TranSystems Corporation - LGM Construction

All site preparation including fill placement and compaction should be observed by
Kleinfelder. It is important that during the site preparation and scarification process, a
representative of Kleinfelder be present to observe whether any undesirable material is
encountered in the construction area and whether exposed soils are similar to those
encountered during the geotechnical site exploration.
8.1.3 Excavation and Backfill
Excavations for footings, utility trenches, or other excavations are anticipated to be
made with either a backhoe or trencher. We expect the walls of trenches less than 5
feet deep to be able to stand temporarily near vertical without support. We do not
anticipate excavations greater than 5 feet. If excavations greater than 5 feet are
anticipated, please contact us.
Where trenches or other excavations are extended deeper than 5 feet, the excavation
may become unstable and should be evaluated to monitor stability prior to personnel
entering the trenches. Shoring or sloping of any deep trench wall may be necessary to
protect personnel and to provide stability. All trenches should conform to the current
OSHA requirements for work safety. Excavations should be located so that no
structures, foundations, or slabs are located above a plane projected 45 degrees
upward from any point in an excavation, regardless of whether it is shored or unshored.
Backfills for trenches or other small excavations beneath slabs should be compacted as
noted in Table 2. Special care should be taken in the control of utility trench backfilling
under structural, pavement, and slab areas. Poor compaction may cause excessive
settlements resulting in damage to overlying structures and slabs.
Where utility trenches extend from the exterior to the interior limits of the building,
clayey soils or lean concrete should be used as backfill material for a distance of
approximately 2 feet laterally on each side of the exterior building line to reduce the
potential for the trench acting as a conduit for the exterior surface water. Utility trenches
located in landscaped areas should also be capped with a minimum of 12 inches
compacted clayey soils.
94240/1(OAK8R061)/es Page 19 of 29 June 13, 2008
© 2008 Kleinfelder