Reset of Secondary Compression Clock for Peat by Cyclic Straining

Abstract

This is the final authors’ version. We are not permitted to 2 upload the typeset version due to copyright law. The 3 publisher’s version of the manuscript may be found at the 4 following URL: http://ascelibrary.org/doi/abs/10.1061/%28ASCE 6 %29GT.1943-5606.0001286 Reset of Secondary Compression Clock for Peat by 9 Cyclic Straining 11 Ali Shafiee, S.M.ASCE 1 ; Jonathan P. Stewart, F.ASCE 2 ; and Scott J. Brandenberg, M.ASCE 3 13 Peat soils are widely recognized as being highly compressible. The virgin compression index, C c , 14 is often 5 to 20 times larger than for soft clay, and the secondary compression index, C  , is in the 15 range of (0.05 to 0.07)C c , which is also higher than for typical clays (Mesri and Ajlouni, 2007). 16 Secondary compression is often the dominant source of volume change in peat over time. The 17 compressibility of peat has typically been investigated due to total stress increase imposed by 18 static loads. This manuscript discusses time-dependent volumetric strains due to cyclic shear 19 straining. A multi-stage cyclic simple shear laboratory testing program using the UCLA digitally 21 controlled direct simple shear device (Duku et al. 2007), modified for constant height testing, 1 1 PhD Candidate, Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095. 3 2 Professor and Chair, Department of Civil and Environmental Engineering, University of California, Los Angeles, CA 90095. 5 3 Associate Professor and Vice Chair, Department of Civil and Environmental Engineering, University of California, Los Angeles, CA