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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>
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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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    <item>
      <title>Prediction of the Soil-Water Characteristic Curve Based on Grain-Size-Distribution and Index Properties</title>
      <link>https://trid.trb.org/View/2149319</link>
      <description><![CDATA[The grain-size-distribution (GSD) of a soil is intimately related to its pore size distribution and hence, the GSD holds a close relation with the soil-water characteristic curve (SWCC). In addition, the plasticity index (PI) is a measure of the water holding capacity of the soil and therefore, it plays an important role in shaping the SWCC. This paper presents two sets of statistically derived equations that describe the SWCC of non-plastic and plastic soils. Data from 154 non-plastic soils and 63 plastic soils were analyzed. Soil samples were collected as part of the National Cooperative Highway Research Program (NCHRP) 9–23 project entitled Environmental Effects in Pavement Mix and Structural Design Systems. Samples were obtained from underneath paved roads of 30 sites located throughout the United States. The soil samples were subjected to laboratory testing that included index testing and SWCC testing. SWCCs were determined using a newly developed pressure plate device capable of overburden pressure application, continuous measurements of moisture content, and volume change monitoring. In addition to the collected field data, a database of published soil index properties and SWCCs was incorporated to the analysis. Each SWCC data set was fitted with Fredlund and Xing curve, which provided an S-shaped curve with four parameters, af, bf, cf, and hrf. Using multiple regression analysis, equations were derived for these four parameters based on predictors derived from GSD and PI. The equations presented in this paper are useful in predicting the SWCC of any given soil without carrying out actual SWCC testing and they can easily be incorporated into computer codes to solve various unsaturated soil mechanics problems such as determining moisture beneath covered areas.]]></description>
      <pubDate>Wed, 13 Sep 2023 10:23:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/2149319</guid>
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    <item>
      <title>Cement Treatment of Frost-Susceptible New England Base Materials Blended with Reclaimed Asphalt Pavement</title>
      <link>https://trid.trb.org/View/2160562</link>
      <description><![CDATA[Full-depth recycling in conjunction with cement stabilization is an increasingly popular method of reconstructing deteriorated asphalt pavements; in cold regions, cement treatment is especially useful for improving the strength and durability of frost-susceptible materials. The purpose of this research was to characterize the properties of cement-treated base materials constructed from reclaimed asphalt pavement (RAP) and aggregate materials obtained from several locations in New England. The aggregates and RAP were blended in approximately equal proportions by weight, and extensive laboratory testing was performed to evaluate the strength and durability of each blend in the untreated condition and after treatment with various levels of cement. Testing included determinations of particle-size distributions, moisture-density relationships, unconfined compressive strengths, and moisture susceptibility classifications for the materials. The results of the laboratory testing were used to establish design parameters for field test sections constructed in the summer of 2005. Field testing, including stiffness evaluations using a falling-weight deflectometer, was conducted to characterize the structural properties of both cement-treated and untreated sections subjected to early trafficking. This research suggests that modest amounts of cement can greatly improve the strength and durability of base materials, which should in turn increase their resistance to frost damage.]]></description>
      <pubDate>Wed, 28 Jun 2023 16:29:16 GMT</pubDate>
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    <item>
      <title>Long Term Performance of a Reinforced Base Layer on a Gravel Road</title>
      <link>https://trid.trb.org/View/2160331</link>
