concrete bed
71tunnels and underground excavations — ▪ engineering Introduction Great tunnels of the world Great tunnels of the worldhorizontal underground passageway produced by excavation or occasionally by nature s action in dissolving a soluble rock, such as limestone. A vertical opening …
72Gravel — For other uses, see Gravel (disambiguation). Gravel (largest fragment in this photo is about 4 cm) …
73Seismic retrofit — Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. Other retrofit techniques are applicable to areas subject to tropical cyclones,… …
74Fly ash — Photomicrograph made with a Scanning Electron Microscope (SEM): Fly ash particles at 2,000x magnification Fly ash is one of the residues generated in combustion, and comprises the fine particles that rise with the flue gases. Ash which does not… …
75George Massey Tunnel — Descending into the Massey Tunnel Overview Location Metro Vancouver Coordinates …
76Nord Stream — Location of Nord Stream Location Country Russia, Germany General direction …
77Frankford Creek — is a minor tributary of the Delaware River in southeast Pennsylvania. The stream originates as Tookany Creek at Hill Crest in Cheltenham Township and meanders eastward, then southeastward, throughout Cheltenham Township, until a sharp bend near… …
78British hardened field defences of World War II — Hexagonal pillbox (type 22) British hardened field defences of World War II were small fortified structures constructed as a part of British anti invasion preparations. They were popularly known as pillboxes by reference to their shape.[1] Con …
79Petrosomatoglyph — This footprint carved into the rock on Dunadd, in Argyll, is linked to the crowning of the Scots kings of Dál Riata. A petrosomatoglyph is an image of parts of a human or animal body incised in rock. Many were created by Celtic peoples, such as… …
80death — /deth/, n. 1. the act of dying; the end of life; the total and permanent cessation of all the vital functions of an organism. Cf. brain death. 2. an instance of this: a death in the family; letters published after his death. 3. the state of being …
