, were continuously measured and recorded for more than a year. By using laboratory secondary compression index (Ca) and post-surcharge secondary compression indices (C'a and C"a) derived from the field data, the projection of embankment performance over the pavement design life was made.]]></description>
      <pubDate>Tue, 30 Apr 2019 09:21:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1593879</guid>
    </item>
    <item>
      <title>Performance of Multi-Helix Pile Embedded in Organic Soil Under Pull-out Load</title>
      <link>https://trid.trb.org/View/1583445</link>
      <description><![CDATA[The performance of multi-helix plate piles under pull-out load in organic soils is tested through an experimental investigation on helical piles. On the basis of experimental tests, this study presents the feasibility of multi-helix pile behavior installed in organic soil. Tests were carried out on two different densities of organic soil. The helix piles were made of 16-mm-diameter mild steel shafts to which mild steel plates of 50 mm for both diameter and pitch were welded. Tests were performed on single-, double-, triple-, and quadruple-helix cylindrical screw piles with helix spacing to diameter ratios varying from 0.1 to 0.5. A set of tests was also performed to evaluate efficiency. The results of the tests are used to illustrate the difference in ultimate capacity for the different geometry anchors. The results showed that the helical pile behavior depends essentially on pile geometric characteristics and soil density. According to the achievements, pull-out load capacity of helical piles depends on spacing ratio (S/D) and number of plates.]]></description>
      <pubDate>Mon, 01 Apr 2019 10:15:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1583445</guid>
    </item>
    <item>
      <title>Rigid Inclusion System Supports Multi-Story Residential and Parking Garage Structures in Organic Soil Profile</title>
      <link>https://trid.trb.org/View/1559742</link>
      <description><![CDATA[Boston is notorious for challenging soils. The highly organic peat and variable fill soils littered throughout the city commonly result in risk of unfavorable settlements of buildings if supported on shallow foundations or the need for expensive deep foundation solutions. However, due to advancements in ground improvement, aggregate piers, and rigid inclusions are rapidly becoming a preferred foundation solution at such challenging sites. This paper discusses one such site, for which both rigid inclusions and aggregate piers were used to reinforce urban fill and organic soils for support of a 5-story parking garage and the surrounding mixed-use structures. The paper walks through the ground improvement solution, the innovative quality control program used during construction, and the results of the load testing program. Ultimately, the rigid inclusion elements exceeded the performance requirements for the project and provided suitable support and settlement control for the proposed structure. This project is of particular importance because it demonstrates that the QC method used for rigid inclusion installation is a key consideration in verifying the element quality and capacity.]]></description>
      <pubDate>Fri, 26 Oct 2018 17:15:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/1559742</guid>
    </item>
    <item>
      <title>Soil Mixing Design Methods and Construction Techniques for Use in High Organic Soils</title>
      <link>https://trid.trb.org/View/1371519</link>
      <description><![CDATA[Organic soils present a difficult challenge for roadway designers and construction due to the high compressibility of the soil structure and the often associated high water table and moisture content. For other soft or loose inorganic soils, stabilization via cement or similar binders (a method called soil mixing) has proven to be an effective and predictable solutions; the Federal Highway Administration (FHWA) has published a comprehensive design manual for these techniques. Organic soils, however, are not addressed therein to a level of confidence for design as organic soils do not follow the trends of inorganic soils. In short, the high porosity, high water content, and high levels of humic acids differentiate organic soils from all other soils where soil mixing has been proven successful. To combat these effects, more cement content is required to bring the water/cement ratio down to acceptable levels and even more cement is required to offset the acidity. Extending the observations of past researchers, a threshold cement content was defined below which no strength gain was achieved. This threshold was then defined as a cement content offset above which the measured strengths matched well with other soil types. This report presents the findings from a thorough literature search, laboratory bench tests, large scale laboratory tests, field evaluation of past and on-going projects and concludes with recommendations for designing for soil mixing applications in highly organic soils.]]></description>
      <pubDate>Fri, 23 Oct 2015 09:35:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1371519</guid>
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