Geotechnical Engineering Commons^™

Experimental Investigation On Quantitative Evaluation Of Rock Hardness Based On Impact Energy Dissipation Index, Rui-Lang Cao, Yu-Jie Wang, Bo Xing, Yu-Fei Zhao, Qiang Shen

Rock and Soil Mechanics

Rock hardness is an important indicator reflecting the relative hardness, drillability, and blastability of rock formation. Accurate interpretation of the response of percussion drilling tools can provide new possibilities for in-situ, rapid, and quantitative evaluation of rock hardness. High-precision digital displacement, hydraulic pressure, and rotational speed sensors were used to monitor the key transmission parts of the percussion drill, and a digital monitoring system for the drilling process was then established. Rock hardness measurement and orthogonal tests of percussion drilling were parallelly carried out, and a standard database containing response data of the drill when drilling various types of rocks …

Multi-Directional Cyclic Simple Shear Behaviour Of Loose Sand Under Complex Initial Stress States, Yao Li, Jia-Ping Li

Rock and Soil Mechanics

Loose sand is highly susceptible to liquefaction, and small changes in stress state can affect its liquefaction characteristics. Based on multi-directional cyclic simple shear tests, this study conducted cyclic simple shear tests on loose sand under different magnitudes and directions of static shear stress, and complex shear paths. The cyclic simple shear characteristics of loose sand under complex initial stress states are studied. The main conclusions are drawn as follows: (1) As the static shear stress ratio increases, the peak shear stress of the specimen increases, the increment of pore water pressure in the first cycle increases, and the specimen …

Characteristics And Mechanism Of Soil Heave At The Bottom Of Ultra-Deep Circular Shafts In Soft Soil Areas, Ya-Fei Qiao, Kai Yan, Teng-Teng Zhao, Wen-Qi Ding

Rock and Soil Mechanics

Based on an ultra-deep circular shaft project in Shanghai, the field data of soil heave at the bottom of the pit during the construction were collected, and the vertical distribution pattern, evolution law and main influencing factors of soil heave at the bottom of the pit were summarized. An axisymmetric numerical model was then built and verified to investigate the effect of the excavation-induced unloading, dewatering, diaphragm wall and soil mechanical properties on the soil heave, then the mechanism of soil heave was revealed. Soil heave was the combined result of the soil mechanical response under the excavation-induced unloading, dewatering, …

Numerical Simulation Of Three-Dimensional Rock Fragmentation By Disc Cutters Of Tunnel Boring Machine Using Peridynamics, Jian Zhou, Xiao-Nan Shang, Fu-Shen Liu, Jun-Yi Shen, Xing-Chuan Liao

Rock and Soil Mechanics

Peridynamics is a non-local mesh-free numerical method which has great advantages in simulating dynamic damage and fracture. This work proposes to use the peridynamics to simulate rock fragmentation by TBM disc cutters and seven tests are simulated to verify this idea. The feasibility of peridynamics in simulating rock fragmentation by TBM disc cutters is demonstrated by comparisons with the punch indentation tests. A nonlinear short-range force contact model is proposed to better reflect the variation of the disc cutter normal force with respect to indentation depth, and can also calculate the changing contact area between the disc cutter and the …

Shaking Table Test Study On The Influence Of Seismic History On Liquefaction Resistance Of Soils At Different Depths, Xiao-Lei Wang, Li-Teng Liu, Run Liu, Li-Bo Liu, Lin Dong, Hai Ren

Rock and Soil Mechanics

Earthquake-induced liquefaction can cause significant damage to geotechnical structures, and the aftershocks accompanying the earthquakes may cause the sandy soils to liquefy again. To investigate the effect of free-field subsurface seismic history on the liquefaction resistance of saturated sandy soils at various depths, a series of shaking table tests was designed and conducted. Four shaking events with different accelerations, subdivided into seven smaller events, were input to the sandy soil in the tests. The excess pore pressure ratio, acceleration response, and soil settlement were calculated and compared for each vibration event to investigate the variation laws of soil liquefaction resistance …

