Page 440 - Trenchless Technology Piping Installation and Inspection

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observations have been made, there is always a small probability that
something could be overlooked. By having a procedure in place, the
operating crew will have a set of written instructions to follow that
can greatly reduce the downtime related to a strike. A list of all utili-
ties, along with their phone numbers and contact personnel, should
be kept at the jobsite.

9.3.5 Contingency Plans
The last step a company has to plan for in avoiding pitfalls during a
trenchless project is to have contingency plans developed before the
job starts to reduce delays. Regardless of the amount of investigation
or research that may have been done to find existing utilities or struc-
tures, not everything can always be found or located. Even if the
existing utilities are found, there may be other obstructions; both
manmade and natural may exist below the surface. A construction
site of a building long since torn down may have had a pile of dumped
concrete left during its construction stage. Years ago many low areas
became dumping areas of old building materials mixed with lumber
or other organic materials. Only an open-cut method would be able
to determine what types of materials have been buried.
Natural obstructions that may be present include the root system
of a large tree that has since been cut down. In gravelly areas, large
boulders may be present. A contingency plan has to be developed
before the start of a project if an obstruction is found. Depending on
what other obstructions may be in the area, changing location of the
drill is not always possible. Even if an alternative location were pos-
sible, pulling a drill bit would leave a void beneath the surface, which
needs to be filled with grout.

9.3.6 Communication
Communication guidelines should be established prior to the com-
mencement of trenchless work. There should be good communication
between the operator and other personnel (usually general laborers)
to coordinate the drilling operation. Radios should be used for com-
munication, but there should also be hand signals agreed to before-
hand in the case the radios fail or reception is bad.
For example, communication breakdown can lead to delays
through contact with existing utility companies if the drill-rig opera-
tor does not understand the direction being given to him or her.
Because the general laborers may speak very little English, it is impor-
tant that, if the job-site foreman does not speak the language of the
laborers, at least hand signals are set up that all parties understand.
One last item that must be investigated during the planning/
design stage is the geotechnical makeup of the soil along the length of
the bore area. Because of the importance and complexity of this por-
tion of the planning stage, it is discussed in Sec. 9.2.3.