Performance of a novel sediment sampler as an add‐on unit for portable free‐fall penetrometers: Combining in situ geotechnical testing with sediment sampling

Abstract

The investigation of mobile and loose surficial sediment layers is essential for a comprehensive seabed characterization. Portable free‐fall penetrometers (PFFPs) can deliver in situ geomechanical information about surficial sediment layers, which are difficult to preserve with traditional sampling tools. However, PFFP data interpretation can be hampered by the lack of high‐quality physical sediment samples for further verification and calibration. In this study, four new sampler configurations are tested as add‐ons for PFFPs to conduct high‐quality sediment sampling and geotechnical profiling simultaneously. Laboratory results showed that the recovery ratio of the collected samples decreased with increasing impact velocities of the probe. For impact velocities ≥ 2 m s−1, a cylindrical sampler body performed better than a conical body reaching a higher recovery ratio with less disturbance on density and saturation. Sharper carvers also increased the recovery ratio and decreased the disturbance. Field results revealed that the sample retention was challenged by energetic hydrodynamics in combination with coarse sediments (significant wave height in excess of 2 m). Overall, utilization of suction proved to be the most promising retaining mechanism under various hydrodynamic and soil conditions. Geomechanical profiles obtained with the sampler add‐ons were successfully calibrated to records obtained with the traditional PFFP tip geometries. In conclusion, the study introduced a novel sediment sampler configuration suitable for simultaneous geotechnical seabed profiling and sediment sampling using PFFP and provided insights into the impacts of sampling mechanisms on sample quality.

The Connection between a Suspended Sediments and Reservoir Siltation: Empirical Analysis in the Maziarnia Reservoir, Poland

“…Analysis of stable carbon isotopes showed that the most-enriched entrapped sediment was located near the reservoir inflow, while the most-depleted was obtained near the dam. Depletion or enrichment of entrapped sediments in 13 C was, respectively, associated with highest and lowest observed concentrations of total phosphorus (TP S ), as confirmed by a statistically significant inverse correlation (r s = −0.68). This dependent relationship may prove important in assessing a reservoir's sources of phosphorus, and in forecasting deposition of loads in reservoir sediments.…”

“…The sediments most enriched in 13 C were those near the inflow (δ 13 C-TOC = −29.35‰), while those found to be most depleted were close to the dam (δ 13 C-TOC = −31.92‰) (Figure 8a). The depletion or enrichment of sediment organic matter in the heavier 13 C isotope was associated with either the highest or lowest contents of total P.…”

Numerical simulation and experimental study on seafloor sampling of an anchor-type mud collector based on SPH-FEM coupling method

“…Experts and scholars at home and abroad have successively researched on mud collectors with various functions and structures in different regional application scenarios such as lakes, riverbeds and oceans. Bilici and Stark 8 studied a new sediment sampler with a cylindrical sampler in the structure, which used a free-fall gravimeter for geotechnical seabed profiling and sediment sampling, but due to the mechanical constraints it was less effective for rocky clays. Mackie and Bailey 9 introduced an inexpensive river sampler called T-type sampler.…”

Effectiveness Assessment of a New System of Sediment Trap in the Investigation of Matter Sedimentation in a Reservoir—A Case Study

“…The formation of aggregate is dependent on the physical, chemical and electrochemical conditions characterising liquids, as well as the properties of elementary particles, the content of organic matter and the water flow rate [12,13].Knowledge of the specificity and deposition rate of suspended particles in water at the reservoir bottom is of great importance to ensure a given reservoir's proper use. The sediment trap system can deliver in situ information about surficial sediment layers, which are difficult to explore with traditional sampling tools [14].Over the past few decades, various tools and techniques have been developed to determine the streams of sedimentary particles in water environments. The oldest and simplest method is the sediment trap.…”

“…Knowledge of the specificity and deposition rate of suspended particles in water at the reservoir bottom is of great importance to ensure a given reservoir's proper use. The sediment trap system can deliver in situ information about surficial sediment layers, which are difficult to explore with traditional sampling tools [14].…”