00069935

open access

Version of Record

チュウクウ ネジリ シケン オ モチイタ エキジョウカ カテイ ニオケル ケイシャ ノ コウフク AE トクセイ ノ ケンキュウ

Yielding and Acoustic Emission Characteristics of Silica Sand during Liquefaction Testing Using Hollow Cylinder Torsional Test Apparatus

Japanese (日本語)

神戸大学都市安全研究センター研究報告

5

61-69

神戸大学都市安全研究センター

2001-03

2007-04-12

In this paper, the Yielding and acoustic emission characteristics of silica sand were studied by performing a series of undrained cyclic loadings tests using hollow cylinder torsional test apparatus.In the study, the performance of test apparatus was also examined by setting up the hollow cylinder specimen using a specially designed sand raining equipment. The equipment was to produce a specimen with its bedding plane of soil particle being nearly horizontal as much as possible. By changing the rotational directions of undrained shear both in monotonic and cyclic modes, it was found that the specimen has its bedding place nearly horizontal but that improvement are needed in the cyclic loading procedure so that time duration of loading being equal in both rotational directions. The yielding characteristics of silica sand during undrained cyclic loading showed that the yield locus changes its shape and size with the increases of cyclic loading. The yield locus skews its shape towards the direction of previous undrained shear and its size decrease as the excess pore pressure increases. Thus the yield locus changes its shape and size as if the soil behaves as an anisotropic hardening plastic model. The yielding behavior was also examined by performing triaxial compression and extension loadings after the undrained cyclic shear. It is also found that the yield stress changes its magnitude as the direction of subsequent shear is changed from the horizontal to the inclined direction with respect to the horizontal bedding plane. Such aspect of yielding behavior during the liquefaction test needs to be studied further.

紀要論文