Ground Conditions Research Articles

Research on controlling measures of snowdrifts around Arctic ground-based buildings through shape optimization

Elevated structures in the Arctic region have proven effective in mitigating surrounding snowdrifts by enhancing the airflow beneath, and serve as a preferred architectural form. However, ground-based buildings still occupy the dominant position due to the constraints posed by construction costs and foundation conditions. One of the effective measures to reduce and prevent snowdrifts around such buildings is to modify their aerodynamic shapes. Therefore, this research endeavors to explore measures for controlling snowdrifts around ground-based buildings through shape optimization. Initially, the predictive accuracy of a refined Mixture model for simulating snowdrifts around ground-based structures was checked against wind tunnel test results. Based on the validated numerical model and representative Arctic meteorological conditions, the snowdrift controlling effects by changing the overall and local building shapes were investigated separately. Overall, the snow reduction and prevention effects can be effectively achieved for ground-based buildings with smoother sidewalls, such as those featuring a circular plane. Conversely, for traditional rectangular ground-based buildings, a larger downwind aspect ratio and a more inclined windward surface can significantly diminish peak snow depth. Additionally, the measures by adding windward side chamfering can effectively manage the locations of snow erosion areas, thereby enabling flexible placement of entrances and exits.

Analysis and Design of a Multistorey Building on Sloped and Flat Grounds (Stilt + Ground + 4)

This project focuses on the planning, static analysis, and structural design of a (Stilt + Ground + 4) residential building, located on both sloping and flat ground, using ETABS software. The primary goal is to study the impact of ground conditions on the structural behavior and design considerations of the building. The project incorporates planning principles to create a functional and efficient layout, ensuring compliance with Indian Standard codes for beams, columns, slabs, and other structural elements. Key aspects such as load distribution, stability, reinforcement detailing, and member sizing are thoroughly examined to ensure the building's safety and adherence to IS guidelines. A comparative analysis between sloping and flat ground conditions highlights the differences in design parameters, such as member forces, moments, and reinforcement requirements, with particular attention to the unique challenges posed by sloping ground. The findings of the study aim to offer insights into cost- effective and optimized design strategies that cater to different site conditions. By exploring these variations, the study contributes to the development of advanced modeling techniques for structural analysis and design. It also emphasizes the importance of adaptable strategies to ensure safe, resilient, and efficient residential buildings, regardless of topography. This research enhances the understanding of how varying ground conditions influence the design process and promotes the development of residential structures that are both safe and cost-efficient across diverse terrains. Keywords: Residential Building Design, Sloping Ground, Flat Ground, ETABS, Static Analysis, Structural Components, Indian Standards, Comparative Study, Planning Principles, Reinforcement Detailing.

Natural Creation of Large Rock Cavern: Can We Construct Them? Jenolan Caves as a Case Study

The Jenolan Caves are the most spectacular limestone caves in Australia. Within this cave system, the Grand Arch, which is 24 m high, 55 m wide, and 127 m long, is the largest open cave in the country. A cave of this size could potentially accommodate small city streets, buildings, and other facilities. This paper examines a stability simulation of the Grand Arch, using numerical models to deduce foundational insights into rock openings under different geological and rock mass conditions. Following this, using numerical analysis, we investigate the creation of a man-made rock opening with the same span, height, and ground conditions of the Grand Arch but formed in two different arch shapes (i.e., with and without rock reinforcement as a stabilization measure). With all stability simulations conducted in this study, a clear explanation to describe the relationship and interaction between various parameters, such as rock mass structure and quality, rock mass strength, and in situ stress field, as well as different arch roofs shapes of the rock opening, is provided. Through its comparisons between natural rock cave and man-made rock openings, this study provides some findings and deep insight, as well as further questioning on creating a large size rock-reinforced cavern in different shapes to be opened in a range of rock conditions.

Thomas Brassey, the Hauenstein tunnel and the Swiss Federal Court

It has recently been suggested that the work of Thomas Brassey, a major nineteenth century contractor, is worthy of further study. Unfortunately, he instructed that his papers should be destroyed upon his death. However, court papers were published concerning his claim against his client for compensation for additional costs as the result of adverse ground conditions during the construction of the Hauenstein tunnel in Switzerland and his client’s counterclaim for the effects of late completion. These documents, along with a descriptive account written by the client’s former section engineers, enable a reconstruction of events placed in their geological and contractual background. The developing breakdown of the relationship between contractor and client is apparent. A description of the current understanding of the geology of the tunnel is given. For comparison, the pre-contract prediction and an immediate post-construction interpretation of the geology is included. The contents of the claim, counterclaim and court decision are summarised. Aspects of the character of Brassey revealed are found to differ from the descriptions provided by his nineteenth-century biographer.

