May
2007Gravity Sewer
Installed in City of Port Hueneme by Nada Pacific Corporation
using Akkerman 308 GBM System
In March of
this year, crews from Nada Pacific Corporation (under
general contractor, Don Kelly Construction) installed a gravity sewer
line connecting
the City
of
A total of 3,018 feet of 12” vitrified clay pipe (VCP) was installed from nine launch shafts and eight reception pits that varied in depth from eight to 28 feet. The VCP was installed through seventeen bores that ranged in length from 49-224 feet with precision line and grade offered by Akkerman’s Guided Boring Machine (GBM) 308 system. The launch and reception pits were lined with corrugated steel with an injection grout around the bore entrances and exits due to the moist sand, clay, and silt soil conditions.
At the outset of the job, Kit Nell, City Engineer, was concerned about how the job could impact traveling public and the flowing soil. Nada Pacific’s presentation of the microtunneling method mitigated those concerns. Akkerman’s compact GBM 308 jacking frame minimizes surface disruption since all it needs to operate is an 8 foot diameter launch shaft. Additionally, the application of pilot tube microtunneling excels in flowing soil conditions.
Akkerman’s
standard
GBM system includes a jacking frame, a hydraulic power pack to provide
power to
the frame, a guidance system and set of pilot tubes. The 4.25 inch
dual-walled
pilot tube, unique to Akkerman Inc., houses an illuminated LED target
directed
by the guidance system and monitored by the operator via video
surveillance in
the power pack. The three pass system begins with the installation of
pilot
tubes. Next, casings and augers are driven along the same path as the
pilot
tubes, creating a larger tunnel for the 12” I.D. VCP. With the addition
of each
section of casings and augers, a section of pilot tube is removed in
the
reception shaft. Lastly, each addition of the 12” VCP advances a
section of
casing and augers into the reception shaft.
The work was
completed ahead of schedule in May 2007 in a
total of 210 working days. Nell states that the City of
Nada
Pacific
Corporation, of Caruthers (
In 1973, Akkerman
Inc. of