Early-Age Strength And Failure Characteristics Of 3d Printable Polymer Concrete: Numerical Modelling And Experimental Testing, Mohammad Amin Dehghani Najvani

Civil Engineering ETDs

The time-dependent rheological and early-age strength parameters of Polymer concrete (PC) were investigated. PC flow decreased, and the static yield stress and thixotropy increased as the specimen aged, while the dynamic yield stress remained unchanged. The study found that the Herschel-Bulkley model can accurately describe the PC’s rheological behavior over time. The change in cohesion strength and internal friction angle over time was observed using uniaxial unconfined compression and direct shear tests of fresh PC. A time-dependent MohrCoulomb failure criterion was established. Temperature analysis was used to determine the gel time and explain the evolution of the time-dependent early-age strength …

Modeling Of Asphalt Concrete For Cross-Anisotropic Visco-Elasticity And Heterogeneity, Zafrul Hakim Khan

Civil Engineering ETDs

Asphalt Concrete (AC) is a cross-anisotropic viscoelastic material. This study has developed a methodology to backcalculate the cross-anisotropic properties of the AC layer from the Falling Weight Deflectometer (FWD) sensor and pavement response data from embedded sensors inside a pavement section. This study has also developed a two-way coupled Multiscale Finite Element Model (MsFEM) with Phase Field Fracture (PFF) to study the microstructural heterogeneity and damage of the AC layer based on the actual field loadings. A Finite Difference Time Domain (FDTD) and Machine learning-based backcalculation algorithm were developed to determine the layer thickness and dielectric constant from air-coupled Ground …

Dynamic Response And Effect Of Loading Rate Of Soil Under Impact Loading, Yong-Jian Liu, Yang-Pan Fu, Ming-Yang Lai, Zhang-Ming Li, Hao-Yuan Fang, Zhi-Kun Xie

Rock and Soil Mechanics

To study the dynamic response characteristics of soil under impact load, plate dynamic load tests (PDLT) with different load levels and loading rates were carried out on two typical soils (sand and clay) in Guangzhou University Town by using the self-developed additional excitation force-type PDLT system, obtaining three characteristic curves of load-time curve, displacement-time curve, and load-displacement curve, establishing the empirical formula of dynamic deformation modulus and loading rate, and comparing the effects of loading rate of the two soils under impact load. It shows that: (1) There is a threshold of charging voltage in the PDLT test of sand. …

Enhancing Wettability Prediction In The Presence Of Organics For Hydrogen Geo-Storage Through Data-Driven Machine Learning Modeling Of Rock/H2/Brine Systems, Zeeshan Tariq, Muhammad Ali, Nurudeen Yekeen, Auby Baban, Bicheng Yan, Shuyu Sun, Hussein Hoteit

Research outputs 2022 to 2026

The success of geological H2 storage relies significantly on rock–H2–brine interactions and wettability. Experimentally assessing the H2 wettability of storage/caprocks as a function of thermos-physical conditions is arduous because of high H2 reactivity and embrittlement damages. Data-driven machine learning (ML) modeling predictions of rock–H2–brine wettability are less strenuous and more precise. They can be conducted at geo-storage conditions that are impossible or hazardous to attain in the laboratory. Thus, ML models were utilized in this research to accurately model the wettability behavior of a ternary system consisting of H2, rock minerals (quartz and mica), and brine at different operating geological …

Study Of Multi-Dimensional Transfer Effects In Applied Smouldering Systems, Seyed Ziaedin Miry Mr

Electronic Thesis and Dissertation Repository

Smouldering is a flameless form of combustion that is driven by oxygen directly diffusing into the surface of condensed phase fuel (liquid or solid) and involves a complex interplay between heat and mass transfer through porous media, chemical reactions, and multiphase flow. Applied smouldering systems have been gaining popularity for a variety of applications including (i) energy and resource recovery, (ii) waste-to-energy, (iii) pyrolysis and gasification, and (iv) applied smouldering of organic liquids/solids for environmental benefits. In all contexts, smouldering is a complicated oxygen-limited phenomenon where multi-dimensional transfer effects (i.e., non-uniformities in …

The Utilization Of Repurposed Whole Textiles To Modify The Mechanical And Hydrogeological Soil Properties: Green Media, Angelis Almanzar-Chevalie, Yehya Elfgeeh, Calvin O. Walters Jr.

