An 11-ton microtunneling machine has arrived and will soon be boring under the Ala Wai Canal and Kaiolu Street in Waikiki.
The million dollar machine will chew its way at a rate of four to five feet an hour. It will result in the installation of two sets of wastewater pipes that are key parts of the Beachwalk Wastewater Emergency Bypass project.
The BWEB project was launched last May following a devastating break in an aging sewer line under Kaiolu Street.
That old line will be replaced by the two new lines that will go under the canal and Kaiolu Street. They will hook up to the existing pipe on the bottom of the canal, allowing contractors to dismantle and remove the above-ground pipes and pumps along the Ala Wai Boulevard.
Looking like a jet engine, the auger cutting tool at the front of the eleven-foot long machine will chomp through dirt and rock and allow contractors to push in twenty foot lengths of steel casing pipes. The operation will begin in the mauka pit, located near the Ala Wai Community Gardens, and stretch 1,220 feet to the makai pit, located at the corner of Kuhio Avenue and Kaiolu Street.
Workers will use hydraulic jacks to push twenty foot lengths of steel casings underground. The jacks are capable of applying up to four hundred tons of pressure.
Once they install the steel casing, they will insert a fiberglass pipe that will eventually carry the wastewater.
Workers also continue jet grouting operations on Kaiolu Street to strengthen the subsurface soils before the sewer pipe is installed below ground.
Jet grouting involves drilling deep holes and installing underground cement pillars. The jet grouting on Kaiolu Street will run typically from 6am to 6pm with occasional later shifts to finish jet grout columns in progress. The free on-street parking will remain closed while jet grouting continues.
The BWEB project has already resulted in the construction of a temporary bypass line that can be activated in the event of another break in the aging sewer line. This represented phase one, and it was completed in July, just three months after the massive project was launched.
The phase two microtunneling operation completion date has been extended due to the long lead time to fabricate and ship key piping system components. There were also changes to the original plans that extended earlier completion projections.
The project originally called for temporary lines under Kaiolu Street, but has since changed to make those lines part of the permanent fix to upgrade the city’s sewer system. Also, original plans called for one microtunnelled line, but that has been changed to two lines, giving the city an emergency backup in the event one line goes down. It will also allow greater flexibility for needed maintenance.
Gov. Linda Lingle on Jan. 26 extended the emergency proclamation for the project that she first issued on May 24, 2006. It had been set to expire Jan. 31, 2007. The governor extended it to July 31, 2007.
Check this site — http://www.beachwalkbypass.com — for weekly updates. For further information, call 808-543-8374.