bluuebunny/crossref_metadata_2025 huggingface dataset:
Модель безпеки взаємоповязаних обчислювальних пристроїв на основі полегшеної схеми шифрування для IoT.
Authors: Rozlomii I. , Symonyuk V. , Naumenko S. , Mykhailovskyi P.
Published: June 2024

У сучасному світі число пристроїв, підключених до інтернету речей (IoT), стрімко зростає, що породжує нові виклики у сфері забезпечення їхньої безпеки. Стаття присвячена розробці моделі безпеки для IoT пристроїв, яка враховує обмежені обчислювальні ресурси і мінімальне енергоспоживання, необхідні для ефективного функціонування криптографічних алгоритмів. Проблема полягає у відсутності універсальних полегшених криптографічних рішень, здатних забезпечити надійний захист в умовах IoT без значного збільшення витрат енергії чи обчислювальних ресурсів. У статті представлено аналіз сучасних досліджень та публікацій у цій сфері, зокрема, розглянуто новітні розробки в галузі полегшеної криптографії, що оптимізовані для IoT пристроїв. Особлива увага приділена легким криптографічним алгоритмам, які можуть забезпечити високу безпеку при мінімальному використанні ресурсів, таких як енергія та обчислювальна потужність. Запропонована модель включає як апаратні, так і програмні рішення для шифрування та управління ключами, з метою мінімізації ризиків компрометації даних. Досліджуються методи оцінки ефективності засобів захисту та моделі врахування обмежень ресурсів. У статті також розглядаються перспективи використання квантово-стійких криптографічних протоколів, які можуть стати основою для майбутніх стандартів безпеки IoT. Висновки підкреслюють важливість постійного вдосконалення захисних механізмів для підвищення рівня безпеки IoT технологій, що сприятиме зростанню довіри користувачів до цих систем і забезпечить надійний захист даних у глобальних мережах. Розробка та імплементація таких полегшених криптографічних рішень є критично важливими для захисту даних і забезпечення стабільної роботи IoT екосистем в умовах сучасних кіберзагроз.
Система для відстеження руху очей на основі машинного навчання.
Authors: Sedinkin O. , Derkach M. , Skarga-Bandurova I. , Matiuk D.
Published: June 2024

У статті розглянута актуальна технологія визначення точки фіксації погляду, що надає можливість інтерактивної взаємодії у різних сферах, зокрема у вдосконаленні комп’ютерних інтерфейсів. Розроблена система для відстеження руху очей ґрунтується на методі HOG та лінійному алгоритмі машинного навчання SVM й реалізована на мові програмування Python з підключенням бібліотек: OpenCV, Dlib, numpy. Представлена система виділяє зіниці на зображенні обличчя людини, визначає координати зіниць лівого і правого ока, визначає напрямок погляду людини.
Комп’ютерне моделювання для медицини катастроф. Підхід до автоматизованого аналізу рішень з організації мобільних медичних шпиталів
Authors: Chybiriak Ya. , Zakharova A. , Lavrov Ye. , Siryk O. , Tatarchuk R.
Published: June 2024

Засоби імітаційного моделювання все частіше використовуються спеціалістами органів управління для оцінювання ефективності роботи медичних організацій.  У роботі запропоновано структуру та розроблено імітаційну модель мобільного медичного шпиталю, яка дозволяє оцінити робоче навантаження на окремі відділення шпиталю у залежності від інтенсивності вхідного потоку поранених. Побудовано імітаційну систему аналізу та візуалізації даних, що може бути використана для прийняття рішень щодо розподілу, мобілізації сил та засобів медичних служб в умовах бойових дій. Дані для побудови моделі були отримані з довідкової медичної літератури, також надавалися пропозиції від окремих медичних організацій міста Суми та від бойових медиків з прикордоння. Імітаційне моделювання здійснюється у програмі FlexSim. Дискретно-подійна модель побудована на базі математичного апарату, який використовується для оцінювання часових показників проведення лікувальних заходів під час обстрілів, пожеж та інших надзвичайних ситуацій. До них відносяться такі параметри, як тривалість надання медичної допомоги, середній час очікування поранених в чергах та ін. параметри. Імітаційна модель надає можливість виводити інформацію про завантаженість окремих відділень, це дозволяє швидко приймати рішення про зосередження сил і засобів у потрібних підрозділах шпиталю. Впровадження імітаційної моделі медичного шпиталю в діяльність ВСУ дозволить у режимі реального часу управляти ефективністю надання медичної допомоги пораненим у зонах воєнних конфліктів.
Роль UML-діаграм у плануванні проєкту інформаційної системи на прикладі системи піших туристичних маршрутів
Authors: Deineko L. , Kunanets N.
Published: June 2024

