Grouting Construction Technique Study About Yele Hydroelectric Project Diaphragm Wall And Deep And Thick Overburden On Right Bank

Yele Hydroeletric Project, With the leading reservior station of Nanya river cascade development, is located on Nanya River in Mianning county and Shimian county of Sichun Province . The purpose of power station is generating,without the multi purpose of navigation,floating wood,flood control,irrigation.The project is mixed development power station.The project consists of head key buildings,diversion works and underground power station .The rock-fill dam use the asphalt concrete core,with the maximum height of 125.5m and the dam crest length of 411m .The normal storage level is 2650m.The power station posses pluriennal regulation capacity with a total reservior capacity of 2980×106m3 and regulation reservior capacity 2760×106m3.There are two sets ㎏of bucket water –turbine generator 120MW,with the Max.water head 644.8m,the Min. head 546.7m and rated head 580m. The dam is founded on the foundation of the deep and thick overburden.The geology condition of the left and right abutment is non-symmetrical.The left bank and river basin foundation consist of quartz-diorite.The right bank and lower riverbed composed of gravel,silty loam and blocky debris of quaternary system,forming a set of thick ice-water-sedimentary formation of fluvial facise since Pleistocene epoch. According to sedimentary environments,lithologic character and engineering geology character,there are five non-homogeneity layers from the lower to upper. The thesis makes analyses about the foundation treatment measurement of the deep and thick overburden, and concludes the construction method,according to the Yele power station under construction. So that other project draw on the experience. The important topic of the thesis is the construction measurement study about the dam foundation impervious wall and the curtain grouting of the deep and thick overburden under right gallery. The thesis analysis the various parameters of the diaphragm wall, such as crude material, mix proportion, construction plan ,hole-making method, joint pattern, flute dividing and quality valuation etc.There are five kinds of the diaphragm wall joint pattern in Yele power station, such as arc-hyperbolic joint, milling joint etc. The hole-making method consists of impact chisel,hydraulic milling groove etc. The hole-making equipment have wire water-closet churn drill, hydraulic milling groove etc.nearly including the total equipments used in the current construction of diaphragm wall. The thesis make the assessment on the quality of the diaphragm wall, depending on hole deflection, hole bottom deposit thickness, concrete strength , wall-hole percolation, checking hole croing etc. The other important topic of the thesis is the curtain grouting construction measurement study of the deep and thick overburden under the right gallery diaphragm wall.The grouting treatment of the deep and thick overburden under the right gallery is the key of the overall dam anti-seepage.The thesis studies the grouting parameter,grouting method according to field grouting test.The grouting quality is valuated by specific consumption,frequency curve,water-pressure lugeon of checking hole etc,The grouting treatment improves the dam foundation anti-seepage condition.