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Articles 1 - 30 of 4988

Full-Text Articles in Engineering

Identifying Payable Cluster Distributions For Improved Reservoir Characterization: A Robust Unsupervised Ml Strategy For Rock Typing Of Depositional Facies In Heterogeneous Rocks, Umar Ashraf, Aqsa Anees, Hucai Zhang, Muhammad Ali, Hung Vo Thanh, Yujie Yuan Dec 2024

Identifying Payable Cluster Distributions For Improved Reservoir Characterization: A Robust Unsupervised Ml Strategy For Rock Typing Of Depositional Facies In Heterogeneous Rocks, Umar Ashraf, Aqsa Anees, Hucai Zhang, Muhammad Ali, Hung Vo Thanh, Yujie Yuan

Research outputs 2022 to 2026

The oil and gas industry relies on accurately predicting profitable clusters in subsurface formations for geophysical reservoir analysis. It is challenging to predict payable clusters in complicated geological settings like the Lower Indus Basin, Pakistan. In complex, high-dimensional heterogeneous geological settings, traditional statistical methods seldom provide correct results. Therefore, this paper introduces a robust unsupervised AI strategy designed to identify and classify profitable zones using self-organizing maps (SOM) and K-means clustering techniques. Results of SOM and K-means clustering provided the reservoir potentials of six depositional facies types (MBSD, DCSD, MBSMD, SSiCL, SMDFM, MBSh) based on cluster distributions. The depositional facies …


Stress-Dependent Mohr–Coulomb Shear Strength Parameters For Intact Rock, Hao Li, Leo Pel, Zhenjiang You, David Smeulders Dec 2024

Stress-Dependent Mohr–Coulomb Shear Strength Parameters For Intact Rock, Hao Li, Leo Pel, Zhenjiang You, David Smeulders

Research outputs 2022 to 2026

Rock strength is imperative for the design and stability analysis of engineering structures. The Mohr–Coulomb (M-C) criterion holds significant prominence in geotechnical engineering. However, the M-C criterion fails to accurately capture the nonlinear strength response and neglects the critical state of rocks, potentially leading to inaccuracies in the design phase of deep engineering projects. This study introduces an innovative stress-dependent friction angle and cohesion (SFC) for the M-C criterion to capture the nonlinear strength responses of intact rocks, spanning from non-critical to critical states (brittle to ductile regions). A novel method for determining these stress-dependent parameters at each corresponding σ3 …


Assessment Of Efficiencies Of Different Additives To Improve Cbr Value For The Highway Industry, Ahmed H. El-Bosraty Eng., Ahmed M. Ebid Dr., M. Bahr Prof. Sep 2024

Assessment Of Efficiencies Of Different Additives To Improve Cbr Value For The Highway Industry, Ahmed H. El-Bosraty Eng., Ahmed M. Ebid Dr., M. Bahr Prof.

Future Engineering Journal

The structural design of flexible or rigid paving layers depends on the strength of the foundation soil, which is expressed by the California Bearing Ratio (CBR). Soil strengthening and improvement techniques vary according to the type of soil, whether it is granular or cohesive. This study is concerned with evaluating the efficiency of three techniques used to improve the properties of granular soil, the first by using natural fibers, the second by using synthetic fibers, and the third by mixing with powders. The study methodology relies on reviewing, studying, classifying and comparing the previously published work in this context to …


Balancing Results From Ai-Based Geostatistics Versus Fuzzy Inference By Game Theory Bargaining To Improve A Groundwater Monitoring Network, Masoumeh Hashemi, Richard C. Peralta, Matt Yost Aug 2024

Balancing Results From Ai-Based Geostatistics Versus Fuzzy Inference By Game Theory Bargaining To Improve A Groundwater Monitoring Network, Masoumeh Hashemi, Richard C. Peralta, Matt Yost

Plants, Soils and Climate Student Research

An artificial intelligence-based geostatistical optimization algorithm was developed to upgrade a test Iranian aquifer's existing groundwater monitoring network. For that aquifer, a preliminary study revealed that a Multi-Layer Perceptron Artificial Neural Network (MLP-ANN) more accurately determined temporally average water table elevations than geostatistical kriging, spline, and inverse distance weighting. Because kriging is usually used in that area for water table estimation, the developed algorithm used MLP-ANN to guide kriging, and Genetic Algorithm (GA) to determine locations for new monitoring well location(s). For possible annual fiscal budgets allowing 1-12 new wells, 12 sets of optimal new well locations are reported. Each …


