Experimental and numerical analysis of deep excavations

The goal of this study is to investigate how the distance between foundation and sheet pile (L) and excavation depth (He) will affect deflection of the sheet pile and ultimate bearing capacity of the foundation model under axial loading for the same materials using relative density 10% only. Finite element method and statistical method was also used in this research to study the behaviour of the sheet pile, foundation model and lateral pressure under axial loading. A sandbox which dimensions are 0.75x0.75x1m is filled with Dr=10% dry sand. A steel plate (12x12cm) is used as foundation model; steel sheet pile model with dimensions of 75x40x0.3 cm is used. For this purpose 10 tests were performed to study the deflection of the sheet pile, bearing capacity of the soil and lateral pressure of the soil on the sheet pile, one of the test was performed without the sheet pile and other nine tests were performed with three different (L) and three different (He). From the experimental results, time-deflection and load-deflection behavior of sheet pile and timesettlement and load-settlement behavior of the foundation are obtained. In order to determine the effects of L and He, these results are compared. It is observed that, when the distance between foundation and sheet pile (L) was increased the deflection of the sheet pile decreased and load capacity on the foundation is increased for the same excavation depth. It is also seen that when the excavation depth (He) was increased the deflection of the sheet pile increased and load capacity decreased for the same distance between foundation and sheet pile. Also the results from Plaxis 3D finite element programs indicated that the deflection of the sheet pile model increases with increasing (He) and decreasing (L), and there is a good agreement between experimental results with finite element programs results. Lateral pressures measured by using pressure transducers. These pressures analyzed statistically to derive a relation between test systems geometrical conditions and measured lateral pressures. An appropriate correlation (R2=0.95) has been determined.