Study On The Seepage Flow Character Of The Earth Dam Material In The XIXIAYUAN Project

XIXIAYUAN project pertains to the project in Xiao Langdi waterconservancy hinge of the Yellow River, its task is to accommodate mainly thehydropower station of Xiao Langdi, to exert fully its synthetical benefit aswater supply , irrigate and generate electricity etc. XIXIAYUAN reservoirdam type is earth dam , Built on gravel stone ground , Its permeated stabilityis one of the key problems in this engineering design . In the course ofdesigning, the seepage calculation is important extremely. To steadycalculation of the dam, The most important thing is the correct choice of theseepage characteristic parameter . contraposing the seepage question of thedam body and dam foundation , Launch the research that including thephysical characteristic of dam material , seepage characteristic , allowablehydraulic grads and finite element seepage calculate ect. Have obtained theachievement with practicability and deep understanding, afforded the essentialanalysis achievement and the referential gist to engineering design. The mainachievement is as follows:Useing the concept and character of spline fit approximation, drew thecurve of the dam material particle magnitude, Utilize spline function tocalculate the characteristic particle diameter and asymmetry coefficient of thegravel stone. Adopting Mann-Whitney U method of verify inspection , makeup statistical analysis to BAIPO material field and PUZI particle,they belongto one and the same. Established relevant relations between particle grade andporosity.According to the information of the osmosis test, have established arelation between the seepage coefficient and the control granule diameter, andthe gravel percent, and the function of hole percent. Adopting the K-S methodto verify single swatch, inferred the logarithm of seepage coefficient obeyingnormal distribution. The method of utilizing multinomials to fit , has got theprobability density of permeates coefficient.According to the information of permeating distortion test, haveresearched the critical hydraulic grads. Further , have produced the allowablehydraulic grads, regarded as standard to judge that osmosis destroy the dam ornot.grounding on the basic theories seepage and the structure ofXIXIAYUAN earth dam ,the geologic condition, adopting the seepageanalytical method of continuous medium, set up the models for analyzingseepage of the dam. Utilizing the finite element principle to calculate theseepage , has received the influent characteristic under many kinds ofoperating modes, According to the analysis result under the state of differentprevention of seepage , have recommended the scheme of rational preventionof seepage.Being based upon influent analysis , have proposed two suggestions inthe prevention of seepage. First,, according to the different results ofcalculation, propose setting up filtrating layer at the backward lower reachesof the dam , taking the effective protective measure to the dam body. Second,according to the influent characteristic of the dam body at the time of partdamage of got-up geotechnological membrane, propose taking the protectivemeasure in the course of transporting and laying the got-up geotechnologicalmembrane, to prevent got-up geotechnological membrane damage from andincrease its permeability;When the got-up geotechnological membrane iswelded or the sticky seam , should control quality.