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<export-example>
  <doc>
    <id>30683</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>2457</pageFirst>
    <pageLast>2478</pageLast>
    <pageNumber/>
    <edition/>
    <issue>4</issue>
    <volume>56</volume>
    <type>articler</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2023-04-06</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">Experimental investigations on hydro‑mechanical processes in reconstituted clay shale and their significance for constitutive modelling</title>
    <abstract language="eng">The hydro-mechanical processes of a reconstituted clay shale (Opalinus Clay) were studied and implications for constitutive modelling of swellable clay shales derived. The study aims to provide further insights into these coupled processes. For that, oedometric swelling tests with varying boundary conditions and loading paths, oedometric compression tests under dry and saturated conditions, and permeability tests were performed. The results showed a unique preloading line for the dry state when plotting the void ratio against the vertical stress. For saturated states, this line was shifted to the left (to smaller stresses) which revealed a severe reduction of preloading stress due to saturation. All loading paths converged in a normal compression line (NCL) regardless of the mechanical boundary conditions during saturation. A trend line affine to the NCL was established for swelling pressures at different initial void ratios. The influence of saturation on the mechanical properties became further evident, as the un-/reloading stiffness was significantly reduced. A linear relationship between volumetric deformation and saturation was found. A severe swelling induced reduction of permeability in the saturated state was demonstrated and confirmed by the analysis of consolidation processes during oedometric loading. The experimental findings were used to derive fundamental assumptions for constitutive modelling and were discussed within a numerical framework for expansive soils.</abstract>
    <parentTitle language="eng">Rock Mechanics and Rock Engineering</parentTitle>
    <identifier type="doi">10.1007/s00603-022-03202-1</identifier>
    <identifier type="issn">1434-453X</identifier>
    <identifier type="issn">0723-2632</identifier>
    <enrichment key="BTU">an der BTU erstellt / created at BTU</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="Fprofil">1 Energiewende und Dekarbonisierung / Energy Transition and Decarbonisation</enrichment>
    <author>
      <firstName>Antonia</firstName>
      <lastName>Nitsch</lastName>
    </author>
    <submitter>
      <firstName>Luisa</firstName>
      <lastName>Näke</lastName>
    </submitter>
    <author>
      <firstName>Julia</firstName>
      <lastName>Leuthold</lastName>
    </author>
    <author>
      <firstName>Jan</firstName>
      <lastName>Machaček</lastName>
    </author>
    <author>
      <firstName>Carlos Eduardo</firstName>
      <lastName>Grandas Tavera</lastName>
    </author>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Hydro-mechanical behaviour</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Swelling</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Oedometric compression</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Permeability</value>
    </subject>
    <subject>
      <language>eng</language>
      <type>uncontrolled</type>
      <value>Constitutive modelling</value>
    </subject>
    <collection role="institutes" number="6303">FG Bodenmechanik, Grundbau, Geotechnik</collection>
  </doc>
  <doc>
    <id>30922</id>
    <completedYear/>
    <publishedYear>2022</publishedYear>
    <thesisYearAccepted/>
    <language>eng</language>
    <pageFirst>4313</pageFirst>
    <pageLast>4331</pageLast>
    <pageNumber>19</pageNumber>
    <edition/>
    <issue/>
    <volume>17</volume>
    <type>articler</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2023-05-15</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="eng">A 1D Hypoplastic constitutive model for expansive soils</title>
