1993 Fiscal Year Final Research Report Summary
Collapse Analysis of Underground Structures by Computational Mechanics
| Project/Area Number |
03660252
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
農業土木
|
|---|
| Research Institution | Miji University |
|---|
Principal Investigator |
TANAKA Tadatsugu Faculty of Agriculture, Department of Agriculture, Professor, 農学部, 教授 (70167500)
|
|---|
| Project Period (FY) |
1991 – 1993
|
| Keywords | Model Test / Underground Structures / Collapse / Finite Deformation Analysis / Scale Effect / Progressive Failure / Shear Band / Anisotoropic Hardening |
|---|
| Research Abstract |
1. Models of arch-type underground structures are prepared using a thin plastic film and the air-pluviated Toyoura sand. The pressure is applied on the sand layr by an air-bag and collapse loads of the underground arches are obtained. The finite element analyzes of the model underground structures are carried out. In the analyzes, a constitutive equation including shear band effects for the sand layr is used and finite deformation analysis is applied. The comparable results are obtained but in the analyzes the collapse loads are very sensitive to the conditions of end portion of the arches i.e., completely fixed or partially fixed.
2. Scale effects of the soil structures such as bearing capacity of footings and pullout resistance of anchors, are currently investigate using centrifuge model tests. The scale effects are considered to be due to the reduction of the internal friction and progressive failure accompanying the shear banding. The effect of the progressive failure is not properly taken into account only using centrifuge model tests. In this study, we clarified that the sacle effects are depend on particle size of the sand both by the experimental observations under normal gravity conditions and the finite element analysis with the constitutive equation including the shear band effect.
3. The earthquake-resistant design of the soil structures needs dynamic response analysis which take into account the failures. The fill-type model is prepared using the Toyoura sand and dynamic load is applied by earthquake simulator. The finite element analysis is carried out and compared to the model experimental results. The consistent results are obtained by the constitutive equation with a anisotropic hardening and the shear banding.
|