Applications of Kuz–Ram Models in Mine-to-Mill Integration and Optimization—A Review

The Mine-to-Mill (M2M) approach aims to enhance efficiency and reduce costs in the mineral processing industry by optimizing the mining and processing stages. M2M integrates orebody characterization, blasting, and downstream processes, such as grinding and flotation, demonstrating that material fragmentation directly impacts downstream efficiency. This review studies the development and applications of fragmentation models in M2M integration and optimization, finding that their study is divided into three phases. In the first, the potential of M2M is investigated through simulation models that improve fragmentation in blasting to optimize grinding. The second focuses on the practical application of these models in mines, while the third phase integrates geometallurgical data into mine block models, enhancing production planning and selective ore extraction. The M2M integration has demonstrated significant improvements in plant performance, particularly in increasing grinding efficiency through optimized blast fragmentation. The literature also emphasizes the role of optimizing crushing and grinding conditions through models and circuit adjustments to enhance performance and reducing energy consumption. Geometallurgy plays a crucial role in plant optimization by identifying areas with better processing characteristics and adjusting operating parameters to maximize efficiency. Recent studies have shown how the implementation of integrated models can increase the profitability and sustainability of mining operations.

Model Predictive Control Strategies for Turbine Electrified Energy Management

Abstract The increasing electrification of aircraft propulsion systems is leading to new control architectures being developed to address integration between electric machines (EMs) and gas-based turbine engines. For hybrid-electric propulsion systems, current conceptual architectures often couple electric machines with the shafts of gas turbine engines and introduce energy storage. Leveraging the electrical power system of hybridized engines, turbine electrified energy management (TEEM) is a recent control approach that improves transient operability in an effort to enable more efficient and lighter weight turbomachinery. This study seeks to expand TEEM's application beyond traditional proportional-integral (PI) control by presenting linear model predictive control (MPC) schemes to execute the TEEM concept. Through constraint selection and cost function design, transient operability goals for TEEM are considered with no external logic or saturation. Unique to the designs are the use of a washout filter, which simplifies transient detection and motor activation logic. The proposed architectures are implemented with both centralized MPC (CMPC) and distributed MPC (DMPC) approaches, and comparisons are drawn to a benchmark PI controller simulated on a nonlinear turbofan engine model at one ground condition and one cruise condition. Performance is evaluated using compressor maps, stall margin performance, and two novel metrics: transient stack usage (TSU) and transient excursion integral (TEI). Results reveal that the linear MPC scheme performs comparably to the baseline controller and can be implemented in at least two distinct configurations with potential for further modifications, thus establishing the groundwork for future investigations.

An Effective Alternative to the Open Trench Method for Mitigating Ground-Borne Environmental Body Waves: Corrugated Cardboard Boxes Reinforced with Balsa Wood

This research develops and evaluates a recyclable corrugated cardboard vibration isolation box reinforced with balsa wood as an alternative to traditional open trench methods for mitigating ground-borne environmental body waves. This study includes designing and testing scaled prototypes, laboratory analyses, prototype fabrication, and full-scale field experiments. In soft ground conditions, ensuring slope stability during deep excavations is a key engineering challenge for open trenches. For this purpose, scaled prototypes were subjected to laboratory tests to assess the resistance of the wave barrier’s wall surface. Numerical analyses were also conducted to evaluate the strength of the internal lattice structure under various loads. A prototype was fabricated for on-site experiments simulating real-world conditions. Field experiments evaluated the vibration isolation performance of the proposed barrier. Accelerometer sensors were strategically placed to gather data, analyzing ground surface vibrations for free field motions to assess the vibration shielding efficiency of both the open trench method and the corrugated vibration isolation box, with and without Styrofoam infill. This study concludes that the recyclable corrugated vibration isolation box is a viable alternative, offering comparable or improved vibration isolation efficiency in soft soil conditions while promoting environmental sustainability using recyclable materials.

Near-Time Digital Mapping for Geoforensic Searches

Inadequate base maps with poor scale or low resolution demonstrate the need for contemporary topographic maps when conducting geological mapping. In neotectonic regimes and areas of dynamic geomorphology, archival or large-scale maps require time-consuming, on-site manual updating while mapping bedrock and superficial geology. In contrast, stable ground conditions may have suitable legacy maps in some locations but not in others, such as where surveying is absent, incomplete or subject to legal restrictions. The geologist tasked with mapping may have to do this on short notice at their first site visit with no time to search for or create digital or physical copies of background maps on a suitable scale. The field mapper may encounter any of the above scenarios, especially the Geoforensic specialist tasked with Search and Rescue, hazard assessment or preparation and desktop study for subsequent search teams or law enforcement. Drone-derived orthoimagery and digital surface modelling can be conducted on-site in near real time to provide high resolution georeferenced maps for direct input of geological information, thus bypassing either non-existent or unsuitable base maps.