    <abstract language="eng">This paper presents a simple hypoplastic constitutive model that describes the essential features of the material behaviour of partially saturated clayey soils observed in oedometric compression tests. The model is formulated in terms of net stress and degree of saturation. The total strain rate is decomposed into a portion related to the changes in saturation and a portion for the evolution of net stress. However, no distinction is made between plastic and elastic strains. With this strain rate decomposition, the maximum swelling strain/stress are obtained by simulating wetting processes under constant stress/strain conditions. In addition to the void ratio, the model includes two scalar variables to track the loading history (preloading). The calibration of the model constants using common laboratory tests is discussed. Confined and unconfined swelling tests under oedometric conditions with subsequent loading and unloading phases carried out on three different materials were satisfactorily simulated by the model. Its promising results call for an extension to a 3D formulation.</abstract>
    <parentTitle language="eng">Acta Geotechnica</parentTitle>
    <identifier type="doi">10.1007/s11440-022-01548-y</identifier>
    <identifier type="issn">1861-1133</identifier>
    <identifier type="issn">1861-1125</identifier>
    <enrichment key="BTU">an der BTU erstellt / created at BTU</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">false</enrichment>
    <enrichment key="Fprofil">1 Energiewende und Dekarbonisierung / Energy Transition and Decarbonisation</enrichment>
    <author>
      <firstName>Carlos Eduardo</firstName>
      <lastName>Grandas Tavera</lastName>
    </author>
    <submitter>
      <firstName>Carlos Eduardo</firstName>
      <lastName>Grandas Tavera</lastName>
    </submitter>
    <author>
      <firstName>Antonia</firstName>
      <lastName>Nitsch</lastName>
    </author>
    <author>
      <firstName>Jan</firstName>
      <lastName>Machaček</lastName>
    </author>
    <collection role="institutes" number="6303">FG Bodenmechanik, Grundbau, Geotechnik</collection>
  </doc>
  <doc>
    <id>32211</id>
    <completedYear/>
    <publishedYear>2023</publishedYear>
    <thesisYearAccepted/>
    <language>deu</language>
    <pageFirst>689</pageFirst>
    <pageLast>698</pageLast>
    <pageNumber/>
    <edition/>
    <issue>11</issue>
    <volume>100</volume>
    <type>articler</type>
    <publisherName/>
    <publisherPlace/>
    <creatingCorporation/>
    <contributingCorporation/>
    <belongsToBibliography>0</belongsToBibliography>
    <completedDate>2023-12-19</completedDate>
    <publishedDate>--</publishedDate>
    <thesisDateAccepted>--</thesisDateAccepted>
    <title language="deu">Validierung und Kalibrierung eines hypoplastischen Stoffmodells für expansive Böden</title>
    <abstract language="deu">Einige Böden neigen aufgrund ihrer tonmineralogischen Zusammensetzung bei Kontakt mit Wasser zur Volumenänderung, welche sich phänomenologisch entweder als Expansion oder durch eine Quelldruckentwicklung äußert. In der Baupraxis müssen sowohl die Quellphänomene als auch das hydromechanisch gekoppelte Materialverhalten allgemein z.B. bei der Bemessung von Tunnelbauwerken oder Abdichtungen berücksichtigt werden. Existierende empirische Modelle sind für komplexe Randbedingungen oft unzureichend, doch die Anwendung höherwertiger mechanischer Stoffmodelle stellt aufgrund komplexer Modellformulierungen und meist aufwendiger Bestimmung der benötigten Materialparameter eine große Hürde dar. In diesem Aufsatz wird ein von den Autor:innen kürzlich vorgestelltes neuartiges hypoplastisches Stoffmodell für expansive Böden durch die Anwendung auf weitere experimentelle Studien validiert. Zur Erleichterung der Anwendung des Stoffmodells in der Praxis wird eine vereinfachte Parameterkalibrierung erläutert, die keine aufwendige experimentelle Untersuchung erfordert.</abstract>
    <parentTitle language="deu">Bautechnik</parentTitle>
    <identifier type="doi">10.1002/bate.202300062</identifier>
    <identifier type="issn">0932-8351</identifier>
    <enrichment key="BTU">an der BTU erstellt / created at BTU</enrichment>
    <enrichment key="opus.source">publish</enrichment>
    <enrichment key="opus.doi.autoCreate">false</enrichment>
    <enrichment key="opus.urn.autoCreate">false</enrichment>
    <enrichment key="Fprofil">1 Energiewende und Dekarbonisierung / Energy Transition and Decarbonisation</enrichment>
    <author>
      <firstName>Antonia</firstName>
      <lastName>Nitsch</lastName>
    </author>
    <submitter>
      <firstName>Antina</firstName>
      <lastName>Schmidt</lastName>
    </submitter>
    <author>
      <firstName>Jan</firstName>
      <lastName>Machaček</lastName>
    </author>
    <author>
      <firstName>Torsten</firstName>
      <lastName>Wichtmann</lastName>
    </author>
    <author>
      <firstName>Carlos Eduardo</firstName>
      <lastName>Grandas Tavera</lastName>
    </author>
    <collection role="institutes" number="6303">FG Bodenmechanik, Grundbau, Geotechnik</collection>
  </doc>
</export-example>
