bluuebunny/crossref_metadata_2025_split huggingface dataset:
Design of falling rock preventive countermeasure based on three-dimensional simulation
Authors: Kitauchi H , Nishiyama S , Song J 
Published: January 2023

Abstract
To rationally design rockfall countermeasures, detailed rockfall behavior must be predicted using numerical simulations based on the conditions of slopes and rockfalls. In this study, we perform a rockfall simulation using discontinuous deformation analysis. This method is used to analyze the motion between blocks composed of polygons of arbitrary elastic bodies; furthermore, the energy conservation law and the uniqueness/convergence of the solution are guaranteed for the entire analysis target. Additionally, the rockfall shape is reproduced in detail. Both the rockfall shape and a parameter known as the velocity energy ratio, which indicates the decay of energy at the collision time of the rockfall, significantly affect the rockfall behavior. In this study, we model the actual slope shape from data measured via airborne laser and quantitatively evaluate the effect via simulations by changing the rockfall shape and velocity energy ratio. In this paper, we consider how to use the simulation for the design of rockfall countermeasures based on the results such as the change in the amount of jumping due to the difference in slope shape, geology, and rockfall shape.
The effectiveness of epoxy coating for preventing microbially induced corrosion of rock bolts
Authors: Chen H , Kimyon O , Chen R , Gunawan C , Ramandi H Lamei , Canbulat Ismet , Saydam S 
Published: January 2023

Abstract
In the past two decades, the corrosion failures of rock reinforcement bolts in underground coal mines have been increasingly reported. Preliminary studies have shown that these failures were predominantly related to pitting and stress corrosion cracking. The analyses in affected mines indicated microbially induced corrosion (MIC) as one of the primary corrosion causes. As such, there is an urgent demand from industries to develop methods to mitigate MIC-associated failures of rock bolts in underground coal mines. This study examined epoxy coating to determine its effectiveness in preventing biofilm formation on steel surfaces and, in turn, averting MIC. The corrosion-causing bacteria were isolated and enriched from groundwater samples collected from the affected mine sites. Coated and uncoated rock bolt samples were prepared from the bolts and incubated in media in the absence and presence of the corrosion-causing bacteria. Fluorescence microscopy imaging found no evidence of bacterial biomass growth on the surface of the epoxy-coated steel surfaces after 30 days, while the non-coated surfaces were colonised by biomass. The observations suggest the potential of epoxy coating for bolt MIC prevention. Future studies to assess the applicability of epoxy coating in the underground mine environment are recommended.
An issue in the current definition of the factor of safety for rock slopes and suggestions for improvement
Authors: Li Charlie C , Høien Are Håvard 
Published: January 2023

Abstract
To evaluate the stability of a rock slope a common practice is to calculate the factor of safety by dividing the driving forces on the resisting. Hoek and Bray [1] proposed a formula for the calculation of the factor of safety FS for rock slopes reinforced by pre-tensioned bolts and anchors, so-called active support devices. The formulas have been used worldwide for active support of rock slopes in the past 40 years and are also incorporated in different rock slope stability software. The reinforcement force of the active support is in the formula considered a negative driving force. On the other hand, for passive support, referring to reinforcement by non-tensioned bolts and anchors, the reinforcement force is counted as an additional resisting force in the calculations. In this paper, the two definitions to the factor of safety are examined with the help of an example of simple block equilibrium, which demonstrates issues regarding the formula for active support. It is concluded that the reinforcement force should always be counted as a resisting force in the calculation of the factor of safety regardless it is active or passive support. Concepts of factors of safety for shear failure and collapse are proposed and verified with a calculation example.
Improving Rock Pillar Stability Guidelines Through Detailed Numerical Investigation
Authors: Dressel E J , Diederichs M S 
Published: January 2023