Publications and Research

The utilization of repurposed whole textiles to modify the mechanical and hydrogeological soil properties investigates the impact of adding repurposed textiles to lightweight engineered soil, documenting changes in unit weight, water content, and hydraulic conductivity. This study builds upon prior findings, which demonstrated significant alterations in hydrogeological properties when incorporating textile fabric (3% by weight at an aspect ratio of 1:1). Functioning as reinforcement, these fibers enhance the soil's strength, stability, and structural integrity—especially advantageous in erosion-prone areas, regions susceptible to landslides, or locations requiring heightened load-bearing capacity. The outcomes of this parametric study lead to green roof farms playing …

Lining–Stratum Interaction Mechanism Of Mountain Tunnel Based On Static Pushover Model Test, Qin-Wu Lu, Zhen-Chang Guan, Lin Lin, Shu-Jing Wu, De-Jie Song

Rock and Soil Mechanics

With the rapid development of traffic infrastructure construction in western mountain area, the lining-stratum interaction mechanism of mountain tunnel under seismic effects has attracted increasing attentions. Based on the prototype of a regular two-lane highway tunnel section with V-grade surrounding rock, a static pushover model test for mountain tunnel was conducted. The variations of stratum displacement, stratum strain and ground pressure with pushover distance were carefully studied, and the lining-stratum interaction mechanism was thoroughly discussed. The test results show that: the lining-stratum interaction can be generally divided into compacting stage, overturning stage, and dragging stage. The stratum tends to circumferentially …

Temperature Effect On Water Retention Capacity Of Nanning Expansive Soil And Its Microscopic Mechanism, Zhao-Tian Zeng, Zhe-Qi Cui, De-An Sun, Zhi Yao, Bin Pan

Rock and Soil Mechanics

To explore the variation of water retention capacity of expansive soil at different temperatures, the calibration curves of Whatman No.42 filter paper were measured by vapor equilibrium method at 5, 25, 40 ℃ and 60 ℃, and the bilinear calibration equation considering temperature effect was established. The results show that the water retention capacity of the filter paper decreases with the increase of temperature, and the effect on the high suction section of calibration curve is weaker than the low suction section. On this basis, Nanning expansive soil is taken as the research object, and the soil-water characteristic curves of …

Effects Of Skeleton Void Ratio On The Strength And Deformation Characteristics Of Coarse-Grained Soil, Jia-Jun Pan, Xiang-Jun Sun, Yong-Zhen Zuo, Jun-Peng Wang, Yi-Wei Lu, Bing Han

Rock and Soil Mechanics

The strength and deformation characteristics of coarse-grained soil are closely related to the initial gradation and dry density during specimen preparation. To study the strength and deformation characteristics of coarse-grain materials with different gradations and densities, a simple and generalized method for calculating the skeleton void ratio of coarse-grained soil is proposed. The results of laboratory tests show that there is an obvious monotonic variation between the skeleton void ratio obtained by this calculation method and the mechanical properties of coarse-grained soil. When the specimen size is consistent, with the decrease of the skeleton void ratio, the failure shear stress …

A Study About The Influence Of Joint Roughness On The Volume Of Rock Blocks, Tie-Xin Liu, Jia-Qi Li, Jian-Hui Deng, Zheng-Hu Zhang, Jun Zheng

