Numerical Simulation Of Corner Effect For Deep Excavation

Computation on deep excavation corner effect is performed by ADINA 3D static nonlinear FEM in the thesis. Corner effect is thoroughly analyzed listed as the following aspects: the variable earth pressure and influential distance considered corner effect; corner-brace installed in corner effect influence areas; the effect of retaining wall distortion and axial forces of corner brace considering different excavation manners. The main results are listed as follows:1. The coefficient of active earth pressure corner effect is brought when the corner effect is considered .It is final brought when some factors affecting corner effect are considered,such as the rigidity of retaining wall, the erth under the excavation, the different soil body of excavation, the load is piled on the ground surface. The spatial distribution of active earth pressure can be calculated when it is multiplied with the assurance coefficient according to the grade of excavation and the active earth pressure,which are calculated from the 2D FEM,the earth pressure theory of Rankine and Conlomb and other earth pressure theory amended from classical Rankine and Conlomb theory.2.The distortion of retaining wall can be suppressed obviously when the corner -braces are installed properly, if the sphere of corner effect of earth pressure is known after the factors are analyzed, which the corner-braces installed are affected. The corner-brace and the retaining wall will not bear bigger earth pressure from the soil body behing the excavation, they tend to be safe, the strength of themself can be fully used and the safe and economy are all considered. It can provide some reference for designing of the retaining wall and the corner-brace.3.The whole body rigidity of corner is enlaged according to the corner effect .The distortions of retaining walls are suppressed by corner-brace installed befor excavation or corner-brace installed and excavation as the same time, which is better than excavation in only one time, considering making good use of the rigidity near the corners .The construction manners should be avoided that the corner-brace is installed after excavation.A case history is simulated with the software program ADINA using 3D FEM. Result is basically in agreement with the field result. It is indicated that numerical methods for case history is reasonable.