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
Further development of integer programming in earthwork optimization
The objective of existing linear programming methods of earthwork-system optimization in road construction has been either minimizing the cost or maximizing profit, generally without considering the project duration. This paper develops a linear programming model incorporating the project duration. The model attempts to optimize a comprehensive earthmoving system in road construction by comparing alternative fleets (from available fleets) to provide an optimum material distribution and appropriate plant fleets to complete a project within the specified time. The situations where different degrees of compaction, availability of various soil strata at cut sections and borrow pits, and selection of borrow/disposal sites are also incorporated. Among the possible extensions, equipment sharing between fleets and sequence of operations present at cut and fill sections are examined. The validity of the model is demonstrated by applying it to a numerical example, providing additional tools to the management such as the minimum project-completion time, the cheapest project cost and corresponding duration achievable with available resources.
Flow in a branching open channel: a review
Branching channel flow refers to any side water withdrawals from rivers or main channels. Branching channels have wide application in many practical projects, such as irrigation and drainage network systems, water and waste water treatment plants, and many water resources projects. In the last decades, extensive theoretical and experimental investigations of the branching open channels have been carried out to understand the characteristics of this branching flow, varying from case studies to theoretical and experimental investigations. The objectives of this paper are to review and summarise the relevant literatures regarding branching channel flow. These literatures were reviewed based on flow characteristics, physical characteristics, and modeling of the branching flow. Investigations of the flow into branching channel show that the branching discharge depends on many interlinked parameters. It increases with the decreasing of the main channel flow velocity and Froude number at the upstream of the branch channel junction. Also it increases with the increasing of the branch channel bed slope. In subcritical flow, water depth in the branch channel is always lower than the main channel water depth. The flow diversion to the branch channel leads to an increase of water depth at the downstream of the main channel. From the review, it is important to highlight that most of the study concentrated on flow characteristics in a right angle branch channel with a rigid boundary. Investigations on different branching angles with movable bed have still to be explored.