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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>
    <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>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Research on the mechanical properties of composite wet joints in large-span open-cut tunnels</title>
      <link>https://trid.trb.org/View/2599380</link>
      <description><![CDATA[This study proposes a novel inverted-T composite wet joint for the Chongqing Xinsen Avenue Tunnel – an eight-lane, large-span prefabricated open-cut highway tunnel – aiming to streamline construction and improve structural performance. Full-scale laboratory bending tests were conducted on the joint under varying axial loads and reinforcement lap lengths, characterising its load-bearing capacity, stiffness, and failure modes. A detailed finite-element model using the Concrete Damaged Plasticity (CDP) approach was calibrated against the test results and used for parametric analyses of key design variables. In parallel, a three-dimensional soil–structure interaction model of a complete tunnel ring was developed to simulate the staged construction process, capturing the evolution of internal forces, deformations, and failure mechanisms. The results show that the composite joint typically fails in a highly eccentric compression-bending mode, and that increasing the reinforcement lap length yields only limited improvement in flexural capacity. Enhancing the strength of the post-cast concrete, providing sufficient lap length, and detailing the interface with chamfers and shear keys improves joint performance. The full-ring analysis reveals that under staged loading the lining transitions from elastic behaviour to a four-hinge mechanism, and that controlling crown settlement within prescribed limits is critical for serviceability. Overall, this combined experimental and numerical study clarifies the mechanical behaviour and failure mechanisms of inverted-T composite wet joints, providing theoretical guidance for the design of such joints in large-span prefabricated arch tunnels.]]></description>
      <pubDate>Wed, 24 Sep 2025 15:39:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2599380</guid>
    </item>
    <item>
      <title>Hydraulic Anisotropy of Varved Glacial Silts and Its Influence on Dewatering Behavior</title>
      <link>https://trid.trb.org/View/2452739</link>
      <description><![CDATA[This paper presents the evaluation of dewatering behavior of varved glacial silts for cut-and-cover construction of an underground subway station in Manhattan, New York. Diaphragm walls were adopted as retaining walls with an embedded length below the excavation base for groundwater cutoff. The dewatering system consisted of a combination of sumps and vertical pressure relief ejector wells. Back-analysis of pumping test results using numerical seepage modeling indicated the glacial silts were highly anisotropic with the ratio of horizontal to vertical hydraulic conductivity in the order of 5−10. Comparison of piezometric measurements inside and outside of the excavation showed the external groundwater table was not significantly influenced by dewatering operations inside the excavation. However, the varved character of the glacial silts resulted in low residual piezometric pressures beneath the station invert slab after the pressure relief system was deactivated. It was postulated that the ejector wells promoted rapid dewatering of the glacial silts below the excavation subgrade via horizontal flow through sandy seams between the varved clay laminations during active dewatering. Upon deactivation of the pressure relief system, restoration of piezometric pressures was inhibited by the much slower recharge of groundwater in the vertical direction across the less permeable clayey laminations. Residual piezometric pressures in the dewatered zones were observed to be lower where the diaphragm walls were deeper reflecting the increased frequency of varved laminations at depth.]]></description>
      <pubDate>Sat, 30 Nov 2024 11:49:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2452739</guid>
    </item>
    <item>
      <title>Ground Loss behind Floating Diaphragm Walls in Soft Ground Excavation</title>
      <link>https://trid.trb.org/View/2452743</link>
      <description><![CDATA[This paper investigates the performance of floating diaphragm walls embedded in soft ground and their influence on ground loss behind the wall, based on recent experience from a cut-and-cover construction of an underground subway station in Manhattan, New York. An approximately 50- to 60-ft deep internally braced excavation was supported by diaphragm walls installed up to 100 ft below ground surface terminating in weak varved glacial silts. A temporary traffic deck was constructed spanning between the top of the diaphragm walls with utilities hanging from below it. The diaphragm walls were subjected to vertical loading arising from dead and live loads from the traffic deck and struts, as well as self-weight of the diaphragm walls. Vertical load resistance was provided mainly by side-wall shear resistance since the end-bearing component at the wall toe was small in the weak soils. It was observed that ground loss behind a floating diaphragm wall was much greater than a conventional retaining wall that typically terminates in a competent soil layer. Large lateral wall deflections observed by in-wall inclinometers suggest significant lateral earth pressures were generated on the active side. This increase in active earth pressure was attributed to the reversal in the direction of side-wall shear resistance when a floating diaphragm wall settles relative to the soil under vertical loading.]]></description>