      <description><![CDATA[On a local gravel road at Leppävirta, Central Finland (about 62° 27' N, 28° E), test pavements were constructed in the fall of 1996 to strengthen a gravel road, suffering from thaw damage. The improvement methods studied were bitumen stabilization in situ of the base layer, and a macadam overlay reinforced with a steel net. In the primary monitoring in 1997–98 it was fond that the improvement of the surface modulus was significantly higher at the reinforced pavement than a non-reinforced one. The estimated material modulus of the reinforced macadam layer (200mm thick) during thaw was 300–500 MPa. According to the FWD measurements in the spring of 2005, the back-calculated, equivalent material modulus of the reinforced layer during thaw had decreased to about a half of the value estimated after construction. The modulus in summer state was not observed to have significantly changed. In the test pit excavated across the road down to the reinforcement, and the leveling of the reinforcement it could be observed a bending (rutting) of the reinforcement. The estimated rut depth was 25 – 85 mm, and it was increasing with decreasing minimum thaw modulus of the gravel pavement. The rutting of the pavement was relatively low. Thus, it seems obvious that the reinforcement should be treated, not only applying as stiffening of the overlay, but also as an anchoring element, preventing the horizontal and shear stresses below.]]></description>
      <pubDate>Thu, 18 May 2023 17:08:49 GMT</pubDate>
      <guid>https://trid.trb.org/View/2160331</guid>
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    <item>
      <title>Field Evaluation of the Mine Hammer: A Landmine Neutralization Mechanism</title>
      <link>https://trid.trb.org/View/1806558</link>
      <description><![CDATA[An antipersonnel landmine neutralizing mechanism, called the Mine Hammer, was designed with a prototype developed by the Agriculture and Bioresource Engineering Department, University of Saskatchewan and Defence Research and Development Canada -- Suffield. The Mine Hammer technology combined flail mechanisms and agriculture tillage interaction mechanics. The prototype was retrofitted to be powered by a 78.4 kW tractor and was field evaluated in August 2002. The test plots represented gravel road, prairie clay soil with stubble and full stand of Kochia weed for vegetation and simulated tree stump terrains. Dummy or mechanical replicas of antipersonnel landmines were placed at 0, 25, 50, 100 and 200mm depths. The Mine Hammer triggered and/or fragmented the replica landmines. Its mechanical neutralization effectiveness over the five test plots was 97%. The Mine Hammer produced a two layer overburden consisting of a loose till above a dense, compact soil layer. Non-neutralized mine replicas were buried within the compact layer and were not triggered when subjected to loads from human footsteps, jumping and stomping.]]></description>
      <pubDate>Thu, 09 Dec 2021 10:26:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1806558</guid>
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    <item>
      <title>Technische Lieferbedingungen für Geokunststoffe im Erdbau des Straßenbaus: TL Geok E-StB</title>
      <link>https://trid.trb.org/View/1695748</link>
      <description><![CDATA[Die Forschungsgesellschaft für Straßen- und Verkehrswesen hat nun die "Technischen Lieferbedingungen für Geokunststoffe im Erdbau des Straßenbaus" (TL Geok E-StB) mit einer Ausgabe 2019 herausgegeben. Sie ersetzen die gleichnamige Ausgabe 2005. Die TL Geok E-StB beziehen sich auf die in den "Zusätzlichen Technischen Vertragsbedingungen und Richtlinien für Erdarbeiten im Straßenbau" (ZTV E-StB) geregelten Anwendungen. Weitergehendes ist dem "Merkblatt über die Anwendung von Geokunststoffen im Erdbau des Straßenbaus" (M Geok E) zu entnehmen. Die TL Geok E-StB enthalten Anforderungen an Geokunststoffe, die im Erdbau und in Entwässerungsanlagen des Straßenbaus verwendet werden. Sie berücksichtigen die Festlegungen der Europäischen Normung. Im Regelwerk wird zu den unterschiedlichen Anforderungen unter anderem an die Umweltunbedenklichkeit, an das Zugkraftdehnungsverhalten, an die Dicke, an die Geotextilrobustheitsklassen, zu den Funktionen Trennen, Filtern und Schützen, an die hydraulischen Eigenschaften, an die Beständigkeit, an Schichten sowie an Dichtungsbahnen ausgeführt. Im Weiteren werden die Prüfverfahren sowie die Lieferbedingungen in eigenen Kapiteln ausführlich behandelt.]]></description>
      <pubDate>Fri, 07 May 2021 10:19:16 GMT</pubDate>
      <guid>https://trid.trb.org/View/1695748</guid>
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    <item>
      <title>Tunnel Gotschna: Instandsetzung von Quellhebungen in einem bestehenden Strassentunnel − Konzept, Massnahmen, Materialanforderungen</title>
      <link>https://trid.trb.org/View/1515167</link>
      <description><![CDATA[Der einroehrige im Gegenverkehr betriebene Gotschnatunnel der Nationalstrasse N 28 ist 4.207 m lang, stellt die Umfahrung von Klosters sicher und ist seit Dezember 2005 in Betrieb. Bereits waehrend des Baus wurden Sohlhebungen und Rissbildung im Parament festgestellt. Anhydritquellen wurde als Ursache identifiziert. Die Sohlhebungen betragen bis zu 20 mm/Jahr und nehmen noch immer quasi linear zu. Das Instandsetzungsprojekt sieht in den betroffenen Deformationszonen ein neues, bewehrtes Sohlgewoelbe und Verstaerkungen im Paramentbereich vor. Der zu ertuechtigende Querschnitt wird nach dem Widerstandsprinzip dimensioniert. Unterhalb des Sohlgewoelbes wird mit einer nachgiebigen Knautschzone erreicht, dass einerseits lokale Spitzenquelldruecke ausgeglichen werden koennen und anderseits der Zeitpunkt der Einwirkung des vollen Quelldrucks zeitlich hinausgezoegert wird. Die Anforderungen an das deformierbare Material wurden in Eignungsversuchen geprueft. (A)]]></description>