Rock and Soil Mechanics

The structure of a rock mass directly controls its mechanical and hydraulic properties, and the distribution of rock block volumes can directly reflect the structural characteristics of the rock mass. Currently, many studies simplify the joint surfaces as planes and ignore the influence of roughness on the volume of rock blocks. In this study, the Hurst exponent (H) and root-mean-square height (Rq) were used to characterize joint roughness, and the influence of joint roughness on the quantity and volume distribution of rock blocks was investigated. The results show that: (1) H and Rq control the roughness of the joint, and …

A Calculation Method For Deformation Of Diaphragm Wall Of Narrow Deep Foundation Pit In Soft Soil Considering Spatio-Temporal Effect, Kun-Yong Zhang, Meng Zhang, Bin Sun, Fu-Dong Li, Yong-Zhou Jian

Rock and Soil Mechanics

To accurately evaluate the safety of foundation pit construction in soft soil area and its impact on the surroundings, the time and space influencing factors during excavation cannot be ignored. In this paper, based on the excavation of a deep foundation pit in the soft soil area of the Yangtze River floodplain, a 3D finite element model was established considering the combination of bottom-up and top-down constructions, and the calculated values of horizontal displacement of the diaphragm wall were compared with the measured values to verify the reliability of the finite element calculation. Based on theoretical analysis, numerical calculation and …

Reliability Analysis Of Rock Tunnel Stability Based On Interval Non-Probability Under Multiple Failure Modes, Xiang Li, Jing-Tong Wang, Heng Wei

Rock and Soil Mechanics

For the reliability analysis of rock tunnel stability, considering the difficulty in obtaining the statistical data on rock mass parameters, there is the potential inadequacy when using the probabilistic reliability method; on the other hand, the rock tunnel stability is intimately pertinent to a variety of failure modes, meaning it is necessary to consider the issue on structural system reliability. First, based on the interval theory, the uncertainty parameters were represented by adopting the interval variables. Subsequently, aiming at the coexistence of multiple failure modes in rock tunnel engineering, the concept of structural system reliability was introduced, and then a …

Experimental Study On Sand Anti-Seepage By Microorganism–Bentonite Combined Mineralization, Yu Zhang, Xiang He

Rock and Soil Mechanics

The seepage of sandy foundation would lead to the collapse of foundation and the destruction of engineering structure. A series of large-scale sand column seepage model experiments was carried out by using microorganism–bentonite combined mineralization method. The in-depth discussion was conducted for the effects of sand particle size, slurry liquid-to-solid ratio and treatment cycles on the permeability, internal erosion characteristic and bentonite and calcium carbonate precipitate distribution of sand. Moreover, the stability of sealing and the microstructure were thoroughly investigated, and the treatment effect of microorganism–bentonite combined mineralization method was evaluated. It was found that this method could improve the …

Optimal Strut Position Of Deep Foundation Pit With Convex Corner Under Surcharge Of Adjacent Building, Bao-Guo Chen, Zeng-Pan Jia

Rock and Soil Mechanics

Since the mechanical behavior of the convex corner is complex due to surcharge near the excavation, it is of great importance to evaluate the influence of changes in strut position on the convex corner. Field monitoring and numerical simulations were used to analyze the influence law of the changes of strut position on the deformation and stress characteristics of the convex corner area. The axial force of inner strut, the lateral earth pressure on the pile, the horizontal displacement of the pile, the settlement of adjacent building and the bending moment of the pile were obtained. The research results show …

3d Experimental Studies Of Temperature And Crystallographic Effects On Creep And Strength In Rock Salt, Amirsalar Moslehy

Doctoral Dissertations

Salt domes utilization as storage reservoirs in the energy sector has led to extensive studies on rock salt’s mechanical and geothermal behavior. These important facilities’ safety and serviceability rely on understanding rock salt’s compressive strength and creep behavior under various loading directions, water contents, in-situ stresses, and temperatures. Despite numerous studies on rock salt’s mechanical behavior in the literature, there are still many unanswered questions about rock salt’s behavior. This dissertation was aimed at utilizing state-of-the-art experimental techniques such as 3D synchrotron micro-computed tomography (SMT) and 3D x-ray diffraction (3DXRD) along with hundreds of compression and creep experiments to enhance …