Base Case Shear-Wave Velocity Profiles And Non-Linear Material Property Models Of Local Site Conditions In South Carolina For Seismic Site Response Analyses, Ali Sedaghat Shirehjini Aug 2024

Base Case Shear-Wave Velocity Profiles And Non-Linear Material Property Models Of Local Site Conditions In South Carolina For Seismic Site Response Analyses, Ali Sedaghat Shirehjini

All Dissertations

This dissertation presents the development of base case small-strain shear-wave velocity ( ) profiles and non-linear materials property models of local site conditions in South Carolina for seismic site response analyses. The need to address South Carolina's seismic hazards is partly motivated by the 1886 Charleston earthquake (moment magnitude, Mw= 6.7 to 7.5). Required inputs for seismic site response analysis include profile down to a specified reference outcrop condition and non-linear material properties for each layer in the profile. Although firm rock (i.e., ≥ 2,500 ft/s) or hard rock (i.e., ≥ 9,850 ft/s) is commonly assumed for the …


Time-To-Failure Prediction Of Fine-Grained Soil Slopes Subject To Weather-Driven Deterioration, Arm M. Morsy Aug 2024

Time-To-Failure Prediction Of Fine-Grained Soil Slopes Subject To Weather-Driven Deterioration, Arm M. Morsy

Mineta Transportation Institute

Embankments have been widely used in the construction of transportation and flood defense infrastructure. Embankments constructed from clays experience a suite of weather-driven deterioration processes that lead to a progressive loss of hydromechanical performance, causing potentially severe and costly consequences. This study aimed to predict the time to failure of aging, deteriorating clay embankments supporting transportation infrastructure. A multi-phase numerical modeling approach was developed to replicate the long-term, weather-driven, hydromechanical behavior of clay embankments. This model simulated the behavior of a number of well-documented embankment failure case studies that had sufficient data to derive the necessary soil properties and climate …


Rock Structural Changes Monitored By Fibre Bragg Grating Sensors And Nuclear Magnetic Resonance During Static And Dynamic Carbonated Brine Core Flooding Experiments, Bruno Da Silva Falcão, Lionel Esteban, Ausama Giwelli, Ahmed Al-Yaseri, Alireza Keshavarz, Jeremie Dautriat, Stephanie Vialle, Stefan Iglauer Jul 2024

Rock Structural Changes Monitored By Fibre Bragg Grating Sensors And Nuclear Magnetic Resonance During Static And Dynamic Carbonated Brine Core Flooding Experiments, Bruno Da Silva Falcão, Lionel Esteban, Ausama Giwelli, Ahmed Al-Yaseri, Alireza Keshavarz, Jeremie Dautriat, Stephanie Vialle, Stefan Iglauer

Research outputs 2022 to 2026

One proposed solution to reduce greenhouse gas emissions is the capture and storage of carbon dioxide (CCS) in geological formations such as depleted oil and gas reservoirs. Injected carbon dioxide (CO2) forms carbonic acid once dissolved in the formation water, which can lead to dissolution of certain types of rock minerals. This may weaken rock geomechanical properties that can jeopardize the safety of long-term storage. In this work, the use of Fibre Bragg Grating (FBG) sensors associated with Nuclear Magnetic Resonance (NMR) was investigated to measure the change in rock strain during core flooding experiments. Optical fibres were glued onto …


Advance On Rock-Breaking Cutter Steels: A Review Of Characteristics, Failure Modes, Molding Processes And Strengthening Technology, Ying Jiang, Bai Xin Dong, Jun Fan, Feng Qiu, Hong Yu Yang, Shi Li Shu, Fang Chang, Qi Chuan Jiang, Lai Chang Zhang Jul 2024

Advance On Rock-Breaking Cutter Steels: A Review Of Characteristics, Failure Modes, Molding Processes And Strengthening Technology, Ying Jiang, Bai Xin Dong, Jun Fan, Feng Qiu, Hong Yu Yang, Shi Li Shu, Fang Chang, Qi Chuan Jiang, Lai Chang Zhang