Будь-який процес вимагає попереднього аналізу та планування. Сучасні інформаційні системи стають щоразу більш складними, а, відповідно, етап планування потребує додаткового часу та уваги. Одним з інструментів, що активно використовується фахівцями з розроблення ІТ-продукції, є UML - мова моделювання, що дозволяє описати та відобразити логіку системи. У цій статті розглянуто використання UML-діаграм на етапі планування та вплив даного інструменту на загальний результат розробленого рішення. Дане дослідження базується на прикладі системи піших туристичних маршрутів та розробці окремої реальної системи. Обґрунтовано важливість використання такого підходу в інженерії вимог, що дозволить прослідкувати залежність між наявністю моделей та якістю системи. У даній роботі проаналізовано не тільки переваги моделювання, а й виклики та складнощі, що можуть виникати під час аналізу нефункціональних вимог до системи. Це дослідження дозволило підсумувати роль UML-діаграм та окреслити основоположні принципи, що значною мірою покращать досвід використання такого підходу на різних етапах життєвого циклу інформаційних систем. Дана робота закладає підвалини для подальших досліджень та дозволить масштабувати вже здобуті результати для виявлення додаткових особливостей і деталей застосування моделювання. Варто підкреслити, що такі дослідження можуть стосуватися різних областей та аспектів UML, наприклад, у якості інструменту для пошуку недоліків чи покращення комунікації в команді спеціалістів загалом. Отримані результати можна застосувати у сфері тестування, бізнес-аналізу та під час розробки архітектури програмних рішень.
Effects of urine and hygienized feces on cocoa production in the village of Blanfla (Bouafle, Côte d'Ivoire)
Authors: Marius Yapi Ellélé Aimé , Raymond N’Krumah Tanoh Amany Serge , Théophile Gnagne
Published: June 2024

Ecological sanitation involves the use of hygienized human excreta as fertilizer in agriculture. This study aimed to establish the effects of hygienized urine and feces on cocoa production in the village of Blanfla in the Bouaflé Department of Côte d'Ivoire. To this end, 539 people from 100 households were trained in the use of urine-diverting dry toilets (UDDTs) and in fertilizing cocoa plantations with hygienized excreta from UDDTs. The study ran from 2014 to 2017, during which time 6 months were spent building the TSDUs and 1.5 months were monitoring their use. For 2 years, three categories of plantations (young, mature and old) with a total surface area of 285 ha were fertilized by the application of almost 445 m3 of urine and 100 tonnes of hygienized feces. The quantity of biofertilizer applied to the three groups of plantations almost doubled the annual cocoa production (RP=1.95). In all three plantation categories, crop production was significantly associated with BF application (r = 0.993; p = 0.007/r = 0.975; p = 0.025) but not with temperature or rainfall. The use of hygienized urine and feces as biofertilizers through the ecological sanitation approach should be popularized, as it increases agricultural productivity and farmer incomes.
A Rare Presentation of Metastatic Breast Carcinoma to the Thyroid Three Years after Mastectomy: A Case Report
Authors:   Mohammed Duhileb, Al Duhileb Mohammed Al
Published: June 2024

Abstract Introduction: Breast cancer is the most common cancer in women. Yet, metastasis to the thyroid is a rare occurrence. Here we present the case of a patient with breast cancer metastasis to the thyroid gland to discuss the management of such presentations compared to the current literature. We also present this case to add to the existing literature and aid in the expansion and better understanding of rare incidences as such. Presentation of Case: A 38-year-old female with no chronic medical illnesses was diagnosed with invasive ductal carcinoma of the right breast T3N0M0 in 2017. Chemotherapy eight cycles of neoadjuvant chemotherapy followed by right simple mastectomy, sentinel lymph node biopsy, and adjuvant radiation to the chest wall. The patient has been on hormonal therapy since diagnosis. In 2020, the patient presented with a left neck mass and underwent a total thyroidectomy. Pathological analysis of the specimen confi rmed the presence of poorly differentiated cells consistent with mammary ductal cells while the right thyroid lobe demonstrated features of papillary thyroid carcinoma. Conclusion: Intrathyroidal metastasis of extrathyroidal cancers is rare but should be considered when patients are present with a history of cancer. Thyroidectomies in isolated secondary thyroid cancers have been shown to prolong the disease-free period but are not a defi nitive cure
Slope Instability on the Egyptian Slope: Potential; Link to History [?]
Authors: Wood G , Hough G , Hampson K , Noll C , Hill A W
Published: June 2024

In 2015, PhPc discovered a major gas and condensate field in the Atoll Prospect. As part of the field development, a significant integrated site investigation programme was undertaken in 2016 to identify and evaluate potential sources of geohazard risk to the proposed development. Early indications of 'recent' slope stability had been identified on Regional 3D seismic data in development of an early Ground Model, but a full Slope Stability Assessment was required to mitigate any potential risks. Seabed and very high-resolution seismic data were acquired from a traditional survey vessel, supplemented with ROV mounted sensors, and calibrated with shallow geotechnical data. Age dating of the core material, which included calcareous micro fossil, palynology and C14 analyses produced some surprising results, which, as this paper will discuss, has potential to be linked to Historical Events within the last 1000 years.
Understanding Vibro-Hammer Performance
Authors: Irvine J , Germano V , Ozsu E , Falepin H , Bryan H , Montalti L
Published: June 2024