Effects of foundation conditions on failure modes of jacket type offshore platforms using incremental irregular wave dynamic analysis

Quantitative assessment of environmental conditions and their loading effects is crucial for the optimal design of marine structures, especially offshore platforms subject to extreme environmental conditions. Wave load, particularly irregular wave load, significantly influences the structural response and ultimate strength of jacket-type offshore platforms (JTOPs) throughout their operational life. The dynamic nature of these irregular wave loads necessitates the use of advanced time history analysis to accurately capture their impact. This study aims to enhance the understanding of how foundation conditions impact failure modes and the structural response of JTOPs through an innovative incremental irregular wave dynamic analysis procedure. By focusing on an existing steel jacket-type platform in the Persian Gulf, this research evaluates six models with varying soil profiles and pile conditions to assess their effects on structural performance. The application of incremental irregular wave dynamic analysis provides a more precise and realistic modeling of wave impacts compared to traditional methods. The findings demonstrate that stronger soil profiles and improved pile conditions significantly enhance structural integrity, particularly under extreme loading conditions. Specifically, optimizing pile configurations is critical for enabling the structure to endure larger waves, whereas variations in the yield stress of steel material have a lesser impact on the platform's response. Additionally, the dynamic results are compared with pushover analysis, which serves as a benchmark to evaluate the accuracy and effectiveness of the pushover analysis compared to incremental irregular wave analysis method used in this study.

An Experimental Investigation into the Enhancement of Surface Quality of Inconel 718 Through Axial Ultrasonic Vibration-Assisted Grinding in Dry and MQL Environments

Ultrasonic vibration-assisted grinding (UVAG) has proven to be beneficial for grinding difficult-to-machine materials. This work attempts to enhance the grinding performance of Inconel 718 through a comprehensive study of UVAG characteristics. Grinding experiments were performed in both dry and Minimum Quantity Lubrication (MQL) environments, and assessment of the grinding forces, specific energy, residual stress, and surface topography was done. A substantial reduction of both surface roughness and grinding force components was observed in UVAG compared to conventional grinding (CG). Utilizing UVAG with MQL at the maximum vibration amplitude led to a 64% reduction in tangential grinding force and a 51% decrease in roughness parameter, Ra, when compared to CG conducted in a dry environment. The high-frequency indentations of the abrasives in UVAG generated compressive residual stresses on the ground surface. Surface parameters pointed to uniform texture and SEM images showed widening of abrasive grain tracks on the workpiece surface during UVAG. The utilization of UVAG under MQL produced a synergistic impact and resulted in the lowest grinding forces, specific energy, and optimal surface quality among all the grinding conditions investigated. Overall analysis of the results indicated that the axial configuration of the vibration set-up is favorable for UVAG, and the high-frequency periodic separation-cutting characteristic of the process improves lubricating efficiency and grinding performance.

Electrical and Financial Impacts of Inverter Clipping on Oversized Bifacial Photovoltaic Systems

This paper studies the impacts of inverter clipping on bifacial PV modules under different weather and ground reflectivity. A 5 kW bifacial array was connected to a 3.8 kW grid-tied inverter, a 10 kWh Li-ion battery, and an EV charger. A PV output calculation model was developed to compare the estimated output of the modules with the actual measurements to evaluate the relation between ground reflectivity and clipping loss. The results showed that clipping potentially occurs on sunny days in summer from 10:00 to 15:00 during the period with the highest solar irradiance. Three colors of ground cover were also examined to compare the performance of bifacial modules under different albedo reflective properties. The results indicated that the white ground in winter leads to the highest bifacial gain (13.1%) and daily DC efficiency (22.2%) due to the combination of high reflectivity with low solar angle giving maximum upward reflection of direct sunlight. This same combination shows a minimal advantage in summer due to the clipping. The proposed model is evaluated, demonstrating 98.2% agreement between modeled and actual data for all conditions. Furthermore, simulation models based on the actual system with different system sizes and ground reflectivities have been studied to evaluate the impacts of the clipping in terms of technical losses and financial returns. The analysis shows that a high reflective ground condition can provide the best financial benefit, and the clipping loss does not have a great effect on the finance of the project since the loss is less than 4% of the annual production even in an extreme case.