Abstract
Pillar stability guidelines have been presented by numerous authors in the past, based on a combination of empirical observations (mostly visual) from mining applications and simple numerical (elastic or simple continuum plasticity) models. In many cases, the resulting design limits for pillar dimensioning are presented as universal for all rockmass conditions and stress regimes. There have been numerous developments in the past decades in mechanistic classification (brittle spalling, effective continuum rockmass, structural control) and mechanism-appropriate modelling and design metrics. These new tools and paradigms for rockmass behaviour allow for a modelling-based revision of the empirical guidelines from the past century that still form the basis of many performance critical designs. This paper includes the consideration of rockmass deformation and yield (rockmass strength approach), brittle strength, and damage behaviour where appropriate. This paper presents correlations for residual GSI and the effects of Hoek-Brown dilation on pillar behaviour. The investigation includes generating 3D FEM synthetic pillar models with equivalent elastic and plastic continuum.
Clay–rock fracturing risk assessment under high gas pressures in repository systems
Authors: Mollaali Mostafa , Buchwald Jörg , Montoya Vanessa , Kolditz Olaf , Yoshioka Keita 
Published: January 2023

Abstract
At the interface between the steel canister and the bentonite in a nuclear waste repository, we expect generation of hydrogen gas because of corrosion processes. The pressurized gas might fracture the engineered or natural clay barrier system, enhancing radionuclide transport into the geosphere. To assess the long-term integrity of the clay host rock under various conditions and scenarios, we need a large number of numerical simulations. However, a simulation tool for complex fracture propagation is often prohibitively expensive to run many realizations. Here, we developed a risk analysis tool based on the Design of Experiments to overcome the computational challenges by generating a computationally inexpensive proxy fracture model using a set of critical factors known as heavy hitters. We provided parameters and their probability distributions that are subject to uncertainty, as well as an objective function that assesses the risk of fracturing due to high gas pressures. Through various scenarios, we found that the fracture toughness dominates the impact on the risk.
The relict landslide in bimsoils in downtown Genova, Italy: a new modeling approach
Authors: Napoli M L , Barbero M , Minuto D , Morandi L , Ullah H 
Published: January 2023

Abstract
Stability problems occurring in geological units with a block-in-matrix fabric are often analyzed with deterministic approaches and/or assuming block-in-matrix rocks/soils (bimrocks or bimsoils) to be homogeneous equivalent geomaterials. However, recent studies have demonstrated that since these formations are characterized by a great (dimensional, spatial and lithological) variability, reliable results can only be obtained if a stochastic approach accounting for different block arrangements and dimensions is used.
This paper extends and improves a previous study from Minuto and Morandi (2015) to evaluate the stability of a relict landslide in bimsoil located in downtown Genova (Italy), where a deterministic approach and the traditional limit equilibrium method were used. In this work, different slope models with elliptical blocks of variable eccentricity, size and positions are generated by means of a stochastic approach and are analyzed with the FEM code RS2. Moreover, since the slope can be considered to be a bimsoil, interfaces between the blocks and matrix are introduced in order to better simulate the lower strength at the block/matrix contacts. The numerical analyses of the slope reveal that shallow failure surfaces have a higher probability of occurrence as compared to the deep failure surfaces considered by Minuto and Morandi (2015). Furthermore, lower safety factors are obtained when a block-matrix interface strength smaller than that of the matrix (i.e., a bimsoil) is simulated.
Vertical Well Assisted Hydraulic Fracturing in Mudstone Interlayer of Terrestrial Ultra-heavy Oil Reservoir
Authors: Wang Qiqi , Chen Mian , Lin Botao , Huang Yong , Chen Sen 
Published: January 2023

