Research On Seepage And Stability Numerical Analysis Of Tingkou Counter Reservoir Embankment Dam

Embankment dams have the advantages of simple structure, convenient construction and operation management, strong adaptability to the natural environment, and so on, it has become the preferred dam type in the dam construction.Due to the embankment dams exist seepage phenomenon, and if the seepage problem is light,it can reduce the reservoir flow, if it is weight,it is likely to lead to the dam burst and reservoir crash,it will cause serious impacton on the country’s economic development and people’s lives and property.Therefore,with the construction and development of all kinds of large embankment dams,the research on seepage and stability of embankment dams has been paid great attention by academic circle and engineering circle.This paper is based on summarizing the predecessors’ study results, and summarized and discussed in detail on research status and basic principle of embankment dam seepage and stability, and combined with the engineering example.Based on Tingkou reservoir embankment dam, building embankment dam seepage stability finite element analysis model, contraposing embankment dam seepage and stability numerical simulation went on detailed analysis and study, And comparing with the water conservancy engineering industry engineering design commonly used software and analysis.The main contents of the paper are as follows:(1) In stable seepage period, using advanced simulation finite element COMSOL multiphysics calculated phreatic line overflow point is in the downstream water level above 4m prism drainage slope, while the Lizheng software seepage calculated phreatic line overflow point is at the intersection of the downstream water level and prism drainage slope. COMSOL to simulate the real process of downstream water overflow, and Lizheng software can not reflect the real flow overflow process, offer reference for engineering such as earth rock dam seepage.(2) Combined with Tingkou reservoir dam project example.By using COMSOL Multiphysics advanced simulation finite element software’s Richards saturated-unsaturated equation of Flow Module Subsurface Module in the cases of the steady seepage and unsteady seepage flow analyzes and solves.In addition, in order to evaluate the result of seepage analysis of the dam from all sides and roundly, By using the flow module of Beijing Lizheng Geotechnique software that is widely used in the industry carryed on seepage calculation as the same scheme and the same conditions, and comparing with COMSOL calculation results and analyzing.By using COMSOL Multiphysics advanced simulation finite element software, based on the results of dam seepage action under the anti slide stability analysis. On the basis of seepage stability analysis of the dam, using the Geomechanics Module of COMSOL Multiphysic Elastic Linear Material and the strength reduction finite element method carrys on the analysis calculation of anti-sliding stability; In addition, in order to evaluate the result of anti-sliding stability analysis of the dam from all sides and roundly, by using AutoBank software that is widely used in the industry carryed on anti-sliding stability calculation as the same scheme and the same conditions, and comparing with COMSOL calculation results and analyzing.(3) Through COMSOL seepage calculation and analysis, it is known that the landing speed is the key factor to determine the characteristics of the unsteady seepage field, upstream slope of penetration than down with the drawdown increases gradually, the drawdown rate is high, the osmotic gradient is greater; when the drawdown of potential line and slope tended to parallel and flow direction of slope, rather than traditionally believed to flow parallel to the slope or the slope above the water line and formed by pointing upstream dam slope direction of penetration, the penetration is not conducive to the slope stability.(4) Through analysis and Research on the slowdown of upstream dam slope ratio, penetration of the dam slope ratio changes on the dam stable, and there is no influence and increase the dam stability against sliding; for laying geomembrane scheme, of earth rock dam seepage stability and anti sliding stability are favorable; through homogeneous dam and grit pressure scheme of slope of the comparative analysis, the former of the dam body stability is the most unfavorable, the safety coefficient was the highest.(5) The seepage stability of earth rockfill dam and the original design of anti sliding stability do not meet the standard requirements; the change of upstream dam slope, seepage stability does not meet the standard requirements, meet the requirements of anti sliding stability; based on the original scheme in the upstream dam slope laying geomembrane as impervious body, seepage stability and anti sliding stability can meet the specification requirements; the basis of dam upstream part of the region in the original dam type into gravel slope, considering safety, reasonable and economic point of view, after the final trial of a slope, soil slope upstream determine the ratio of 1:2.15, analysis of seepage and stability on the basis of the analysis, by calculation results of seepage stability and anti sliding stability can meet standard requirements, the latter will composite geomembrane laying as a safety measures between the gravel area and upstream soil slope.