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

该仪器将支持系统的调查的性质和性能的建造土壤膨润土泥浆沟截水墙的原位地质环境遏制。本研究的总体目标是弥合我们对土-膨润土防渗墙行为的理解之间的差距，这种理解传统上基于对模型回填土的实验室研究，而实际防渗墙在现场尺度上的行为。已选择的仪器提供最大的效益，为研究领域规模的性能的以下关键方面：（1）现场规模的变化，土壤膨润土泥浆沟防渗墙的水力传导性;（2）土壤膨润土泥浆沟防渗墙在其原位环境中的可持续性;（3）土壤膨润土泥浆沟防渗墙的原位污染物传输特性。设备和附件将与巴克内尔大学现有的大量仪器组合使用，以执行现场和实验室测试的综合计划，以评估防渗墙的深度、纵向位置和时间特性和性能。该设备包括一台阿克钻井公司的履带式钻机，该钻机能够进行空心杆钻井、旋转冲洗钻井、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，包括我们现有的压锥膨胀计、叶片剪切仪、马尔凯蒂膨胀计和土压力传感器。该设备还包括空心钻、钻杆、钻头、用于标准贯入试验的对开式筒取样器和用于回收相对未受扰动的土壤-膨润土样品以供随后在实验室进行评价的薄壁活塞取样器。该仪器支持的研究活动将提高所有巴克内尔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。巴克内尔还致力于在一个新的外展计划中使用仪器，该计划针对当地高中生，包括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，并与目前在国家一级正在进行的努力，以解决知识差距和评估与工程屏障系统的性能的预测，测量和监测相关的当前方法相一致。PI将通过向技术期刊提交论文并在适当的技术会议上展示研究结果，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.