Rock Mass Quality Value Of Dam Foundation & Optimization Analysis Of Construction Base Level

The Hoek-Brown failure criterion ï¹  RMR system method is a wide-use rock mass quality value method, it was used in some big-type water and electricity engineering and obtained good results. But to mid-mini type dam construction, it is improper to use traditional RMR ï¹  H-B method to evaluate the quality of joined rock mass, because the RMR system is build on the basis of the probability statistic model of geological data. We must do a lot of things to collect enough data to ensure that we have correctly assessed the character of the jointed rock mass. And the parameters m, s in H-B criterion and rock mass elastic modulus are variable because there are some uncertain factors when using RMR system. What's more, the affection of intact rock elastic modulus to rock mass elastic modulus is always not considered. So this thesis improves on the system and makes it more suitable to mid-mini type dam construction, the detailed account is as follows:Firstly, according to the geometry parameters of the discontinuities collected before, we separate the discontinuities that affect the stability more obviously with clustering analyze method. And combining the lithology and construct area, we divide the whole dam area into different zones, ensure each zone have an uniform lithology and composing distributing character, thus the rock mass in each zone can be considered as an equivalent continuum.Secondly, find out representative element volume of each zone, then do numerical experimentation on it, simulate uniaxial compressive strength, uniaxial pull strength, strain and stress curve of REV (abbr. of representative element volume). Since the H-B criterion can describe the destroy of rock mass, we can suppose that the destroy rule of the REV obey H-B criterion, then we can get m, s through putting the results of numerical experimentation into H-B criterion. And the distortion parameter can be drawn from strain and stress curve. In this way, the parameters we got can representative the property of the zone where that REV was collected. Thirdly, optimize the building base level through numerical analysis. In this course, finite element method is used to analyze the stability of dam foundation rock mass, and the discontinuities is considered as joints element in numerical analysis. We can correct the model as we get more accurate data from the actual locale, make sure the model isas accurate as it really is, then on the basis of numerical analysis, we can coach construction, find out the most proper building base level.Lastly, taking Shalaohe water head engineering of Guiyang north suburb water factory as an example, this thesis illustrates the application of the system it has brought forward.