EAGER: Shaking Table Testing to Evaluate Effectiveness of Vertical Drains for Liquefaction Mitigation

这项探索性研究（EAGER）的早期概念资助研究将在布法罗的NEES大学使用层流剪切箱和振动台系统在可液化砂中进行全尺寸垂直排水试验。 这些测试旨在评估垂直排水沟防止液化和限制相关沉降和侧向变形的能力。 与传统的致密化缓解策略相比，排水理论上可以减少50%至75%的成本和处理时间。 此外，消除了与后处理验证测试相关的成本和时间延迟。 不幸的是，没有全尺寸的排水装置受到地震引起的地面运动。 这种在全尺寸条件下的性能数据的缺乏是扩大这种技术的使用的主要障碍，因为工程师不愿意冒险采用未经测试的系统。 本研究中的测试将涉及水平地面和倾斜地面（2º坡度），并将与目前正在进行的先前资助的NEESR研究相结合，以便在没有排水的情况下进行控制测试。 砂将以约40%的相对密度进行水力浇筑。 监测孔隙水压力、沉降、横向位移和加速度的传感器将允许直接比较有排水管和无排水管的性能。 与完全独立的研究相比，这种合作方法将大大降低研究成本。 此外，还将提供排水管土壤剖面性能与涉及桩的后续试验之间的比较。 此外，将使用数值模型对试验结果进行详细分析，作为配套FHWA集合基金研究的一部分。

This Early-Concept Grant for Exploratory Research (EAGER)research study will conduct full-scale tests with vertical drains in liquefiable sand using the laminar shear box and shaking table system at NEES-Univ. of Buffalo. These tests are designed to evaluate the ability of vertical drains to prevent liquefaction and limit associated settlement and lateral deformation. In comparison with conventional densification mitigation strategies, drainage can theoretically reduce cost and treatment times by 50% to 75%. In addition, the cost and time delay associated with post-treatment verification testing is eliminated. Unfortunately, no full-scale drain installation has been subjected to earthquake induced ground motions. This lack of performance data under full-scale conditions is a major impediment to expanding the use of this technique as engineers are reluctant to take the risk of employing an untested system. Tests in this study will involve both level ground and sloping ground (2º slope) and will be integrated with a previously funded NEESR study currently underway so that the control tests without drains will already be available. The sand will be hydraulically placed at a relative density of about 40%. Sensors to monitor pore water pressure, settlement, lateral displacement, and acceleration will allow direct comparisons of performance with and without drains. This collaborative approach will significantly reduce the cost of the study in comparison to a completely independent study. In addition, it will provide a comparison between the performance of the soil profile with drains relative to subsequent tests where piles will be involved. Furthermore, detailed analyses of the test results using numerical models will be performed as part of a companion FHWA pooled fund study.