A Comparison Study on the Effect of Various Layered Sandy Soil Deposited on Final Settlement under Dynamic Loading

Abstract

The foundation is expansion in base of column, wall or other structure in order to transmit the loads from the structure to under footing with a suitable pressure with soil property. There are two conditions to design foundation: 1. The stress is applied by footing on soil is not exceeded allowable bearing capacity ( ). 2. The foundation settlement and differential settlement are due to applied loads are not exceeding the allowable settlement that based on the type and size of structure, the nature of soil. Rigid square machine footing with dimension 200*200 mm with two types of relative density (50 and 85)% medium and dense density respectively are using in this study in different 28 models to show the effect of layered sandy soil in two configuration, medium-dense MD and dense-medium DM on the final settlement in magnitudes and behaviors under dynamics loads applying with different amplitude of loads (0.25 and 2) tons at surface with amplitude-frequency 0.5 Hz with explain the effect of reinforcements material on reduction the magnitude of settlement. The final results appeared with respect to the specified continuous pressure and the number of loading cycles, the resulting settlement from the dynamic loading increases with the increase in the dynamic pressure magnitude, the variation on densities of layered soil effect on the amount of settlement due to different loads applied. It’s found that for increasing load amplitude increasing of settlement values particularly with low density soil when other variables are constant. As the amplitude of loading is increased from 0.25 ton to 2 tons, the settlement has been increased. MD soil density lower values of settlement can be obtained with type I of reinforcement where load amplitude equal to 0.25 ton with percent of enhancement between (28.4-34.3)% for different configuration of layers of reinforcement, for load amplitude equal to 2 tons the value of enhancement of settlement reached to about (35-38.4)%; while for DM density soil values of settlement can be obtained with type I of reinforcement where load amplitude equal to 0.25 ton percent of enhancement between (20-34.35)% for different configuration of layers of reinforcement, but the best value of enhancement of settlement get with load amplitude equal to 2 tons reached to about (38.7-41.17)%.

Keywords

• multilayered soils
• machine footing
• reinforcement’s material
• medium density
• dense density