Title Material parameters for describing the time-dependent, nonlinear stress-deformation behavior of firn as a function of its density [Materialparameter zur Beschreibung des zeitabhängigen nichtlinearen Spannungs- Verformungsverhaltens von Firn in Abhängigkeit von seiner Dichte]
Author Bässler, K.
Author Affil Bässler, K., Berufsförderungswerk der Bauindustrie Nord Rhein-Westfalen, Ausbildubgszentrum Essen, Essen, Germany
Source Berichte zur Polar- und Meeresforschung, Vol.611, 110p. . Publisher: Alfred-Wegener-Institut für Polar- und Meeresforschung, Bremerhaven, Germany. ISSN: 1866-3192
Publication Date 2010
Notes In German with English summary. Includes appendices; re-publication of a doctoral dissertation accepted by the University of Bremen, 2009. 59 refs. Ant. Acc. No: 91615. GeoRef Acc. No: 310330
Index Terms compressive properties; creep; deformation; density (mass/volume); experimentation; firn; fracturing; ice; ice mechanics; mathematical models; mechanical properties; rheology; strains; stresses; temperature; viscosity; Antarctica--Queen Maud Land; Antarctica; compressive strength; constitutive equations; density; Ekstrom Ice Shelf; elasticity; experimental studies; failures; field studies; ice cores; laboratory studies; Neumayer Station; nonlinear processes; Queen Maud Land; rates; strain; stress; thermal effects
Abstract The aim of this work is the derivation of material parameters of polar firn as a function of its density to describe the time- dependent deformation behaviour under compressive stress. The total pressure corresponding to the in situ depths of the firn layer is taken into account. The linear and the nonlinear stress-strain relation will be investigated. The use of simple constitutive equitation to describe settlement measurements in boreholes near the Georg von Neumayer Station in Antarctica yields material parameters to describe the time-independent linear deformation behaviour. Results of uniaxial and triaxial compression and creep tests on "in-situ ice cores" under high pressure are first described by a nonlinear constitutive equitation which yields the material parameters without consideration of the time dependency. A further consideration with the same nonlinear constitutive equitation will take into account the time dependency, and the resulting density-dependent material parameters will be identified. After conversion of the constitutive equitation to calculate the stress and in consideration of the strain at failure compressive strength are calculated. The indirect theoretically determined compressive strength (follows the above mentioned procedure) correspond well with those identified in laboratory tests
URL http://hdl.handle.net/10013/epic.34656.d001
Publication Type monograph
Record ID 65007239