Vibro-hammers are being increasingly considered for the installation of offshore piles due to increased speed and reduced noise pollution. However, there are still concerns regarding the effectiveness of vibro-hammers in a range of soil profiles including dense sands and high strength clays. Most common methods involve the application of empirical coefficients based upon the soil description to the Soil Resistance to Driving (SRD) calculated using conventional methods and conventional wave equation software. The soil resistance reduces due to (partial) liquefaction induced by the vibro-hammer. The paper aims to provide improved performance predictions by relating the reduction in penetration resistance using established liquefaction analysis methodologies to understand the likely degree of stress reduction induced by the vibro-hammer and the associated reduction in resistance. This is then utilized by the dynamic installation analysis.
Integrated Hazard Assessment of Lake Tsunamis Triggered by Subaqueous and Subaerial Landslides
Authors: Strupler M , Bürgler M , Vetsch D F , Kremer K
Published: June 2024

Historical chronicles together with geophysical, geotechnical, and sedimentological investigations have demonstrated that both subaqueous and subaerial landslides can lead to tsunamis on lakes. Previous work has shown that lakes in the alpine and peri-alpine settings in Switzerland provide prime preconditions for subaqueous mass movements, due to the glacially excavated basin geometry, the continuous sediment supply, and the related mechanical characteristics of the slopes. In addition, steep alongshore topography favours subaerial mass movements. The increasing settlement and infrastructure development along the shores and the lake tsunami history emphasize that assessing the tsunami hazard on Swiss peri-alpine lakes is essential. In a holistic approach that combines limnogeological, geomorphological, seismological, geotechnical, geospatial techniques with hydrodynamic simulations, we construct a workflow for the assessment of the landslide-tsunami hazard on peri-alpine lakes. GPU-accelerated numerical simulation using the freely available software BASEMENT allows for a rapid calculation of various inundation parameter distributions, considering uncertainties in landslide parameters. In the workflow, tsunami generation can be simulated both for subaqueous and subaerial mass movements. Hence, the hazard of lake tsunamis can be assessed comprehensively. Next to presenting the workflow, we provide recommendations for future work.
Modelling the Generation of Cyclically-Induced Excess Pore Pressures Below a GBF
Authors: Meijers P , Elkadi A S
Published: June 2024

In offshore wind, the stability check, during storm loading, of Gravity Based Foundations (GBF) on partially saturated sand, requires good prediction of the excess pore pressures. Predicting these excess pore pressures is not straightforward. As the situation during storm loading is partially drained, pore pressure generation and dissipation occurs simultaneously. For a proper and reliable prediction of the amount of excess pore pressures, relevant aspects should be considered. This requires a good understanding of the behaviour of sand during cyclic loading. An important, but often overlooked, aspect is the effect of pre-shearing on the pore pressure generation. Pre-shearing is the effect that (small) changes in soil fabric occurring during previous load cycles have a significant effect on the amount of generated pore pressures. Ignoring this aspect will overestimate the amount of excess pore pressure leading to possible overdesign. This paper describes an approach that considers the simultaneous effect of pore pressure generation and dissipation. In addition to the standard procedure, also the effect of pre-shearing is taken into account. The approach is described and illustrated using a case study. In the description of the case, attention is paid on how to account for the storm history, the effect of smaller storms preceding the design storm, and the effect of a random wave field.
The Geotechnical Challenges Associated with Carbon Capture and Storage (CCS)
Authors: Muggeridge A
Published: June 2024

This paper reviews carbon dioxide capture, transportation and geological storage before discussing the associated civil engineering, geotechnical and geomechanical challenges, focusing on North Sea settings. The demands of CCS are contrasted with those relating to oil and gas production. Areas requiring further research include the pipeline performance, the potential overpressuring of storage sites and hazardous leakage events as well as the impact of climate change on hydrodynamic loading and hydrate stability.
Demystifying the Connections Between Gaussian Process Regression and Kriging Theories
Authors: Suryasentana S , Sheil B B
Published: June 2024

Gaussian Process (GP) regression is a flexible, non-parametric Bayesian approach towards regression problems that has seen increasing adoption for machine-learning (ML) applications. Despite its recent popularity within the ML community, GP regression has a long history in geostatistics, where it is better known as kriging and is commonly used for spatial interpolation. The rapid development of GP regression in ML presents significant opportunities for advanced knowledge transfer to the geotechnical engineering community. However, this knowledge transfer has often been inhibited by the different terminology and conventions adopted in both fields. This obscures the underlying science and introduces much potential for confusion. Therefore, this paper aims to reveal the connections between GP regression and kriging theories, with a view of acting as a bridge to increase the uptake of the latest developments in each field.
Unlocking the Shallow Overburden Understanding of Ubadari Gas Field in Indonesia Using High-Resolution Shallow Datasets
Authors: Putri S A , Panggeleng I , Nauw M , Maulana A , Bachtiar L , Birt C S , Galanes-Alvarez H
Published: June 2024

Ubadari is an undeveloped shallow-water gas discovery in Bintuni Bay, West Papua, Indonesia. The field will be developed as part of the Tangguh UCC (Ubadari, Carbon Capture, and Compression) project, supplying an LNG site onshore. The seabed and shallow overburden are complex at Ubadari. Highly variable soils, liquefaction risk and widely distributed shallow gas, make jack-up rig and platform placement challenging. To support the development, a comprehensive high-resolution shallow geophysical data was acquired in 2016 and geotechnical boreholes were acquired in 2017. In 2020, these diverse datasets were integrated into a comprehensive ground model, and they revealed significant, previously unidentified, shallow overburden features that, allowing delivery of detailed shallow hazards and risks identification. The primary mitigation strategy is to identify and avoid, where possible, known hazardous conditions and hence the ground model was used to assist Ubadari platform locations selection, well trajectory planning and subsea pipeline routing.
Analysis of Stress Variation Around Spudcan Subjected to Cyclic Loading
Authors: Ragni R , Amodio A , Zhou H
Published: June 2024

