Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...

4.2.2 Timeline for Fieldwork.
Tuesday, October 27, 2009
7:00 AM Contractor’s (Brannan) crew began staging equipment and preparing the site for
the excavation.
7:30 AM Precut portion of the concrete paving slab in the alley was removed.
7:50AM After removal of the concrete slab, a soil sample was taken at the sub-grade level,
immediately beneath the concrete slab (sample No. 1 of 6).
8:00AM Excavation was halted and sample No. 2 of 6 collected from the bottom of the
trench, 2 ft below sub grade.
8:20AM Excavation was halted and sample No. 3 of 6 collected from the bottom of the
trench, 4 ft below sub grade and approximately 10 in. above the crown of the
pipe.
8:25AM One of the Brannan crew members hand dug with a shovel and sample No. 4 of 6
was collected just above the crown of the pipe.
8:30AM Hand digging continued and sample No. 5 of 6 was collected along the spring line
of the pipe.
8:40AM Sample No. 6 of 6 was collected with continued hand digging at the invert of the
pipe. Work was suspended while waiting for the Hydrovac truck to arrive.
10:50AM Hydrovac truck arrived and removed the soil around the host pipe to minimize
disruption.
11:40AM Removal of the soil immediately surrounding the pipe was completed by hand
digging and a plastic shrink wrap material was applied in multiple layers to
support the pipe joints.
12:00N A support cribbing, constructed of two 2 in. × 12 in. wood planks was joined
together to form a “V” shaped support for the specimen. This was placed under
the specimen and the voids between the pipe and the support structure were filled
for added support with foam packing material. The 6 ft specimen was then lashed
to the wooden support structure with bungee cords, and additional layers of the
shrink wrap material were applied. Two lifting slings were then fitted to the pipe
specimen and the excavator. Support tension approximating the weight of the
specimen was applied to minimize stress and movement during the cutting and
extraction of the specimen.
12:10PM A gasoline powered cut off saw with a diamond dust embedded blade was used to
cut the specimen, and the specimen was lifted from the trench by the excavator
and held suspended for annular gap measurements.
12:15PM Measurements of the annular gap between the host pipe and liner were taken with
a feeler gauge at both ends of the specimen and at both ends of the remaining pipe
before the repair was made. The annular gap measurements were taken from the
crown and at 45 degree intervals along the circumference of the pipes, moving
clockwise while facing the end of the pipe being measured.
12:40PM Measurements were completed and Brannan crew finished wrapping the
specimen (lifting straps enclosed in wrapping) and loaded the specimen into the
bed of a truck for transport to Crating Technologies (see Figure 4-1).
Monday, November 2, 2009
Specimen was received at TTC.
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