Gravel Conveyance System: An Evaluation On E. Coli Removal Capabilities, Madison Grace

<strong> Theses and Dissertations </strong>

In many rural, low-income communities such as the Black Belt of Alabama, there is a lack of wastewater infrastructure and solutions leaving homeowners non-compliant to state and federal law and with potential health risks on their property. New regulations have allowed for onsite, surface discharge for single family homes that are not connected to a centralized sewer or large flow development. These new regulations also contain strict disinfection criteria for the treated wastewater that will be discharged. A low-cost and low-maintenance treatment system that provides adequate disinfection is necessary to allow homeowners to take advantage of the new opportunity for …

Co2 Storage Capacity And Injectivity Of Stacked Carbonates Of The Pennsylvanian And Permian In Western Nebraska, Lateef Lawal

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

Geological carbon storage (GCS) is a critical aspect of carbon capture and storage (CCS) in which captured CO₂ from power plants and industrial processes is injected and stored securely underground. Potential subsurface rock formations include saline aquifers, depleted oil and gas reservoirs, unmineable coal seams and volcanic rocks. GCS technology has been proven in the United States and many other parts of the world as a net-zero carbon emission strategy to mitigate the current climate crisis of our planet. Unlike other states such as Wyoming, GCS projects are still in the early phases in Nebraska. The goal of this …

A New Approach To Predicting Vertical Permeability For Carbonate Rocks In The Southern Mesopotamian Basin, Emad A. Al-Khdheeawi, Raed H. Allawi, Wisam I. Al-Rubaye, Stefan Iglauer

Research outputs 2022 to 2026

Reservoir performance depends on many factors, and the most important one is permeability anisotropy. In addition, with high heterogeneity, it is essential to find unique relationships to predict permeability. Therefore, this study aims to predict vertical permeability based on horizontal permeability and porosity and to find new equations for carbonate reservoirs. This work relied on the 398 measured points of cores data collected from several wells in carbonate reservoirs. A new correlation for predicting vertical permeability for the whole data (369 samples) as a function of horizontal permeability and porosity has been developed. The results indicate that this new correlation …

Residual Trapping Of Co2, N2, And A Co2-N2 Mixture In Indiana Limestone Using Robust Nmr Coreflooding: Implications For Co2 Geological Storage, Amer Alanazi, Auby Baban, Muhammad Ali, Alireza Keshavarz, Stefan Iglauer, Hussein Hoteit

Research outputs 2022 to 2026

Carbon capture and sequestration (CCS) in geological formations is a prominent solution for reducing anthropogenic carbon emissions and mitigating climate change. The capillary trapping of CO2 is a primary trapping mechanism governed by the pressure difference between the wetting and nonwetting phases in a porous rock, making the latter a key input parameter for dynamic simulation models. During the CCS operational process, however, the CO2 is prone to contamination by impurities from various sources such as surfaces (e.g., pipelines and tanks) and the subsurface (e.g., existing natural gas). Such contamination can strongly influence the overall CO2 wettability, storage capacity, and …

Initiation Criteria For The Onset Of Geomagnetic Substorms Based On Auroral Observations And Electrojet Current Signatures, Mayowa Michael Kayode-Adeoye

<strong> Theses and Dissertations </strong>

In recent years, several substorm onset criteria have been developed, either from auroral observations (many authors) or from auroral electrojet properties such as those described by (Forsyth et al., 2015; Maimaiti et al., 2019; Newell & Gjerloev, 2011; Partamies et al., 2011) The different criteria are being investigated using a low order physics model of the magnetosphere called WINDMI (Spencer et al., 2009) and inferences are being made in line with the WINDMI model. The model variables will be compared with the criteria for substorm onset proposed by examining the SML index.

