Marine Deep-Water Free-Fall Cpt Measurements For Landslide Characterisation Off Crete, Greece (Eastern Mediterranean Sea) Part 1: A New 4000M Cone Penetrometer

Stegmann, Sylvia; Kopf, Achim J

doi:10.1007/978-1-4020-6512-5_18

Cited by 5 publications

(3 citation statements)

References 11 publications

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“…Instruments frequently used for geotechnical in situ tests are dynamic penetrometers (consider the use of, e.g., Stoll and Akal 1999;Stoll et al 2004;Aubeny and Shi 2006;Stegmann et al 2006a, b;Kopf et al 2007;Stegmann and Kopf 2007;Stark and Wever 2008;Stark et al 2009a). Many of the coastal areas investigated in these studies consist mainly of sand.…”

Section: Introductionmentioning

confidence: 99%

Geotechnical Properties of Sandy Seafloors and the Consequences for Dynamic Penetrometer Interpretations: Quartz Sand Versus Carbonate Sand

et al. 2011

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The societal usage of coastal zones (including offshore wind energy plants, waterway deepening, beach conservation and restoration) is of emerging importance. Sediment dynamics in these areas result in sandy deposits due to strong tidal and wave action, which is difficult to simulate in laboratory geotechnical tests. Here, we present data from in situ penetrometer tests using the lightweight, free-fall Nimrod penetrometer and complementary laboratory experiments to characterize the key physical properties of sandy seafloors in areas dominated by quartzose (North Sea, Germany) and calcareous (Hawaii, USA) mineralogy. The carbonate sands have higher friction angles (carbonate: 31-37°; quartz: 31-32°) and higher void ratios (carbonate: 1.10-1.40; quartz: 0.81-0.93) than their siliceous counterparts, which have partly been attributed to the higher angularity of the coralderived particles. During the in situ tests, we consistently found higher sediment strength (expressed in deceleration as well as in estimated quasi-static bearing capacity) in the carbonate sand (carbonate: 68-210 g; quartz: 25-85 g), which also showed a greater compressibility. Values were additionally affected by seafloor inclination (e.g., along a subaqueous dune or a channel), or layering in areas of sediment mobilization (by tides, shorebreak or currents). The study shows that the differences in in situ measured penetration profiles between carbonate sands and quartz sands are supported by the laboratory results and provide crucial information on mobile layers overlying sands of various physical properties.

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Section: Introductionmentioning

confidence: 99%

Geotechnical Properties of Sandy Seafloors and the Consequences for Dynamic Penetrometer Interpretations: Quartz Sand Versus Carbonate Sand

et al. 2011

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“…Şekil 1. Hazar Gölü'nün yer belirleme haritası (MTA, 2012) Dünya'da özellikle 1980'lerden sonra denizaltı sedimentleri ve kütle hareketleri konusunda yapılan çalışmaların (Auffret vd., 1982;Cochonat vd., 1993;Lee vd., 1993;Mulder vd., 1994;Elverhøi vd., 1997;Imran vd., 2001aImran vd., , 2001bKim ve Kim, 2001;Hühnerbach ve Masson, 2004;Rajasekaran, 2006;Stegmann vd., 2006;Yun vd., 2006;Förster vd., 2007;Stegmann, 2007;Förster vd., 2008;Winters vd., 2008;Lee, 2009;Ioualalen vd., 2010;Förster vd., 2010aFörster vd., , 2010bFörster, 2011;Strozky vd., 2010;Lee vd., 2011;Ai vd., 2014;Kopf vd., 2016;Stegmann ve Kopf, 2017) artarak günümüze değin devam ettiği görülmektedir. Araştırmacılar bu çalışmalarda, genellikle sualtı kütle hareketleri ve oluşum mekanizlamaları ile denizaltı çökellerinin mühendislik özellikleri konusunda araştırma yapmışlardır.…”

Section: Introductionunclassified

Hazar Gölü’ndeki (Elazığ/Doğu Türkiye) çökellerin mühendislik özelliklerine ve sualtı kütle hareketlerine genel bir bakış

Aslan¹,

Gürocak²

2021

Gümüşhane Üniversitesi Fen Bilimleri Enstitüsü Dergisi

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Bu çalışmanın amacı, Doğu Anadolu Fay Zonu içerisinde yer alan ve Türkiye'nin önemli tektonik göllerinden birisi olan Hazar Gölü yamaçlarındaki çökellerin ve yamaçlarda belirlenen su altı kütle hareketlerinin mühendislik özelliklerinin belirlenmesidir. Bu amaçla, gölde gerçekleştirilmiş olan yüksek çözünürlüklü sığ-sismik veriler kullanılarak belirlenen noktalardan alınan örselenmemiş zemin örneklerinde laboratuvar deneyleri gerçekleştirilmiştir. Deney sonuçlarına göre, akarsuların Hazar Gölü'ne boşaldığı alanlardaki zeminler inorganik iri silt (MLN), gölün orta kesimlerinde ise yüksek plastisiteli silt (MH)'dir. Zeminlerin doygun birim hacim ağırlık değerleri derinlikle artarken, porozite ve boşluk oranı değerleri ise azalmaktadır. MLN sınıfı zeminlerin dayanımı MH sınıfı zeminlere göre oldukça yüksektir. MH sınıfı zeminlerin dayanımı ise yeterince sıkılaşma olmadığından oldukça düşüktür. Hazar Gölü'ne ait sismik profillerde, eğimin dik olduğu yamaçlarda zemin kalınlığı maksimum 3 m civarında iken, eğimin daha az olduğu yamaçlarda zemin kalınlığı 10 m'ye kadar ulaşabilmektedir. Zemin kalınlığının fazla olduğu yamaçlarda, özellikle zeminin kendi ağırlığı ile gelişmiş su altı kütle hareketleri mevcuttur. Bu kütle hareketleri, plastik deformasyon izlerinin ve dairesel kayma yüzeylerinin açıkça görülebildiği slump tipi kaymalardır. Hazar Gölü yamaçlarındaki zeminlerin oldukça düşük dayanımlı olduğu göz önüne alınırsa, bu kütle hareketlerinin çökellerin kendi ağırlığının etkisiyle kayarak oluştuğunu ve Doğu Anadolu Fay Zonu (DAFZ)'nda meydana gelen depremlerin de bu kütle hareketlerini kolaylaştırdığı söylenebilir.

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“…For deep waters, heavy lance-like systems are mainly applied (Beard 1981;Stegmann and Kopf 2007). 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).…”

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confidence: 99%

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

Stark

Dantec

Corella

et al. 2013

Limnology & Ocean Methods

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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.

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Marine Deep-Water Free-Fall Cpt Measurements For Landslide Characterisation Off Crete, Greece (Eastern Mediterranean Sea) Part 1: A New 4000M Cone Penetrometer

Cited by 5 publications

References 11 publications

Geotechnical Properties of Sandy Seafloors and the Consequences for Dynamic Penetrometer Interpretations: Quartz Sand Versus Carbonate Sand

Geotechnical Properties of Sandy Seafloors and the Consequences for Dynamic Penetrometer Interpretations: Quartz Sand Versus Carbonate Sand

Hazar Gölü’ndeki (Elazığ/Doğu Türkiye) çökellerin mühendislik özelliklerine ve sualtı kütle hareketlerine genel bir bakış

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

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