Optimization Model for Earth-Rock Allocation System in Large-Scale Hydraulic Engineering and Application in Shuibuya Project
Much importance is attached to the earth-rock allocation problem in the construction of many large-scale hydraulic engineering. Based on systemic view, the paper analyses the composition of the system and mutual relations among the elements. According to the analysis work, a linear programming model is constituted to optimize the operation of earth-rock allocation system to minimize the cost of the system. And the optimization model is put into operation in Shuibuya project in China. The calculating results by the model are economical and feasible in project construction
Linear programming model for finding optimal roadway grades that minimize earthwork cost
Abstract The cost of earthwork involved in road construction can vary widely based on the roadway grades chosen by the designer. There is almost an infinite number of feasible grades available to the designer to choose from, all of which satisfy the geometric specification of the road. For every feasible grade selected, a transportation problem must be solved, which is a very tedious task. The roadway grade selection is usually considered as a stage and the earthwork (transportation) is another stage. These two stages have always been treated separately in the literature. The model presented here combines the roadway grade selection stage and the earthwork transportation stage in a single linear programming problem, thus guaranteeing global optimality.
EARTHWORK ALLOCATIONS WITH NONCONSTANT UNIT COSTS
Existing linear programming methods of earthwork allocations in road construction assume that the unit costs of earthwork activities are constant. This paper investigates the factors that affect the variations of unit costs and presents a model of earthwork allocations that incorporates nonconstant unit costs. The unit costs may vary with the total quantity of materials moved from cut to fill sections or disposal sites and from borrow pits to fill sections. For earthwork from cut sections, the unit costs can be established from the known quantities of cut sections (and other operating conditions) and can then be treated as constants in the model. For earthwork from borrow pits, the unit costs also vary with the total quantity to be moved from a borrow pit to fill sections, but this quantity is unknown. These unit costs are formulated as three‐component stepwise functions. The solution of the model is explored and a computer program, EARTHN, which solves the model quite efficiently, is developed. The model...