Study On Engineering Properties Of The Mixed Polypropylene Fiber Solidfied Soil For Canal Liner

Soil stabilizer is one of new building materials, which can felt face of soil grains and make chemical reaction with aluminum-silicate minerals forming gum materials. Because its stabilized object is natural soil, this method have many advantages such as using local materials,reducing sand masses,no environmental pollution and saving engineering costs ,for it having important significance in technology and economy, Many countries all over the world have applied it in many kinds of engineering and its potential will be widely.Focusing on the urgently-solving problems existing on solidified soil used as a canal liner material, such as its low-strength,easily-cracking,bad impermeability and frozen–resistance and so on., analogized with effects of steel fiber in Steel Fiber Reinforced Concrete (SFRC),the paper advanced a new method that mixed random distributing polypropylene fiber into solidified soil. The strength and durability of solidified soil would be improved owing to fiber's bridging and reinforcing effects. According to achievements in the fields of mathematical statistics and experiment design, we researched soil adaptability ,unconfined compressive strength and durability,construction technique parameters of fiber solidified soil, and finally reached following conclusions:(1)The stabilizer amount is an important factor effecting strength and durability of solidified soil. In the same mixing ratio, its strength higher than cement-stabilized soil but seepage coefficient lower. In condition of 0.9kg/m3 fiber amount, for chosen soil 1:8 stabilizer amount is optimum.(2)When stabilizer amount fixed, mixing polypropylene fiber into solidified soil would increase its compressive strength. For Yangling soil used in experiments, when fiber amount is 0~0.9kg/m3 , compressive strength of solidified soil become higher and higher; when fiber amount is 0.9~1.5kg/m3 , strength reduces with fiber amount increasing; 0.9kg/m3 fiber amount produced the highest compressive strength, higher 29 % than solidified soil with no polypropylene fiber.( 3 ) Mixing polypropylene fiber into solidified soil can remarkably increase impermeability of solidified soil. For the chosen Yangling soil, fiber amount of 0.5~0.9kg/m3 produced the lowest seepage coefficient, lower 27 % than solidified soil with no polypropylene fiber.(4)Mixing polypropylene fiber into solidified soil would be evidently helpful in increasing its frozen -resistance, and reach the best in the condition of 1:8 stabilizer amount and 0.9 kg/m3 fiber amount.(5)Compressive coefficient is a major factor effecting strength and durability of solidified soil. The greater of compressive coefficient, the higher of strength, and it has more remarkable influence on solidified soil with lower mixing ratio. The experimental results indicate that compressive coefficient should be above 0.9. Considering economic benefits and project benefits, it is suggested that compressive coefficient is 0.95.(6)Curing method is also an important factor effecting strength of solidified soil. It has distinct distinguish in strength under different curing methods, of which we obtain the highest compressive strength in covering plastic membrane curing.