Jack-ups are used in offshore wind and Oil - Gas industries alike. The legs of the jack-up are lowered to the seabed until the spudcan foundations touch-down, followed by a pre-loading stage and then operation. Whilst the jack-up is on site, the spudcans can undergo significant cyclic loading due to storm or seismic events. This paper analyses stress variations around spudcans during multi-directional cyclic loading, by means of FLAC3D-based numerical modelling. Stress conditions at a soil element level - which vary spatially around the foundation - are continuously monitored. The variation in soil stress state at different phases of the loading cycle is illustrated. Considerations around principal stress orientation are advanced to (i) reveal links between spudcan response and failure modes of the soil, and (ii) demonstrate differences in response between common laboratory tests and boundary value problems. Ultimately, this provides guidance on the relevant laboratory tests and selection of appropriate cyclic strengths.
Obtaining Representative Stiffness Degradation Parameters From the Resonant Column
Authors: Wen K , Buckley R M , Byrne B W
Published: June 2024

Offshore wind turbines (OWT) are emerging as a crucial component of renewable energy in Europe, reinforcing the importance of efficient and reliable foundation designs to ensure long-term economic viability. The determination small strain stiffness parameters of soil, including shear stiffness (G0 ), shear degradation (G/G0 ), linear (γtl) and volumetric threshold shear strain (γtv) using the Resonant Column Apparatus (RCA) is now routine in most offshore site investigations. Accurate measurements of such properties are essential for dynamic loading conditions such as those experienced by OWT. This paper presents the results of RCA tests on a naturally occurring sand from a site representative of offshore conditions. A key observation in this study was that the measured stiffness degradation within the elastic region of soil ranged from G/G0 = 84%-96% corresponding to γtv values of 0.1-7.7 x 10-3%, beyond which non-elastic behaviour was observed. The RCA has capabilities of inducing strains up to 10-2%, at least a magnitude of order higher than γtv. The results demonstrate the need for small strain checks to be incorporated in routine RCA testing to establish the true limit of elastic soil behaviour. The results have implications for the use of the RCA in the calibration of degradation threshold strains such as, γ0.7, the shear strain where G/G0 =70%. A combination of test methods is advised for accurate determination of this value.
Advanced Rock Berm Design in Iceberg Plough Marks for Pipeline Support
Authors: Olsen C , Lodahl M R , Kristoffersen A
Published: June 2024

Iceberg plough marks from the last glacial period cover the seabed at water depths of -250-500m in the Norwegian Sea. Occasionally, pipelines can free span across these, and pipeline design aspects may lead to filling the plough marks with rock to support the pipelines. This paper presents the geotechnical design for the Hasselmus pre-lay rock berms. Approx. 275 000 tonnes of rock were installed pre-lay. The rock berms were installed in 2022 at 64 locations along the route. The Hasselmus pre-lay geotechnical rock berm design is particularly advanced due to the following design aspects: All rock berms were installed on extremely soft clay and slope up to 20degs;. The design tackles complex geometry, given the shape of the iceberg plough mark and the rock berm installed. The main design was completed in PLAXIS 2D and spot checks were performed in PLAXIS 3D Due to some rock berms heights exceeding 5m, a split campaign philosophy was introduced, where a 2m rock carpet was installed early to consolidate the soil prior to installation of the remaining berm. This paper will in addition present some results from the as-built survey and compare the theoretically installed volume with the as-installed tonnage.
Cyclic Installation of Suction Caissons: an Overview of Mitigating the Effect of Pressure Cycling on the Tensile Resistance – Part IV
Authors: Hamdan N , Powell T , MacBeath M , Joseph T , Mallikarachchi H , Jones L
Published: June 2024

Two-way pressure cycling installation can potentially reduce the required pressure in cohesive soils. This is due to remoulding the soil strength along the caisson wall, hence, degrading the shaft friction as a result of the applied extra shearing on the soil. The current industry standards, codes and recommended practices do not provide guidance on the effect of pressure cycling installation of suction caissons on the tensile resistance. This paper discusses various methods for mitigating the effect of pressure cycling on the tensile resistance when compared to monotonically installed caissons. Pre-emptive and reactive methods are presented, along with their merits and disadvantages. Based on the discussed methods, a procedure is proposed to mitigate the effect of cyclic installation on the tensile resistance. This procedure is believed to provide a basis for future improved guidance for the assessment of tensile resistance of cyclically installed suction caissons for offshore wind farm (OWF) structures.
Improving the quality of geotechnical datasets: A rules-based approach
Authors: Senanayake A , Peng X , Lewis E
Published: June 2024

