Development of the methods of safety evaluation in land improvement facilities

土地改良设施安全评价方法的开发

• 批准号: 11556042
• 负责人: SHIMIZU Hideyoshi
• 金额: $ 2.37万
• 依托单位: Gifu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1999
• 资助国家: 日本
• 起止时间: 1999 至 2001
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11556042/
• 关键词: see page failure; two dimensional concentrated flow; fracture toughness; hydraculic fracturing; wedge insertion experiment; tensile 80ftening curve; probability of liguefaction; ground improvement; 縦亀裂; 破壊力学; 軸対称流; 破壊パラメータ; 水理破砕; Prismatic fa; see page failure; two dimensional concentrated flow; fracture toughness; hydraculic fracturing; wedge insertion experiment; tensile 80ftening curve; probability of liguefaction; ground improvement; 縦亀裂; 破壊力学; 軸対称流; 破壊パラメータ; 水理破砕; Prismatic fa

1. Safety evaluation in seepage flow The safety factor to the seepage failure of the foundation ground is defined by using the prismatic failure concept. The limit water head is analyzed in case- of two dimensional concentrated flow by varying the setting depth of sheet piles and the width of digging of ground. As a result, it is clarified that the smaller the width of digging and the deeper the setting depth is, the more decreasing the stability to the seepage becomes. In addition, it is also shown that the stability of the ground decreases when the ratio ofanisotopic:2. Hydraulic fracturing in fill material Considering the tensile failure generally occurs in the material when its character changes, soil is thought to cause a similar mannec Tri-axial compression tests are conducted on samples taken from a foundation in a small earth dam to examine the generation of the vertical crack with varying water content As a result, it is confirmed that a vertical crack occurs at a considerably … More early stage and lower water content in the experiment, so it suggests the hydraulic fracturing possibly occurs when reservoir water level rises.3. Safety evaluation in concrete structures The wedge insertion technique under two axial stresses is performed. In two types of concrete with river gravel and crushed stone, each breaking energy is obtained from the measurement of load-opening displacement As a result it is clarified that the breaking energy decreases compared with the case of the uniaxial stress, and the one with crushed stone is larger than that with the river gravel. In addition, the multi straight line approximation method is applied from the measurement data. It is also shown that the shape of softening curve differs each other, and the Young's moduli decrease, increasing in the compressive stress ratio.4. Reliability design of reclamationtlvke A calculation method of probability of liquefaction in reclamation dyke is proposed considering the spatial variability of soil parameters for the dynamic strength, N-values, median grain size, fine contents and the statistical characteristics of the earthquake occurrence. Using this method, the reliability design of the sand compaction piles is discussed for the ground improvement against the liquefaction. As a result, it is shown that the optimum sand replacement rate is determined so as to minimize the total cost Less

1。渗水流中的安全评估通过使用棱镜衰竭概念来定义基础理由的渗漏故障的安全因子。在二维浓缩流中分析极限水头，通过改变薄板桩的设置深度和地面挖掘宽度，来分析限值。结果，可以澄清的是，挖掘的宽度越小，设置深度越深，渗漏的稳定性就越降低。此外，还表明，当各向异性的比率：2时，地面的稳定性下降。考虑到拉伸材料的液压破裂，考虑到材料的特征变化时通常发生在材料中，土壤被认为会导致类似的MANNEC三轴压缩测试进行类似的样品对从小地球大坝中的基础中取出的样品进行样本，以检查垂直裂纹的产生，从而确认垂直的水分，并降低了垂直的阶段，并且在垂直的阶段中进行了较低的阶段，并在垂直的阶段进行了较低的阶段，并且在一个有利的阶段中，它会在一个较低的范围内进行，并具有更低的水平。当储层水位上升时，可能会破裂。3。混凝土结构中的安全评估在两个轴向应力下进行楔形插入技术。在两种具有河流重力和压碎石材的混凝土中，从测量荷载式位移的测量中获得了每种破裂能量，因此，与单轴应力相比，断裂能量的降低，而碎石碎石的情况比河流大于河流。另外，从测量数据中应用了多直线近似方法。还表明，软化曲线的形状彼此不同，而年轻的模量减小，压缩应力比增加。4。填海tlvke的可靠性设计考虑到土壤参数在动态强度，N值，中位晶粒尺寸，细晶粒尺寸和地震发生的统计特征的空间变化中，提出了一种恢复堤的概率的计算方法。使用这种方法，讨论了沙子压实桩的可靠性设计，以改善液化的地面。结果，确定了最佳沙子替换率，以最大程度地减少总成本