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Introduction
Published in Burt G. Look, Earthworks, 2023
Geotechnical engineering is the branch of civil engineering concerned with the engineering behaviour of earth materials. Geotechnical engineering is not simply the sum of soil mechanics + rock mechanics as closely allied terminology and overlapping fields of expertise include geo-environmental engineering, geological engineering, and engineering geology. In the late twentieth century, geotechnical engineering was considered a specialisation. Yet further specialisation is occurring within the “broad” field of geotechnical engineering.
Electric Motor Industry and Switched Reluctance Machines
Published in Berker Bilgin, James Weisheng Jiang, Ali Emadi, Switched Reluctance Motor Drives, 2019
The processing of rare-earth elements into high-purity rare-earth oxides is a highly-specialized chemical process and it requires significant know-how in mineral processing. Therefore, producing rare-earth materials is not a process that can be addressed just by opening new mines. The same applies to the production of rare-earth permanent magnets. Producing high-quality permanent magnets require expertise and know-how as well. The Japanese organization, Hitachi, holds more than 600 patents on the production of high-quality neodymium-iron-boron magnets, which makes it difficult for other corporations to produce these magnets [27]. Mining and extraction of rare-earth materials can have adverse environmental effects, which also increase the cost of production. Besides the political reasons, environmental concern is also a factor for the quota China is applying on the rare-earth exports [31].
Ground Water
Published in Richard J. Chorley, Introduction to Physical Hydrology, 2019
The study of ground water, whether for the purpose of determining its value to man or to see how it interacts with the earth through which it passes, must begin with a study of the geologic framework. Earth materials are usually classified geologically as to origin, i.e., igneous, metamorphic, or sedimentary. This classification, however, is not suited for studies of ground water. In terms of their effect on the occurrence of ground water, two broad categories of earth material are more suitable: a category which includes all unconsolidated materials, and a category which includes all indurated materials.
Engineering behaviour of MICP treated marine clays
Published in Marine Georesources & Geotechnology, 2020
Earth and earth materials form the elements for major parts of infrastructure and many coastal earth structures such as dikes. Consequently, any modification brought about to their quality will have a direct impact on the cost of the whole infrastructure development project. The demand for higher quality material is already enormous, and is expected to rise, with an estimated investment requirement in US alone of US$1.6 trillion (DeJong et al. 2010). The presently used soil improvement techniques are mostly mechanical (e.g., preloading, use of geosynthetics) or chemical (e.g., addition of cement, fly ash) methods. Environmental impacts of these methods are to be considered for usage in the longer run, especially in the present scenario with much focus on sustainable development worldwide. The adverse effects of chemicals such as cement and fly ash have been extensively investigated by many authors over the years (e.g., Page, Elseewi, and Straughan 1979; Mishra 2004; Huntzinger and Eatmon 2009; Ahmaruzzaman 2010; Chen et al. 2010), with the cement industry reported to represent 5%–7% of the total anthropogenic CO2 emissions (Hendricks et al. 1998; Humphreys and Mahasenan 2002) and fly ash reported to have tremendous impact on environment and human health alike (Mishra 2004). Application of biological processes in geotechnical engineering was identified as an important alternative by the US national research council for the 21st century (NRC 2006). In line with that, development of cost effective and environmental friendly biological methods for ground improvement is gaining huge appraisal among researchers. One such technique which is emerging is biocementation. The technique involves use of certain species of bacteria as catalysts to bring about chemical reactions in the soil, resulting in ground improvement (e.g., Ivanov and Chu 2008). The current paper discusses the potential utilisation of biocementation in improving shear strength and volume change behaviour of marine clays. Subsequent sections present an overview of the technique, review of literature on application of the technique, the experimental study conducted, discussion of results, and the salient findings of the present study.
Selected AI optimization techniques and applications in geotechnical engineering
Published in Cogent Engineering, 2023
Kennedy C. Onyelowe, Farid F. Mojtahedi, Ahmed M. Ebid, Amirhossein Rezaei, Kolawole J. Osinubi, Adrian O. Eberemu, Bunyamin Salahudeen, Emmanuel W. Gadzama, Danial Rezazadeh, Hashem Jahangir, Paul Yohanna, Michael E. Onyia, Fazal E. Jalal, Mudassir Iqbal, Chidozie Ikpa, Ifeyinwa I. Obianyo, Zia Ur Rehman
With the increasing growth in the use of science and technology in solving everyday life problems, the need for methods that understand complex and ambiguous problems becomes greatly inevitable. Soft computing is an emerging collection of various methodologies aimed at finding a balance to poor precision, uncertainty, and unclear truth by applying a collection of statistical, probabilistic, and optimization tools in analyzing sets of data, classify the data, identify new patterns and predict next trends within the shortest convenient time. Soft computing has three main branches which are artificial neural networks, genetic algorithms, and fuzzy logic; these branches tend to build intelligent and wiser machines that behave like the human mind and can answer questions explicitly and not just provide answers. The application of soft computing in branches of civil engineering such as geotechnics has been a breakthrough of the 21st century with these techniques helping solve different cumbersome mathematical problems in a space of seconds. Geotechnics is one of the most relevant branches of civil engineering, which deals with the study of the engineering behavior of the earth materials using the principles of soil mechanics and material engineering in finding lasting solutions to earth problems. The complexity accompanying geotechnical engineering has further led to the need to apply these soft computing techniques in solving earth problems such as swelling potentials of soils as recorded by Alaneme et al. (2020) in the modeling change in volume properties of hydrated lime activated rice husk ash modified soft soil using artificial neural network. This study x-rays the application of ANN model in estimation of the swelling and shrinkage potential and consistency indices of the stabilized soil by adopting the soil HARHA replacement ratio and corresponding Atterberg limit responses as the network input variables while the shrinkage, clay activity, and swelling characteristics were utilized as the network output parameters using Levernberg Marquardt (LM) training and feed—forward back-propagation algorithm with 5-9-6 network architecture. He recorded that the application of the ANN model in his research saved cost, made the best use of research materials, and was time efficient. Kayadelen et al. (2009) studied a model for the swelling potential of compacted soils, adaptive neuro-fuzzy model was applied on compacted soils sourced within Nigde, Turkey, parameters such as the coarse grain fraction ratio, and fine-grained fraction ratio, plasticity index, and maximum dry density were presented to the model as input. The results obtained showed that the ANFIS model is a more reasonable model for predicting the swelling potential of soils. Furthermore, soft computing in geotechnics have been applied in the determination of mixture designs, predicting shallow foundations, predicting and modeling soil behaviors, study of pile cap resistance, etc. At the moment soft computing-based techniques are becoming more popular in the field of geotechnics with several works on the application of neural networks and fuzzy logic and little work done on the application of genetic algorithms in this field.