The WINDMI model uses solar wind and IMF …

Effect Of Methylene Blue On Wetting Characteristics Of Quartz/H2/Brine Systems: Implication For Hydrogen Geological Storage, Fatemah Alhamad, Mujahid Ali, Nurudeen P. Yekeen, Muhammad Ali, Hussein Hoteit, Stefan Iglauer, Alireza Keshavarz

Research outputs 2022 to 2026

Hydrogen (H2) is considered a promising replacement for fossil fuels due to its enormous potential as an environmentally friendly and sustainable option compared to carbon-based fossil fuels. However, storing the vast quantity of H2 required to satisfy the global energy demand on the earth's surface can be difficult due to its compressibility and volatility. The best option for large-scale storage is underground H2 storage (UHS), which can be retrieved when needed. Rock wettability is vital in UHS because it determines the H2 storage capacity, containment security, and potential withdrawal and injection rates. Organic acid inherent in storage formations could make …

Compound Flooding In A Non-Stationary World: A Primer For Practice, Gerarda M. Shields, J. Rolf Olsen, Miguel Medina Jr., Jayantha Obeysekera, Poulomi Ganguli, Carlo Demichele, Gianfausto Salvadori, Mohammad Reza Najafi, Hamed Moftakhari, Ferdinand Diermanse, Amir Aghakouchak

Publications and Research

Compound flooding conditions present a significant challenge for civil engineers in their pursuit to design for and maintain the integrity of a structure’s entire life cycle. Coupled with non-stationary processes due to a changing climate and land use change, risk is a moving target. Through the support of ASCE’s Task Committee on Compound Flooding, the Hydroclimatology Engineering Adaptation (HYDEA) sub-committee is developing a Manual of Practice (MOP) to provide a synthesis of available tools and methods of best practice for civil engineers designing for compound flooding conditions. This paper presents a primer for practicing civil engineers on this work. Hydrodynamic …

Investigation Of The Fracture Process Zone And Behavior Of The Macro-Scale Fatigue Cracks In Brittle Rock Specimens, Nazife Erarslan

Rock and Soil Mechanics

The importance of this study is to explain the fatigue damage mechanism while addressing the effect of fatigue on the fracture toughness (KIC) using the brittle Brazilian specimens and to show for the first time in the literature the behavior of macroscale cracks that open and close in brittle rock without leading to eventual failure. The KIC was reduced by 35% due to the cyclic loading, and the reduction of the indirect Brazilian strength was found to be reduced by 30%. The fatigue cracks were observed to open and close elastically without failure and have been recorded by a camera …

Mode I Crack Morphology And Fracture Surface Roughness Of Granite Under Impact, Xue-Song Wang, Lian-Jun Guo, Xin Liu, Ding Deng, Jiu-Yang Zhang, Zhen-Yang Xu

Rock and Soil Mechanics

To study the response of mode I cracks under impact loading, the dynamic fracture test on the single cleavage triangle (SCT) granite specimens with the lateral opening was carried out using a split Hopkinson pressure bar test system. The Hough transform method was used to quantitatively describe the distributions of the surface crack lengths and angles, and the relationship between them and the absorbed energy of the specimen was analyzed. The three-dimensional (3D) point cloud data of the fracture surface was obtained by using a 3D surface topography detection device, and a fracture surface reconstruction method based on the threshold …

Upper Bound Analysis Of Uplift Piles In Saturated Clay And Soil Plug Effect, Ke-Wen Zhu, Jian Yu, Mao-Song Huang

Rock and Soil Mechanics

A new mechanism is established and applied to the upper bound analysis of uplift piles in saturated clay. Upper bound solutions of uplift capacities of closed and open-ended piles are analyzed. The new mechanism is verified by comparing with elastoplastic finiteelement, existing lower bound and API solutions. Its reliability is assessed through case studies including one centrifuge test and two field tests. The effects of the pile length-diameter ratio, pile surface roughness, non uniformity of undrained soil strength and length of soil plug on the uplift bearing capacity are considered. A formulation predicting the net bearing capacity of closed-ended uplift …