Experimental Study On Influence Factors Of Horizontal Foundation Coefficient's M–value Of Sheet-wall Under Large Displacement

Sheet wall is a flexible retaining diaphragm structure, the main force on it is soil pressure, and it's stability is mainly rely on soil resistance. Because of the wall's bending distortion, the soil pressure on the sheet wall will redistribute, then the internal force and bending distribution will be effected. So, there is a complex relationship between soil and sheet wall, which makes the calculation of sheet wall become complex and difficult.Through compare, it is shown that the method of vertical beam on elastic foundation could properly reflect the complex relationship between wall and soil, and it is fit for the calculation of sheet wall. The key of the method of vertical beam on elastic foundation is choosing the groundwork resistance coefficient correctly. Usually, m-method is chosen to get horizontal groundwork resistance coefficient, namely the groundwork resistance coefficient has a direct ratio to the depth the sheet could reach, the proportion coefficient is m. M-value could get from horizontal loading experiment, or select from criterion. The m-value in the criterion is from space pile experiment, but the sheet structure is a plane structure. So there are some differences between them, some special study of m-value should be given to minish it. And because of the appearance of great deep water sheet harbor, the problem that the mud-layer displacement goes beyond the m-value from criterion addenda A becomes more important.Based on the situations above, it use m-method thrust model experiment to study the m-value's changing theory in the horizontal displacement and especially in the big displacement(1~5cm) in different soil condition, different intensity and different depth it could reach. Use the bending movement and thrust got from experiments to get the m-value. Then based on this data calculate bending movement and displacement through m-method. Comparing the outcome with the experiments', it showed that the tolerant between those two is very minor. It also institutes some factors that could affect the m-value a lot and uses FEM model to test them. It found that soil condition (compactness) could affect the m-value most: the bigger the density is, the bigger the m-value is. The factor that could affect the m-value less is mud-layer displacement, they have power function relationship. The sheet wall and the depth it could reach are the less important factors, they could be studied further.