Research And Practice Of Anti Filter With Thin Cement & Clay Wall Technique

From the establishment of P. R. China, the government and Communist Party pay effort to construct hydraulic works, invest a lot of labor and material power, but for the limit of historical term and produce ability, most of the embankment and dam exist the weaknesses, which bring out poor quality, speeded aging etc. during the operation. Loosen filling, poor resistance of filter, lack of strengthen of groundwork, in the different depth of the area of downstream and middle stream, the existence of biology caves, rotted roots and seepage eroding in the old dykes are the serious damage of the safety operation of dyke project. Therefore, the mission of reinforcement and filter resistance are urgent.The technology of anti filter with thin cement & clay wall is the fruit of the development of the technology of underground continuum wall, it is the first time to be researched and applied about its equipment and process within China, it also developed the technology of deep mixed cement picket wall, brings a pioneering work in the field of rock. The technology of anti filter with thin cement & clay wall is widely applied in the dykes of Yangtse River, and also be widely applied in the dyke anti filter by Yangtse Hydraulics committee, it was authenticated by China Hydraulics Ministry, and put into application, gains a lot of achievements during the adoption in the projects in the Yangtse River, Yellow River, Hai River, Huai River, Songhua River, and Liao River, as well as in Xinjiang, Hainan etc. At the same time, there are a lot of work of anti filter and strengthen are to be done in the dyke works. Therefore, this technology are to be widely applied in anti filter with prosperous future.The Anti-filter wall with mixed picket of cement and clay takes the cement as solidify chemical, under the deep basement, the soil are forced to be mixed by picket machine, a series of physical and chemical reaction are introduced between soil and water with the solidify chemical. ① The reaction of hydrolyze and hydrate of cement ;② the ions exchange and the reaction of agglomerate ；③the reaction of rigidly coagulate；④the reaction of carbonic acid. The hydrate reaction reduce the moisture contained in the soft soil, enhanced the stick strength between particles; the ions exchange and the reaction of agglomerate forms the solid combination; the reaction of rigidly coagulate can increase the strength of cement clay and the sufficient water stability; the reaction of carbonic acid will add the strength of cement clay furthermore. So the ground will be concentrated to be anti filter wall of cement clay with quite integrity, water stability, waterproof and sufficient strength. Meanwhile, with the certain pressure, cement slurry flow within holes of underground soil, then fill the holes around the anti filter wall after its concentration, cut the filter channel of basement, increases its ability on anti filter, thereby, the strengthen and anti filter of the dykes are realized. With the compare of the same technology, the technology of anti filter with thin cement & clay wall is of the advantages as following: ① the wall are even and continuous, and the coefficient of anti filter fulfills the requirement of dyke anti filter; ② the construction are free of notching, so problems increased by notching as caves collapse, the breast wall of caves by slurry are difficult, as well as the fulfilling back of burying soil, the tamp of the fulfilled soil in the slot, simultaneity, the construction will not damage the dyke; ③ it is applied in the different layers of the earth, including clay, grit, powder clay, sandy gravel, silt, even the caves；④ the construction is of high efficiency, and can be done even during the flood season；⑤ the cement & clay wall for anti filter is of the high endurity and strength, escapes the damage by the caves of animals；⑥ the wall is with the low cost, the cost is equal to the 1/5 of the anti filter wall made by high spray, and 1/3 of the concrete anti filter wall, and the same cost with the upright ⑦the buildi...