      <pubDate>Sat, 30 Nov 2024 11:49:35 GMT</pubDate>
      <guid>https://trid.trb.org/View/2452743</guid>
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    <item>
      <title>IH-35 - Ben White Boulevard to Williamson Creek Drainage Tunnel: Report Regarding the Concept Development</title>
      <link>https://trid.trb.org/View/2449512</link>
      <description><![CDATA[This document summarizes the construction and design concepts developed to support the layout and subsurface geotechnical characterization associated with a system of water transport structures planned to provide for drainage of the new I-35 and Ben White Interchange. The drainage system will consist of a set of vertical drop shafts, in soils and bedrock, and a conduit sited in the Austin Chalk (AC) bedrock. It will convey runoff from the interchange south to Williamson Creek. The main tunnel structure is sited in the AC below the interface between weathered rock and fresh rock. Experience has shown the AC to present relatively good tunneling conditions and, at the depths of the alignment, relatively low rock loading is anticipated on the peripheral rock mass and structural linings. Clay-rich layers, faulting, and deep weathered zones may locally require some special treatment to support the rock mass and to mitigate the impact of any local water inflows. Because AC has previously proven highly amenable to excavation by mechanical means, both Tunnel Boring Machine (TBM) and roadheader mining methods will be considered in the development of the structural designs under an adequate amount of unweathered rock cover. At the southern end of the alignment, where rock cover is inadequate, cut and cover construction techniques will be used. Auger drilling, which has also been used to good effect in this material, is assumed in the excavation of drop shafts, as envisaged to convey surface runoff water to tunnel level.]]></description>
      <pubDate>Mon, 18 Nov 2024 17:16:32 GMT</pubDate>
      <guid>https://trid.trb.org/View/2449512</guid>
    </item>
    <item>
      <title>Discrete-Element Investigation on the Progressive Failure of Cut-and-Cover Tunnel Lining with Various Section Features</title>
      <link>https://trid.trb.org/View/2431621</link>
      <description><![CDATA[Similar to the deep-buried tunnel, the lining of the cut-and-cover tunnel (CCT) exhibits varying degrees of cracking failure during ultrahigh backfill. To explore the whole progressive failure process of a high-filled cut-and-cover tunnel lining structure from the mesodamage to the macrolocal failure and then to the overall instability during backfill, based on the discrete-element program PFC2D, the authors simulated the mechanical behavior and fracture characteristics of the CCTs with rectangular, circular, and arch lining section features with the backfill height. Two load-reduction measures—load-reduction material (LRM) and the interaction of LRM and concrete walls—were then further proposed, and the impact of load-reduction measures on the progressive failure of CCT lining was analyzed. The simulation results show that the various lining section features indicate differences in the distribution and value of lining stress and fracture. But the CCT lining with features of the three sections exhibits a progressive failure process from cracking to local collapse and falling and finally to overall instability as the backfill height increases. Furthermore, the LRM and concrete walls can effectively reduce the vertical stress of the lining vault and the horizontal stress of the haunch, respectively, to ensure the stability and integrity of the CCT.]]></description>
      <pubDate>Tue, 15 Oct 2024 09:17:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2431621</guid>
    </item>
    <item>
      <title>Numerical Modeling of Permanent Ground Deformation Hazard to a Natural Gas Pipeline in California</title>
      <link>https://trid.trb.org/View/2217241</link>
