Study On The Optimization Of Earthwork Allocation In Harbin Qunli New District

Earthwork allocation is an important project in the early stages of large urbancluster development construction projects, which inevitably result in huge cost.Thus, using scientific mathematical optimization models to make a rationalearthwork allocation program before the start of the earthwork project is of greatsignificance for the reduction of total cost. Taking Harbin Qunli New District as anexample, this paper studied the optimization model for earthwork allocation whenmultiple soil types exist in the allocation areas.Firstly, the paper defined some basic concepts related to earthwork, andanalyzed the elements and key factors which affect the allocation of earthwork. Acomparison is made among the widely used earthwork allocation methods home andabroad: Mass-Haul Diagram, Linear Programming, and Simulations, analyzed theirshortcomings and problems in practices respectively.The paper then decomposed the earthwork problem as a system, analyzed theearthwork flows in the system and the composition of project cost. The unit cost ofearthwork allocation is classified into two types: one is associated with the cutsections, and the other associated with the borrow pits. Based on this classification,concluded that the cut section associated unit cost can be calculated beforehandusing relative project materials, while the borrow pit associated unit cost is astepwise function, and the paper introduced a three-stepwise unit cost function ofpurchase and excavation for borrow pits. By introducing binary variables, weconstructed a mixed integer-linear programming model for earthwork allocation.Using Visual Basic 6.0 as the development tool, the paper analyzed the functionalmodules of the earthwork allocation software system and the access technology ofthe project data base, and established the project data tables.Finally, a case study is carried out taking the starting area of Qunli NewDistrict as the example. Considering the project characteristics of Qunli NewDistrict and the purpose of this study, the paper simplified the mathematical modelconstructed in Chapter 3, neglected the unit cost for earthwork compaction, onlytake the purchase cost, excavation cost and hauling cost into account for theoptimization of earthwork allocation. The paper demonstrated the calculationprocess of unit cost through numerical examples, and solved the model of the casestudy using Lingo 9.0. The result of the case study showed that the optimizationmodel introduced in this paper had strong practicability in practices, especially in the earthwork allocation of large scale urban cluster development constructionproject. The paper concluded that there are two critical factors that may have greatimpact on the results of the optimization model: work scope of the earthworkallocation areas and deployment of the construction equipments.