[en] A powerful new computer is now in use at the Portuguese National Foundation for Scientific Computation (FCCN Lisbon), set up in 1987 to help fund university computing, to anticipate future requirements and to provide a fast computer at the National Civil Engineering Laboratory (LNEC) as a central node for remote access by major research institutes

[en] Tailings pond plays a very important role in the construction of mine engineering. At the same time, tailings pond also produces huge pollution to the environment. If dam break occurs, it will cause loss of people and property. In this paper, a tailings pond management system based on RSCIC is studied, the monitoring content of the system is determined, the more innovative system and hardware are emphasized, the program flow chart of digital processing is put forward. Adopting scientific and effective means to manage the tailing dam automatically can not only strengthen the safety protection of the tailing dam, but also provide a certain theoretical basis for the construction of other digital tailings dam projects. (paper)

[en] The limited choice of construction materials under the extreme conditions of the Russian Arctic and the necessity to solve the ecological problems after the intense development of territories in the USSR raise the issue of utilizing the unnecessary dwelling and industrial buildings and using the obtained wastes. The most widespread material is reinforced concrete. The authors propose using concrete with angular aggregate made of crushed concrete. Based on the properties analysis and the technology of producing and processing both materials, the authors regard the possibility and area of their application. The aim of the research was to prove the possibility of using the construction materials based on utilization of the secondary raw materials – crushed reinforced concrete – under the extreme conditions of the Russian Arctic and to define the spheres of application. The main method was comparing the experience of using crushed concrete on the continent and in the Arctic. The possibility is studied to use the crushed concrete for low-burden foundations and basements, and as coarse aggregate for concrete when erecting buildings, constructions, and motor roads in the Russian Arctic. The crushed concrete and the concrete with aggregate made of crushed concrete can be used in the Russian Arctic provided certain conditions are observed related to the volume of the crushed concrete in the mix and the maturing of concrete under positive temperatures till the critical strength is achieved. (paper)

[en] When increasing the degree of fluidity of previously aerated cementitious mixtures, there is a problem of maintaining their correct aeration. Most of the available superplasticizers cause a significant increase of the air content of concrete mixtures. The problem of compatibility of superplasticizer and air-entraining admixture increases in case of multicomponent Portland cement, due to different effects of these additives. It comes down to achieving a compatibility of the three variables mentioned in the title of the paper, due to the required air entrainment and consistency of mixture. Achieving compatibility of such a system requires a series of experimental studies that were presented in the paper together with their resulting indications. In case of previously air-entrained concrete that is made with an air-entraining cement, after the addition of new generation SP occurs very large increase in air entrainment. The air-content of mixture according to EN 480-1 may be higher than 13%. (paper)

[en] This paper has been inspired by the principal author’s life-time research at the cutting edge of the concrete industry and is propelled by recent research undertaken with his co-authors, which is referenced fully in this paper. In the main, this work has been created to show that the use of sustainable construction materials, in making concrete, should be carefully evaluated for their rheological, engineering and long-term durability effects, in the relevant exposure classes, as well as environment impacts, in the form of leaching, as a material and whilst in use. Failure to do so, can, in the long-term prove to be disappointingly counterproductive in achieving the estimated sustainability benefits from the use of such materials in concrete, and may even prove disastrous. (paper)

[en] Shotcrete technology is one of the necessary part of support system in tunnel engineering, and the support effect of shotcrete is getting more and more attention. We improve the materials and technologies and propose a new shotcrete supporting method, high pressure hydraulic shotcrete. The high pressure hydraulic parameters of C20, C25 and C30 concrete is studied. Several key factors and problems of the parameters are expounded. The engineering application shows that, compared with ordinary shotcrete technology, high pressure hydraulic shotcrete can effectively reduce the shotcrete resilience and the content of dust, and the later strength loss of shotcrete is less than 10%, which has a good popularization and application value. (paper)

[en] A modification of the method for calculating the horizontal cable consumption of SCS established at civil engineering facilities is proposed. The proposed procedure preserves the prototype simplicity and provides a 5 percent accuracy increase. The values of the achieved accuracy are justified, their compliance with the practice of real projects is proved. The method is brought to the level of the engineering algorithm and formalized in the form of 12/70 rule. (paper)

[en] Mechanical systems, including building ones, consist of a huge number of elements. Thus, traditional methods of reliability block diagram and logical schemes, oriented to small-element systems, aren’t appropriate for reliability analysis. In this paper a fundamentally new method for reliability assessment of mechanical systems is considered. It’s based on the reliability matrix. The reliability matrix is the difference between the characteristic matrix and the connection matrix, which are formed from the structural scheme. Probability of failure or probability of success of the system is equal to determinant of the reliability matrix. The use of the matrix method proposed by the authors in conjunction with computer software has more perspective, it allows to work with complex mechanical systems, significantly reduces the time of analysis and decrease the risk of errors. This method of calculation is optimized for inclusion in Civil Engineering CAD software. (paper)

[en] In this article theoretical calculations of the construction of the underground passages under the influence of seismic forces are conducted and refined by a series of experiments. As a result of experimental studies, the authors have clarified the value of the active pressure of the ground on the construction and the active seismic inertial forces, taking into account the design. As a result of theoretical and experimental studies of seismic resistance of underground pedestrian crossings at different ground, areas of stress concentration in these constructions have been determined, which allows these sections to provide anti-seismic beams, which ensures the safety of the constructions to an earthquake or significantly reduce the degree of damage. (paper)

[en] After entering the new era, China’s railway transportation industry has developed rapidly, and many high-speed railway projects have been emerging. Compared with ordinary railways, the trains on the high-speed railway have higher running speed, which need higher requirements on the rigidity of the bridge. In response to this situation, long-span continuous beam construction techniques are widely used in high-speed railway projects. Based on engineering cases, this paper analyzes the key technology for high-speed railway long-span continuous beam construction. (paper)