Development of vertical and horizontal disk transducers for wave velocity measurements in a large rectangular specimen
Development of vertical and horizontal disk transducers for wave velocity measurements in a large rectangular specimen
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开发用于大型矩形样本波速测量的垂直和水平圆盘传感器
DOI：
10.1051/e3sconf/20199202001
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发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Takeshi Sato
中科院分区：
文献类型：
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作者：
Troyee Tanu Dutta; Masahide Otsubo; Reiko Kuwano; Takeshi Sato
对于承受静、动载荷的结构的精确设计，弹性波速度和小应变刚度是必不可少的参数。已经开发了许多技术来估计岩土材料的波速。目前广泛采用的弯曲单元是一种侵入性的单元，不适用于粗颗粒材料的波速测量。在目前的研究中，新的设计配置的圆盘传感器已被引入到测量的垂直和水平波速度的粗颗粒土考虑多方向振荡的传播波。在一台大型三轴仪上，采用压缩型和剪切型两种单元的创新布置，测定了236×236×500 mm矩形试件的波速。所述材料为丰浦砂（D50= 0.24 mm）和大矶砾石（D50= 11.8 mm）。这种布置使得能够测量九种类型的波速，从而量化刚度各向异性。对于Oiso砾石，剪切波和压缩波的水平波速度均大于垂直波速度。对于丰浦砂，剪切波速度在水平传播方向上较高，而从水平和垂直方向上观察到相似的压缩波速度。
For the accurate design of structures subjected to both static and dynamic loadings, elastic wave velocity and small strain stiffness are essential parameters. Numerous techniques have been developed to estimate wave velocities of geomaterials. Bender elements which are widely adopted for wave velocity measurements are invasive in nature and are not suitable for coarse-grained materials. In the present study, new design configuration of disk transducer has been introduced to measure both vertical and horizontal wave velocities for coarse granular soils considering multidirectional oscillation of propagating waves. An innovative arrangement of both compression and shear type elements has been installed in a large-sized triaxial apparatus having rectangular specimens of size 236×236×500 mm to assess the wave velocities. The materials described are Toyoura sand (D50= 0.24 mm) and Oiso gravel (D50= 11.8 mm). This arrangement enables measurements of nine types of wave velocities, and thus the stiffness anisotropy to be quantified. For Oiso gravel, horizontal wave velocities are greater than vertical wave velocities for both shear and compression waves. For Toyoura sand, shear wave velocities are higher in horizontal direction of propagation, whereas similar compression wave velocities are observed from both horizontal and vertical directions.