The Standard Penetration Test (SPT) is the most popular example of dynamic probing, a large category of soil testing techniques. Understanding and interpretation of these tests is hampered by the difficulties of reproducing them under controlled laboratory conditions. The virtual calibration chamber technique, based on the Discrete Element Method (DEM), may supplement or substitute this complex experimentation. In this paper SPT in sand are analyzed considering the energy transfer involved. Energy balances are written for the penetrating rod and for the material in the chamber. All the terms are computed for a number of cases in which the main variables controlling test response in the field -initial density and stress level- are systematically varied. The analysis confirms previous field observations indicating that, when an energy-based interpretation is used, SPT provides a value of equivalent penetration resistance that is the same that would be obtained with a static cone penetration test. The analyses also provide an unequivocal explanation for this observation: although the impacting rod shows complicated dynamics the response of the sand is quasi-static.

标准渗透测试（SPT）是动态探测的最流行示例，这是一大类土壤测试技术。在受控的实验室条件下，很难再现和理解这些测试。基于离散元素方法（DEM）的虚拟校准室技术可以补充或替代这种复杂的实验。在本文中，考虑了能量转移，分析了沙子中的SPT。为穿透杆和腔室内的物料编写能量平衡。在许多情况下计算所有这些术语，在这些情况下，控制现场测试响应的主要变量-初始密度和应力水平-有系统地变化。分析证实了先前的现场观察表明，当使用基于能量的解释时，SPT提供的等效渗透阻力值与静态圆锥渗透测试所获得的值相同。这些分析也为这一观察提供了明确的解释：尽管冲击棒显示出复杂的动力学，但砂土的响应是准静态的。