      <description><![CDATA[An extensive Permanent Ground Deformation (PGD) study was conducted on a proposed natural gas pipeline to be located north of Sacramento, in Colusa and Butte Counties, California. The majority of the 30-inch (76.2-cm) diameter and 25 mile long buried steel pipe will be cut and cover construction; however several portions of the pipeline will be installed by horizontal directional drilling methods (HDD). The natural gas pipeline will traverse areas of two potential PGD hazards: faulting deformation and lateral spreading. The pipeline crosses the Willows fault, and an HDD portion of the pipeline will underlie the Sacramento River where a potential lateral spreading hazard exists. A detailed analysis was carried out to evaluate the magnitude of PGD and potential impacts to the pipeline associated with each of these potential PGD hazard sources. This paper addresses PDG associated with faulting. Two and three-dimensional numerical modeling of fault deformation using the finite difference computer program FLAC (Fast Lagrangian Analysis of Continua) are presented and discussed. FLAC was used to simulate the fault rupture mechanism considering a 3.3-foot (1-meter) reverse and 1.8-foot (0.55-meter) strike slip displacement across the fault at approximately 1600 feet (488-meter) below the ground surface. The model captured the resulting ground surface deformation patterns. The 3D FLAC results were used in detailed stress-strain evaluations of the pipeline response using another commercially available finite element computer program, ANSYS. Results compared favorably to the allowable limit states that have been established in the American Lifelines Alliance Guidelines for the Design of Buried Steel Pipe.]]></description>
      <pubDate>Thu, 06 Jun 2024 09:24:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/2217241</guid>
    </item>
    <item>
      <title>Vertical Earth Pressure for a High-Filled Cut-and-Cover Tunnel: Site Measurements and DEM Simulations</title>
      <link>https://trid.trb.org/View/2265749</link>
      <description><![CDATA[Determining vertical earth pressure (VEP) is crucial in designing high-filled cut-and-cover tunnel (CCT) structures. This parameter directly influences the safety and economy of the structure. However, the current pressure formulations do not adequately account for the numerous influencing factors that affect VEP for CCTs, including filling height, slope rate, and tunnel span. In this study, the effects of these factors on VEP were investigated through a combination of field tests and discrete element method (DEM) simulations. An empirical formula for VEP suitable for high-filled CCTs was obtained through mathematical regression. The findings indicated that the soil arching effect is present in high-filled CCTs once the backfill reaches a certain height. The final VEP on the vault was only 0.74 times the total overburden weight. The pressure reduction coefficient decreased with increasing filling height and slope rate but increased with rising tunnel span. The proposed empirical formula for VEP took into account the discount of earth pressure under various factors. It is consistent with the field test results, providing a better reflection of the actual VEP for high-filled CCTs.]]></description>
      <pubDate>Thu, 09 Nov 2023 09:19:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2265749</guid>
    </item>
    <item>
      <title>Überarbeitung des Leitfadens für die Planungsentscheidung ,,Einschnitt oder Tunnel"</title>
      <link>https://trid.trb.org/View/2265644</link>
      <description><![CDATA[Als Planungshilfe für die Straßenbauverwaltungen der Bundesländer hat das Bundesverkehrsministerium den Leitfaden für die Planungsentscheidung "Einschnitt oder Tunnel" herausgegeben und 1998 eingeführt. Der Leitfaden soll der Planungsentscheidung Tunnel, Einschnitt, Teilüberdeckung, Einhausung oder Galerie eine einheitliche Bewertungsmatrix zu Grunde legen, die dann anzuwenden ist, wenn alternative technische Lösungen vergleichend zu bewerten sind. Der Leitfaden basiert im Wesentlichen auf Vorgaben aus den Jahren 1986 bis 1993, die zwischenzeitlich fortgeschrieben wurden. Des Weiteren haben umwelt- und naturschutzrechtliche Belange im Planungsprozess erheblich an Bedeutung gewonnen. Zudem sind im Zusammenhang mit einer Baumaßnahme Defizite des Leitfadens in Folge unberücksichtigter Anforderungen der Bundeshaushaltsordnung (BHO) aufgefallen. Ziel des Forschungsprojekts ist die Erstellung eines Leitfadens für die Planungsentscheidung "Einschnitt oder Tunnel“, der den aktuellen Vorgaben und Anforderungen entspricht, damit künftige Wirtschaftlichkeitsuntersuchungen methodisch korrekt und nachvollziehbar durchgeführt werden können. ABSTRACT IN ENGLISH: As a planning aid for the road construction administrations of the federal states, the Federal Ministry of Transport has published a guideline for the planning decision "Cut or tunnel" and introduced it in 1998. It is to be used for the planning decision "tunnel, cut, partial cover, enclosure or gallery" and is intended to form the basis of a uniform evaluation matrix for planning decisions which is to be applied when alternative technical solutions are to be evaluated comparatively. The guideline is essentially based on specifications from 1986 to 1993, which have been updated in the meantime. Furthermore, environmental and nature conservation issues have become considerably more important in the planning process. Additionally, in connection with a construction project deficits in the guideline as a result of unconsidered legal requirements have been noticed. The aim of the research project is to create a guideline for the planning decision "Cut or tunnel" that corresponds to the current specifications and requirements so that future economic feasibility studies can be carried out in a methodologically correct and comprehensible manner.
