Discussion of 'State-of-the-Art of Integral Abutment Bridges: Design and Practice' by M. Arockiasamy, Narongrit Butrieng, and M. Sivakumar

摘要

The authors mention difficulty in determining the point at which the pile becomes fixed. Cummings (1937) proposed a solution that was based on the assumption that a pile subjected to a lateral load will deflect in the direction of the load at the point of load application and will remain undeflected at some point below the ground. Castigliano's second theorem states that in any statically indeterminate stucture, the total internal work accomplished during its deformation under load is a minimum consistent with equilibrium. By using this principle of least work, the discusser has derived the following six equations for length to fixity. (Kocsis 1968) The length to fixity is the distance below the ground surface at which the pile becomes vertical. Refer to Figs. 1(b, d, and e). In Fig. 1(b), a horizontal load H is applied to a free head pile; in Fig. 1(d), a moment M is applied to a free head pile; and in Fig. 1(e), a horizontal load H is applied to a fixed head pile (no rotation).