Daishowa Slide Repair
In early January 2016, Doublestar Drilling (DSD) was awarded the Daishowa – Slide Repair Tangent Pile Wall Project. The purpose of the pile wall was to permanently stabilize the slope that was failing causing damage and the potential closure of highway 986 North of Peace River. DSD was responsible for installing 118ea, CIP Concrete Piles 1200mm in diameter to depths of 28.5m. Due to soil conditions each pile required segmental casing up to 15.0mbg to prevent sloughing and soil loss. DSD’s Liebherr LB36 and LB28 drill rigs were used to install the piles.
By the middle of March 2016, DSD completed the piling portion of the wall and began installing the deepest row of permanent DCP anchors, to a depth of 37m. In total there were 354 anchors to a combined length of 11,192m. Solid and Hollow stem auger drilling systems were required due to highly variable soil conditions on the project. Anchor rows 2 and 3 required coring through the 1200mm CIP Piles at a 30 degree angle. DSD’s two Davey Kent 725 and Soilmec SM-14 drill rigs were used to install the anchors that were completed on schedule by the end of June 2016.
Pre-project planning and communication between project management and site personnel was essential to the success of the project due to the remoteness of the site and schedule requirements. Changing soil conditions also presented challenges trying to maintain production when casing and/or hollow stem augers were required on over 50% of the anchor boreholes
In the end DSD completed the Tangent Pile Wall and DCP Ground Anchors on schedule and budget. The project is being highly monitored by means of SAA’s (shape array accelerometer), strain gauges and loads cell. After 1 year of monitoring the wall is performing extremely well.