TY - JOUR
T1 - Some remarks on the seismic behaviour of embedded cantilevered retaining walls
Y1 - 2014
A1 - Riccardo Conti
A1 - F. Burali D'Arezzo
A1 - Giulia M.B. Viggiani
AB - This paper is a numerical investigation of the physical phenomena that control the dynamic behaviour of embedded cantilevered retaining walls. Recent experimental observations obtained from centrifuge tests have shown that embedded cantilevered retaining walls experience permanent displacements even before the acceleration reaches its critical value, corresponding to full mobilisation of the soil strength. The motivation for this work stems from the need to incorporate these observations in simplified design procedures. A parametric study was carried out on a pair of embedded cantilevered walls in dry sand, subjected to real earthquakes scaled at different values of the maximum acceleration. The results of these analyses indicate that, for the geotechnical design of the wall, the equivalent acceleration to be used in pseudo-static calculations can be related to the maximum displacement that the structure can sustain, and can be larger than the maximum acceleration expected at the site. For the structural design of the wall, it is suggested that the maximum bending moments of the wall can be computed using a realistic distribution of contact stress and a conservative value of the pseudo-static acceleration, taking into account two-dimensional amplification effects near the walls.
PB - Thomas Telford
UR - http://urania.sissa.it/xmlui/handle/1963/35073
U1 - 35308
U2 - Physics
U4 - 2
ER -
TY - JOUR
T1 - On the behaviour of flexible retaining walls under seismic actions
JF - Geotechnique, Volume 62, Issue 12, December 2012, Pages 1081-1094
Y1 - 2012
A1 - Riccardo Conti
A1 - G.S.P. Madabhushi
A1 - Giulia M.B. Viggiani
KW - Centrifuge modelling
AB - This paper describes an experimental investigation of the behaviour of embedded retaining walls under seismic actions. Nine centrifuge tests were carried out on reduced-scale models of pairs of retaining walls in dry sand, either cantilevered or with one level of props near the top. The experimental data indicate that, for maximum accelerations that are smaller than the critical limit equilibrium value, the retaining walls experience significant permanent displacements under increasing structural loads, whereas for larger accelerations the walls rotate under constant internal forces. The critical acceleration at which the walls start to rotate increases with increasing maximum acceleration. No significant displacements are measured if the current earthquake is less severe than earthquakes previously experienced by the wall. The increase of critical acceleration is explained in terms of redistribution of earth pressures and progressive mobilisation of the passive strength in front of the wall. The experimental data for cantilevered retaining walls indicate that the permanent displacements of the wall can be reasonably predicted adopting a Newmark-type calculation with a critical acceleration that is a fraction of the limit equilibrium value.
PB - ICE Publishing
UR - http://hdl.handle.net/1963/6933
U1 - 6912
U2 - Mathematics
U4 - -1
ER -
TY - JOUR
T1 - Numerical modelling of installation effects for diaphragm walls in sand
JF - Acta Geotechnica, Volume 7, Issue 3, September 2012, Pages 219-237
Y1 - 2012
A1 - Riccardo Conti
A1 - Luca de Sanctis
A1 - Giulia M.B. Viggiani
KW - Constitutive relations
AB - The scopes of this work are to study the mechanisms of load transfer and the deformations of the ground during slurry trenching and concreting in dry sand and to evaluate their effects on service structural loads, wall deflections and ground displacements behind the wall caused by subsequent excavation. A series of three-dimensional finite element analyses was carried out modelling the installation of diaphragm walls consisting of panels of different length. The soil was modelled as either linearly elastic-perfectly plastic or incrementally non-linear (hypoplastic) with elastic strain range. Plane strain analyses of diaphragm walls of identical cross section were also carried out in which wall installation was either modelled or the wall was wished in place (WIP). The analyses predict ground movements consistent with the experimental observations both in magnitude and trend. The results also show that the maximum horizontal wall deflections and structural loads reduce with increasing panel aspect ratio towards a minimum which is about twice the value computed for WIP analyses. Panel aspect ratios should be larger than about three to take advantage of the three-dimensional effects. The pattern and magnitude of surface vertical displacements obtained from linearly elastic-perfectly plastic analyses, no matter whether three- or two-dimensional, are unrealistic.
PB - Springer
UR - http://hdl.handle.net/1963/6934
U1 - 6916
U2 - Mathematics
U4 - -1
ER -