Enhancing SPT data by reducing uncertainty in energy corrections and leveraging input energy for stratigraphic interpretation

标准贯入试验（SPT）是世界上最常用的调查工具之一，用于了解特定土壤的特性（例如变形性，强度），用于设计涉及破土动工的建筑项目。SPT包括将采样器打入地面：将采样器驱动特定距离所需的锤击次数决定了设计的土壤参数。SPT的局限性主要与不同的SPT系统对每次锤击施加不同的能量（即力）有关。这种能量损失导致使用SPT关联土壤参数时存在很大的不确定性，从而影响土方工程的安全设计。尽管研究人员已经测量了许多系统的SPT能量损失，但能量修正的范围使其在其他系统中的应用不确定。拟议的研究旨在加强在加拿大西部的几个项目中使用的SPT系统。该SPT系统使用自动锤滴，可重复测量每次锤击的能量。该研究将提供能量损失的测量和系统特定的能量校正，可用于加拿大的其他项目。这些能量测量将根据输送的能量量化系统的可变性，提供了一种在SPT结果中计算系统不确定性的方法。系统特有的不确定性将与广泛使用的能量修正相关的不确定性进行比较，以测量SPT结果置信度的改进。此外，本研究建议评估SPT传递的能量（即吹入地面）作为地面地震和声学层析成像源的适用性。增强的SPT系统将改善岩土工程从业人员的SPT结果，并使加拿大岩土工程界能够迅速吸收结果。这将提高对更安全岩土结构的设计信心，并使SPT结果与土壤参数之间的区域特定相关性具有更高的信心水平。

The Standard Penetration Test (SPT) is one of the most used investigation tools in the world to understand a specific soil's characteristics (e.g. deformability, strength) which are used to design construction projects involving breaking ground. The SPT consists of hammering a sampler into the ground: the number of hammer blows required to drive the sampler a specific distance determines the soil parameters for design. The limitations of the SPT are mostly related to different SPT systems applying different amounts of energy (i.e. force) for each hammer blow. Such energy losses have led to significant uncertainty when correlating soil parameters using SPT, which affect the safe design of earthworks. Although researchers have measured SPT energy losses for a number of systems, the ranges in energy corrections make their application to other systems uncertain.The proposed research aims to enhance an SPT system being used in several projects in western Canada. This SPT system uses automated hammer drops for repeatability and continuous measurements of the energy for each hammer blow. The research will provide measurements of energy loss and a system-specific energy correction that can be used in other projects across Canada. These energy measurements will quantify the variability of the system in terms of the energy delivered, providing a means of calculating the system uncertainty in SPT results. The system-specific uncertainty will be compared against the uncertainty associated with widely used energy corrections to measure the improvements in SPT result confidence.Furthermore, this research proposes to evaluate the suitability of the energy delivered by the SPT (i.e. blows into the ground) as a source for seismic and acoustic tomography of the ground. The enhanced SPT system would improve SPT results for geotechnical practitioners and allow for quick uptake of the results by the geotechnical community in Canada. This will result in increased design confidence for safer geotechnical structures and will allow region-specific correlations between SPT results and soil parameters with higher levels of confidence.