Drainage Specifications-Lucas



                               XII.

                            GRUBBING.
   All grubbing or clearing of stumps, trees or brush, and the re-
 moval of all loose stone necessary for the construction of said
 ditch, shall be done by the contractor and shall be removed out-
 side the waste banks of 'the ditches.

   This as well as other requirements should be known to the con-
 tractor before he submits his proposal. In this way he protects
 himself by including the cost of grubbing in the price.


                              . v.

                            QUICK SAND.
  If encountered in prism of the ditch, the commisisioners shall
be notified immediately and may order the, grade of the ditch
lowered and the slopes 'made less steep and continue at such in-
creased depth and decreased slope until said sand disappears
from the prism of Ithe ditch, or until such increased depth is con-
sidered unnecessary by the commissioners, and the additional ma-
terial removed shall be, paid for at unit prices.  Any filling of
the ditch because of quick sand after its construction in accord-
ance with the directions of the commissioners shall not be cause
for refusal Ito accept the ditch when completed.

  It is almost impossible to tell beforehand whether quick sand
will be met with in the construction of the work, or when or at
what point. The term "quick sand" is variously defined by en-
gineers and contractors.  My own judgment is that quick sand
proper is a sand that by friction has had the sharpened edges of
the sand worn off so that the sand particles are more spherical
in form than ordinary sand and by reason of its rounded condi-
tion, as well as being filled with water, it has little resistance. Oft
times when a ditch is being constructed, it is found that the soft
muck or soil, lying just beneath the surface flows into the ditch
and many speak of this soil as being quick sand. In fact this is
not quick sand, and is found practically only in marshes that are
very wet. The top soil as a rule is more firm and is bound to-



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