]]></description>
      <pubDate>Wed, 11 Oct 2023 05:01:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/2265644</guid>
    </item>
    <item>
      <title>Low lateral stiffness underground structures for improved seismic performance. Application to the Kobe Daikai station</title>
      <link>https://trid.trb.org/View/2197009</link>
      <description><![CDATA[Underground cut-and-cover structures are commonly designed as rigid box sections; however, in practical applications, connections between walls and slabs are frequently rather hinged (because of ease of construction). The abovementioned rigid configurations are highly sensitive to seismic ground motions, due to their important lateral stiffness and internal hyperstaticity; conversely, structures with articulated (or sliding) members have a smaller lateral stiffness, and would be significantly less affected by seismic waves, as would simply accommodate the imposed strains. This flexible solution has been widely considered in practice, but has received little attention from the academic community; this paper tries to close this gap by investigating preliminarily the seismic performance of box-section underground structures with hinged or sliding members. The well-known Daikai Station, damaged by the 1995 Kobe earthquake is analyzed in this paper as a highly relevant case study. An alternative solution is proposed for that station; both simplified and precise calculations have been performed. The simplified calculations are linear static analyses of the station-soil system; the soil-structure interaction is represented by a simple classical model. The precise calculations are nonlinear time-history analyses of an integrated finite element model of the station and the surrounding soil. Both types of analyses refer to the traditional and the proposed solutions of the station. The results of the static and dynamic analyses are satisfactorily compared; they prove that the proposed flexible solution is fully feasible and provides better seismic performance. Finally, another paper by the same authors presented a supplementary case study on a 2-story 3-bay subway station; the outcomes of these two studies could contribute to ground this constructive solution for shallow underground rectangular cut-and-cover structures in seismic areas (both for new construction and retrofit). Noticeably, this approach can be utilized for both cast-in-place and precast structures.]]></description>
      <pubDate>Wed, 19 Jul 2023 09:38:26 GMT</pubDate>
      <guid>https://trid.trb.org/View/2197009</guid>
    </item>
    <item>
      <title>Catastrophic Failure of Shanghai Metro Line 4 in July 2003: Postaccident Rehabilitation</title>
      <link>https://trid.trb.org/View/2096502</link>
      <description><![CDATA[The destructive failure of Shanghai Metro line 4 across underneath the Huangpu River on July 1, 2003, led to massive ground subsidence and collapse of pre-existing structures in the proximity; additionally, the failure generated large amounts of human-made rigid obstructions in the strata, which made rehabilitation of the collapsed metro line be very technically challenging. By extensive comparisons in terms of technical difficulties, economic costs, and construction durations, a plan of reconstruction of the collapsed metro line at its original location rather than relocation was selected finally for the postfailure rehabilitation. The majority of the failed metro line was replaced by a 262-m-long×23.7-m-wide×38.5–41.2-m-deep cut-and-cover tunnel bottoming out in the confined aquifer, whose two ends were connected with the existing intact metro line via two 10-m-long tunnels mined within the aquifer by the ground-freezing method. Excavation of the cut-and-cover tunnel was retained by 1.2-m-thick and 65-m-high perimeter diaphragm wall panels braced by 9–10 levels of steel-reinforced concrete struts. To ensure the project safety and mitigate potential adverse influences of field works on the urban environments, extensive innovative construction plans, measures, and techniques were designed and then implemented into the reconstruction, e.g., a lightweight cofferdam and pile-supported steel platform for diaphragm walling through the existing metro line underneath the river; unique protective solutions and construction techniques for execution of vertical and horizontal ground-freezing programs for diaphragm walling and mining; special procedures of cleaning up the existing tunnels previously filled with water, sand, and cement; innovative joints and grouting measures adopted between the reconstructed tunnel and the pre-existing intact metro line, and so on. Furthermore, the initial designs were optimized and adjusted with the progress of field construction works. Lastly, the long-term field performance data demonstrated the success of this rehabilitation project, which affected the urban environments rarely. The construction plans, measures, and techniques outlined in this paper are practical, useful references for professionals worldwide to deal with similar underground projects in the future.]]></description>
