The Study of Ground Deformation Risk With Seismic Applications

As it is Kown, analysis are made with various methods in studying the grounds which convey the deformation risk under the influence of any force. In the analysis which are made mostly by assumptions, each method has its advantages and disadvantages. Most methods which are applied are not sufficient alone and the decision is made according to the experience and comments of the engineer most of the time and there may exist ambiguity in these comments. As it is Kown, besides most data obtained by the seismic applications; rigidity, porosity, saturation and the layer thicKess of a ground is also determined. The data concerning the rigidity and porosity of the ground, landslide, liquefaction, consolidation, plasticity, etc. is obtained as well, moreover, a general result is achieved by evaulating all of the calculated dynamic paramaters. This study is made on two different areas in Istanbul-Esenyurt which have similar litological and morphological slopes. In the first study area, the risk factor is tried to be determined in the deformed region which has 10-25% morphological slope and in the remaining region. In the second study area the data obtained from two study areas are compared and the landslide risk of the ground having slope in the range 10- 25% is examined. As the conclusion of the study, ground deformation is examined with the seismic and dynamic data. In the landslided areas or in the areas having potential landslide risk; it is understood that the seismic reflection data are untolerably diversing from the N30 data obtained from the SPT experiments done in borehole studies. In this study, according to the results achieved by seismic applications, it is observed that the grounds which have undergone deformation depending on the litological structure have Vp/Vs ratio greater than 4 or the shear wave velocity Vs smaller than 222 m/s. In this study again, in the area which ground deformation is expected, it is observed that Vp/Vs ratio is between 4,44-8,85, shear modules between 568-2381 kg/cm'2, and the shear wave velocity is smaller than 334 m/s. These values are approximate to the values obtained from the area in which deformation is observed. In the light of this data, it is obviously seen that the layers mentioned so far have deformation risks