Seite - 1416 - in Book of Full Papers - Symposium Hydro Engineering

6. INTERPRETATION OF GEOTECHNICAL PARAMETER OF SPILLWAY TRENCH SLOPE Previous research has been carried out location of critical slip surface [1,2,3]. Considering the obtained (field and laboratory) results and summation of the geotechnical parameter values in the sub-surface sediments and layers of the slope and spillway structure area in the left and right abutments allows dividing the sub-surface profile into three parts: 1. Upper part, the silty-clayey surface soil in the first 10 m and mainly in the first 4 to 5 m. 2. Middle part, marly-siltstone layer down to the depth of 20 m, 3. Lower part, including the bed rock-mainly of limestone that continues down to lower depths. Generally, the conclusion from the obtained results indicates that under natural and dry conditions, mean geotechnical parameters of the sub-surface sediments and layers do show stability of the slope and the spillway structure area. This is while under saturation conditions, strength is decreased, where appropriate excavation slope is selected for stability analysis purposes. 7. SLOPE STABILITY ANALYSIS AT THE APPROACH CHANNEL OF SPILLWAY In the preliminary Slope Stability Analysis at the Approach Channel of spillway Trench at the Right and Left Abutments, based on estimated values for C and φ of the soil and soft rock mass of the Neogene era and based on Lab and NSPT tests in the spillway, stability safety factor had been calculated. However, to elaborate design of slope stability and excavation procedure to meet appropriate width to constructing broad spillway, based on the in-situ tests, calculations and selection of design parameters in the slope of the spillway approach channel trench slopes should be separately calculated for the right and left abutments. This additional analyze refined design parameters selected in calculations of the first alternative, where C and F have been estimated based on the NSPT of the exploration boreholes and test pits (it is pointed out that all SPT tests had shown more than 50 blows in different points for 30 cm penetration). Now, with regard to the drilling of three boreholesnBH-22, BH-23 and BH-24 at the right abutment and that of BH-25 and BH-26 at the left abutment and performing pressure meter tests in each meter and in each section, the dry and saturated states have been tested and measured. The results have been provided in table 1 for calculation of the modulus of elasticity, eudiometry, C, φ, Ko factor, and the elastic modulus. Meanwhile, table 2 shows the in-situ plate loading tests for identification of the situation of soft rocks and soils resulted from the Neogene formation (in the dry and saturated states, in the locations shown on the spillway plan). For the 1416