ABSTRACT It is well established that nonnative species are a key driver of global environmental change, but much less known about the underlying drivers outbreaks themselves. In present article, we explore concept and implications sleeper populations in invasion dynamics. Such persist at low abundance for years or even decades—a period during which they often go undetected have negligible impac...

Günümüzün yüksek hız ve tonajlı, yoğun işletim şartları altında demiryolu yapı elemanları sıklıkla rezonans hasarlarına uğramakta fiili servis ömürleri kısalmaktadır. Ayrıca dünyada mevcut çelik donatılı, öngerilmeli veya öngerilmesiz beton travers modelleri, öngerilme işlemi etriye kullanım zorunluluğu getirmektedir. Bunun dışında tipler, üretimin hemen ertesi gün gerdirme kuvvetine maruz kala...

This paper summarizes the results of laboratory tests in which authors investigated effects extremely high vertical load to a railway track segment. The segment consisted cut concrete sleeper (contact area: 290×390 mm) with pair direct-elastic rail fasteners; pieces had standard, full height; structure typical 350 mm depth ballast, underneath approx. 200 sandy gravel supplementary layer. whole ...

The control of vibration generated by railways in tunnels is complicated by the dynamic interaction between tunnel and track. Conventional methods (floating slab track, ballast mats, under-sleeper pads) do not perform as well as might be expected and it is the purpose of this paper to explore the sources of error. The major factors which must be taken into account pertain to the three-dimension...