Permeability Measurements from Routine On-the-fly CPT Sounding: Validation Against High-Quality Vis-CPT and In Situ Permeability Measurements

圆锥贯入仪测试(CPT)是一种快速、连续地测定土体强度、变形能力、密度、应力状态和循环移动性的有用工具。尽管不断改进用于确定这些土壤参数的锥度测量指标，但还没有比较有效的方法来确定原位渗透率的连续剖面。考虑到环境服务行业需要快速和精确地重建渗透性区域，以设计污染物控制和补救系统，这是特别有先见之明的。该项目将评估直接根据现场记录的常规测量的锥体测深指标确定现场渗透率剖面的可能性。将建立现场渗透率与渗透引起的孔隙压力、锥体端部承压和套筒摩擦之间的预期相关性，并用高质量的现场数据进行验证，这些数据将在本研究中收集。具体地说，我们将：制造现场锥形可展开渗透率计，以检测渗透仪诱导的干扰对测量的渗透率大小的影响。将这些渗透率计与VISUAL-CPT同时部署，以收集独特的集合数据，将CPT探测指标与同一位置测量的渗透率和目测到的细微尺度土壤质地联系起来。以异常高的空间分辨率测量渗透率大小，并将其与来自VISUAL-CPT的土壤质地的直接目视观测相关联。应用集合数据来建立动态CPT测深指标和渗透率之间的相关性。开发和改进尖端过程区机械和流体传输行为的模型，尊重现场观测数据，并解释观测关联。与渗透率的独立现场测量同处一处的CPT测深很少。这项研究将补充这些数据，通过增量渗透率测试对渗透率测量施加异常约束，并通过VISUAL-CPT直观识别土壤质地，并通过直接使用模型开发和量纲分析来开发和探索CPT-渗透率相关性。这项工作解决了一个尚未解决的问题--即快速确定现场渗透率剖面。独一无二的是，这项研究假设并提供了初步评估，以严格使用CPT测深数据来确定渗透率剖面。这些预期关系的保真度将使用异常严格的现场测量来探索和精炼。如果得到确认，这些建议的相关性将能够使用标准圆锥度量快速和连续地分析土壤渗透性，这在目前是不可能的。渗透率剖面随后可以根据世界范围内丰富的可用压电锥数据进行后验评估。结合孔隙度和结构的现场视觉识别以及污染物浓度和流体饱和度的直接测量，这些集合技术将提供一个重要的工具，以确定在相关空间尺度上自由相和水组分在松散的多孔介质中的运移速率。这项研究将涉及研究生的培训，研究结果将在课堂、报告和出版物中传播。

Cone penetrometer testing (CPT) is a valuable tool for the rapid and continuous profiling of strength, deformability, density, stress-state, and cyclic mobility of soils. Despite the continuous refinement of cone-measured metrics for the determination of these soil parameters, no comparably validated method exists to determine continuous profiles of in situ permeability. This is especially prescient given the needs of the environmental services industry for the rapid and precise reconstruction of permeability fields for the design of contaminant containment and remediation systems. This project will evaluate the potential to determine in situ permeability profiles directly from routinely measured cone sounding metrics recorded on-the-fly. Prospective correlations between in situ field-scale permeabilities and penetration-induced pore pressures, cone end-bearing, and sleeve-friction will be developed and verified against high-quality field data, to be gathered in this study. Specifically, we will:Fabricate in situ cone-deployable permeameters that examine the effects of penetrometer-induced disturbance on measured permeability magnitudes. Deploy these permeameters concurrently with the visual-CPT to gather unique ensemble data that link CPT sounding metrics with co-located measured permeabilities and visually observed fine-scale soil texture. Measure permeability magnitudes at unusually high spatial resolution and correlate these with direct visual observations of soil texture derived from the visual-CPT. Apply the ensemble data to establish correlations between on-the-fly CPT sounding metrics and permeabilities. And, Develop and refine models for mechanical and fluid transport behavior in the tip process zone that honor observed data in situ, and explain observed correlations.CPT soundings, co-located with independent in situ measurements of permeability are meager. This study will add to these data, apply unusual constraint to permeability measurements through incremental permeability testing and visual identification of soil texture via the visual-CPT, and develop and explore CPT-permeability correlations through the directed use of model development and dimensional analysis. This work addresses an unresolved problem - that of rapidly determining in situ permeability profiles. Uniquely, this study hypothesizes, and provides preliminary evaluations, for the rigorous use of CPT sounding data to determine permeability profiles. The fidelity of these prospective relationships will be explored and refined using unusually well-constrained in situ measurements. If affirmed, these proposed correlations will enable rapid and continuous profiling of soil permeabilities using standard cone metrics, that is currently not possible. Permeability profiles may subsequently be evaluated a posteriori from the wealth of piezocone data available, worldwide. Combined with the in situ visual identification of porosities and texture, and direct measurements of contaminant concentrations and fluid saturations, these ensemble techniques will provide an important tool to determine rates of migration of free-phase and aqueous components in unconsolidated porous media at spatial scales of relevance. This study will involve the training of graduate students and the findings will be disseminated in classes, presentations, and through publications.