Engineering properties of some weak Icelandic volcanic rocks

In Iceland an increasing engineering activity, especially construction of hydroelectric power plants at sites containing volcanic rocks in subaquatic facies, has neccitated better understanding of their geotechnical behavior. The subaquatic vol-canics, which to a great extent most probably formed subglacially beneath Pleistocene glaciers are very heterogeneous, grading from highly jointed pillow-lavas and intrusions to much weaker pyroclastic rocks, the hyaloclastites.