Test Study On The Technique Of Dam Construction Method Of Hydraulic Flushing And Filling With Fly Ash

Fly ash is a disused material dumped out from thermal power plant or cement mill which use coal as a kind of fuel. China has become the largest country draining off the fly ash. Fly ash brings great damage to our living environment. Thermal power plant spends enormous manpower and money to deal with it every year. Also disused fly ash contaminate environment and occupy large lands. Therefore, how to utilize the vast harmful fly ash resources is the urgent thing we must do. This paper studied the effect of engineering application in dam construction of hydraulic flushing and filling with fly ash.The peculiarity of fly ash is the premise of comprehensive utilization. Firstly we discussed about the process of formation and the way of discharge of fly ash, expounded the properties of fly ash such as particle shape, fineness, specific gravity, chemical constitution, mineral composition, performance of pozzolane, and pointed out the difference of particle dimension and chemical composition is the predominant reason between fly ash and soil as a sort of building material. By doing laboratory experiments, the physical and mechanical characteristics are studied of fly ash deposited from Shengli thermal power plant. Results show that silt is the major constitution of the fly ash particles, and the fly ash has a middling permeability and a higher internal friction angle and a quick concretion velocity. The fly ash is a suitable material to built dam with method of hydraulic flushing and filling. The thickness of flushing and filling is the critical factor in construction dam with method of hydraulic flushing and filling with fly ash. A series of indoor analog test are done simulating the site of building dam, including bilateral and single drainage with different thickness with 20cm, 30cm and 40cm. Study indicates that it has a better flushing and filling effect with good compaction density and minor thickness. And it raise the compaction degree of 4.5%. From the aspect of saving money and timelimit for a project, the thickness of 40 centimeter is a good thickness to form dam with method of hydraulic flushing and filling with fly ash.Also some observation work are done during the dam construction using the method of hydraulic flushing and filling with fly ash. The effect of this method to form dam is evaluated from the result of monitoring construction dam. The result of observation shows that settlement per day is only two millimeter in settlement deformation and the deformation of dam foundation is slight. And the pressure of pore water dissipated rapidly in short times. All this indicates that it is safe and reliable to form dam use the method of hydraulic flushing and filling with fly ash. In the last of this paper, some problems are posed during the process of construction dam with the method of hydraulic flushing and filling with fly ash in the second term engineering of heightening dam and put out some suggestions to improve this work method. Especially in the construction technique, it will have a good effect that take the place of way of slope protection after whole finishing flushing and filling with the way slope protection with flushing and filling. This is a good advice for constructor and designer about using the method of hydraulic flushing and filling to form dam with fly ash resources.