A key challenge as we progress through this age of abundant data is to ensure the quality of vast amounts of data being collected, stored, and shared. Though geotechnical engineering is not typically considered a data-intensive discipline, large amounts of geodata are frequently generated in site characterization programs for projects with large spatial footprints. Traditional quality assurance processes that rely on manual checking do not scale well to these large data sets as they become expensive, slow, and unreliable. Automated testing and validation of data using a rules-based approach is a better alternative. This paper presents two testing frameworks that leverage AGS4 and DIGGS data interchange formats together with opensource software libraries that have been developed around them. They allow custom data rules to be easily defined in either Python or Schematron. Results from such scripts are repeatable and reproducible, therefore can be shared between various parties in a project or published for general use. Increases in speed, efficiency, and reliability that this approach brings can produce significant economic benefits to both data producers and data consumers.
Underbase Grouting of Suction Caissons for Offshore Wind Turbines: Is It Necessary?
Authors: Tapper L , Sturm H , Klinkvort R T , Westgate Z J
Published: June 2024

Suction caisson foundations can be an attractive alternative for supporting offshore wind turbine substructures. Standard practice when installing suction caissons is to fill the void remaining beneath the caisson lid with grout to ensure full base contact with the seabed. However, the underbase grouting operation adds capital cost and offshore installation time. This paper challenges the assumption that underbase grouting is required by investigating and comparing foundation performance with and without underbase grouting. A series of 3D finite element analyses have been undertaken to compare suction caisson performance under different vertical (V), horizontal (H) and moment (M) loading conditions for when the void between the caisson lid and the seabed is either grouted or left water-filled. This is analysed for undrained loading, representing a caisson subjected to short term peak loads during a storm. The finite element analysis has been used to compare the soil-foundation stiffness response and ultimate capacity of the caisson when load transfer occurs via a grouted or water-filled void. The results presented in this paper can be used to assist geotechnical and structural engineers in understanding the impact and necessity of underbase grouting for short term performance for offshore wind turbine foundations.
Numerical Study of the Lateral Response of Offshore Rock Anchors
Authors: Genco A , Ciantia M O , Brown M , Previtali M , Ivanovic A , Cresswell N
Published: June 2024

The widespread use of Rock Anchor (RA) systems supported by the increasing demand of offshore energy requires the development of a design method that should be simple to use, efficient and most importantly reliable. In the past decade the development of such analytical tools has proven to be successful if based upon both experimental and advanced numerical analyses. Herein the Geotechnical Particle Finite Element Method (GPFEM) has been employed to assess the response of RA under lateral loading. A non-local Structured Modified Cam Clay (S-MCC) model is used to represent the mechanical behaviour of Berea sandstone. First, by means of large strain 2D plane strain simulations for horizontal sections of the anchor, the p-y response of the RA at various depths is derived numerically. The p-y curves are then used to obtain a rock anchor head horizontal displacement curve, by assuming a Bernoulli beam as representative for the RA. The newly developed p-y approach is then compared to full 3D rock-anchor interaction GPFEM simulations, to the available p-y curves, and analytical approaches found in the literature. The results show that for the type of rock investigated, the 2D plane strain simplification used to numerically retrieve p-y curves for RA is promising and sensibly efficient.
Optimisation of Rock Berm Shapes for Pipeline Protection
Authors: Maconochie A
Published: June 2024

In shallow water rock dump berms are routinely employed for product protection. Conventional berm shape is based on a minimum 0.6m rock cover height, 1m wide crest and 1:3 slopes. This paper presents the results of physical model tests undertaken to assess the effectiveness of conventional berm design to mitigate trawl gear loads on rock-dumped pipelines and assess the benefits from adopting alternative berm shapes. Testing was undertaken at SINTEF's test facilities in Trondheim, Norway, and comprised a series of scale model tests to assess the impact of trawl gear on various rock berm configurations. Both the trawl gear and the berms were fully modelled allowing the true trajectory of the trawl to be assessed as it was pulled over the berms. Penetration of the trawl gear and the resultant loads imposed on buried pipelines during the trawl pull overs were captured. Comparisons between alternative and conventional rock berm configurations were made. The findings indicate similar levels of protection can be achieved by using alternative berm configurations. However, these alternative berm configurations offer significant reductions in rock volumes required to form the berms which first reduce their environmental impact and secondly reduce rock berm installation time and costs.
Evaluation of Submarine Mass Movements in Sulafjorden, Norway
Authors: Carlton B , Fornes P , Hansen R C , Forsberg C S , Vanneste M , Løvholt F , Forsberg C F
Published: June 2024

The Norwegian Public Roads Administration evaluated different concepts for a crossing of Sulafjorden, in western Norway. At the selected crossing, Sulafjorden is 3.3 to 4.5 km wide and 450 meters deep, with steep, sediment laden slopes that necessitate a slope stability assessment. The following analyses were performed: 1D slope stability analyses for the entire project area to identify critical zones; 2D slope stability analyses to refine the identified critical zones and estimate failure volumes; quasi-3D landslide dynamic simulations using the estimated failure volumes as input to predict landslide runout paths. Analyses were conducted assuming earthquakes with return periods of 2,750 and 10,000 years as triggers. The results show that the likelihood of landslide impact to the planned bridge foundation locations is low, and mitigation measures are not necessary. This paper demonstrates the need for multidisciplinary geohazard studies for infrastructure projects in locations with complex bathymetries, such as fjords or subsea canyons.
Application of the Neural Network Model in Predicting the Three-Dimensional Response of Suction Caissons on Clay
Authors: Yin X , Wang H , Pisanò F , Gavin K , Askarinejad A , Zhou H
Published: June 2024

