Optical Characterization of Intrinsic Properties and Fabric of Coarse-Grained Soils

粗粒土固有性质和结构的光学表征

• 批准号: 1300010
• 负责人: Roman Hryciw
• 金额: $ 39.82万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1300010&HistoricalAwards=false
• 关键词: Optical; Characterization; Intrinsic; Properties; Fabric

This research project aims to bring intrinsic soil properties including particle shape, angularity and surface roughness as well as soil fabric into wider common practice and research through development of optical methods for rapidly quantifying them at no extra time or cost than required to develop grain size distributions. To accomplish this, a sediment imaging (Sedimaging) system will be used for particles smaller than 2 mm and a translucent segregation table (TST) will be used for the coarser fraction. Both systems rapidly sort a statistically representative soil specimen prior to image capture. Most importantly, although the particles are sorted, they need not be separated from contact with each other. This allows for a large number of particles to be rapidly evaluated. Furthermore, because of the recent introduction of high resolution cameras approaching 40 MPix, only one high resolution photograph is needed in each test. The major research tasks include: development of advanced Sedimaging and TST systems; segmentation of particles from images of 3D assemblies and selection of segmented particles for shape analysis; quantification of particle shape of segmented particles; comparison of particle Roundness and Sphericity obtained from Sedimaging and TST images with traditionally obtained (ex-situ) measures; determination of typical shape distributions as a function of particle size within specimens; establishing minimum particle size for which shape descriptors should be determined; evaluation of surface roughness by corner detection methods; development of a wavelet-based index for soil fabric potential; performance of laboratory tests for confirmation of previous findings on particle shape and fabric effects; and extension of methods to images collected in-situ by the vision cone penetrometer.Broader impacts will be addressed on three distinct fronts. First, the Sedimaging and TST tests will become regular and distinct laboratory exercises in the undergraduate Introductory Geotechnical Engineering course at the University of Michigan. This will demonstrate that research findings and developments do transfer into engineering practice. Secondly, working with the University of Michigan Ergonomics Research Center and three local sand and aggregate producers, the geotechnical laboratory work environment will be evaluated with emphasis on improvements created by the Sedimaging and TST systems that relieve workers from the tedium of particle size and aspect ratio testing. Finally, the impediments to technology transfer (from research to practice) in geotechnical and geoenvironmental engineering will be investigated and documented by geotechnical specialty area (i.e soil improvement, deep foundations, retaining structures, etc.).

该研究项目旨在通过开发光学方法将土壤固有特性（包括颗粒形状，棱角性和表面粗糙度以及土壤结构）纳入更广泛的常规实践和研究中，以便在不需要开发粒度分布所需的额外时间或成本的情况下快速量化它们。 为此，将对小于2 mm的颗粒使用沉积物成像（Sedimaging）系统，并对较粗的部分使用半透明分离台（TST）。 这两个系统在图像捕获之前快速地对具有统计学代表性的土壤样本进行分类。 最重要的是，尽管颗粒被分选，但它们不需要从彼此接触中分离。 这允许快速评估大量颗粒。 此外，由于最近引入了接近40 MPix的高分辨率相机，因此每次测试仅需要一张高分辨率照片。 主要研究任务包括：开发先进的Sedimaging和TST系统;从三维组件图像中分割颗粒并选择分割颗粒进行形状分析;量化分割颗粒的颗粒形状;将从Sedimaging和TST图像获得的颗粒圆度和球度与传统获得的（非原位）测量值进行比较;确定典型的形状分布作为样本内的颗粒大小的函数;确定形状描述符应确定的最小颗粒大小;通过拐角检测方法评估表面粗糙度;开发基于小波的土壤结构潜力指数;进行实验室测试，以确认以前关于颗粒形状和织物效应的研究结果;将方法扩大到使用视锥光度计现场收集的图像。首先，Sedimaging和TST测试将成为密歇根大学本科生岩土工程导论课程中定期和独特的实验室练习。 这将证明研究成果和发展确实转移到工程实践中。 其次，与密歇根大学人类工程学研究中心和三个当地的沙子和骨料生产商合作，将对岩土实验室的工作环境进行评估，重点是Sedimaging和TST系统所带来的改善，这些系统将工人从颗粒尺寸和纵横比测试的繁琐中解脱出来。 最后，将按岩土专业领域（即土壤改良、深基础、挡土结构等）调查和记录岩土和地质环境工程技术转让（从研究到实践）的障碍。