Combined method of compaction of collapsible soils

The writer proposes a combined method of compaction of collapsible soils. He presents results of investigations carried out to study compacted zones of pads punched (tamped-out) by rammers 10 and 20 tons in mass, as well as a comparative analysis of the pads over against compacted zones obtained by means of plane rammers. The analysis results are illustrated by the “arch effect” on the stress conditions of the soaked soil mass. NIIOSP Institute. Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 1, pp. 19–21, January–February, 1994.     

Installation of Underground Stories on Fill Soils and Soil Prone to Slump-Type Settlement

Proposals are discussed for the installation of underground stories on loess soils prone to slump-type settlement and fill soils of graded embankments as one of the most reliable and economic measures to ensure the strength and serviceability of buildings and structures erected under there conditions. Basic technico-economic and social advantages of the proposed technical solutions are cited. Publicly owned joint-stock company Tsentr Sotsal'noi Ekspertizy __________ Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 22–27, September–October, 2005.     

Unanticipated accidents in sodium-cooled fast reactors

The definitions and requirements of normative documents for unanticipated accidents at nuclear power plants with fast reactors are analyzed. Definitions are constructed between one another and with a collection of scenarios which can lead to unanticipated accidents, likewise determined by normative documents independently of the probability of these accidents actually happening. It is concluded that the normative approaches to fast-reactor safety must be refined with respect to strengthening the probabilistic criteria as a tool limiting the list of required unanticipated accidents for validating reactor safety. Special attention is devoted to the need to strengthen the motivation of designers to make the maximum possible use of passively triggered safety systems.     

Chemical reactions in the Mo-W-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> system at 2400 K and 100 Pa

We examine the behavior of the Mo-W-Al₂O₃ system at T = 2400 K and p = 100 Pa and identify the main chemical reactions that lead to the oxidation of Mo and W. The results indicate that, under these thermodynamic conditions, direct reaction between Mo, W, and molten Al₂O₃ is impossible, and oxidation processes are indirect and involve vapor species. For a Mo: W: Al₂O₃ molar ratio of 1: 1: 1, we calculate the gas-phase composition and demonstrate that the predominant vapor species are Al, AlO, Al₂O, MoO, MoO₂, and WO₃.