I have added zip file of lightning design system which contains fonts,icon,images,style folders. in this svg icons are in icons/utility-sprite/svg folder, i have set the path but it;s not reflecting on visualforce page.
<svg class="slds-icon slds-icon_small" aria-hidden="true">
<use xlink:href="{!URLFOR($Resource.SLDS080,'/icons/utility-sprite/svg/symbols.svg#alert')}"/>
</svg>