Study Of Seepage Around The Earth-rock Dam Based On Coupling Analysis Of Seepage Field And Stress Field

Earth-rock dam's seepage problem is a key factor affecting their security and economy. As the restrictions on development conditions and other factors, many hydraulic complex, especially in the northern desert and semi-desert areas, the construction had to face the special geological conditions which extremely detrimental to the dam anti-seepage works,deep permeable sand layer in abutment, making the problem seepage around the dam became one of the key issues constrainting to the design and construction of these projects.Combining the built hydraulic complex which exist with seepage around the dam, analysis geological conditions which may lead to seepage around the dam, anti-seepage design against seepage around the dam, monitoring facilities and condition of seepage around the dam on operating period.On this basis, summary features,causes and treatment measures of seepage around the dam.Based on the basic theory and methods of seepage analysis, summarize analysis methods of the problem seepage around the dam, analyze the advantages and disadvantages of various methods. Study calculation principle, calculation steps, and other key issues of finite element method,which often used in engineering. Considering seepage field and stress field coupling impact to seepage around the dam, further propose finite element method considering coupling of seepage field and stress field:dual-field iterative solution method and the method based on consolidation theory, analyzing principle of the later method, which applied in this paper. Based on a user-defined material subroutine UMAT providing by large general-purpose commercial software,in its materials library,joining the Duncan-Chang E-B constitutive model, establish analysis model for seepage around the dam considering coupling of seepage field and stress field, obtained an effective way of three-dimensional finite element method calculating seepage around the dam considering coupling of seepage field and stress field. Combined of practical projects, using traditional hydraulics law, finite element method without regard to coupling of seepage field and stress field, finite element method taking coupling of seepage field and stress field into account, around the different anti-seepage programs (anti-seepage wall thorough abutment with different length), analysis seepage discharge around the dam, seepage gradient, seepage exit surface height,and comparatively analysis the calculation results of the three methods. The results show that coupling of seepage field and stress field have a certain influence to seepage around the dam, should be considered in analysis of seepage around the dam.In this paper, the above-mentioned models and methods lay a necessary theoretical basis for the research and forecasting of seepage around the dam considering coupling of seepage field and stress field, and the analysis calucation achievement also has an important reference and application value to the similar projects.