Research outputs 2022 to 2026

Rock breaking has always been a challenging problem that must be solved in projects such as excavating mountains, drilling wells, and constructing railways. Among the rock-breaking cutter steels, AISI H13 steel and wear-resistant high manganese steel have become the best choices. From the characteristics and failure modes of the two, rock-breaking cutter steels should simultaneously have high strength, high toughness and high wear resistance to avoid short-term fracture/damage and cost increase. Analyzing the problems existing in the molding process of rock-breaking cutter steels such as die casting, forging, and hot stamping, traditional strengthening technologies such as alloying optimization, heat treatment, …


Liquefaction Case Histories From Oceano, California During The 2003 San Simeon Earthquake, Hayden Brake Jun 2024

Liquefaction Case Histories From Oceano, California During The 2003 San Simeon Earthquake, Hayden Brake

Master's Theses

On December 22nd, 2003, the Mw=6.5 San Simeon earthquake occurred 12 kilometers east of San Simeon, California, causing damage to buildings, roads, and other infrastructure throughout the central coast. The community of Oceano, 80 kilometers southeast of the epicenter, experienced damage to foundations, roads, and utilities due to liquefaction and lateral spreading. The unique geologic environment in Oceano caused a local amplification of ground motions, liquefaction, and lateral spreading. This study entailed developing ten liquefaction case histories from Oceano during the 2003 San Simeon earthquake. Four of the ten case histories are liquefaction cases and six are non-liquefaction cases, with …


Insight Into The Application Of Engineered Phenol Polymer Nanocomposites For Geothermal Well Applications To Modify Fracture Permeability, Fatemeh Hamidi May 2024

Insight Into The Application Of Engineered Phenol Polymer Nanocomposites For Geothermal Well Applications To Modify Fracture Permeability, Fatemeh Hamidi

Civil Engineering ETDs

In enhanced geothermal systems, the efficient transfer of heat from the formation to the fluid circulating through the fracture network can be compromised when thermal short-circuiting occurs due to preferential flow through highly conductive fractures. This study introduces a pioneering approach using newly developed phenol polymer nanocomposites as an engineering solution to address the challenges associated with preferential flow in geothermal wells, which can lead to thermal short-circuiting. Multiple phenol polymer nanocomposites were formulated, incorporating aluminum oxide, COOH-functionalized graphitized multi-walled carbon nanotubes (MWCNTs), and graphene nanoparticles, each with a 0.5 wt.% polymer dosage. This research successfully modified the crosslinking process …


Effect Of Waste Covid-19 Masks On Compaction Characteristics Of Silty-Clay Soil, Sydney K. Lawson May 2024

Effect Of Waste Covid-19 Masks On Compaction Characteristics Of Silty-Clay Soil, Sydney K. Lawson

Honors College Theses

The present study aims to explore the effect of adding shredded waste Covid-19 masks to silty-clay soil on the soil’s compaction characteristics for beneficial use in embankment, the subgrade of roadways, or backfill. This was accomplished by using two different types of masks: blue surgical masks and KN95 masks. Both mask types were hand shredded into half-inch sections using safety-scissors. The maximum dry density (MDD) and optimum moisture content (OMC) are the two most important compaction characteristics, and they were determined by the Standard Proctor Compaction Test (ASTM D698 / AASHTO T99). The change of both the MDD and OMC …


The Use Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Properties Of Green Roof Media And Granular Soils, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr. May 2024

The Use Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Properties Of Green Roof Media And Granular Soils, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr.

Publications and Research

This study investigates using repurposed whole textiles to modify the mechanical and hydrogeological properties of lightweight Green Roof media and granular pavement soils.

