Study on passive control of earth structure by introducing material anisotropy

通过在土壤结构中引入材料的各向异性和非均匀性，可以改变地基的刚度和强度，从而可以实现地震期间的预期变形模式。为了研究地基材料的基本特性，对干砂进行了空心圆柱循环剪切试验和室内小型模型试验。研究的重点是通过改变砂样的形成来研究结构各向异性，即，平床和斜床抗剪切。(1)在循环剪切试验中，无论砂土的相对密度如何，砂土的抗剪强度都是在试样呈倾斜坡形时达到最大。(2)模型试验结果表明，由倾斜斜坡组成的路堤对动力的抵抗能力最大。

By introducing material anisotropy and heterogeneity in soil structure, rigidity and strength of the ground can be modified so that intended deformation pattern during earthquakes may be achieved. To investigate basic characteristics of the ground material, dry sand is tested through hollow cylindrical cyclic shear tests and small model tests of embankments. The investigation is focused on studying structural anisotropy by varying formation of sand specimen, i.e., flat bed and inclined bed against shear. (1) From the cyclic shear tests, regardless of the relative density of sand, the maximum shear resistance of sand was obtained when the specimen is formed as dip slope. (2) After the model test, embankment constituted of dip slope showed maximum resistance to dynamic force.