Abstract
The widely developed impermeable interlayers hinder the migration of steam and condensate in a steam stimulation project, bringing the difficulty of developing the formation part overlying the interlayer. Hydraulic fracturing the interlayer through an existing neighboring observation (vertical) well can break through the interlayer without significantly increasing the budget. In this study, the laboratory test results of true triaxial hydraulic fracturing experiments and CT tests were analyzed to investigate the fracture propagation in the oil sand-mudstone multi-layer samples. A geological model was established to simulate the crack expansion using the finite element (FE) method by employing the cohesive element to represent fracture apertures. Furthermore, the geological model after the fracturing treatment was imported to a thermo-hydro-mechanical simulator to predict its mechanical and production behavior under steam circulation. It was found from laboratory experiments that the hydraulic fractures that initiated in the mudstone layer effectively propagated into the oil sand layer. The FE simulation shows that vertical fractures can be formed under field stress conditions. The fracture would extend into the overlying and underlying oil sand layers passing through the lithological interface. Accordingly, the fractures caused by hydraulic fracturing treatment can accelerate the diffusion of injected steam and the flow of crude oil after substantial viscosity reduction by steam heating. Future research is dedicated to generating a more complex fracture network in the mudstone interlayer so that the oil and steam flow paths can be strengthened considerably.
Blominmäki wastewater treatment plant’s sewage tunnels: Challenging connection of a vertical shaft to the existing operating offshore tunnel.
Authors: Konstantas Ioannis , Paajanen Janne , Salmelainen Juha , Yli-Kuivila Jukka 
Published: January 2023

Abstract
The sewage tunnels of the Blominmäki Wastewater Treatment Plant (WWTP) consist of approximately 20 kilometers of inlet and discharge tunnels, access tunnels and shafts. The most challenging and technically critical part of this project was the connection of the operating offshore tunnel of the old treatment plant with the Blominmäki discharge route, through a vertical shaft. Lack of information regarding the exact location, the shape and the geological conditions of the existing tunnel called for an accurate excavation design to avoid a potential tunnel collapse and rock blocking or massive waterflow during breakthrough. An additional complexity related to the continuous operation of the tunnel in question, as both non-stop flow of treated wastewater and cooling water of the nearby heat and powerplant, had a huge impact to the ways that all work phases were carried out. All parts involved, including the clients, the contractor and a variety of consultants cooperated in order that one of the most demanding shaft excavations in Finland be carried out successfully. This paper aims to present an overview of the related challenges, along with the detailed design, risk assessment and respective mitigation measures, information about problem solving and lessons learned during the execution.
The Allegory of the Rock Engineering Cave
Authors: Elmo D , Yang B , Shapka-Fels T , Tsai R 
Published: January 2023

Abstract
Geoscientists and engineers are part of a system that produces changes to the world we live in. As machines are expected to gradually replace humans in various technical tasks (e.g., data collection and data characterisation), it becomes crucial to apply critical thinking and to question the foundations of commonly accepted practices. The challenge is to accept that empirical methods are shaped by cognitive biases, which result from our mind interpreting data by a process of data simplification. Indeed, it is possible to draw an analogy between rock engineering methods and Plato’s Allegory of the Cave. The fire casting the shadows along the cave walls represents the process of quantification of qualitative assessments of commonly accepted data collection methods. The chains holding the engineers as prisoners in the cave are empirical methods accepted as industry standards despite important limitations. Engineering judgment alone will not allow engineers to break free of those chains, and to emerge from the confined spaces of the cave and see things for what they really are (i.e., introduce truly objective data collections methods that better reflect failure mechanisms). In this paper the authors use philosophical arguments to justify the need to “dequantify” the GSI classification system and to teach us that engineering design should always be driven by the important questions of how, why, and whether.
Investigation, numerical model, and monitoring for Follo line - a metro project in Oslo
Authors: Trinh Nghia Quoc 
Published: January 2023

