Direct shear testing on unsaturated silty soils to investigate the effects of drying and wetting on shear strength parameters at low suction

A modified conventional direct shear device was used to measure unsaturated shear strength of two silty soils at low suction values (0 ~ 50 kPa) that were achieved by following drying and wetting paths of soil water characteristic curves (SWCCs). The results revealed that the internal friction angle of the soils was not significantly affected by either the suction or the drying wetting SWCCs. The apparent cohesion of soil increased with a decreasing rate as suction increased. Shear stress-shear displacement curves obtained from soil specimens subjected to the same net normal stress and different suction values showed a higher initial stiffness and a greater peak stress as suction increased. A soil in wetting exhibited slightly higher peak shear stress and more contractive volume change behavior than that of soil in drying at the same net normal stress and suction.

Reproduction of painted portrait of Marcus Elias Marcus, age 76. Portraits Men

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Reproduction of painted portrait of Marcus Elias Marcus, age 76 Portraits Men

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Gottschalk family on vacation in front of Kurhaus Brunig; Norderney, Germany.

From left to right: man with camera: Karl Gottschalk; sitting on stairs: Fritz Gottschalk, unidentified woman, Therese Gottschalk nee Molling, Hans Ludwig, Kurt Gottschalk, unidentified woman (maid?) and Elizabeth Gottschalk

Portrait of Arno Nadel holding a copy of Wagner's "Tannhauser"; Hamburg Portraits; Men

Handwritten on verso: "Hamburg den 27 11.17 Sontag"

Portrait of Alice Bendix Portraits Women

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Portrait of Alice Bendix outdoors Portraits Women

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New Year's greetings postcard with portrait of Sigmund and Toni Feist with two unidentified boys (perhaps students at Feist's private school in Mainz) Portraits; Groups

Printed: Prosit Neujahr!; Handwritten dedication

Portrait of Gertrud (Trude) Guttmann Portraits Children

Born September 8, 1905, worked in a Jewish orphanage in Berlin and was deported to Auschwitz May 17, 1943, where she died.

Portrait of Gertrud (Trude) Guttmann (on right) with unidentified woman Portraits Groups Women

Born September 8, 1905, worked in a Jewish orphanage in Berlin and was deported to Auschwitz May 17, 1943, where she died.

Jacob Judey-Barosin with his wife Sonia nee Finkel after the end of World War II; Paris Portraits Couples

Early in 1943 the Barosins were arrested and sent to the deportation camp in Gurs. They were freed by French authorities and went into hiding until their liberation in 1944 in Paris. In 1947 they emigrated to the United States.

Reproduction of painted portrait of Marcus Elias Marcus, age 76. Portraits Men

Digital Image

Reproduction of painted portrait of Marcus Elias Marcus, age 76 Portraits Men

Digital Image

Gottschalk family on vacation in front of Kurhaus Brunig; Norderney, Germany.

From left to right: man with camera: Karl Gottschalk; sitting on stairs: Fritz Gottschalk, unidentified woman, Therese Gottschalk nee Molling, Hans Ludwig, Kurt Gottschalk, unidentified woman (maid?) and Elizabeth Gottschalk

Portrait of Arno Nadel holding a copy of Wagner's "Tannhauser"; Hamburg Portraits; Men

Handwritten on verso: "Hamburg den 27 11.17 Sontag"