b. Costs may be higher, although not necessarily prohibitive, in unstable soils and embankments containing
boulders, stumps, waste from rock cuts, or similar obstructions.
c. Before it is decided that jacking is the proper method to use, all conditions involved in the operation should
be investigated. Cost estimates for open cut placement or tunneling should be compared with the probable
cost for jacking and/or boring. Such estimates should include expenses due to interference with traffic and
excess maintenance until embankment becomes stabilized. Additionally, relative safety of the various
installation methods must be considered. The exposed vertical face associated with the jacking operation
may not be desirable in certain soil conditions and should be addressed by a qualified engineer.
d. It is recommended that pipe boring and jacking operations be performed by an experienced specialty
contractor normally engaged in performing this type of service. Most railroad maintenance-of-way
departments are not equipped to undertake such a project.
e. For further information on earth boring and jacking methods refer to Reference 27.