UBC Theses and Dissertations
Comparison of mass diagram and linear programming methods of mass allocation in forest road design Haudenschild, Urs Emanuel
Accessibility of the forest is a basic requirement for a commercially managed forest. Logging in British Columbia often is carried out in remote areas where log transportation is primarily by truck hauling on forest roads. Forest road construction and particularly earth moving are significant elements in the total cost of forest products. Proper choice of road design elements will determine the optimum economy of any forest road. The derivation of road design elements is shown in detail as an introduction to the earth allocation problem. Minimization of costs of main forest access roads is studied in this thesis and alternate methods of mass allocation are presented. A semi-graphical method of mass allocation (mass diagram) is compared with a method employing the electronic computer and the tools of operations research (linear programming). The theory of linear programming (LP) is shown as the optimization technique used for minimizing the earth moving costs. The LP assumptions and limitations are discussed. The two methods were tested on the forest main haul road C in the University of British Columbia Research Forest. Calculations of volume distribution and the required intermediate calculations are carried out with an electronic computer for comparison with traditional methods. The mass diagram method might be used for a long time due to its simplicity, whilst LP provides a more precise solution. The costs of earthmoving and planning are $84.00 or 0.6% of the total earthwork and planning costs less by using LP rather than the mass diagram in the example calculated. The use of dynamic programming (DP) to determine the optimum road lay-out is suggested as a topic for further research, a preliminary step for optimization in mass allocation.
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