      <pubDate>Tue, 21 Mar 2023 09:22:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/2096502</guid>
    </item>
    <item>
      <title>Control of Seepage Pressures beneath Cut-and-Cover Excavation in Varved Glacial Silt</title>
      <link>https://trid.trb.org/View/1929432</link>
      <description><![CDATA[This paper presents the design and implementation of groundwater cutoff and dewatering scheme for cut-and-cover construction of an underground subway station in Manhattan, New York. The excavation was approximately 60 ft wide and 1,800 ft long with depths ranging from 60 to 70 ft below street level. The invert of the station rested partially on rock at one end but mostly on weak glacial deposits for the remaining portion of the station and a transition tunnel. Groundwater cutoff was achieved using secant pile walls and diaphragm walls. A dewatering system consisting of a combination of shallow sumps and pressure relief ejector wells was adopted. Hydraulic properties of the soils were evaluated from particle size distribution, in situ falling head tests, and a full-scale pumping test. Field pumping volumes were recorded using flowmeters at discharge points to ensure pumping capacity was adequate at all times. Piezometric head within the excavation was observed using selected ejector wells as open standpipe piezometers. Hydraulic pressure build-up beneath the invert slabs were closely monitored as the pressure system was progressively deactivated to ensure the partially completed underground structure was stable against uplift water pressures. The varved character of the glacial deposits resulted in varying residual pressures acting at the invert base after the pressure relief system was de-activated.]]></description>
      <pubDate>Tue, 24 May 2022 10:08:10 GMT</pubDate>
      <guid>https://trid.trb.org/View/1929432</guid>
    </item>
    <item>
      <title>Numerical and experimental analyses for rubber-sand particle mixtures applied in high-filled cut-and-cover tunnels</title>
      <link>https://trid.trb.org/View/1879175</link>
      <description><![CDATA[With the rapid development of the automobile industry and transportation, the disposal of scrap tires has become an internationally recognized economic and environmental problem. Fortunately, high-filled cut-and-cover tunnels (first construction and then layered backfill) provide ideal solutions for waste treatment and resource reuse as mixtures of scrap tire rubber particles and sand are used as lightweight fill material (LFM) in high-fill cut-and-cover tunnels (HFCCT). Because the backfill above the cut-and-cover tunnel (CCT) requires a large quantity of material, an appropriate ratio of scrap tire rubber particles and sand should be selected as the LFM mixture. If LFM of different thicknesses is buried above the CCT, it will inevitably bring varying degrees of influence on the earth pressure around the CCT, leading to structural deformation and soil settlement above the CCT. In this paper, a method of combining numerical simulation and model test is presented to help analyze the macroscopic and micromechanical properties of LFM through the stress–strain change and the contact force chain distribution. In the model test, certain factors influencing the earth pressure, the structural deformation, and the soil settlement mentioned above are considered, including the fill height and the embedding depth of the LFM. The results show that when the rubber fraction by volume (RF) is between 30% and 45%, the deformation and load-bearing capacity of the LFM are the most stable. Moreover, a suitable rubber fraction by volume (RF = 40%) and backfill height (between 0.63 ∼ 0.83 times the height of the CCT) can eliminate the stress concentration at the top center of the CCT.]]></description>
      <pubDate>Fri, 29 Oct 2021 15:40:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/1879175</guid>
    </item>
    <item>
      <title>Möglichkeiten der Prognose von Setzungen beim Schildvortrieb − Stand der Technik und praktische Anwendung</title>
      <link>https://trid.trb.org/View/1755621</link>
      <description><![CDATA[Bei der Planung von Tunnelbaumaßnahmen unter bestehender Bebauung stellt sich die Frage, welche Verformungen oberhalb des Tunnels auftreten und ob diese Verformungen bauwerksschädlich sind. Insbesondere bei innerstädtischen Schildvortrieben gestaltet sich die Setzungsprognose als eine anspruchsvolle Aufgabe, da neben geologischen Randbedingungen zusätzlich auch maschinell bedingte Einflussparameter (Stützdruck, Konizität, Schildschwanzverpressdruck) berücksichtigt werden müssen. Die Prognose von Setzungen beziehungsweise Sackungen oberhalb eines Schildvortriebs kann durch die Ausweitung von Erfahrungen und Messungen aus vorangegangenen Tunnelbauprojekten - der empirischen Prognose − oder aber durch numerische Setzungsberechnungen erfolgen. In der Veröffentlichung werden empirische und numerische Berechnungsverfahren zur Abschätzung der Setzungen bei Schildvortrieben dargestellt sowie deren Möglichkeiten und Grenzen erläutert. Anhand eines Praxisbeispiels − Tunnel Starnberg − wird die Anwendung der möglichen Verfahren zur Setzungsprognose veranschaulicht. (A)]]></description>