      <pubDate>Wed, 01 Aug 2018 09:23:40 GMT</pubDate>
      <guid>https://trid.trb.org/View/1515167</guid>
    </item>
    <item>
      <title>Ten Years of Edmonton's North East Roads Program</title>
      <link>https://trid.trb.org/View/1511382</link>
      <description><![CDATA[In 1999 roadways in four north east Edmonton neighbourhoods began to show significant structural failures earlier than expected. As a result of continued roadway failures a study was carried out by the City of Edmonton Geotechnical Section of Engineering Services in August 2002 to identify the issue and its extent. The original study and a successive study carried out by Golder Associates in 2005 revealed that water was softening the subgrade soils causing these failures to occur. The issues include subgrade soils that were susceptible to water softening, additional surface drainage from private sump pumps and poor subgrade drainage.  With this information, the City developed several options for remediation of the failed roadways as well as to reduce the availability of water to the subgrade soils. The plan chosen involved full reconstruction of the roadway and installation of edge (periphery) drains. The new roadway cross section consisted of, non-woven geotextile, installation of 200mm diameter perforated PVC lateral drains along curbs on both sides of the road connected to the stormwater system, recycled 63mm granular base, geogrid, virgin granular base course and asphalt concrete. In 2006 the first project with sub-drains was constructed and consisted of approximately 550m of roadway with a cost of approximately $1.5 million.  Over the past ten years the treatment plan has shown to be working to address the issues and the City currently has two annual contracts each completing approximately 1,300 to 1,400m of roadway reconstruction at a cost of approximately $3.0 million dollars per year. In the past ten years the City has completed approximately 14 km of roadways within the neighbourhoods that were part of the original study and has locations for the next three years in place. Many construction techniques have been learned including how to work around utilities, development of drain wells and maintaining access for residents.  Late 2016 additional neighbourhoods were starting to show distresses similar to those reviewed in the study. As such, in 2017 neighbourhoods outside of the original study area will be reconstructed and others that are starting to show earlier signs of similar failures will be monitored regularly through visual inspections and structural testing.]]></description>
      <pubDate>Thu, 03 May 2018 15:16:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1511382</guid>
    </item>
    <item>
      <title>Permafrost-Related Embankment Deformations along the Qinghai-Tibet Railway</title>
      <link>https://trid.trb.org/View/1361125</link>
      <description><![CDATA[The Qinghai-Tibet Railway traverses 550 km of permafrost region. After embankment construction in 2003, considerable detrimental permafrost-related embankment deformations developed along the railway. Based on field monitoring data collected from 2005 to 2012, typical embankment deformations, as well as their mechanisms along the railway were analyzed, taking into account the thermal regime and ice content of the subgrade soil layers. Results showed that frost heave of the embankment was slight and only occurred on a few in-cut roadbeds and air convection crushed rock embankments (ACCEs) in colder permafrost regions (< −1.5 °C). It mainly developed with upward movement of the permafrost table under the roadbed during the first 3–4 years after embankment construction. Settlement of embankments was significant, and some already threaten the railway’s safe operation. As ACCEs successfully cooled the shallow subgrade and underlying permafrost, embankment settlement was relatively slight and acceptable. Settlement of traditional sand gravel embankments (TSGEs) was generally greater than that of ACCEs. In warmer permafrost regions (> −0.7 °C), thaw consolidation of the underlying permafrost resulted in significant settlement on TSGEs, some of which reached 40 cm.]]></description>
      <pubDate>Tue, 28 Jul 2015 15:51:44 GMT</pubDate>
      <guid>https://trid.trb.org/View/1361125</guid>
    </item>
    <item>
      <title>Scour Characterization due to Water Free Fall</title>
      <link>https://trid.trb.org/View/1336984</link>
