Comparison between the Strengths of Undisturbed and Reconstituted Sands from Niigata, Japan.

摘要

Laboratory cyclic triaxial strength tests were performed on undisturbed and reconstituted sand specimens from Niigata, Japan, to help evaluate how tests on reconstituted specimens can evaluate the cyclic strength of insitu cohesionless soils. Undisturbed specimens obtained from careful sampling with a large diameter sampler appeared to be of high quality, yet cyclic triaxial strengths measured in the laboratory were not particularly high. Specimens failed at cyclic stress ratios of about 0.15 at 20 stress cycles. Reconstituted specimens prepared by pluviating sand through water were weaker than undisturbed specimens by factors of about 1.22 to 1.16. The cyclic strength difference between reconstituted specimens prepared by pluviating sand through water and reconstituted specimens prepared by moist tamping was about the same as the strength difference between reconstituted specimens prepared by pluviating sand through water and undisturbed field specimens. Thus sand reconstitution techniques such as wet tamping may better model insitu soil behavior than reconstitution techniques such as pluviation for sands such as these at Niigata, Japan. (Author)