Engineering geological stratigraphy and physical properties of the loess in eastern Gansu

For the thick loess formation, a reasonable division of the loess strata in engineering geological aspects is the basic issue for site assessment of engineering geology. Therefore, a well of 100 m deep, which was dug in 1960's for fetching water and now has been abandoned, are logged in detail along the well wall and along the outcrop below the well bottom. Referring the standard loess profiles, the paleomagenetic polarity, lithological stratum and geological period of the logged profile are determined. Samples were collected at a vertical interval of 0.5 m at the profile and used to measure the particle size and basic physical property indexes. Based on the logging, clay content and the physical properties, the whole loess profile is divided into 16 engineering geological strata. Because of the wind-blown origin, the loess properties of a stratum in a deposit environment is relative uniform, so the division strategy can provide a reference for the whole loess plateau.