Pipe-soil interaction (PSI) tests such as interface shear box (ISB) and tilt table (TT) tests are now routinely performed to develop undrained and drained residual interface strength envelopes representing the seabed soil and an interface that simulates the pipe surface roughness. The interface strength envelopes are used to estimate the frictional resistance against axial and lateral movement of the pipe based on SAFEBUCK and DNV design guidelines. This paper presents a method to calibrate the parameters of the interface strength envelopes (model) based on an existing global database of PSI test results (prior) and project-specific data (experimental observations) using the Bayesian paradigm. The method outputs probability distributions (posterior) of the model parameters that incorporate the uncertainties associated with the global database and the project-specific data, which helps to offset the subjectivity in assigning uncertainty to project-specific test results inherent with small population datasets. The resulting distributions of the model parameters can be used in probabilistic PSI calculations to narrow ranges of input parameters for structural pipeline analysis.
Potential of the Medusa DMT for Offshore Geotechnical Investigation
Authors: Monaco P , Chiaradonna A , Marchetti D , Amoroso S , L-Heureux J S , Li T M H
Published: June 2024

The Medusa DMT is the newest fully automated version of the flat dilatometer popularly used in soil investigation. The Medusa DMT can operate autonomously without the traditional control unit, the gas tank and the pneumatic cable which is an advantage for offshore testing. The seismic version (Medusa SDMT) incorporates additional sensors for measuring the shear wave velocity. Due to improved accuracy in pressure measurements and controlled pressurization rate, the Medusa DMT is useful for testing soils frequently encountered in coastal and nearshore/offshore environments. This paper presents early findings obtained from field tests carried out in Norway at two benchmark Geo-Test Sites, Onsoy (soft clay) and Halden (silt), managed by the Norwegian Geotechnical Institute. The soils at these sites, though onshore, have marine origins and resemble the offshore soil conditions at several oil/gas fields in the North Sea. The findings shed light on the potential use of the Medusa DMT for offshore investigation.
Whole-Life Design Applied to Pipeline Bundle Towhead Foundation System
Authors: Panayides S , Powell T , White D J , Gourvenec S M
Published: June 2024

Geotechnical design aspects of tolerably mobile mudmat foundations for offshore structures have been investigated and published in recent years. Most of the work to date has focussed on application to pipeline end termination or in line structures for deep-water applications. This paper demonstrates the applicability of a published analytical framework for tolerably mobile mudmat foundations, validated for PLET and ILS geometry and loading conditions, to predict the foundation response of a bundle towhead. The purpose is to quantify the field-life performance of bundle towhead structures. Bundles combine all flowlines and controls within a single carrier pipe and bundle towhead structures house the valve and control assemblies. Towheads are typically designed as gravity-based structures to statically resist in-place loads, whilst being engineered to displace longitudinally across the seabed due to thermal expansion and contraction cycles of the bundle system. Results from three-dimensional finite element analyses of bundle towhead structures designed for a typical North Sea field comprising soft clay are presented and compared with predictions from the analytical framework. The paper also discusses areas of potential further investigation to improve the understanding of tolerably mobile foundations behaviour over their field life.
Assessment of p-y Approaches to Estimate the Lateral Response of Driven and Vibrated Piles in Sand
Authors: Wang H , Lehane B M
Published: June 2024

Given the popularity of the p-y approach to model laterally loaded piles, this paper evaluates the predictive performance of six existing p-y approaches for piles in sand against a new database of lateral pile tests comprising driven and vibrated piles with a range of aspect ratios. This database includes results from a new series of lateral pile tests designed to assess the effect of installation method on lateral response. It is shown, for driven piles, that the API p-y formulation overestimates lateral stiffness significantly while predictions obtained using CPT-based p-y formulations are reasonable at large lateral pile displacements but underestimate the lateral pile head stiffness of piles with D <0.5 m by about 30%. This conservatism reduces with increasing D and increasing L/D and is such that predicted lateral stiffness values of driven piles in the database with D of 4.3 m and L/D>20 are well predicted by the CPT methods. The new series of lateral tests and other tests reported in the literature indicate that the lateral stiffness of vibrated piles in medium dense and dense sand is between 80% and 90% of that of driven piles.
Pile Setup in Sand: Analysis of the Large Diameter Pile Testing Data From Trans Tokyo Bay Highway
Authors: Cathie D , Silvano R , Zarzouras O , Prearo C , Ozsu E , Jardine R
Published: June 2024