      <description><![CDATA[Characterization of scour due to free fall of water during storm surge is important for transportation related structures. The roads and streets behind levees are the most typical structures, which are vulnerable to storm surge. A sustained storm surge overtopping a floodwall or weir can cause scour of landside embankment soils, which can compromise embankment stability. Presence of wave action also contributes to scour progression and loss of lateral support. As lateral support is reduced, the overloaded retaining structure can start tilting and exacerbating the instability. Scour depth and stresses due to vertical flow are dependent on shear stresses induced by the plunging water or vertical jet, height of the wall, storm surge and wave heights, depth of the plunge pool on the landside of the retaining structure or a floodwall, and erosion rate of the levee soils. This paper focuses on estimating scour depth and hydraulic stresses imposed by overtopping due to a sustained storm surge. The analysis results are compared to observed scour depths on the landside of floodwalls after Hurricane Katrina along the Inner Harbor Navigation Channel (IHNC). The findings show that for transportation structures which are prone to water free fall during storms, it is important to consider impinging effect of water on soil supporting transportation structures.]]></description>
      <pubDate>Tue, 27 Jan 2015 11:23:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1336984</guid>
    </item>
    <item>
      <title>Assessing the Potential of a Technology to Map the Subgrade Stiffness Under the Rail Tracks</title>
      <link>https://trid.trb.org/View/1337901</link>
      <description><![CDATA[Canadian railways pass through a wide variety of terrains, with the most problematic foundation soils being the glacio-lacustrine clays and very soft muskeg. Soft subgrade materials are prone to sudden failure and large plastic deformation which are a safety concern for rail operations. The locations of soft subgrade are not known due to the lack of an economical method to map the extent of track stiffness. A new technology developed at the University of Nebraska–Lincoln (UNL) (Greisen, 2010; McVey et al., 2005) allows for the measurement of the vertical deflection of the track structure under constant axle loads moving at normal track speeds. This paper presents the preliminary findings from testing of the technology to map the subgrade stiffness on Canadian National’s Lac la Biche subdivision (LLBS). The resultant data showed that the system is sensitive to the effects of track joints. This sensitivity obscures the larger scale variations in deflection due to soft subgrades. To mitigate the impact of the joints, a simple filtering procedure has been proposed to interpret the data at a large scale. The filtered data are used to map the relative stiffness of the subgrade along the LLBS. In addition, the historical track geometry defects data on the LLBS has been used to quantify the impact of soft foundations on degrading track geometry. The preliminary results show that the UNL system has the potential to be used as a measure of rail track performance.]]></description>
      <pubDate>Tue, 27 Jan 2015 11:22:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/1337901</guid>
    </item>
    <item>
      <title>An application of the SBAS-DInSAR technique for the assessment of structural damage in the city of Rome</title>
      <link>https://trid.trb.org/View/1323970</link>
      <description><![CDATA[The remote sensing technique known as Differential Synthetic Aperture Radar (SAR) Interferometry (DInSAR) allows the detection and monitoring of ground settlements, by generating deformation velocity maps and displacement time-series having centimeter to millimeter accuracy. These measurements can contribute to the evaluation of the structural conditions of the constructions. Given the settlements, different approaches exist for the assessment of the structural damage, ranging from empirical estimates to detailed finite element calculations. In this work, the authors integrate the results of a DInSAR analysis with an intermediate semi-empirical model to investigate three buildings located in the southern part of the city of Rome. The model, originally proposed by Finno et al. [(2005). ASCE Journal of Geotechnical and Geoenvironmental Engineering, 131(10), 1199–1210], considers each building as an equivalent laminated beam, where the layers represent the floors and the core material reproduces the infill walls. The results obtained by the model have been compared to the damages observed on the buildings, showing a good agreement and demonstrating that the proposed approach represents an effective and, at the same time, simple assessment tool for rapidly evaluating the conditions of several structures.]]></description>
      <pubDate>Fri, 10 Oct 2014 08:55:01 GMT</pubDate>
      <guid>https://trid.trb.org/View/1323970</guid>
    </item>
    <item>
      <title>Effect of Footing Rigidity on Contact Stress</title>
      <link>https://trid.trb.org/View/1317142</link>