Green Roof Media Green roofs aim to bring the advantages of suburban agriculture to urban environments while improving energy efficiency and enhancing stormwater management in public, commercial, and residential buildings. Previous studies by City Tech undergraduate research assistants demonstrated significant modification in hydrogeological properties when incorporating textile fabric up to 3% textile by weight (%Tex) at an aspect ratio of 1:1. The effects of mixing repurposed whole textile fiber with Green Roof media is evaluated with regards …


Development Of A Clay Characterization Procedure Using Atterberg Limits For Additive Manufacturing, Rakesh K. Pandit May 2024

Development Of A Clay Characterization Procedure Using Atterberg Limits For Additive Manufacturing, Rakesh K. Pandit

Electronic Theses and Dissertations

Recently, additive manufacturing (AM) using earthen materials (natural earth components such as clay, silt, and sand) has been proposed as a sustainable alternative to conventional concrete-based construction practices for its potential to reduce carbon footprint. Some research groups suggest zero-transportation construction can be achieved using local or “indigenous" soils. However, the heterogeneous nature of these soils can impose significant challenges associated with fine-tuning the soil mixture and the printing parameters for the extrusion, deposition, and curing process. Understanding the mechanical links between the extrusion process and the behavior of earthen materials is critical to developing the potential of AM using …


Experimental Investigation And Numerical Modeling Of Carbonation Of Non-Plastic Soils Mixed With Hydrated Lime, Andres F. Espinosa May 2024

Experimental Investigation And Numerical Modeling Of Carbonation Of Non-Plastic Soils Mixed With Hydrated Lime, Andres F. Espinosa

Electronic Theses and Dissertations

Soil Carbonation presents an approach for chemically stabilizing subgrade materials, inducing cementation within the soil matrix by generation of a calcium carbonate binder. Unlike conventional methods, which rely solely on additives, soil carbonation introduces carbon dioxide gas to trigger a reaction, precipitating carbonate minerals that enhance the soil’s strength and stiffness. A notable advantage of this method is carbon sequestration, reducing significantly the carbon footprint compared to traditional techniques reliant on chemical additives, which makes it a sustainable stabilization alternative. Reaction kinetics and gas mobility largely dictate the rate of carbonation and binder formation within the soil matrix. In this …


Primary Consolidation Settlement Of South Louisiana Clay Deposits In Marsh Environment, Alice E. Stark May 2024

Primary Consolidation Settlement Of South Louisiana Clay Deposits In Marsh Environment, Alice E. Stark

University of New Orleans Theses and Dissertations

Accurate estimation of primary consolidation of in-situ marsh soils is inherently difficult in south Louisiana due to the soft, settlement prone soils and variable alluvial material. To investigate the accuracy of settlement analysis methods commonly utilized in local practice, estimates from numerical models were compared to the results of a settlement monitoring program at a project site during construction. Sensitivity analyses were then performed using several parameters that were used in the settlement analysis, and the results were compared to the field observations.

The disagreement of observed settlement data and settlement estimates produced with a model that did not include …


Development And Application Of Discrete Element Models For Granular Materials - From Rigid Spheres To Complex-Shaped Flexible Particles With Breakage, Zakia Tasnim May 2024

Development And Application Of Discrete Element Models For Granular Materials - From Rigid Spheres To Complex-Shaped Flexible Particles With Breakage, Zakia Tasnim

All Dissertations

Granular materials, which can range from nanometers to centimeters, are widely encountered as particles or powders in nature and in engineered systems. Some examples of granular materials include sands, gravels, biomass feedstocks, rice grains, pharmaceutical pills, glass beads, and lunar or martian regolith simulants. The attributes of and the interactions between constituent particles dictate the bulk mechanical properties and behavior of granular materials. The discrete element method (DEM), a particle-based modeling technique, has become a useful numerical tool for modeling the bulk behavior (such as mechanical, flow, and breakage behavior) of granular materials, where interactions between the granular materials' individual …


The Role Of Grain Morphology And Individual Grain Fracture On Granular Material Behavior, Anne Katherine Turner May 2024

The Role Of Grain Morphology And Individual Grain Fracture On Granular Material Behavior, Anne Katherine Turner

Doctoral Dissertations

Granular materials, such as sand, are multi-scale materials combining an immense number of crushable particles to create an assembly. Numerical approaches to modeling sand’s mechanical behavior often use simplifications, such as treating the volume as a continuum or representing the particles with rigid, idealized spheres using the discrete element method. These approaches overlook crucial nonlinear phenomena, such as individual grain morphology and fracture, which have been shown to influence sand’s strength and plasticity behavior. This research investigated methods to incorporate such phenomena , focusing on simulating single grain crushing tests and 1D confined compression of Ottawa sand using finite element …


