Deep Mixing Pile Plain Reservoir Seepage Control And Research

The seepage flow problem is the important problem of the developments of the plain reservoirs. On one hand, it can cause the seepage failure of dam body, dam foundation, on the other hand, it would not only result in the reservoir water losses, but also can result in swamping or uplifting the underground water level of the croplands at the back of the dam and influencing the agriculture production.Along with the quick developing of economy in the last few years and the amount of rainfall increasingly reducing, more and more plain reservoirs of Shandong province is under construction.Seepage defending of plain reservoirs becomes a problem of to be solved widely and urgently.The technology of deep mix round pile is a seepage cutting technology which making use of the deep mix round machine of small diameter multi- head ejecting and mixing round cement clay in original soils to defending seepage.Aiming at the geology and engineering conditions of plain reservoirs, the deep mix round pile technology is more suitable to the stratum and have a more credibility of wall quantity and seepage assurance than other seepage defending technologies.The research of deep mix round pile technology is based on the routine mix round pile foundation technology. With a construction thickness of multi-head little diameter deep mix round pile of 8cm~45cm, current maximum construction depth is 18 m.This seepage defending technique already extensively applied in the drainage area of Yangtze River, Songhuajiang River Huaihe River and Tai Lake etc. with good results. It have already obtained the good and social performance.Along with the decreasing of thickness of the wall, it brings important variety in technique and economy.By using the finite element method, this paper carried through the 2-D FEM calculation of an actual engineering that is Jinan east lake dam.By creating mathematical model suitable to geology and engineering conditions, the paper protracts the seepage field, and brings up the mathematical method of solving the seepage problems of plain reservoir.On base of bringing up every kind of factors that affect the plain reservoir seepage flow, this paper analyzed the influences of different foundation circumstance, dam patterns, downstream water level and seepage cutting channel etc. to seepage, and suggest that factors reducing seepage flow should be considered synthetically, so optimize design of dams.Aiming at different working conditions of double deck foundation, weak seepage storey foundation and none weak seepage storey foundation, it compared the effects of seepage defending of the conditions mentioned above, and bring up a reasonable arrange of the seepage defending wall.Aiming at the characteristics of the deep mix round pile, this paper brings up reasonable coefficient of permeability, the thickness of seepage defending walls, anti-seepage decline etc., constituting the theory base of the seepage defending design.Finally, the paper also introduces the practical problems in construction of deep mix round pile, including construction principle, construction request, control of construction technique, and mass examination etc.