Failure Behavior of Soil Structures by Centrifuge Model Test

利用离心机对自重固结作用下模型粘土地基的变形特性和模型土结构破坏行为进行了研究。结果，得到了如下结果1.通过软土自重固结试验，研究了自重和层厚变化对软土填海地基和海床沉降点的变形和超孔压性状的影响。采用含水率为135~200%的高岭土，在单次排水条件下，施加50g离心力加速进行固结。地表沉降量和底部超孔压的实测结果与Mikasa提出的自重固结微分方程的分析结果相吻合。模型层状边坡的破坏试验离心机模型试验和基于变分方法的稳定性分析是…更多的是用来研究边坡的破坏特征。从均匀模型出发，通过对观测结果的反分析，我们展示了材料强度是如何被动员到滑动面上的。通过对夹有粘土层的压实砂质边坡的试验，明确了粘土层的埋深、倾角、位置等因素对破坏特征的影响，并通过简单的稳定性分析对其进行了较好的模拟。饱和粘土地基的局部排水特性利用离心机对模型粘土地基施加气压或水压，考察不同施加速度和不同地基刚度对地基强度特性的影响。采用参数反分析和土-背分析中的平面应变单元试验确定数值分析所需的参数。为了了解土体单元的变形和强度特性，进行了平面应变单元试验。较少

Using the centrifuge apparatus, we study the deformation behavior of model clay ground due to self-weight consolidation and the behavior of model soil structures leading to failure. As a result, The following results are obtained.1. Self-Weight Consolidation Test of Soft ClayCentrifuge self-weight consolidation tests are conducted to evaluate the behavior of deformation and excess pore pressure for a soft reclamation ground and sea-bed depoint, which is affected by self-weight and varying layer depth. Kaolin clay prepared with water content of 135-200% is used for consolidation by applying 50g centrifugal acceleration in the single drained condition. The measured results of settlement at the surface and excess pore pressure at the bottom are shown to agree with the analytical results of the differential equation for self-weight consolidation proposed by Mikasa.2. Failure Test of Model Layered SlopesThe centrifuge model test and a stability analysis based on the variational approach are … More employed to investigate the failure characteristics of the slope. From the homogeneous models, we show how the material strength is mobilized on the slip surface by back analysis of the observed results. From the experiments of a compacted sand slope which sandwiches a clay layer, we make clear the failure characteristics affected by the way how the clay layer is deep, inclined and where it is located, and those are mostly simulated well by a simple stability analysis.3. Partially Drained Behavior of Saturated Clay FoundationUsing the centrifuge apparatus, a model clay foundation is locally applied by air pressure or water pressure to examine the strength characteristics mobilized by the different applying speed and the different stiffness of the foundation.4. Back analysis of Parameters and Plane Strain Element Test of SoilBack analysis is applied to identify the parameters necessary for the numerical analyses. The Plane strain element test is conducted to understand the deformation and strength characteristics of soil elements. Less