The Effect Of Methylene Blue On Stearic Acid-Aged Quartz/Co2/Brine Wettability: Implications For Co2 Geo-Storage, Fatemah Alhammad, Mujahid Ali, Nurudeen P. Yekeen, Muhammad Ali, Hussein Hoteit, Stefan Iglauer, Alireza Keshavarz May 2024

The Effect Of Methylene Blue On Stearic Acid-Aged Quartz/Co2/Brine Wettability: Implications For Co2 Geo-Storage, Fatemah Alhammad, Mujahid Ali, Nurudeen P. Yekeen, Muhammad Ali, Hussein Hoteit, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Carbon dioxide sequestration in geological formations has been proposed as a promising solution to reach net zero carbon emissions but the success of underground CO2 storage in sandstone formations depends on the brine/CO2 wettability of sandstone. Research evidence showed that natural geological formation is hydrophobic even in the presence of minute concentration of inherent organic acids. This study investigates the effect of methylene blue (MB) on CO2 wettability of organic-acid contaminated quartz through the tilted plate contact angle measurement method. Pure quartz substrates were aged in a stearic acid/n-decane solution for one week and subsequently modified with different concentrations of …


Enhanced Hoek-Brown (H-B) Criterion For Rocks Exposed To Chemical Corrosion, Hao Li, Leo Pel, Zhenjiang You, David Smeulders May 2024

Enhanced Hoek-Brown (H-B) Criterion For Rocks Exposed To Chemical Corrosion, Hao Li, Leo Pel, Zhenjiang You, David Smeulders

Research outputs 2022 to 2026

Underground constructions often encounter water environments, where water–rock interaction can increase porosity, thereby weakening engineering rocks. Correspondingly, the failure criterion for chemically corroded rocks becomes essential in the stability analysis and design of such structures. This study enhances the applicability of the Hoek-Brown (H-B) criterion for engineering structures operating in chemically corrosive conditions by introducing a kinetic porosity-dependent instantaneous mi (KPIM). A multiscale experimental investigation, including nuclear magnetic resonance (NMR), X-ray diffraction (XRD), scanning electron microscopy (SEM), pH and ion chromatography analysis, and triaxial compression tests, is employed to quantify pore structural changes and their linkage with the strength responses …


Assessment Of Improvement In Unpaved Roadway Performance Using 3d Geogrids Under Cyclic Loading, Munibhaskar Pagadala Apr 2024

Assessment Of Improvement In Unpaved Roadway Performance Using 3d Geogrids Under Cyclic Loading, Munibhaskar Pagadala

Doctoral Dissertations and Master's Theses

Geogrids have been used for decades to improve the performance in both paved and unpaved road construction. This research focuses on quantifying the performance and optimizing the design of unpaved roadways using the results from an extensive cyclic triaxial testing program. Twenty-seven cyclic triaxial tests were performed, consisting of unreinforced (control) and reinforced samples using two types of 3D geogrids: Grid1 and Grid2. The samples measured 150 mm in diameter and a height of 300 mm. The tests were run under different loading sequences ranging from 41 kPa to 55 psi (6 psi to 8 psi of confining stress and …


Performance Assessment Of Microencapsulated Phase Change Materials With Low To High Thermoregulation Range In Asphalt Binder, Anil Kumar Baditha, Ayyaz Fareed Mar 2024

Performance Assessment Of Microencapsulated Phase Change Materials With Low To High Thermoregulation Range In Asphalt Binder, Anil Kumar Baditha, Ayyaz Fareed

Graduate Student and Postdoctoral Fellow Symposium

Asphalt pavements face significant challenges due to low temperature cracking and rutting caused by extreme temperature fluctuations and traffic loading. These issues result in higher maintenance costs and reduced service life of the pavements. To address this, researchers explored the use of Microencapsulated Phase Change Materials (MPCMs) to induce thermoregulation in asphalt pavements. However, the existing research focused on high-temperature performance of binders, highlighting the need of research on evaluating the low-temperature performance. Therefore, the study aims to evaluate the impact of incorporating MPCMs on low to high temperature performance of binders. Three types of MPCMs were incorporated into asphalt …


Demystifying Utility Coordination: Understanding The Basics, Josshe I. Palm Mar 2024

Demystifying Utility Coordination: Understanding The Basics, Josshe I. Palm

Purdue Road School

This session will explain utility coordination to non-utility coordinators. It will help educate others about the role and responsibilities of a utility coordinator, an OSA, easy UC and design mistakes to avoid, scope and design considerations, items commonly overlooked, when to coordinate SUE, and how to work with your UC to request a letting adjustment. We will also highlight UC submittals and allow time for questions about the UC’s role in a project’s success.


