Study On The Key Technology Of Mechanical Lining For Large-scale Channel Concrete

South-to-North Water Transfer Project, as the biggest one in the world, features long-distance water transfer, and regards the water pipeline as the key point. The water pipeline passes by the regions where there are complex terrain and geology, much different hydrology, meteorology and operating conditions, and the pipeline building faces up with complex meteorology variation when construction and operation. So, it palys a great pole in finishling the whole South-to-North Water Transfer Project perfectly that we solve successfully the impermeability, anti-freeze and melt of pipeline concrete slab, and the autogenous shrinkage, drying shrinkage of the concrete, and the cracking resulting from the large-area, quick and continuous cast-in-place and etc.Based on the Huangnan cannel of South-to-North Water Transfer Project, the effect of cement, fly ash, fine aggregate, and admixture on the strength, deformability, durability and anti-cracking of the concrete is studied deeply, and then the optimal formula of the shrinkage-compensating concrete and the shrinkage-compensating one is obtained in this paper.Addtion of the fly ash in conctete is useful in reducing the cement content, enhancing the workability, durability of the expansive concrete, and it is concluded that the optimal fly ash addtion in the shrinkage-compensating concrete and the shrinkage-compensating one is 10 to 30 percent.Expansive agent is used to reduce the concrete's desiccation crack, strengthen its anti-cracking and anti-permeability when manufacting the shrinkage-compensating concrete, the shrinkage-compensating concrete and self-stress concrete. The optimal addition of expansive agent is about 8-12 percent.The sand contains coarse aggregate and fine aggregate, where, stone powder in fine aggregate affacts the concrete performance greatly. It is concluded that between 6.0 and 18 percent of the content range, the anti-permeabilty of the concrete enhances along with increment of the stone powder content, however, between 6.0 to 11 percent of the content range, the compressive strength, anti-freezing and deformation ability of the concrete keep near constant. Additionaly, increase of the stone powder content results in quick cement hydration which leads to a high insulation temperture rise, and produce a bad effect on the anti-cracking and the freeze resistance. As a result, stone power in the fine aggregate should be kept in a right content range.It is stated out that,the optimal ratio of shrinkage compensating concrete should be 0.4 to 1 for the ratio of water and glue, and the ratio of cement, fly ash, expansive agent and aggregate should keep as 1:0.35:0.16:8.3, with additon to dehydrating agent of 1.2 percent and getter of 0.015 percent of concrete weight respectively. On the other hand, the optimal ratio of micro-expansive concrete should be 0.4 to 1 for the ratio of water and glue, and the ratio of cement, fly ash, expansive agent and aggregate should keep as 1:0.2 5:0.136:8.3, with additon to dehydrating agent of 1.2 percent and getter of 0.015 percent of concrete weight respectively.On account of the fact that it is difficult for the concrete to be paving and dense enough when carrying out the concrete lining technique on slope area, the effect of the concrete viscosity and its slump on its sttength and density is studied deeply. In the study of concrete lining technique, the forming mechanism of vibratory compact of slope concrete is obtained and its viscosity and slump are determined and then the reasonable vibration and viscosity coefficients and slump value are induced. From the experiment result, the rational distance interval between the vibrators is analyzed and then such conclusion is drawn that there is obtained a good vibration enegy transfer when place vibrator pole and concrete bottom in parallel. When the vibrator pole frequency is determined as 200Hz, the vibrator energy shows a smooth transfer and results in a perfect vibrator density. It is stated out that the optimal channel lining construction is as followings:Mechnical or artificial slope cutting, mesurement, base level combined acceptance, water drainage tooth excavation, permeable pipe embedded, sand paving and and press, insulation board paving, geomembrane paving and welding, installation of formwork, concrete pouring, surface finishing and maintenance, expansion joint cutting, closed cell board expansion joint, sealant perfusion.The study in this thesis has found great application in South-to-North Water Transfer Project and every technical index of concrete satisfies the design demand, as a result,7500 ton of cement was saved and 2.25 million RMB of invest was saved.