Search

The paper discusses the negative impact of heaving soil during freezing of a road structure, including heaving formation. The provisions of normative methodology for testing the road structure for frost resistance are considered. The results of indirect and laboratory tests for determining the soil group by the degree of heaving are analyzed. The validity of influence of natural factors on frost heaving is considered. Proposals for improving the normative methodology are put forward.

This paper presents studies on increasing the ice strength using various additives. It is indicated that addition of wood fiber (artificial composition) and vegetable fiber (natural composition - frozen peat) to ice is an energy-efficient method to increase its strength. This enhances the possibilities of using ice during building and construction works in the Arctic. As an example, the authors proposed a floating ice pier design.

The article considers the main provisions of the regulatory methodology for estimation the frost resistance of a road structure. The technique for determining the degree of soil heaving is assessed taking into that the standard for its determination was issued in 1990. The intensity of frost heaving and its curve are being discussed. The characteristic curve of frost heaving intensity is substantiated in relation to road structures. The possibility of its plotting according to laboratory tests is being considered. A new method for testing of a road structure for frost resistance is proposed, the essence of which is illustrated by an example.

Yildiray Yildirim,1 Ibrahim Sahbaz,2 Taner Kar,1 Gamze Kagan,3 Mehmet Tolga Taner,4 Ilker Armagan,2 Begum Cakici21Department of Ophthalmology, Gulhane Military Medical Academy Haydarpasa Training Hospital, Istanbul, Turkey; 2Department of Opticianry, 3Department of Occupational Health and Safety, 4Department of Healthcare Management, Uskudar University, Istanbul, TurkeyPurpose: The aim of this study was to report normative values and ranges of interpupillary distance (IPD) in different age groups of a Turkish population.Methods: A total of 756 healthy subjects were included in this prospective study. After a complete ophthalmic evaluation, subjects were divided into four age groups to assess differences between age groups in relation to IPD. The age groups were 20–30, 31–50, 51–70, and 71–89 years. Far IPD measurements were performed using an autorefractometer (Topcon RM-8800).Results: The mean age was 48.42±20.55 years, ranging from 19 to 89 years. The mean IPD was calculated as 62.5±4.1 mm (range 49–76). The mean IPD value was observed to be significantly higher among males compared to females (P