Large diameter open-ended piles in mainly sand and silty conditions were tested in static and dynamic regimes as part of the Trans Tokyo Bay Highway (TTBH) development. Two sets of piles on 1.6m and 2.0m OD piles were selected for detailed analysis. Both pile test series included dynamic monitoring during driving and restrikes after 76 and 43 hours setup respectively, and static tests after up to 75 and 52 days setup respectively. For the present study, the axial compression resistance was calculated by various CPT-based methods and compared to (1) static compression load tests and (2) CAPWAP signal matching performed for the present study, and (3) original signal matching performed at the time. Further confirmation of the interpreted resistance at End of initial Drive (EoID) and after setup was obtained from the monitored reaction piles. Setup factors, and the change in shaft resistance distribution with time were assessed, providing valuable setup data applicable to large diameter piles.
Predicting Select Geotechnical Sediment Properties at a Carbonate Site Through Inversion of 2D Post-Stack Multichannel Seismic Data
Authors: Osuchowski A , Bransby M F , Watson P G , Dalgaard E , Ross R
Published: June 2024

This paper describes a seismic inversion workflow used to predict geotechnical sediment properties for a carbonate site on the continental shelf offshore Western Australia. The subsurface profile at the study site is composed of carbonate sediments ranging from muds to sands, with zones of variable cementation, thus providing complex conditions with which to test the workflow. A 2D high frequency post-stack multichannel seismic data set was used as input for the inversion. Geoacoustic measurements made on intact sediment samples using bender elements within a triaxial apparatus were used to (1) understand relationships between acoustic (P-wave velocity and acoustic impedance) and geotechnical properties and (2) build a site-specific background acoustic impedance model which was incorporated into the inversion process. Geotechnical property predictions were spatially mapped across a selected 2D section of the subsurface; the quality of the predictions was evaluated by comparing with ground-truth data from an adjacent geotechnical borehole.
Rapporteur’s Report – Innovative Geotechnologies for Energy Transition
Authors: White D J
Published: June 2024

The 9th Society for Underwater Technology (SUT) International Conference on Offshore Site Investigation and Geotechnics (OSIG) closed with a Rapporteur's report given by the author. This paper provides a record of that report, transcribed from a video recording. The presentation slides are shown as Figures.
A Novel Approach to Geohazard Data Interpretation Leveraging Data-Centric AI
Authors: Tustin A , St Clair K , Miller S , Endresen P , Chenin J
Published: June 2024

In recent years machine learning (ML) has been applied to improve the speed and quality of seismic interpretations. However, the diversity of seismic character and geology make it challenging for a pretrained network to deliver optimal results for a range of data sets. Using a data-centric approach instead, where the ML is driven by high-quality geoscience-led input, performance and quality can be significantly improved. Geoscientists can leverage their knowledge on the data and have the flexibility to interpret features that a pretrained network is not conditioned to identify. Real-time feedback provides interactivity, so that the input can be adjusted to produce the best possible result, improving interpretation quality, detail, and ability to generate alternative models. This paper provides an example of data-centric ML being applied to geohazard multihorizon interpretation on a large 2D seismic survey. This novel approach demonstrates the potential data-centric ML has in enhancing geohazard interpretation.
A new load transfer model for axially loaded piles driven in chalk
Authors: Wen K , Kontoe S , Jardine R , Liu T
Published: June 2024

Chalk poses geotechnical challenges for offshore foundation designers, because it can present as either a weak rock or a highly sensitive and putty paste, depending on the loading applied and the chalk's variable natural structure. Piles supporting jacket structures mainly work through an axial push-pull action, while floating Tension Leg Platforms (TLPs) exert mainly axial tension. Their safe and economical design in chalk for dynamically sensitive offshore wind turbines is challenged by uncertainties regarding their axial loaddisplacement behaviour. This paper first introduces a recently developed load transfer model for axially loaded piles driven in chalk, which is expressed as a function of geotechnical properties measured directly by laboratory and in-situ tests, accounting indirectly for installation effects. The main aim of the paper is to assess the performance of the new model based on field pile tests at a well-characterized chalk site, in terms of axial displacements at the pile head, the distribution of axial force over the pile shaft and the profile of local shaft displacement at failure. Good agreement between the computed and measured pile head response demonstrates the applicability of the new proposed model and shows its advantages in comparison with existing industrial design approaches.
Interpreting Interface Shear Strength Parameters for Pipe-Soil Interaction Analysis Using Bayesian Inference
Authors: Das R , Westgate Z J
Published: June 2024

Pipe-soil interaction (PSI) tests such as interface shear box (ISB) and tilt table (TT) tests are now routinely performed to develop undrained and drained residual interface strength envelopes representing the seabed soil and an interface that simulates the pipe surface roughness. The interface strength envelopes are used to estimate the frictional resistance against axial and lateral movement of the pipe based on SAFEBUCK and DNV design guidelines. This paper presents a method to calibrate the parameters of the interface strength envelopes (model) based on an existing global database of PSI test results (prior) and project-specific data (experimental observations) using the Bayesian paradigm. The method outputs probability distributions (posterior) of the model parameters that incorporate the uncertainties associated with the global database and the project-specific data, which helps to offset the subjectivity in assigning uncertainty to project-specific test results inherent with small population datasets. The resulting distributions of the model parameters can be used in probabilistic PSI calculations to narrow ranges of input parameters for structural pipeline analysis.
Merging Individual Acoustic Corer™ Data Sets Into a Unified Volume to Optimize the Identification and Interpretation of Geohazards, Obstructions, and Stratigraphy: Case Studies From the Baltic Sea and Gulf of Mexico
Authors: Abbott S , Kotsi M , Laidley R , Kilic C A , Guigne J Y
Published: June 2024