Soil Nitrate Prediction Using Ftir-Atr, Vis-Nir, And Raman Spectroscopy, Sabiha Ferdous Mar 2024

Soil Nitrate Prediction Using Ftir-Atr, Vis-Nir, And Raman Spectroscopy, Sabiha Ferdous

Department of Biological Systems Engineering: Dissertations and Theses

Fourier transform infrared spectroscopy (FTIR) combined with Attenuated total reflectance (ATR), Visible-Near Infrared spectroscopy (Vis-NIR), and Raman spectroscopy (RS) are non-destructive techniques for rapid determination of nitrogen compounds in soil. Leveraging FTIR-ATR and Vis-NIR spectra using partial least squares regression (PLSR) modeling, the study aims to predict soil nitrate content and explored the feasibility of Raman spectroscopy to detect nitrate (NO3-), nitrite (NO2-), and ammonium (NH4+) in soil. Soil samples were collected from four different fields, dried, sieved (2mm), and then used for collecting spectra (FTIR-ATR and Vis-NIR). Laboratory analysis was …


Experimental Study On Shear Strength Of Unsaturated Soil Over A Wide Suction Range And Its Prediction, Geng Niu, Xiao-Feng Zhu, Jun-Xing Li, Meng-Yuan Lü, Li-Qi An, Zi-Han Chen Feb 2024

Experimental Study On Shear Strength Of Unsaturated Soil Over A Wide Suction Range And Its Prediction, Geng Niu, Xiao-Feng Zhu, Jun-Xing Li, Meng-Yuan Lü, Li-Qi An, Zi-Han Chen

Rock and Soil Mechanics

In this paper, the experimental studies on the water retention and strength properties of unsaturated weakly expansive soil in a wide suction range were carried out, and a strength model of unsaturated soil over a wide suction range was proposed. The results show that in the wide suction range, the stress‒strain curve increases with the increase of suction. The strain hardening occurs in the low suction range, while the strain softening appears in the high suction range. In the low suction range, the sample presents shear contraction, while in the high suction range, the sample begins to show a shear …


Energy Evolution Of Unloading Confining Pressure And Dissipative Energy Damage Constitutive Model Of Coal-Rock Combination, Wen-Kai Ru, Shan-Chao Hu, Di-Yuan Li, Jin-Yin Ma, Chen-Xi Zhang, Ping-Kuang Luo, Hao Gong, Ao-Hui Zhou Feb 2024

Energy Evolution Of Unloading Confining Pressure And Dissipative Energy Damage Constitutive Model Of Coal-Rock Combination, Wen-Kai Ru, Shan-Chao Hu, Di-Yuan Li, Jin-Yin Ma, Chen-Xi Zhang, Ping-Kuang Luo, Hao Gong, Ao-Hui Zhou

Rock and Soil Mechanics

In coal mining, the excavation of a coal-rock roadway and a thin coal seam will inevitably cause radial unloading of the coal-rock combination system. The radial unloading phenomenon is often accompanied by the rapid accumulation and release of energy, so it is necessary to investigate the energy evolution law of coal-rock combination specimens under the unloading confining pressure condition. To this end, the unloading confining pressure tests with different unloading rates were carried out for the coal-rock combination specimens. The results show that: (1) The axial loading and constant stress stages are the main energy storage stages of the combination …


Reliability Of Offshore Plate Anchor Design In Sand For Uplift Limit State, Yu-Ting Li, Xiao-Bin Chen, Peng-Peng He Feb 2024

Reliability Of Offshore Plate Anchor Design In Sand For Uplift Limit State, Yu-Ting Li, Xiao-Bin Chen, Peng-Peng He

