Untersuchungen zur Mikrostruktur und zum Setzungsverhalten von Lossboden (Investigations on the Microstructure and the Settling Behavior of Loess Soils)

Abstract

With the founding of the Geotechnical Properties of Loess working group of the International Union for Quartenary Research (INQUA) it has been possible to point to internationally recognised research in the area of identifying the geomechanical properties of loess soils. The central theme of research to date has been the investigation of so-called Collapse Criteria with a view to making qualitative estimates of subsidence potential as water content increases. In addition geochemical investigations of loess soils describe their chemical composition but offer only a limited description of the water solubility of components and its resultant influence on subsidence behaviour. Research to date has been carried out in terms of the effects of static loads on collapse behaviours of metastable structures of loess soils. The deformation characteristics of loess soils under cyclical loads has so far not been investigated. In the work carried out for this thesis the low soluble mineral component of an Afghan loess soil was investigated for the first time and it was examined on the basis of parameter studies of the influence of the clay and limestone content of the soil on its hydroconsolidation behaviour. Considerations of both the macroscopic and microscopic soil structure permit testable conclusions about the behaviour and significance of pore sizes/volumes during the transition from a metastable soil structure to a denser and more stable condition. The results obtained serve as the basis for the formulation of a new empirical, deductive prognosis method for the qualitative estimations of likely collapse of microstructure as a result of hydroconsolidation. As well as demonstrating the prognosis method for static loads, dynamic triaxial experiments were also carried out as a comparative investigation of the dynamic stability of metastable and ideal density loess soils.

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Document Details

Document Type
Technical Report
Publication Date
Mar 01, 2012
Accession Number
AD1024908

Entities

People

  • Claas Meier

Organizations

  • Bundeswehr University Munich

Tags

Communities of Interest

  • Sensors

DTIC Thesaurus Topics

  • Afghanistan
  • Central Asia
  • Civil Engineering
  • Classification
  • Collapse
  • Earth Sciences
  • Electrical Conductivity
  • Engineering
  • Engineering Geology
  • Erosion
  • Failure Mode And Effect Analysis
  • Geology
  • Geotechnical Engineering
  • Granular Materials
  • Groundwater
  • Materials
  • Mechanical Properties
  • Mechanics
  • Microstructure
  • Moisture Content
  • Soil Mechanics
  • Soil Science
  • Soils
  • Static Loads
  • Two Dimensional

Readers

  • Geotechnical Engineering.
  • Theoretical Analysis.