MRI: Acquisition of Drilling Rig and Accessories for In Situ Investigations of Slurry Trench Cutoff Walls

该仪器将支持系统地调查用于原位地质环境围护的土质-膨润土泥浆沟槽防渗墙的特性和性能。本研究的总体目标是弥合我们对土壤-膨润土防渗墙行为的理解之间的差距，传统上基于模型回填的实验室研究与现实世界防渗墙在现场尺度上的行为。选择该仪器是为了最大限度地提高现场尺度性能的以下关键方面的研究效益：(1)土壤-膨润土泥浆沟防渗墙水力导电性的现场尺度变异性；(2)土-膨润土浆壕防渗墙在原位环境下的可持续性；(3)土-膨润土浆料沟槽防渗墙的原位污染物迁移特性。该设备和附件将与巴克内尔大学现有的大量仪器相结合，执行一个全面的现场和实验室测试项目，以评估截止墙的特性和性能，包括深度、纵向位置和时间。该设备包括一台Acker Drill公司的履带式钻机，能够进行空心杆钻井、旋转洗井、取样工具的部署和样品的回收，以及现场测试设备的部署和操作，包括我们现有的压电锥贯入仪、叶片剪切仪、Marchetti膨胀仪和土压力仪。该设备还包括空心杆螺旋钻、钻杆、钻头、用于标准渗透测试的分桶取样器，以及用于回收相对未受干扰的土壤-膨润土样品的薄壁活塞取样器，以便随后在实验室进行评估。该仪器支持的研究活动将增加所有巴克内尔大学本科生的研究和教育机会，包括来自代表性不足群体的学生。巴克内尔大学还致力于在一项针对当地高中生的新拓展计划中使用该仪器，包括那些邻近经济紧张的煤炭地区的学生。此外，拟议的研究是及时的，与目前在国家层面上正在进行的努力是一致的，以解决知识差距和评估与工程屏障系统性能的预测、测量和监测相关的当前方法。pi将通过向技术期刊提交论文和在适当的技术会议上介绍研究结果，积极寻求传播这项研究的结果。

The instrumentation will support the systematic investigation of the properties and performance of constructed soil-bentonite slurry trench cutoff walls for in situ geoenvironmental containment. The overall goal of this research is to bridge the gap between our understanding of the behavior of soil-bentonite cutoff walls traditionally based on laboratory studies on model backfills to the behavior of real-world cutoff walls at the field scale. The instrumentation has been selected to provide maximum benefit for research into the following critical aspects of field-scale performance: (1) field scale variability in the hydraulic conductivity of soil-bentonite slurry trench cutoff walls; (2) sustainability of soil-bentonite slurry trench cutoff walls in their in situ environment; and (3) in situ contaminant transport properties of soil-bentonite slurry trench cutoff walls. The equipment and accessories will be used, in combination with the vast array of instrumentation already available at Bucknell University, to perform a comprehensive program of in situ and laboratory testing to evaluate cutoff wall properties and performance with respect to depth, longitudinal position, and time. The equipment includes an Acker Drill Company track-mounted drilling rig with capability for hollow-stem drilling, rotary wash drilling, deployment of sampling tools and recovery of samples, and deployment and operation of in situ test equipment including our existing piezocone penetrometer, vane shear, Marchetti Dilatometer, and earth pressure cells. The equipment also includes hollow stem augers, drilling rods, drilling bits, a split-barrel sampler for Standard Penetration Testing, and a thin-walled piston sampler for recovery of relatively undisturbed soil-bentonite specimens for subsequent evaluation in the laboratory. The research activities supported by this instrumentation will enhance the research and educational opportunities for all Bucknell undergraduate students, including students from underrepresented groups. Bucknell also is committed to using the instrumentation in a new outreach program targeting local high school students, including those in the adjacent economically stressed coal region. In addition, the proposed research is timely and consistent with efforts currently underway at the national level to address knowledge gaps and assess current methodologies associated with prediction, measurement, and monitoring of the performance of engineered barrier systems. The PIs will actively seek to disseminate the results of this research by submitting papers to technical journals and presenting the findings at appropriate technical conferences.