Kei FUKUDA
Measuring Method of Small Deformation Characteristics by Combining Monotonic and Cyclic Loadings
Hirofumi TOYOTA
In order to design and construct foundations and underground structures rationally, it is necessary to conduct seismic response analysis in detail. To obtain accurate shear modulus of soil in small strain range is essential for that purpose. In this study, a new method, where the cyclic loading and the monotonic loading tests are combined to measure respectively the deformation modulus in extremely small strain range and the following strain range, was proposed to obtain the correct shear deformation modulus. Specimens are made with changing the angle of sedimentation direction using Toyoura sand and mica. Using those specimens, local small strain (LSS) tests of monotonic loading and cyclic loading, by which deformation modulus can be measured, and bender element (BE) tests were simultaneously conducted in the same specimens.
The knowledge obtained by this study is shown as follows:
1.The method to estimate the correct shear modulus was proposed by combining the cyclic loading and monotonic loading.
2.Using the method combining monotonic loading and cyclic loading, the strain level of real elastic area was able to be estimated more accurately than previous method. Then, it was found that the strain showing elastic was shrink as mica content in sand increased.
3.When mica was mixed in the sand, the elastic shear modulus increased with increasing angle of the sedimentation direction from the horizontal direction.
4.Anisotropy appeared more clearly in deformation characteristics in the soil as mica content increased.
Please use "previous botton" to return the previous page