SMALL-STRAIN STIFFNESS AND DAMPING OF LOESS IN CHINA

Abstract eng:
Loess Plateau of China is one of the most representative geomorphologic regions for loess around the world due to the deep covering layer and wide distribution area. Many catastrophic disasters induced by earthquake had been identified in this area. This study examined systematically the small-strain stiffness and damping of loess in Lanzhou, Northwest of China, through the laboratory resonant column (RC) test method and the field down-hole test method. On the basis of the analyses of test results, it was found that the smallstrain shear modulus G0 of loess was more sensitive to water content than the small-strain damping Dmin. A linear relationship between log(G 0) and log(σ′m) was observed for loess, while the corresponding slope in log-log coordinates decreased with water content increasing. Similarly, log(Dmin) decreased linearly with log(σ′m) as well. G0 of undisturbed loess was much higher than reconstituted ones at low water content and this difference could be negligible for saturated loess. The similar phenomenon was observed for D min too. The pattern of correlation between G 0 and σ′m for loess accorded well with the findings in literature but in the present study, higher values of G 0 could be expected, which may be ascribed to the different device used. In comparison with the down-hole test results, there was a good agreement between RC results and laboratory results for G 0 of loess. Finally, the correlations between G/G0 and γ/γ0.85 could be normalized perfectly for Lanzhou loess, irrespective of water content and confining pressure.

• Export as: BibTeX | MARC | MARCXML | DC | EndNote | NLM | RefWorks
• Add to your basket