Study On The Types Of Rock Mass Structural Plane And Engineering Effects Of Emeishan Basalt

There are plenty of hydroenergy in west China to be exploited. Emeishan basaltis one of the rock mass which has been best widely distributed in southwest China.With development and using of the large hydropower station in Nu river, Yalong river,Jingsha river and Dadu river, the more and more hydropower stations which thefoundation rock mass have been made by Emeishan basalts have been structed insouthwest china. The basic types, distribution features and characteristics of structuralplanes of basalts do have to face up to, especially the basalt structural plane types,distribution, generation regularities and engineering geological grade. By geologicaland geochemistry ways, studying on the structural planes characteristics andengineering effect of Emeishan basalt of the hydropower stations which have beenbuilt and be building in southwest china, have the significance for developinghydropower construction in Emeishan basault distributing regins.According to the systematically collects and processing data of the hydropowerstations of having been built and being built, which foundation rock have been madeof Emeishan basalts on Emeishan basalt regions (west, middle and east) in southwestchina, combing with fieldsurvey and indoor comprehensive, systematically study therock mass characteristics and structural planes features of Emeishan basalt of havingthere of engineering area in southwest china by geological and geochemistry, puttingforward the geological grade of basalt structural planes and discussing in detail typicalstructral planes characteristics and engineering effect. Based on the analysis of thegeological&geochemistry characteristics and forming environment of different areabasalts, discussed their generation regularities and distribution features, and beenmade the fit for relation curve of engineering geological grade of various basaltstructural planes. On this basis, analysis of engineering geological significance andavailability of typical structural planes.(1) According to the basalt space distribution and three-big rock regionsdistributing characteristics in Emeishan, southwest china, studied the basiccharacteristics of regional geological background, petrology, petrography andgeochemistry of the basalt formation, analyzed the tectonic setting of the basaltforming in Emeishan area. The result is that although their tectonic environment are separation continental rift in magmatic rocks area, their sturctural planes are differentbecauce as their eruption environment are different (eastern rock region is continentalfacies, middle rock region is sea-land interberdding facies and the western rock regionis marine.).(2)According to the distribution characteristic of basalt structral planes ofdifferent hydropower stations in three-big rock regions, divids into the different basaltstructral planes by their causes, puts forward the main typies of the basalt structralplanes in different rock areas. The primary structure planes are tuff interlayers,interlayers of volcanic breccia and agglomerat, sedimentary interbeds, columnar jointin eastern rock region; the more significantly structral planes are intrusive structralplane, alteration structral plane and weathering relaxation structral plane in middlerock region; the most developmental structral planes of the basalt rock mass aretectonic structure plane, alteration structral plane and pillow structure in western rockregion.(3)By researching a series facters which play important roles in dam foundationstability, such as basalt structral planes, distribution, spatial distributions, describesthe appearance areas and ditribution of the structral planes according to variousstructral plane characteristics, and study the cause, spatial distribution, developmentcharacteristics and generation regularities of different typies structeral planes ofEmeishan basalt in southwest area.(4)The scale and characters are twe large main controlling factors of theirmechanical effect and rock mass stability of various basalt structral planes, are alsethe basic principle of structural plane classification. By analyzing and summarizingthe scale, characters, engineering geological significance, and engineering geologicalcharacteristics of typical hydropower s planes in Emeishan basalt area, puts forwardthe engineering geological classification scheme of basalt structrual planes, discussesthe scale, characters, material composition, and strength characteristics of each basaltstructural plane in scheme. At last, evaluate the engineering geological characteristicsand availabiligy for each structural plane.