The Acoustic Corer™ (AC) 3-D imaging technology comprises high- and low-frequency chirps and a parametric source with operating frequencies from 1.5kHz-15kHz through a stationary landed platform. Using multi-aspect acoustic imaging, it produces a 14m diameter volumetric image to a penetration depth of 60m below seabed, depending on the geological conditions. Recent multi-core AC surveys within the Baltic Sea and Gulf of Mexico proved that merging individual AC data sets into a unified volume greatly enhanced the data resolution and understanding of the sub-seabed stratigraphy and geohazards and obstructions present within. Specifically, this enabled a more cohesive representation and characterization of boulders, hard layers, and conductor pipes. The ability to merge data sets and maintain data quality suggests that optimal positioning, soil velocity and static corrections were obtained. These case studies, as applied to the renewables and oil and gas sectors, build on the value that the AC delivers for de-risking offshore infrastructure installations and remediation efforts.
Bayesian Strain-Rate Correction Applied to Dynamic CPTu Data
Authors: Collico S , Arroyo M
Published: June 2024

In situ free fall penetration tests (FFP) are performed for cable routes development due to their cost and efficient way to geotechnical characterize near-surface marine sediments. FFP readings differs from quasi-static observations due the higher impact velocity and nonlinear penetration rate of the cone probe. Therefore, application of FFP observations to geotechnical parameters estimation requires a strain-rate correction according to some strain-rate laws. The commonly employed procedure requires matched (i.e., closely located in space and time) quasi-static and FFP measurements, therefore losing the cost and time efficiency of FFP tests. This work illustrates a Bayesian methodology for FFP cone resistance correction from limited unmatched quasi-static CPTU readings. Three different stain-rate laws are exploited in order to assess the most plausible data conversion. The methodology is applied to the port of Nice (France), where in situ investigations are available from previous studies.
Effect of Installation Mode, Pile Shape and Cycling on the Ageing of Shaft Friction of Mild Steel Piles
Authors: Bittar E , Lehane B , Watson P , Shonberg A , Deeks A
Published: June 2024

Significant uncertainty exists regarding the effect of axial cyclic loading and installation technique on the ageing characteristics of displacement piles. To address this, the current study investigates the influence of installation method, pile shape and cyclic loading on the ageing of shaft friction of steel piles in sand. The research is based on field testing that indicated a significant increase in shaft capacity with time for all circular piles. The mode of installation had a notable effect on short-term capacity, although long-term capacity remained largely unaffected. The results also show that one-way tension cycling of piles within the stable zone of the cyclic interaction diagram did not lead to a significant reduction in the growth of shaft friction with time, as observed in first-time tests.
An Application of Machine Learning to the Back Analysis of Monopile Response
Authors: Pirrone A , Taborda D M G
Published: June 2024

Current design approaches for monopile foundations supporting wind turbines frequently rely on three-dimensional finite element analyses (3D FEA). These provide insights into the behaviour of the monopile, enabling the determination of soil reactions and, consequently, the calibration of non-linear springs, which are less computationally expensive. However, the reliability of these analyses is dependent on the accuracy of the chosen constitutive model, and, when using advance constitutive models, their calibration becomes more difficult. Therefore, back-analyses of monitored piles provide an opportunity to characterise the performance of constitutive models. In this paper, results from the field tests undertaken at Dunkirk during the Pile-Soil Analysis (PISA) project are used to calibrate a simple state parameter-dependent sand model. A machine learning technique combined with particle swarm optimisation was used. This procedure reduces the number of required 3D FEA, thus mitigating one of the shortcomings of optimisation algorithms, enabling faster and more accurate back-analyses.
Full Scale Pile Load Testing for an Offshore Wind Farm
Authors: Shonberg A , Harte M , Jardine R J , Schroeder F C , Molyneaux E C G , Perikleous G
Published: June 2024

Offshore wind energy is playing a central role in the global effort to reduce CO2 emissions. As offshore wind farms expand in scope and size, ever more challenging environments are being encountered, including deeper waters, more extreme loading conditions and more difficult ground conditions. Windfarm developments in the Taiwan Strait face such challenges, with foundations required to resist typhoon and earthquake loading at sites where deep layers of recent sediments, comprising low OCR, loose to medium dense sands, silts and very low plasticity silty clays, are encountered. Little foundation design guidance is available for such soils and as such, in 2019, Orsted undertook an offshore pile load test campaign to address the risks that geotechnical uncertainty posed to a number of Taiwan Strait projects. The campaign, believed to be the largest to date for offshore jacket piles, focused on testing six 1.5m diameter, up to 75m embedded length, highly instrumented open tubular steel piles driven at two sites. The testing at each location included dynamic installation monitoring, static maintained tension loading to failure at dates around 50 days after driving, restrikes on separate piles to provide further information on ageing effects, a series of cyclic axial loading experiments and large-displacement lateral load tests. The successful pile load test campaign reduced project risks, enabled considerable economies in steel and installation costs, reduced embodied CO2 emissions and provided new insights into the field behaviour of large offshore piles.