Au Canada, on prévoit que les changements climatiques auront une incidence considérable sur l'industrie forestière. Les routes d'accès sont particulièrement vulnérables aux effets immédiats et à court terme des changements climatiques. Des stratégies d'adaptation pour les routes d'accès et les infrastructures doivent être élaborées et leur mise en œuvre doit commencer, afin de s'assurer que les infrastructures routières nécessaires pour accéder à la forêt soient maintenues et résistent aux effets des changements climatiques. Ce rapport présente les risques et la vulnérabilité des routes d'accès aux changements climatiques, ainsi que des méthodes et pratiques recommandées pour s'y adapter.
The changes to climatic conditions in Canada are anticipated to have a significant impact on the Canadian forest industry. Resource roads are considered particularly vulnerable to the immediate and short-term impacts of climate change. Adaptation strategies for resource roads and infrastructure must be developed and implementation initiated to ensure that the road infrastructure required for forest access is maintained and made resilient to climatic impacts. This report presents the risks and vulnerabilities of resource roads to climate change and suggested adaptation methods and practices.
FLNRO, with technical assistance from the B.C. Ministry of Transportation and Infrastructure and FPInnovations, conducted a case study of the vulnerability to climate change of infrastructure on the 70 km-long in-SHUCK-ch forest service road. The workshop participants followed a process established by the Public Infrastructure Engineering Vulnerability Committee (PIEVC). This case study provided both meaningful analysis of the risks and opportunities faced by the in-SHUCK-ch FSR corridor and the communities it provides access to, and establishes a benchmark for future iterations of the process with resource roads.
A series of recommendations are made that arise from the PIEVC analysis. These recommendations included the need to streamline and focus the PIEVC process specifically for resource roads, capacity building actions by road managers and maintainers, a review of emergency preparedness plans for the communities accessed by the FSR, actions to safeguard FSR infrastructure and residential development on lakeshore debris fans, a general review and inspection of drainage structures, actions to review and improve the resiliency of stream crossing structures and, finally, a recommendation to review the scope and size of the road maintenance program.
In 2009, FPInnovations created a spreadsheet tool based on a culvert length field guide originally developed by Dominico Iannidinardo of Timber West Forest Corp. The FPInnovations’ culvert length estimation tool was developed to assist with estimating culvert barrel length requirements for cross drains and for stream crossings. The tool also provided expert comments on culvert and road cross-section geometry.
In 2014/15, with support from BC Timber Sales, upgrades were made to the culvert length estimation tool. These changes expanded the scope of the tool to include some important design considerations not in the original tool. The upgrades include a function that helps optimize culvert ordering from suppliers, expert comments on fish passage and coupler selection, and determination of appropriate culvert material type and wall thickness. The software is available for download at the FPInnovations website www.fpinnovations.ca
Building roads on steep slopes and difficult terrain is a necessary yet often challenging endeavor in the natural resource industry. The magnitude of earthworks required for forest road construction on steep slopes can require substantial time and cost. The traditional role of planners is to create a road design in road engineering software, and then manually change and optimize its layout to minimize end haul volumes, excavation, and borrow and spoil pit creation.
FPInnovations was approached in January 2015 by the Engineering Brach of the British Columbia Ministry of Forests, Lands and Natural Resource Operations (FLNRO) to assess the state-of-practice of bridge approach alignment design on forest roads, and to make recommendations for the standardization of this process.
Understanding the current state of practice for steep switchback construction in B.C., and how to improve current practices, is important for industry safety, environmental impacts, and economics. In B.C., construction of steep roads and switchbacks is not uncommon, as 24% of the allowable cut annual (AAC) is located on slopes greater than 35%. This amounts to approximately 10 million m3 of harvestable timber volume on the Coast and 8 million m3 of harvestable timber volume in the Interior. Building forest roads in steep and challenging terrain poses safety, construction, environmental, and financial challenges. In some instances, companies have already begun harvesting at high elevations, and are reviewing policies and guidelines for what is considered safe, environmentally responsible operations for road construction and log hauling.
Substantial benefits can be realized by forest companies in British Columbia through implementation of new 9-axle log-hauling configurations. At the request of the British Columbia Ministry of Forests, Lands and Natural Resource Operations, FPInnovations undertook analyses to assess the potential impacts of the new trucks on resource roads and bridges. The analyses considered forestry bridge capacity (up to 36 m spans), vehicle fit to the resource road, gradeability, and road impacts. The vehicle weights and dimensions authorized for designated provincial highways were the basis for the analyses.
Those planning to implement 9-axle configurations on B.C. resource roads are advised to review the capacity of the infrastructure on their networks in light of the findings of this analysis. Bridges with less capacity than L-75 bridges were found to have length restrictions (that is, 9-axle B-trains generated force effects in excess of the bridge design vehicle for spans of 36 m or less). The capacity of L-45, L-60, CL-625, and BCL-625 bridges that exceed the maximum lengths identified in this report should be independently evaluated and certified by a professional bridge engineer for use with the 9-axle B-trains. Concrete beam bridges, designed according to pre-2000 design codes, may be under-designed for shear. This report’s general analysis must not be applied to pre-2000 concrete beam bridges of over 18.5 m span and, instead, a consulting bridge engineer should be engaged to determine their shear capacity.