Abstract
Just south of Oslo Central Station the new high-speed Follo Line railway tunnels pass beneath the existing Ekeberg road tunnels. This paper presents the construction methods, numerical model, and monitoring program used to assess the stability of the E6 road tunnels during the excavation of the Follo Line tunnels only a few metres below. The construction of the Follo Line was approved subject to three conditions: (1) There should be no negative effect on the stability of the Ekeberg tunnels, (2) The traffic flow in the Ekeberg tunnels must be maintained at all times and (3) Any risk of instability in the existing tunnels must be detected beforehand so that necessary precautionary action could be taken in good time. In order to deal with the challenges, SINTEF has carried out different investigations (including rock stress measurements), established a comprehensive numerical model, and a thorough monitoring program for analyses. The activities were combined in a so-called “rock mechanic tool”, and the tool has been used successfully in this project, operating smoothly to provide adequate information for excavation planning and decision making.
3D slope stability analysis of a limestone quarry expansion in Northern Italy
Authors: Martinelli D , Pasqualone G , Cardu M , Gonzalez M Linares 
Published: January 2023

Abstract
Slope stability is a crucial aspect in case in quarrying, both in term of legal and technical restrictions. The availability of data regarding the rock mass characterization is not sufficient to guarantee a satisfactory stability analysis, which must be assessed by means of more accurate procedures. Limit equilibrium analyses have been used since many decades, as they can give satisfactory results for simple cases, such as planar or wedge blocks. Nevertheless, when dealing with more complex cases, such as opencast quarries and mines, where the slope geometry consists on several benches plunging in different directions, this simplified approach cannot give a satisfactory answer. In this scenario, numerical models can return a much more complete and accurate assessment of the overall stability. The paper describes a possible approach to evaluate the stability of the slopes of a limestone opencast quarry in Northern Italy. The country is experiencing a growing demand of limestone for the production of cement for the construction sector and this determined the need to expand the previous exploitations. Since the quarry experienced several expansion plans throughout the years, several site investigation campaigns have been carried out and the results were not always consistent with each other. Starting from the two most recent rock mass characterizations and by using 3D numerical models, the overall stability has been simulated by means of continuum and discontinuum analyses, to obtain a reproduction of the real episodes of instabilities that occurred in the past. The implementation of models with reliable data is essential to obtain results that are comparable with the reality: this would allow to proceed more effectively and safely with the exploitation of the future slopes.
Deployable extrusion bioprinting of compartmental tumoroids with cancer associated fibroblasts for immune cell interactions
Authors: Mazzaglia Corrado , Sheng Yaqi , Rodrigues Leonor Nunes , Lei Iek Man , Shields Jacqueline D , Huang Yan Yan Shery 
Published: January 2023

Abstract
Realizing the translational impacts of three-dimensional (3D) bioprinting for cancer research necessitates innovation in bioprinting workflows which integrate affordability, user-friendliness, and biological relevance. Herein, we demonstrate ‘BioArm’, a simple, yet highly effective extrusion bioprinting platform, which can be folded into a carry-on pack, and rapidly deployed between bio-facilities. BioArm enabled the reconstruction of compartmental tumoroids with cancer-associated fibroblasts (CAFs), forming the shell of each tumoroid. The 3D printed core–shell tumoroids showed de novo synthesized extracellular matrices, and enhanced cellular proliferation compared to the tumour alone 3D printed spheroid culture. Further, the in vivo phenotypes of CAFs normally lost after conventional 2D co-culture re-emerged in the bioprinted model. Embedding the 3D printed tumoroids in an immune cell-laden collagen matrix permitted tracking of the interaction between immune cells and tumoroids, and subsequent simulated immunotherapy treatments. Our deployable extrusion bioprinting workflow could significantly widen the accessibility of 3D bioprinting for replicating multi-compartmental architectures of tumour microenvironment, and for developing strategies in cancer drug testing in the future.
Feasibility and performance analysis of bifacial module under extremely hot and dry climate
Authors: Verma Deepak , Shah Jainam , Patel Nisarg , Patel Rushil , Patel Dhruvil 
Published: January 2023

