Resonant column (RC) is a standard laboratory test for the dynamic characterization of soils. Mass polar moment of inertia (MPMI) of the drive plate of RC is required for the solution of equation of motion for a specimen-mass system in RC. In standard procedure, the MPMI is evaluated by testing of calibration probes. Studies have shown that torsional stiffness of the probes have significant effect on the evaluation of MPMI of drive plate due to contribution from base of RC. The extent of contribution increases with increase in torsional stiffness of probes and consequently error in MPMI increases. This study presents a new calibration method that does not use probes. The MPMI of the drive plate is evaluated by suspension of drive plate with polyamide wire of negligible torsional stiffness and damping. The modified equation of motion is used to evaluate the MPMI of drive plate. Results show that the variation of MPMI with frequency is very small compared to its variation from conventional procedure. The apparent values of MPMI from conventional procedure are found to be higher than its inferred true-value, which results in overestimation of shear wave velocity of soil specimen.

中文翻译：

---

共振柱驱动板质量极惯性矩的新评价

共振柱 (RC) 是用于土壤动态表征的标准实验室测试。RC 驱动板的质量极惯性矩 (MPMI) 是求解 RC 中试样质量系统的运动方程所必需的。在标准程序中，通过测试校准探针来评估 MPMI。研究表明，由于 RC 底座的贡献，探针的扭转刚度对驱动板 MPMI 的评估具有显着影响。贡献的程度随着探针扭转刚度的增加而增加，因此 MPMI 的误差增加。本研究提出了一种不使用探针的新校准方法。驱动板的 MPMI 由具有可忽略的扭转刚度和阻尼的聚酰胺线的驱动板悬挂来评估。修正后的运动方程用于评估驱动板的 MPMI。结果表明，与常规程序相比，MPMI 随频率的变化非常小。传统方法得到的 MPMI 表观值高于其推断的真值，导致高估了土样的剪切波速度。