Log Yard Stabilization Over Poor Soil Conditions

Suffering from heavy loading over soft soil, Neoloy®Geocells provided log yard stabilization to reinforce the base and increase modulus.

The logging yard at Canfor’s Fort St. John mill is subject to the heaviest loading operations in the worst soil conditions. Saturated peat with a CBR <1% and a high water table is not the ideal subgrade for log handling operations – logs that weigh from 600-1000 kg.

Cat 988H loaders weighing more than 43,000 kg, heavy hauling trucks, and other mechanical equipment created heavy rutting in the soft soil. The logs, stockpiled in huge, 6-metre high stacks, suffered from large settlement, which further impeded operations, while frequent access to the log feeder resulted in worse rutting. Coupled with a freeze-thaw cycle, they had the odds stacked against them.

Conditions at the yard meant that the sawmill could not operate at full capacity, while requiring constant, time-consuming and expensive maintenance. Everything turned around for Canfor after hearing of Neoloy Geocells for soil stabilization and soil reinforcement.

sawmill-canada-sub1 sawmill-canada-sub2 sawmill-canada-sub3

Conventional Solution

Previously, Canfor was hauling and applying expensive gravel every year to maintain adequate structure for their log yard operations. In a span of three years, Canfor added 50+ cm height of gravel to the entire site, only to watch as it failed after each and every placement.

Neoloy Geocell Solution

The design was based on one layer on the subgrade to improve the bearing capacity and another layer to reinforce the base and increase its modulus.

330-150-96-C Neoloy was used as a construction layer to stabilize the subgrade and improve its bearing capacity. This layer of geocells was in-filled using locally available sand. On top of this 330-150-96-D Neoloy was installed in the the gravel base layer to reinforce it, distribute loads, enhance drainage and prevent surface degradation.

A non-woven geotextile was laid over the subgrade and a woven geotextile laid over the subbase layer for layer separation in the saturated conditions.

Benefits

Neoloy Geocells made a “world of difference” in the words of the yard manager:

  • Eliminated all downtime caused by soil conditions
  • Increased production enabled the addition of another shift for 24-hour operations
  • Improved mill production, staff morale, and safety
  • Reduced equipment yearly operating costs:
  • $50,000 in fuel savings
  • $125,000 in loader maintenance
  • $75,000 in tyres and parts
  • Avoided production loss of $750,000
  • Utilized local marginal granular infill reducing hauling costs
  • Easy logistics and fast installation
  • Reduced maintenance costs and repairs
  • Higher modulus improvement factor than any other geogrid or geocell