Innovation structures of very lean roller compacted concrete dams

Over the past 20 years, rolled compacted concrete (RCC) dams have continued to be built in many countries because of their technical and economic advantages over conventional dams of vibrating concrete and embankment dams. The aim of this study is the development of new structural and technological solutions in RCC dams in order to reduce the consumption of cement and expand their use on non-rock foundations, which will allow them to successfully compete with concrete face rockfill dams. The numerical analyses of static and seismic stress-strain state (SST) of gravitational dams in roller compacted very lean concrete dams have been made, as well as their stability, strength and cost have been assessed. For rock and dense sandy-gravel foundations the most economical is the concrete face rockfill dam and symmetrical RCC dam of very lean concrete with bases (0.5-0.7) of both slopes and outer zones of conventional concrete and central zone of rockfill strengthened by cement-ash mortar. Taking into account that the cost of diversion and spillway tunnels for very lean RCC dam will be less and the construction period - shorter than for the concrete face rockfill dam, it can be concluded that variant of symmetrical RCC dam of very lean concrete is the technically and economically effective. Symmetrical RCC dams of very lean concrete with 1V/(0.5-0.7)H slopes have more seismic resistance and technical and economic efficiency as compared with conventional gravitational RCC dams and other types of dams. These dams up to 200 m high can be built on rock foundations and up to 100 m high - on dense sandy gravel foundations.

Planetary Cities: Fluid Rock Foundations of Civilization

Whereas recent framings of planetary urbanization stress the planet-scaled impacts of contemporary urban processes, we might also conceive of cities as being constitutively ‘planetary’ from their very outset. This article looks at two ways in which the earliest urban centres or ‘civilizations’ on the floodplains of the Fertile Crescent harnessed the deep, geological forces of the Earth. The first is the tapping and channelling of sedimentary processes, central to what Wittfogel referred to as hydraulic civilizations (1963). The second is the use of high-heat technologies to smelt and forge metals, which can be construed as a capture of igneous processes. What both sets of practices have in common is that they involve skilled intervention in fluid-solid phase transitions between solid rock and flowing particulate matter. Viewing cities as constitutively geological or planetary in this way can help us reimagine the challenges posed to urban spaces by looming transformations in Earth systems.

Use of adaptive neuro-fuzzy inference system and gene expression programming methods for estimation of the bearing capacity of rock foundations

Purpose This study aims to examine the potential of two artificial intelligence (AI)-based algorithms, namely, adaptive neuro-fuzzy inference system (ANFIS) and gene expression programming (GEP), for indirect estimation of the ultimate bearing capacity (qult) of rock foundations, which is a considerable civil and geotechnical engineering problem. Design/methodology/approach The input-processing-output procedures taking place in ANFIS and GEP are represented for developing predictive models. The great importance of simultaneously considering both qualitative and quantitative parameters for indirect estimation of qult is taken into account and explained. This issue can be considered as a remarkable merit of using AI-based approaches. Furthermore, the evaluation procedure of various models from both engineering and accuracy viewpoints is also demonstrated in this study. Findings A new and explicit formula generated by GEP is proposed for the estimation of the qult of rock foundations, which can be used for further engineering aims. It is also presented that although the ANFIS approach can predict the output with a high degree of accuracy, the obtained model might be a black-box. The results of model performance analyses confirm that ANFIS and GEP can be used as alternative and useful approaches over previous methods for modeling and prediction problems. Originality/value The superiorities and weaknesses of GEP and ANFIS techniques for the numerical analysis of engineering problems are expressed and the performance of their obtained models is compared to those provided by other approaches in the literature. The findings of this research provide the researchers with a better insight to using AI techniques for resolving complicated problems.

THE VERNACULAR ARCHITECTURE PRINCIPLES IN MAKING MOUNTAIN ROCK FOUNDATION IN KENDARI CITY

Ordinary audiences who do not have formal education such as builders are called vernacular architects. In Kendari City, in general, public housing is built by a vernacular architect. The foundations made by vernacular architects do not use empty stones and sand dunes. The foundation is made partially in the hole and is made partially on the surface of the soil. This research is aimed to formulate the knowledge of vernacular architect on mountain rock foundation. This type of qualitative research with the descriptive approach used in this research. The resource is determined by the snowball method. Data collection was done by observation and in-depth discussion on three construction workers. Data were analyzed by the descriptive method. The research concludes that the vernacular architect in making the mountain rock foundation is rigid but also flexible, in order to respond to earthquake disaster. Rigid principles are found on mountain rock foundations, empty stone plates, nail terms on empty stones, chicken claw foundations, hierarchy on the floor, sloof and foundation relationships. Flexible principles are found in sand dunes, empty stones, anchor depth, and mortar for plaster.