Rock and Soil Mechanics

The offshore wind industry needs to move towards floating offshore wind turbines (FOWTs) that are secured to the seabed with anchoring systems in order to harness the more substantial amounts of offshore wind resources available in deep waters. The design of the anchoring system for FOWTs is crucial to ensure stability and safety in challenging offshore conditions. As a simplified reliability- based design approach, the partial safety factor method remains important in current offshore foundation design practice, but its effectiveness in achieving the required target safety level still needs to be examined. To achieve this end, a reliability analysis is …


Analysis Of Factors Affecting Permeability Of Calcareous Sand In Salt Solution Environment, Si-Wei Zheng, Ming-Jian Hu, Yu-Long Huo, Yu Li Feb 2024

Analysis Of Factors Affecting Permeability Of Calcareous Sand In Salt Solution Environment, Si-Wei Zheng, Ming-Jian Hu, Yu-Long Huo, Yu Li

Rock and Soil Mechanics

Permeability is the capacity of a soil for transmitting a fluid, e.g., a salt solution, through soil pores. The permeability coefficient K is an important measurement of the soil permeability, which is affected by various factors. The existing research on the permeability of sandy soil is basically carried out in the freshwater environment. However, the calcareous sand is a typical marine sedimentary sand, which is deposited in the seawater environment with certain salt concentrations. In order to investigate the influence of void ratio, particle size and concentration of the salt solution on the permeability of calcareous sand in a salt …


Strength Model Of Anisotropic Rocks Based On Hoek-Brown Criterion, Guo-Xiao Li, Hang-Long Wang, Jun Peng, Lin-Fei Wang, Bi-Bo Dai Feb 2024

Strength Model Of Anisotropic Rocks Based On Hoek-Brown Criterion, Guo-Xiao Li, Hang-Long Wang, Jun Peng, Lin-Fei Wang, Bi-Bo Dai

Rock and Soil Mechanics

In order to improve the applicability of Hoek-Brown failure criterion and reduce subjectivity in the determination of geological strength index (GSI) value for anisotropic rocks, a modified Hoek-Brown failure criterion is proposed, which considers the variation of the GSI value with the bedding angle of anisotropic rocks. Triaxial compression test data of anisotropic rocks with different bedding angles were first collected. The results show that the peak strength of anisotropic rocks exhibits a U-shaped relation with bedding angle . Then, the rock specimen with the bedding angle  = 0º is defined as the intact rock. The uniaxial compressive strength …


Correlation Between Macro And Micro Mechanical Parameters Of Marble Based On Nanoindentation Experiment, Xian-Hui Chen, Yi Cheng, Xin-Yue Xie, Mi-Mi Chen Feb 2024

Correlation Between Macro And Micro Mechanical Parameters Of Marble Based On Nanoindentation Experiment, Xian-Hui Chen, Yi Cheng, Xin-Yue Xie, Mi-Mi Chen

Rock and Soil Mechanics

Nanoindentation experiment is an important means to study micro mechanical properties of rock. Up to now only a few studies have discussed the correlation between the micro mechanical properties of rock and various macroscopic strengths of the rock. Firstly, the nanoindentation experiments on four different kinds of marble were carried out by the continuous stiffness measurement technique to obtain the micro mechanical parameters of dolomite and calcite. Secondly, the microscopic data scale was upgraded by Mori-Tanaka method to obtain the homogenized elastic modulus and Poisson’s ratio. Finally, the correlation between the microscopic parameters and the macroscopic mechanical experiment results was …


Fatigue Analysis Of Jacket Foundations For Offshore Wind Turbines, Yue-Ming Du, De-Qiong Kong, Si-Liu Wang, Bin Zhu Feb 2024

Fatigue Analysis Of Jacket Foundations For Offshore Wind Turbines, Yue-Ming Du, De-Qiong Kong, Si-Liu Wang, Bin Zhu

Rock and Soil Mechanics

Jacket foundations are considered as the most promising solution for offshore wind turbines (OWTs), due to its large lateral stiffness and adaptability to different marine environments. Nowadays, the study on jacket foundations mainly focuses on the bearing and deformation behavior, with significantly less attention being paid to their fatigue damage. Besides, the actual pile-soil interaction is always ignored when assessing the fatigue damage or fatigue life of the foundations for OWTs. This paper presents the development of a three-dimensional numerical model of tetrapod piled jacket foundations, with the interaction between the corner piles and the soil being implemented into it. …