Study On The Use Of Concrete Aggregate Produced From Excavated Spoil Of Structure In Hydropower Project

During the construction of large or medium scale hydroelectric project, lots of excavated spoil will be produced. And it is usually abandoned as wasted slag. But the spoil needs place to be piled, and the place is called spoil yard. Although many measures, such as soil conversation and drainage facility, have been applied to the spoil yard, the environment of the spoil yard is still influenced and destroyed. The fact isn't accepted by some developed countries, which have been appealing for green hydropower project in recent years. Therefore, it is necessary to pay attention to the research of comprehensive utilization technologies of excavation spoil in engineering construction in order to reduce the effect applied to nature by the excavated spoil. This thesis has put main focus on how to apply excavated spoil to make concrete aggregate to meet the need for spoil disposing technologies.The thesis regards rock excavation and concrete pouring as special resources. The optimization theory called as"construction period pegged– resources balanced", which enbeded in MS PROJECT, is used to balancing resources. So the peak intensity of rock excavation and concrete pouring can be reduced under the condition of unaltering the construction period. So the unbalance between excavated spoil and concrete pouring can be decreased, and the capacity of temporary spoil yard and the scale of sand and gravel processing system can be reduced, and the utilization ratio of excavated spoil can be improved.The transportation of excavated spoil to many temporary spoil yards is a problem of multisupply-multirequire. We can optimize the distribution of excavated spoil and choose appropriate temporary spoil yards in order to shorten the conveying distance of spoil. By the optimization of the distribution of excavated spoil appling the linear programming and programming function enbeded in MS EXCEL, the works volume of temporary spoil yard's protection and drainage can be reduced, and the project cost can be cut down too.By optimizing aggregate processing system and tracking the engineering progress, the loss of stone material in the course of aggregate production and transportation can be reduced, and the waste slag can not be generated from the aggragate production. Ultimately, the utilization ratio of excavaed spoil can be improved further.Taking DACHAOSHAN hydropower station as a example, this thesis has studied how to improve the utilization ratio of excavated spoil by planing of material source, technical feasibility analyzation, coordination of rock material excavation and concrete pouring, optimization of temporary spoil yards and aggragate production plants. Discarding good spoil can not happen as long as the quality of rock material's excavation and transportation can be strictly controlled, and excavated face, temporary spoil yards and crushing workshops in aggragate production plants can be jointly maneuvered and managed during the construction. So the direct utilization ratio of excavated spoil can be largely improved. Besides the designers have been tracking the engineering progress analyzing and controling the utilization of excavated spoil in the corse of construction of the hydropower station. So they can provide technical support for the adjustment of material source's plan. To analyze economic benefit, social benefit and enviromental benefit brought by aggragation got from excavated spoil.It is greatly beneficial to protect environment and reduce project cost by the utilization of excavated rock materials. The potentiation to utilize the materials should be adequately investigated for any new hydropower station project.