Earth pressure against the abutments and wing walls of standard motorway bridges

Abstract

Measurements of earth pressures on four standard motorway bridge abutments backtilled with different materials and in different ways, suggest that the geometrical shape of the abutment is important in determining the backfill pressure. The earth pressures recorded showed little correlation, either in magnitude or distribution, with the earth pressures assumed in the design which was based upon an equivalent fluid concept. The results of a three dimensional finite element analysis compare favourably with the field measurements of earth pressures, and this method may represent a more valid design approach for this type of structure. Les mesures des pressions des terres sur quatre culées de pont d'autoroute classique, remblayés avec des matériaux différents et de différentes façons, suggérent que la forme géométrique de la culée est importante dans la détermination de la pression du remblayage. Les pressions des terres enregistées ont montré peu de corrélation, soit en grandeur, soit en distribution, avec les pressions des terres admises, dans le projet qui était basé sur le concept du fluide équivalent. Les résultats d'une analyse aux éléments finis à trois dimensions, se comparent favorablement avec les mesures des pressions des terres faites en chantier, et cette méhode peut représenter un projet d'approche plus valable pour ce genre de structure.

Numerical identification of soil‐structure interaction pressures

“…On the basis of the principle of virtual work it is possible to establish the following relationship between the functions of external pressures, defined by equations (l), and the equivalent nodal forces acting on the nodes v6: f b = T' . Is: NLTT"p' d S (2) In equation (2) fh. is the vector of the nodal force components (equivalent to the applied pressures) in the global reference frame x l r x2, x3 adopted for the entire structure; T is the square matrix relating the force components in the x i , x i , x i reference frame to those in the xl, x2, x3 reference frame; T" is the (3 x 3)-matrix relating the pressure components in the n, rl, r2 reference frame to those in the x i , x i , x i reference frame; and vector p' is defined as…”

“…The relationship between the interaction pressure coefficient vector a and the equivalent nodal force vector f, obtained by writing equation (2) for all the mesh nodes and by suitably adding the contributions of the elements meeting at the same nodes, can be expressed in the following form:…”