探头尺寸对FFP确定海底沉积物性质影响的原位试验研究

自落式贯入仪(Free-Falling Penetrometer, FFP)是一种新型海底沉积物原位测量设备,用于海底沉积物工程性质原位调查。本文基于自主研发的FFP设备在黄海海域开展现场贯入试验,分析探头尺寸对判断沉积物性质的影响。研究表明,在不同沉积物中探头尺寸对贯入深度、贯入阻力和沉积物类型判断有不同影响。在细粒沉积物中探头尺寸对贯入深度、贯入阻力影响较小;在根据贯入阻力变化划定分层时,小直径探头能反应贯入阻力更为细小的变化。在粗粒沉积物中探头尺寸影响更明显,大尺寸探头使贯入阻力变大,贯入深度减小。根据标准化深度和硬度因子可区分粗粒沉积物和细粒沉积物,在粗粒沉积物中探头尺寸增大,硬度因子减小,有利于细化沉积物类型。

In-situ experimental study on the effect of probe size on FFP to determine the properties of submarine sediments

The Free-Fall Penetrator(FFP) is a new type of in-situ measurement equipment for seabed sediments, which is used for in-situ investigation of engineering properties of seabed sediments. Based on the self-developed FFP equipment, field tests were carried out at two stations in the Yellow Sea to analyze the influence of probe size on judging sediment properties. The results show that the probe size has different effects on the determination of penetration depth, penetration resistance and sediment type in different sediments. In fine sediments the probe size has less influence of penetration depth and the penetration resistance. When delineating geological stratification, smaller diameter probes can reflect more subtle changes in penetration resistance. There is more obvious influence of the probe size in coarse sediments. The larger size probe makes the bigger penetration resistance, and the penetration depth is reduced. Depending on the standardized depth and hardness factor, coarse sediments and fine sediments can be distinguished. The size of the probe is increased in the coarse sediment, the hardness factor is reduced, which is advantageous to refine the type of deposit.