15 AUGUST 2005
investigation report due to seasonal or unusual variations or insufficient information,
since the contractor will be held responsible for controlling the groundwater flow into the
excavation regardless of the amount. To this end, the specifications should provide for
requiring the contractor to submit a revised dewatering plan for review where the
original dewatering plan is found to be inadequate.
Shoring and Bracing. The specifications either will require the contractor
to submit for review his plans for the shoring and bracing required for excavation or will
specify shoring and bracing required by subsurface and groundwater conditions and
details of the lines and grades of the excavation. In the latter case, the contractor may
be given the option to submit alternate plans for shoring and bracing for review by the
Contracting Officer. The plans will present the necessary information for the design of
such a system if the contractor is allowed this option.
Stockpiling. Provisions for stockpiling materials from required excavation
according to type of backfill may or may not be included in the specifications.
Generally, procedures for stockpiling are left to the discretion of the contractor, and a
thorough study should be made to substantiate the need for stockpiling before such
procedures are specified. There are several conditions under which inclusion of
stockpiling procedures in the specifications would be desirable and justified. Two such
conditions are discussed in the following paragraphs.
Under certain conditions, such as those that existed in the early stages of
missile base construction where time was an important factor, it may be
necessary or desirable to award contracts for the work in phases. As a
result, one contractor may do the excavating and another place the
backfill. It is probable that the excavation contractor will have little or no
interest in stockpiling the excavated materials in a manner conducive to
good backfilling procedures. When such a situation can be foreseen, the
specifications should set forth stockpiling procedures. The justification for
such requirements would be economy and optimum use of materials
available from required excavation as backfill.
The specifications will contain provisions for removing, segregating, and
stockpiling or disposing of material from the excavation and will refer to
the plans for locations of the stockpiles. The subsoil conditions and
engineering characteristics requirements may state that the specifications
must be quite definite concerning segregation and stockpiling procedures
so that the excavated materials can be used most advantageously in the
backfill. The specification may require that water be added to the material
or the material be aerated as it is stockpiled to approximate optimum
water content, that the stockpile be shaped to drain and be sealed from
accumulation of excess water, and that the end dumping of material on
the stockpile be prohibited to prevent segregation of material size or type
along the length of the stockpile.
An alternative to this latter action would be to specify the various classes
of backfill required and leave the procedure for stockpiling the materials by type to the
discretion of the contractor. In this case, the contractor should be required to submit a