Influence of litological aspects on the strength and durability of volcanic rocks in Urmia Lake Causway

For protection of Urmia lake causeway embankment, were used Zanbil and Eslami mountains rocks. Study of these protecting rocks in point of view weathering and demolition are important. The Urmia lake water is very saline and penetrating saline water to rocks texture and salt crystallization is the one of main reasons for rocks weathering and demolition.
In this paper the influence of litological aspects on the strength and durability of volcanic rocks in Urmia Lake Causeway based on field studies and sampling and pertographical studies and some physical and mechanical tests was considered. Rocks of west side of the causeway were obtained from Zanbi Mountain and the rocks of east side of the cause way were obtained from Islamic island. The most of used rocks are consisted of trachyte, andesite, basalt, tephrite, agglomerate and latite. The Islamic island rocks, except andesite, experienced more weathering. Texture properties like particle size and weathering type has more effect on strength and durability on used rocks. Increasing of particle size is causing decrease of strength and durability. The rocks of eastern side of the causeway due to porphyry texture and the occurrence chemical weathering before using in causeway, with high porosity and high water absorption is severe and deeper than weathering of western part rocks. Also the existence of clay minerals that was produced from weathering is caused low density in the Islamic island rocks.