      <description><![CDATA[Contact stress is related to the normal pressure at the contact surface between the foundation and the supporting soil. Contact stress distribution under the footing depends on the footing rigidity. Rigidity of the foundation-soil system is qualified according to DIN (2005) using the coefficient of rigidity (K). At very low values of K, contact stress is highly concentrated under the footing center, and some unrealistic tension stresses are produced at edges due to the linear elastic soil. This tension disappeared with increasing K, and low compression stresses are produced. With increasing the rigidity, the center contact stress decreased and the edge compression stress increased. When the footing is rigid, the edge stress is highly concentrated and center stresses are low. The increase of concentration of edge stresses leads to increases in the resulting maximum moment. Thus, increasing the footing rigidity is increasing the maximum moment. Footing design using standards always results in a semi-rigid section, which produces concentration of stresses at edges and low stresses at the footing center. Therefore, the calculated maximum bending moment by assuming distributed contact stress, as standards and references, is lower than that calculated considering the effect of soil structure interaction. Most references state that the contact stress in cohesionless soil is concentrated at the footing center and is low at the footing edges. It cannot be done, according to the numerical analysis, except in two cases. Case 1 is the flexible footing, and it is not applicable because the designed footing is considered semi-rigid. Case 2 is the failure condition, which cannot be applicable by calculating footing dimension considering the allowable bearing capacity with an appropriate factor of safety.]]></description>
      <pubDate>Mon, 01 Sep 2014 15:09:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/1317142</guid>
    </item>
    <item>
      <title>Embankments, Dams, and Slopes: Lessons From the New Orleans Levee Failures and Other Current Issues</title>
      <link>https://trid.trb.org/View/1268251</link>
      <description><![CDATA[This Geotechnical Special Publication contains 21 papers on engineering issues related to flow, deformation, and stability of earth structures and on lessons learned from the failure of the New Orleans levees after Hurricane Katrina. The papers on the flow and deformation of earth structures advance the capabilities to model, evaluate, analyze, and monitor flow and deformations of earth structures. The papers on the stability of earth structures examine the design and performance of structural systems used to stabilize slopes and protect rapidly weathering rock. Papers by representatives of teams investigating the damage caused by Hurricane Katrina address issues related to the performance of the levee system as well as perspectives on lessons learned and possibilities for future directions of the Hurricane Protection System for Southeast Louisiana.]]></description>
      <pubDate>Wed, 27 Aug 2014 10:47:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/1268251</guid>
    </item>
    <item>
      <title>Eignungspruefungen bei Bodenbehandlungen / Suitability test for soil treatments</title>
      <link>https://trid.trb.org/View/1321078</link>
      <description><![CDATA[Bodenbehandlungen sind Bodenverbesserungen, qualifizierte Bodenverbesserungen (Bodenverbesserung mit erhoehten Anforderungen) und Bodenverfestigungen mit Bindemittel und werden im Erdbau und im Strassenoberbau eingesetzt. Fuer Bodenbehandlungen werden genormte Bindemittel sowie Mischbindemittel gemaess Merkblatt zur Herstellung und Anwendung von Mischbindemitteln verwendet. Bodenbehandlungen mit Bindemittel sind wirtschaftliche Verfahren und ermoeglichen die Wiederverwendung der ansonsten schlecht geeigneten, ausgehobenen Boeden und schonen wertvolle Rohstoffressourcen, wie zum Beispiel Kiese und Schotter. Die Anforderungen fuer Bodenbehandlungen sowie der Einsatzort mit den Schichten im Oberbau sind in den Zusaetzliche Technische Vertragsbedingungen und Richtlinien fuer Erdarbeiten im Strassenbau (ZTV E-StB) und Zusaetzliche Technische Vertragsbedingungen und Richtlinien fuer den Bau von Tragschichten mit hydraulischen Bindemitteln und Fahrbahndecken aus Beton (ZTV Beton-StB) sowie den Richtlinien fuer die Standardisierung des Oberbaus von Verkehrsflaechen (RStO) festgelegt. Fuer Bodenbehandlungen mit Bindemittel muessen Eignungspruefungen durchgefuehrt werden. Fuer Bodenverbesserungen und qualifizierte Bodenverbesserungen ist die Eignung gemaess Technische Pruefvorschriften  fuer Boden und Fels im Strassenbau (TP BF-StB), Teil B 11.3 "Eignungspruefungen fuer Bodenverbesserungen" nachzuweisen. Fuer Bodenverfestigungen im Erdbau ist eine Eignungspruefung gemaess TP BF-StB, Teil B 11.1 durchzufuehren und fuer Tragschichten mit hydraulischen Bindemitteln im Strassenoberbau