Influence of Sample Holding Time on the Fluvial Erosion of Remolded Cohesive Soils

Despite extensive research on bridge scour and channel erosion, predicting the occurrence and rate of cohesive soil erosion remains problematic. The lack of standard procedures for sample preparation and testing has resulted in wide variations in testing conditions, devices, and soil properties across erosion studies, ultimately preventing the synthesis of cohesive erosion studies and progress in understanding the fundamental processes of cohesive soil erosion. Therefore, the objective of this study was to evaluate the effects of sample holding time on the fluvial erosion of remolded cohesive soils to inform the development of standard testing procedures. Three different soils (fat clay, lean clay, and silty sand) were tested in a flume following multiple sample holding times. Results show that erosion rate can decrease 85-95% within 72 h of soil wetting, depending on clay mineralogy. These results highlight the importance of maintaining a consistent soil preparation protocol in cohesive soil erosion experiments and reporting soil sample holding durations when conducting cohesive erosion research using remolded samples

Geotechnical aspects of reconnaissance findings after 2020 January 24th, M6.8 Sivrice–Elazig–Turkey earthquake

© 2021, The Author(s), under exclusive licence to Springer Nature B.V.On January 24, 2020, Sivrice–Elazig–Turkey earthquake occurred along the East Anatolian Fault Zone. The moment magnitude of the event was reported as 6.8. This paper documents reconnaissance findings performed immediately after the event. Investigated sites namely, Lake Hazar shores, Karakaya Dam Reservoir–Euphrates River shores, Malatya–Battalgazi district and its villages, and Elazig Downtown are predicted to be shaken by rock peak ground acceleration, PGAVS30=1100 m/s, levels of 0.12–0.42 g, 0.05–0.11 g, 0.05 g, and 0.08 g respectively. The documented geotechnical field performances vary from widespread liquefaction-induced sand boils and lateral spreading, to no signs of surface manifestations of permanent ground deformations or soil liquefaction. In Battalgazi district and Elazig Downtown, the foundation performances vary from no signs of permanent ground deformations to 1–3 cm settlements, and 1–2 cm lateral movements. Additionally, the hydraulic structures inspected are estimated to be shaken by PGAVS30=1100 m/s levels of 0.03–0.23 g. Other than a minor longitudinal cracking along a limited section along the crest of a homogeneous earthfill dam, no apparent signs of permanent ground deformations were reported. Last but not least, a number of rock falls were mapped, based on back analyses of which probable peak ground velocities at these rockfall sites were speculated