Técnica de alvenaria adobe: Reprodução do método construtivo com e sem o uso de fibra vegetal

A técnica construtiva do adobe é um método de alvenaria em que se utilizam blocos em terra crua que possui como principal matéria prima o solo. De maneira geral, esta técnica proporcionou grandes feitos na historia da humanidade e reproduz com legitimidade um método construtivo simples, de fácil acesso e sustentável. Esta técnica bioconstrutiva é uma proposta de investimento para vários estudos, pois é um método que acompanhou a história da engenharia e da arquitetura e é possível ser aperfeiçoado podendo ser feita de várias formas possíveis com diversos agregados. Este trabalho apresenta a técnica do adobe que é uma alternativa sustentável para construções artesanais, assim como a experiência com a técnica e a mudança de comportamento para a confecção dos blocos com diferentes proporções de fibra vegetal em sua constituição, sendo que esta adição é normalmente feita para auxiliar na capacidade de resistência mecânica do bloco. Este trabalho consiste na mescla de uma revisão narrativa e a reprodução da confecção da técnica, sendo a primeira baseada em livros, artigos, seminários e demais obras cientifica que abordam o tema de construções em terra crua com destaque na técnica adobe, abordando os principais pontos para a confecção dos blocos e comparando os modos de confecção. Palavras-chaves: construção em terra crua; adobe; bloco de terra crua. Abstract The constructive technique of adobe is a masonry method in which blocks are used on raw earth whose main raw material is soil. In general, this technique provided great achievements in the history of humanity and legitimately reproduces a simple construction method, easily accessible and sustainable. This bioconstructive technique is an investment proposal for several studies, as it is a method that has followed the history of engineering and architecture and it is possible to be perfected and it can be done in several possible ways with different aggregates. This work presents the adobe technique, which is a sustainable alternative for artisanal constructions, as well as the experience with the technique and the change in behavior for the making of blocks with different proportions of vegetable fiber in their constitution, and this addition is usually made to assist in the mechanical strength of the block.This work consists of a mixture of a narrative review with empirical preparation, the first being based on books, articles, seminars and other scientific works that address the theme of constructions on raw earth with emphasis on the adobe technique, addressing the main points for the making of the blocks and drawing a comparison about this production. Keywords: raw earth construction; adobe; block of raw earth.

A brief historical analysis of the formation of engineering geology in the Krasnodar Territory

The article discusses the development of engineering and geological research on the example of prospecting and exploration of popular common (construction) minerals in the Krasnodar Territory. A comparative characteristic of the history of engineering geology development is given by analyzing the data of the Fund of the "KUBANGEOLOGY" and the planned economy of the USSR. The set goals and objectives of the planned economy of the USSR directly stimulated engineering and geological research. The peak of prospecting and exploration of popular common (construction) minerals in the Krasnodar Territory falls on the decade from 1970 to 1980, and the main rates - for the period from 1950 to 1980 - during the intensive growth of road, industrial and civil construction. Having arisen to solve the problems of engineering and economic development of territories, engineering geology developed not only in a geological, but geotechnical channel, as evidenced by the separation of surveys from it. The final differentiation from the beginning of 1960 of engineering geology into engineering-geological surveys and engineering geology of building materials proves the need for separation of surveys due to the accumulated regulatory framework and the scale of engineering-geological research, therefore, of the "KUBANGEOLOGY" switched to monitoring of hazardous processes of the geological environment, which is confirmed by the analysis of the fund.

Evolution of Fighter Aircrafts in the interwar Years: Cluster Analysis in History of Engineering

The article carries out cluster analysis of piston-engine fighters designed between 1920 and 1944 and takes into account more than 500 modifications of aircrafts that were serially manufactured in 18 countries. The author divides the period understudy into five-year segments and studies designs as far as such parameters as maximum speed, wing load and power load are concerned. Correlations of these variables are considered as well and special attention is paid to the correct distance determination. The article demonstrates dynamics of the main fighter characteristics between the world wars. It was found out that the main factor in the growth of fighter speed in 1920-1944 was the wing load related to modernization of profiles, quality and mechanization of the wing rather than growth of engine power of aircrafts. One can see repeating models of development in each period. These are a “power” approach that used new technologies “straightforwardly”, for instance, by totally increasing power loading, and a complex approach that provided for much better results. The author has revealed the leadership of the British aerodynamic school in 1920-1940 and has numerically demonstrated the change in the focus of the US design school from a "powerful engine - light aircraft" method to a "perfect aerodynamics - long flight range" method. He has shown the place of the Soviet design school as well. It has been found out that the last (during this period) sharp increase of wing load was not performed in the USSR and Japan. This led to rather low speed of fighters in these countries during the Second World War. The author discusses the reasons for this as well.

Stability and capacity of walking mechanism for moving of excavators

The authors discuss design of waling mechanisms intended for moving of single-bucket excavators. History of engineering and application of these mechanisms is given in brief. The authors also mention relations obtained for determining pressures and deformation of bearing surface under under the walking mechanism support shoes. The stability of walking excavators is considered with an assumption that the bearing surface deformation linearly depends on the pressure transferred to it by the excavator undercarriage. To understand the changes in the pressure on the bearing surface during walking, the cam walking mechanism work diagram is shown, which is divided into four typical phases for the convenience. The shape and dimensions of the bearing surface of the excavator during walking are studied, which makes it possible to find deformation of the bearing surface under the shoes. The analysis of energy consumed to move the excavator takes into account the gravity and friction forces, as well as the energy intake to overcome the inertial forces of lift and simultaneous turn of the machine in the vertical plane. The requirements of the machine movement are: the pressure under the excavator base must be lower than the allowable pressure for rock mass composing the bearing surface under analysis; the radius of the support base should be such that the pressure center is never beyond the core of crosssection. Determination of power for the operation of the walking mechanism is based on calculation of the energy consumption for lifting the excavator and overcoming friction between the excavator base and the bearing surface. Finally, the main outcomes of the study are summarized: the operation of the walking mechanisms is associated with significant dynamic loads induced in the machine steelworks; the power required for the operation of such mechanisms undergoes significant changes during walking and is mostly spent to overcome the resistance of the machine inertia; the power consumption is mostly associated with superstructure lifting and wheel dragging along the bearing surface given there is no backward slip of the shoes.

Foreword

The fourth issue of the scientific journal prepared by the RTU Research Centre for Engineering History (RCEH) comprises seven studies on Riga Polytechnicum (RP) / Riga Polytechnic Institute (RPI) students, graduates, lecturers and issues related to engineering sciences. The authors of the scientific publications are Latvian scientists, historians of science, museologists, and pedagogues. The articles are mainly based on the presentations made at the RTU 60th International Scientific Conference on 10 October 2019. The research topics are the activities of RP / RPI students, graduates and lecturers, the history of engineering sciences and associations