Further Results on the Effects of the Grinding Environment on the Flotation of Copper Sulphides

Grinding conditions affect the flotation of copper sulphide minerals as changes in the properties of the grinding media and their interactions with the sulphide minerals, and between sulphide minerals themselves, affect the chemical environment in the flotation pulp. Galvanic interactions between steel grinding media and sulphide minerals, and between sulphide minerals, can lower the pulp potential, decrease the dissolved oxygen concentration in the mineral slurry, and lead to the dissolution of iron and copper from the media and the minerals. As a result, the formation of hydrophilic iron hydroxides and their adsorption on the copper sulphide minerals can be deleterious to copper flotation while pyrite (when present) can be activated to flotation by dissolved copper lowering the grade of the copper concentrate. Electrochemically less active grinding media (e.g., chrome alloy balls rather than mild steel media) can have beneficial effects on flotation performance due to the lower oxidation of the grinding media and consequently the lower production of oxidised iron species in the pulp. Copper activation of pyrite can be decreased by chemical additions to the pulp. In this paper, relevant experimental data published in the last 15 years are discussed.

[EMIM]AlCl4-ionic liquid catalyzed mechanochemically assisted green approach towards the synthesis of quinoxaline, 6H-indolo[2,3-b]quinoxaline and benzimidazole derivatives

In the presented work, a convenient and effective methodology for the synthesis of quinoxaline, 6H-indolo[2,3-b]quinoxaline and benzimidazole derivatives has been developed. The reaction of 1,2-diamines with various substituted benzil, isatin and aldehydes produces quinoxaline, 6H-indolo[2,3-b]quinoxaline and benzimidazole derivatives respectively. The reaction between 1,2-diamines with various substituted benzils, isatins and aldehydes was carried out in presence of catalytic amount of [EMIM]AlCl4 (1-ethyl-3-methylimidazolium tetrachloroaluminate) ionic liquid in ethanol under the grinding condition in mortar and pestle. The ease of handling of catalyst, inclusion of eco-friendly solvent, attractive yield of the product, shorter reaction time and overall operational simplicity are some significant outcome of this procedure.

Force model of robot bone grinding based on finite element analysis

Bone grinding represents a formidable challenge during open epiphyseal surgery, as grinding force may result in potential damage to bone and surrounding tissues. To address this issue, this study establishes a correlation between grinding force and bone density, as well as feed rate and rotational speed. Given the limited availability of experimental data on bone grinding, a finite element analysis (FEA) model is developed. Subsequently, the impact of bone density, feed rate and rotational speed on grinding force is determined through linear regression method. The accuracy and sensitivity of the grinding force model are then assessed, revealing a maximum prediction deviation of 4.87%. Finally, based on the established model, safe operating parameters and boundary conditions for robot bone grinding are identified.

Broad-band, high-gain, low-frequency antennas for radio detection of earth-skimming tau neutrinos

A promising approach to detect high-energy tau neutrinos is through the measurement of impulsive radio emission from horizontal air showers initiated in the Earth's atmosphere. Observations at frequencies between 30 and 80 MHz seem particularly promising — if high-gain antennas focused at the horizon and blocking out as much as possible of the noisy sky are employed. Due to the large wavelengths, however, designing an antenna with the required properties is highly non-trivial at such low frequencies. In this article, we explore suitable antenna designs that provide the desired high gain, possess a smooth beam, are insensitive to ground conditions, are easily impedance-matched over the wide band, and are mechanically simple for deployment in large numbers in inaccessible terrain. In particular, we consider the “rhombus” antenna design for both horizontally and vertically polarized radiation a very attractive option for tau neutrino detection efforts in the atmosphere with the radio technique.

Wall Deflection and Ground Surface Settlement due to Braced Deep Excavation in Soft-Soil Ground

An extensive database comprising more than 1,100 case histories of wall displacements and ground settlements due to deep excavations in soft soils created by Long, Moormann, and Wang et al. (2009) was analyzed. The applicability of the criteria for maximum lateral displacements and ground settlements using their database was analyzed. When excavation work is conducted under ground conditions where seaweed cohesive soil is distributed thickly, excessive horizontal displacement is expected to occur owing to low undrained shear strengths. Therefore, ground reinforcement was performed by applying a reinforcement method on the excavation side to secure a stability factor against a basal heave that exceeds 3.0. When using this method, applying the management standard for the maximum horizontal displacement, i.e., 0.3%H of the retaining wall, as the limit value is considered appropriate. This is expected to minimize the horizontal displacement of the retaining wall and the subsidence of the background during excavation work.