ist die Eignung gemaess Technische Pruefvorschriften fuer Tragschichten mit hydraulischen Bindemitteln und Fahrbahndecken aus Beton (TP Beton-StB) zu untersuchen. Die neuen Pruefvorschriften TP BF-StB, Teil B 11.1 und TP BF-StB, Teil B 11.3 enthalten Vorgaben und Arbeitsanweisungen fuer die Untersuchungen des Bodens, des Boden-Bindemittel-Gemischs und der fuer den jeweiligen Handlungszweck erforderlichen Festigkeits- und Frostpruefungen. In den neuen Pruefvorschriften sind Handlungsempfehlungen fuer Bodenbehandlungen mit hydraulischen Bindemitteln, Baukalken und Mischbindemitteln aufgestellt. Sie ersetzen die Teile B 11.1 "Eignungspruefungen fuer Bodenverfestigung mit hydraulischen Bindemitteln" und B 11.5 "Eignungspruefung bei Bodenverbesserung und Bodenverfestigung mit Feinkalk und Kalkhydrat". Im neuen Teil B 11.3 sind neben den Verdichtungspruefungen auch Festigkeitspruefungen zum Nachweis der erforderlichen Tragfaehigkeit auf dem Erdplanum oder bei Hinterfuellungen von Widerlagern mit gemischtkoernigen und feinkoernigen Boeden aufgefuehrt. (A) ABSTRACT IN ENGLISH: Soil treatments are soil improvements, qualified soil improvements (soil improvements with stricter requirements) and ground stabilisation with binders. They are used in earthworks and road constructions. For soil improvement purposes standardised binders as well as mixed binders according to the information sheet for the manufacture and application of mixed binders, are used. Soil treatments are economic processes saving natural resources (e. g. gravel, chippings) and enable the recycling of inappropriate soils. The requirements for soil improvements and the places of application are defined in the German Standards ZTV E-StB and ZTV Beton-StB and RStO. Suitability tests are necessary for soil improvements with binders. The suitability of soil improvements and qualified soil improvements have to be verified according to TP BF-StB, part B 11.3 "Eignungspruefung fuer Bodenverbesserungen". Suitability tests according to TP BF-StB, part B 11.1 "Eignungspruefung fuer Bodenverbesserungen" have to be carried out for soil stabilizations in earthworks. Hydraulically bound base course layers have to be tested according to TP Beton-StB. The new testing regulations TP BF-StB, part 11.1 and TP BF-StB, part 11.3 include guidelines and work instructions for soil tests, tests of the soil-binder-mixtures and tests of the binders, related to the required strength and frost-resistence. They also provide recommendations for the use of hydraulic binders, lime and mixed binders. They replace part B 11.1 "Eignungspruefungen fuer Bodenverfestigung mit hydraulischen Bindemitteln", edition 2005, and part 11.5 "Eignungspruefung bei Bodenverbesserung und Bodenverfestigung mit Feinkalk und Kalkhydrat", edition 1991. The new part B 11.3 includes compaction tests and strength tests to prove the required bearing capacity of subsoils or backfill material consisting of fine and mixed grained soils. (A)]]></description>
      <pubDate>Tue, 26 Aug 2014 13:51:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/1321078</guid>
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      <title>Coupled Computational Simulation of Excavation and Soil Transport in Earth-Pressure Balance Shield Tunneling Machines Using a Viscous Two-Phase Fluid Model for Soil-Foam Mixtures</title>
      <link>https://trid.trb.org/View/1310376</link>
      <description><![CDATA[The excavation process of earth-pressure balance (EPB) shield machines involves the cutting of the ground at the tunnel face and the transport of the soil paste in the excavation chamber. For the numerical simulation of these two processes, a computational strategy, characterized by the coupling of two partial models using the discrete element method (DEM) and the finite element method (FEM) has been developed (Wessels et al., 2013). Excavation is simulated using DEM, with the fracture process being represented by the release of interaction forces between the particles. The transport of the excavated soil mixed with the soil conditioning foam, yielding a pasty soil-foam mixture within the pressure chamber, is simulated by means of a two-phase fluid model in Eulerian description. The two momentum and mixture mass equations are discretized in time by the characteristic-based split method (CBS) (Zienkiewicz et al., 2005). The phase volume fraction equations are solved using upwind weighting functions according to the improved Mizukami-Hughes method (Knobloch, 2006). The proposed model is applied to a coupled analysis of the excavation and transport-mixing flow inside a simplified pressure chamber with foam injections. The mixing process, due to the rotation in the chamber, is preliminarily investigated by the mixing flow in a 2D cavity test case.]]></description>
      <pubDate>Fri, 25 Jul 2014 16:17:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/1310376</guid>
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