Electrical Resistivity Cone Penetration Testing at the Treasure Island National Geotechnical Experimentation Site

本项目旨在评估一种新的现场技术，该技术将在加利福尼亚州旧金山的金银岛国家岩土试验基地（NGES）使用；目的是评估该地点的原地空隙率和土壤结构。该技术包括垂直和水平测量土壤电阻率，使用两个特殊仪器的压电锥同时推入地面。该方法由意大利电力局水力与结构研究中心（ENEL-CRIS）的一个研究小组设计，可以在每个探头的垂直方向和两个探头之间的水平方向上连续测量电阻率。使用地下水和土壤样本的结果是根据在不同密度下重建的样本的实验室测试进行校准的。这种现场技术允许对大量土壤进行测试，避免了设备周围不必要的重塑效应。由于难以获得未受干扰的原位样品用于砂土的实验室测试，这种原位方法在提供预测地震荷载作用下土壤动力响应所需的参数方面显示出巨大的潜力。这种原位电阻率锥体穿透试验的潜力，为评估天然砂土的地震反应提供了新的土壤参数，将推动最先进的技术，并允许快速和经济有效的方法来表征无黏性土壤。

9712852 Benoit This project addresses the evaluation of a novel field technique to be used at the Treasure Island National Geotechnical Experimentation Site (NGES) in San Francisco, California; the objective being to evaluate the insitu void ratio and soil fabric at this site. This technique consists of vertical and horizontal measurements of soil electrical resistivity using two specially instrumented piezocones simultaneously pushed into the ground. The method, designed by a research group in Italy at the Hydraulic and Structural Research Center of the Italian Electricity Agency (ENEL-CRIS), allows continuous electrical resistivity measurements in the vertical direction for each probe and in the horizontal direction between the two probes. The results, using groundwater and soil samples, are calibrated against laboratory tests on samples reconstituted at various densities. This field technique permits a large volume of soil to be tested, avoiding the unwanted remolding effects surrounding the device. Because of the difficulty in obtaining undisturbed insitu samples for laboratory testing of sands, this insitu method shows great potential in providing parameters needed for the prediction of the dynamic response of soils subjected to earthquake loading. The potential of this insitu electrical resistivity cone penetration test to provide new soil parameters to evaluate the earthquake response of natural sand deposits will advance the state-of-the-art and permit rapid and cost- effective methods for characterization of cohesionless soils.