      <pubDate>Wed, 06 Oct 2021 09:19:29 GMT</pubDate>
      <guid>https://trid.trb.org/View/1755621</guid>
    </item>
    <item>
      <title>Kostenmodell zur Abschätzung der Herstellkosten von Tunnelbauwerken</title>
      <link>https://trid.trb.org/View/1707273</link>
      <description><![CDATA[Zur Erarbeitung verlässlicher Grundlagen für die Mittelplanung von Tunnelbauwerken wurde ein Forschungsprojekt über die zu erwartenden Kosten und deren Entwicklung von der Planung über die Vergabe bis zur Abrechnung durchgeführt. Das Ziel, neue Kostenmodelle zur Abschätzung der Herstellkosten von Straßentunneln zu entwickeln, wurde im Rahmen der Untersuchungen erreicht. Die Ergebnisse erster Validierungen zeigen, dass die neuen Prognosen keine großen Abweichungen zu tatsächlich aufgetretenen Kosten aufweisen. Zudem wurden weitere Möglichkeiten der Ergebnisdarstellung und Interpretation sowie die Möglichkeit der Prognose individueller Risiken aufgezeigt. Die entwickelten Kostenstrukturen und Basisvarianten können für zukünftige Planungen verwendet werden. Um auch weiterhin annähernd genaue Kostenprognosen treffen zu können, ist eine regelmäßige Aktualisierung der Modelle erforderlich, einschließlich weiterer Validierungen und bei gleichzeitiger Vergrößerung der Datengrundlage. Auch gilt es, zukünftig Risiken und deren monetäre Auswirkungen besser abzubilden, damit sie in einer frühen Phase der Planung berücksichtigt werden können. (A) ABSTRACT IN ENGLISH: A research project on the expected costs and their development from the planning phase through tendering to invoicing was carried out in order to establish a reliable basis for the resource planning of tunnels. This was investigated by a consortium consisting of the Institute for Tunneling and Construction Management at the Ruhr-University Bochum and the engineering offices BUNG and Schüssler Plan. The study was funded by the Federal Highway Research Institute on behalf of the German Federal Ministry of Transport and Digital Infrastructure. The cost estimations in early planning stages are subject to great uncertainties in tunnel construction compared to building structures. This is mainly due to the geotechnical uncertainties and new emerging challenges in each individual tunnel project. As a result, tunnel construction projects, unlike building construction projects, require different approaches to cost estimation, especially when taking financial risks into account.]]></description>
      <pubDate>Mon, 09 Aug 2021 09:47:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1707273</guid>
    </item>
    <item>
      <title>Classifying the subsoil into homogeneous areas for drives using shield machines</title>
      <link>https://trid.trb.org/View/1703203</link>
      <description><![CDATA[Die Unterteilung des Baugrunds in Homogenbereiche nimmt auch beim Vortrieb mit Schildmaschinen im Lockergestein an Bedeutung zu. lm Rahmen des Beitrags werden daher geotechnische Leitparameter ausgewählt, die für den Einsatz der Schildmaschinen und somit für die Einteilung des Baugrunds in Homogenbereiche wesentlich sind. Zudem werden Vorschläge zur sinnvollen Unterteilung unterbreitet. Der Beitrag soll dem Geotechnischen Sachverständigen sowie dem Planer und Auftraggeber helfen, die für die jeweiligen Randbedingungen maßgebende Einteilung des Baugrunds vorzunehmen. In Kombination mit den durchzuführenden Analysen gemäß der Empfehlung des Deutschen Ausschusses für unterirdisches Bauen zur Auswahl von Tunnelvortriebsmaschinen soll zudem eine geeignete Kalkulations- und Abrechnungsgrundlage für den Auftragnehmer ermöglicht werden. (A) ABSTRACT IN ENGLISH: Division of the subsoil into homogenous areas is becoming increasingly important for drives using shield machines in soft ground. Within the scope of this report therefore, geotechnical key parameters will be selected, which are significant regarding the use of the TBM and as a result also for classifying the subsoil into homogeneous areas. In addition, proposals for practical categorisation are provided. The article is intended to assist the geotechnical expert as well as designers and clients to classify the subsoil in keeping with the given boundary conditions in an appropriate manner. Combined with analyses to be carried out in accordance with the recommendation on selecting tunnel boring machines by the German Tunnelling Committee (DAUB), it furthermore attempts to provide the contractor with an appropriate basis for calculative and accounting purposes.]]></description>
      <pubDate>Thu, 24 Jun 2021 16:47:11 GMT</pubDate>
      <guid>https://trid.trb.org/View/1703203</guid>
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