7
364
Catchment basin. It will not be necessary se repeat
in this Report, what has already been written in respect of the Tunnel and conduit of the Tytam Works. The modifications now submitted in the accompanying plans refer solely to the masonry dam in the Tytam Gorge # the remarks that follow, refer mainly therefore to this particular feature of the proposed new works
made
con
Foundations The foundations of the dam must, where practicable, be carried down to the solid rock. The trial borings that have already been
the site indicate the presence of underlying rock at a practicable depth below the ground-surface for more than three quarters of the width of the Gorge. The ground must therefore be exccuvated until the rock is based, the surface being roughly tabled if necessary, and all fissures carefully cleaned out and filled with liquid cement mortar. The entire floor may then. be covered with a two inch layer of cement morker preparatory to receiving the concrete subchucture: which forms the base or pedestal of the proposed masonry
dam.
-
8. On the West slope of the Gorge where the rock
is far too deep underground to be reached or utilised foundation, the excavation may be stopped as shown in the Drawing & N° 2. a core of earth being left along the centre of the trench with x view to reducing the cube of coment concret that is to fill the trench and form the substructure of the dam.
Should the ground upon being opened out however give any indications of forming crompescille foundation, it will be necessary to do away. this core
with
of earth and to fill the excavation entirely with concrete
3.