Abstract
Solar panels with a bi-facial design provide energy from both sides; thus, it would be interesting to examine the viability of such modules in an extremely hot and dry city like Ahmedabad, Gujarat, India. This study assesses the temperature, efficiency, and bifacial gain of PV bifacial modules as a function of solar irradiation, ambient temperature, wind speed, and additional parameters. The global horizontal irradiance has been used in this study to calculate Direct Normal Irradiance (DNI), Diffuse Horizontal Irradiance (DHI) and Front and Rear Irradiance. The results show that an optimal tilt angle of 43.5° provides the best efficiency of 24% at ambient temperature. For a constant value of tilt angle, the bi-facial gain of the module increases linearly with albedo factor. It has also been discovered that continuing to raise the elevation beyond 1 meter will eventually diminish the bifacial gain because the reflected and diffuse irradiance will become less intense on the rear side of the bifacial module.
Effectiveness of outpatient geriatric rehabilitation after inpatient geriatric rehabilitation or hospitalisation: a systematic review and meta-analysis
Authors: Preitschopf Astrid , Holstege Marije , Ligthart Andrea , Groen Wim , Burchell George , Pol Margriet , Buurman Bianca 
Published: January 2023

Abstract

Background
Due to the increasing number of older people with multi-morbidity, the demand for outpatient geriatric rehabilitation (OGR) will also increase.

Objective
To assess the effects of OGR on the primary outcome functional performance (FP) and secondary outcomes: length of in-patient stay, re-admission rate, patients’ and caregivers’ quality of life, mortality and cost-effectiveness. We also aim to describe the organisation and content of OGR.

Methods
Systematic review and meta-analysis. Five databases were queried from inception to July 2022. We selected randomised controlled trials written in English, focusing on multidisciplinary interventions related to OGR, included participants aged ≥65 and reported one of the main outcomes. A meta-analysis was performed on FP, patients’ quality of life, length of stay and re-admissions. The structural, procedural and environmental aspects of OGR were systematically mapped.

Results
We selected 24 studies involving 3,405 participants. The meta-analysis showed no significant effect on the primary outcome FP (activity). It demonstrated a significant effect of OGR on shortening length of in-patient stay (P = 0.03, MD = −2.41 days, 95%CI: [−4.61—0.22]). Frequently used elements of OGR are: inpatient start of OGR with an interdisciplinary rehabilitation team, close cooperation with primary care, an OGR coordinator, individual goal setting and education for both patient and caregiver.

Conclusion
This review showed that OGR is as effective as usual care on FP activity. It shows low certainty of evidence for OGR being effective in reducing the length of inpatient stay. Further research is needed on the various frequently used elements of OGR.
The frailty index based on laboratory test data as a tool to investigate the impact of frailty on health outcomes: a systematic review and meta-analysis
Authors: Sapp David G , Cormier Brianna M , Rockwood Kenneth , Howlett Susan E , Heinze Stefan S 
Published: January 2023

Abstract
The frailty index (FI) quantifies frailty as deficit accumulation. It has been adapted to employ laboratory test data (FI-Lab). Our objective was to systematically review and meta-analyse the FI-Lab’s ability to predict mortality. Secondary objectives were to review the FI-Lab’s association with adverse health outcomes and whether FI-Lab scores differed between the sexes. A systematic literature search was carried out using six online databases to identify studies that measured the FI-Lab in humans. Hazard ratios (HRs) were combined in a meta-analysis to create a pooled risk estimate for mortality. Of the 1,201 papers identified, spanning January 2010 until 11 July 2022, 38 were included. FI-Lab scores per 0.01 unit increase predicted mortality overall (HR = 1.04; 95% confidence interval (CI) = 1.03–1.05) and for studies with a mean age of 81+ years (HR = 1.04; 95% CI = 1.03–1.05). The quality of evidence for these meta-analyses are moderate and high, respectively. Further, higher FI-Lab scores were associated with more frequent adverse health outcomes. Sex differences in FI-Lab scores varied, with no consistent indication of a sex effect. The FI-Lab is associated with mortality and with a variety of adverse health outcomes. No consistent sex differences in FI-Lab scores were observed, with several studies in disagreement. Notably, these conclusions were most relevant to older (65+ years old) individuals; further evidence in younger people is needed in both clinical and population representative studies.