Experimental Study on Seismic Compression of Chinese Loess under Cyclic Direct Simple Shear Testing

Seismic compression is the accumulation of contractive volumetric strains in unsaturated soil from earthquake shaking. For Chinese loess, behavior seismic extremely significant and has been recognized historical earthquakes. As a main technical mean, dynamic triaxial apparatus employed to study compressibility loess for long time. However, simple shear superior modeling real stress condition under earthquake. Meanwhile, could not measure strain precisely. A series cyclic tests are hereby performed on intact by new direct device developed Xi’an University Technology. The properties specimens analyzed combined conditions four water contents, vertical stresses, six strains. test results reveal that constantly compacted through process load-unloading much larger during loading half-cycle than unloading half-cycle. It found dependent upon density, content, confining pressure, (or stress), cycles. An empirical formula estimate increment per cycle expressed terms amplitude train, dry stress. Moreover, simplified evaluation procedure proposed probable settlements deposits subjected