MONITORING A DREDGED MATERIAL DISPOSAL SITE ON THE CONTINENTAL SHELF USING THE DYNAMIC PENETROMETER<i>NIMROD</i>

Flaim, Bryna K.; Stark, Nina; Moon, Vicki G.; Lange, Willem de; Healy, Terry R.; Kopf, Achim J

doi:10.1142/9789814355537_0048

Cited by 4 publications

(10 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, a geotechnical classification of the sediment using the deceleration profiles and maximum values is justified (Stoll and Akal 1999;Stark and Wever 2009;Stark et al 2009). This can be confirmed by estimating an equivalent of quasi-static bearing capacity (Stark et al 2011) leading to similar trends (estimate of quasi-static bearing capacity for a constant penetration velocity of 2 cm s -1 : Rhône Delta 2.4-3.4 ± 0.5 kPa, Vidy Bay 0.9-1.3 ± 0.2 kPa). The higher sediment resistance in the Rhône Delta can be explained by silty sediments that were found in sediment cores retrieved at the same positions as the Nimrod deployments (averaged shear strength using a vane shear device ≈ 3.7 kPa), whereas in Vidy Bay fine sediments are expected (Pardos et al 2004).…”

Section: Discussionsupporting

confidence: 62%

“…The impact velocity and the penetration depth were determined by single and double integration of the deceleration, respectively. Possible stratification and resulting top layer thickness was estimated from the deceleration profiles and double checked after consideration of changes in penetration velocity and penetration surface area (Stark et al 2011). The water depth was estimated by the MIR's on-board sensors, whereas the hydrostatic pressure corresponded to the results of Nimrod's pressure transducer at the starting point of the penetration process.…”

Section: Stark Et Almentioning

confidence: 99%

“…They are used for, e.g., the investigation of marine and lacustrine slope stability, geology, sedimentation, and sediment dynamics. Concerning the latter, variations in the sediment texture, the state of consolidation, and density can be identified from the derived vertical profile of sediment strength, possibly indicating and quantifying sediment deposition or erosion (Stark and Kopf 2011). A number of different designs are currently used to address such tasks.…”

mentioning

confidence: 99%

“…The devices used in shallow waters (<200 m) include lance-like systems based on standard Cone Penetration Test geometries (Stegmann et al 2006;Mosher et al 2007), fullflow penetrometers minimizing effects of side adhesion and side friction (Mulhearn 2003;Yafrate et al 2009), fluiddynamic shaped penetrometers emphasizing free-fall performance that are decoupled from ship/platform movements (Stoll and Akal 1999;Stark et al 2009) and specially designed penetrometers, e.g., for simulating mine burial (Poeckert et al 1996). As all systems are usually deployed from a vessel or platform at the water surface, the spatial precision of the targeted penetration position at the seafloor is often limited to several meters depending on the water depth and the stability of the vessel (Mulhearn 2003;Stark et al 2011). Generally, this spatial resolution is sufficient to map and profile the sediment strength in survey areas such as bays, river deltas, estuaries, and slopes, as well as along big to medium-sized geoDeployment of a dynamic penetrometer from manned submersibles for fine-scale geomorphology studies Nina Stark 1,2 *, Nicolas Le Dantec 3,4 , Juan Pablo Corella 5,6 , (Stark et al 2011).…”

mentioning

confidence: 99%

“…As all systems are usually deployed from a vessel or platform at the water surface, the spatial precision of the targeted penetration position at the seafloor is often limited to several meters depending on the water depth and the stability of the vessel (Mulhearn 2003;Stark et al 2011). Generally, this spatial resolution is sufficient to map and profile the sediment strength in survey areas such as bays, river deltas, estuaries, and slopes, as well as along big to medium-sized geoDeployment of a dynamic penetrometer from manned submersibles for fine-scale geomorphology studies Nina Stark 1,2 *, Nicolas Le Dantec 3,4 , Juan Pablo Corella 5,6 , (Stark et al 2011). However, the spatial accuracy reached in water depths in excess of 10 m by surface deployments (≥3 m) is not suitable to investigate fine-scale geomorphologic features such as ripple structures (Ashley 1990), pillow-hollow features in the range of decimeters (Lang 1989;Brandl et al 1993), or narrow and steep canyons (Inman et al 1976).…”

mentioning

confidence: 99%

See 4 more Smart Citations

Deployment of a dynamic penetrometer from manned submersibles for fine‐scale geomorphology studies

Stark

Dantec

Corella

et al. 2013

Limnology & Ocean Methods

Self Cite

View full text Add to dashboard Cite

Dynamic penetrometers reveal information about seafloor strength, stratification, stability, and sediment remobilization. However, positioning is often limited to a range of meters making it difficult to target small-scale geomorphologic features. Deployments from submersed vessels (manned or remotely operated) can extend the possibilities of in situ geotechnical surveying in areas of complex bathymetry. The lightweight dynamic penetrometer Nimrod was modified to enable its deployment from the MIR submersibles, and was deployed during two dives in the Rhône Delta and Vidy Bay (both Lake Geneva). In the Rhône Delta, five positions at the floor/levee complex of a submarine canyon were sampled with ~1 m spacing, with good reproducibility of the results. In Vidy Bay, socalled pillow-hollow structures on the lake bottom with dimensions of about 50 cm were targeted. At both sites, the penetrometer was released from a height of about 1-2 m above the lake bottom using the starboard robotic arm of the MIRs leading to impact velocities of ~ 3 m s -1 . The probe reached penetration depths of up to 80 cm with maximum decelerations of up to 2.9 g. Stratification in the deceleration versus penetration depth profiles hinted at recent sediment remobilization processes. Pressure transducer results of the probe were suitable to determine water depth, and estimate trends of excess pore pressure. This article describes the modification of the dynamic penetrometer Nimrod for deployments from the MIR submersibles, assesses the deployment performance, validates the results, and gives an outlook on the application of this technique and the results.

show abstract