Multiple Paths to Green Building Popularization Under the TOE Framework—A Qualitative Comparative Analysis of Fuzzy Sets Based on 26 Chinese Cities

Green buildings are a crucial element in achieving sustainable development. The use of green buildings can save energy and reduce greenhouse gas emissions. Promoting the widespread adoption of green buildings has become a significant concern in many countries or regions. Although previous studies have identified a range of key factors influencing the promotion of green buildings, further analysis of the combination of these critical factors needs to be conducted. Therefore, based on the technology–organization–environment (TOE) framework, this study utilizes the fuzzy-set qualitative comparative analysis (fsQCA) method to analyze survey data from 26 cities in China, resulting in four high-level configuration paths for the widespread adoption of green buildings. The results indicate that (1) achieving high levels of widespread adoption of green buildings does not depend on any single factor; instead, it relies on the collaborative interaction of multiple elements across technological, organizational, and environmental dimensions; (2) the potential substitution relationships between conditional variables among different configurations within the TOE framework indicate that science and technology expenditure and gross domestic product play more significant roles in the path combinations for the promotion of green buildings; (3) through the study of the substitutive relationships of four configuration paths, it was found that when a city faces challenges in the widespread adoption of green buildings, such as an insufficient number of green building technology patents or underdeveloped green finance incentive systems, it can still achieve efficient green building adoption by formulating corresponding policies and enhancing cultural value guidance for groups like developers, contractors, and consumers. Conversely, the same is true. This paper explores the combination of critical factors in green building adoption, providing insights into addressing the differing foundational conditions of cities in the process.

Prediction of TBM cutter wear in heterogeneous ground under high ambient pressure

To prevent tunnel face collapse in heterogeneous ground, the applied face pressure in the excavation chamber can be increased to stabilise the tunnel face, which may hinder cutter rotation during tunnel boring machine (TBM) tunnelling. This study proposes a TBM cutter wear prediction model that considers the impact of the variation in the cutter normal force on the cutterhead owing to the high applied face pressure and low penetration rate. First, the cutter motion mode in heterogeneous ground is investigated. The cutter is found to slide when cutting soft rock based on an analysis of the field data. The evolution process of the cutter wear morphology under heterogeneous ground conditions is summarised. A method for calculating the cutter normal force when the cutter slides on the tunnel face is proposed by referring to the cutting mechanism of the drag bits. The cutter hardness is measured on-site using a portable hardness tester. A semi-empirical model considering the variation in the cutter normal force on the cutterhead is proposed to predict the cutter wear in heterogeneous ground. Wear prediction is compared with other predictive models and field data for validation, and the discrepancies between the different models are discussed. The results show that the proposed model is effective for predicting TBM cutter wear under complex geological conditions.

Shaking table test and numerical simulation of rocking wall frame structure considering dynamic soil-structure interaction

This study investigates the seismic response of a rocking wall frame structure considering dynamic soil-structure interaction (DSSI) through shaking table tests. A comparison with conventional frame structures and structures with fixed-base foundations is made to examine the influence of DSSI effects on various aspects including structural damage distribution, dynamic characteristics, and floor responses. Test results indicate that the presence of a rocking wall reduces structural responses across different site conditions, although the reduction is less significant under soft soil conditions compared to fixed-base foundation conditions. Overall, DSSI diminishes the mitigating effect of the rocking wall on the maximum structural response. Furthermore, a three-dimensional finite element model of the shaking table test is established. The numerical model employs the equivalent linear method to simulate the soil's nonlinear behavior and incorporates the concept of the rocking wall. Comparative analysis between experimental and simulated results demonstrates that the model effectively predicts the dynamic response of the rocking wall frame structure in DSSI systems.

Identification of Technical Requirements for the Initial Design of an Autonomous Fruit-Harvesting Robot

Automation in agriculture is revolutionizing the management of field tasks. This paper focuses on identifying the essential needs and preliminary technical requirements for designing an autonomous robot specifically for fruit harvesting. The study examines the integration of advanced machine vision technologies and neural networks for the accurate detection of ripe fruits and obstacles, optimizing harvesting efficiency. Key features such as proximity and touch sensors are also evaluated to ensure the safe handling of fruits, minimizing damage during harvesting. The technical specifications, including traction, speed, and the robot’s ability to operate on uneven terrain, are analyzed to ensure adaptability across various crops and ground conditions. Perception systems, incorporating cameras and sensors, are crucial for crop inspection and route planning. The main findings of this review establish a set of technical requirements that serve as a foundation for developing efficient and economically viable fruit-harvesting robots. These systems offer significant potential to transform agriculture by addressing labor shortages and improving harvesting precision. However, challenges remain, particularly in adapting to diverse crops and environments, emphasizing the need for further research and development.