Seismic Distress of Broken-Back Gravity Retaining Walls: Fid-Bau Portal

Seismic Distress of Broken-Back Gravity Retaining Walls

Sadrekarimi, Abouzar

AbstractVertical-back gravity retaining walls and, in particular, quay walls have repeatedly experienced large displacements during past earthquakes, causing substantial damage to the facilities and infrastructure built on their backfill. In this analytical study, the possibility of improving the seismic performance of gravity retaining walls by changing their back-face geometry is investigated. Pseudostatic limit-equilibrium analyses are carried out to examine and compare the external and internal (structural) stability of vertical-back and broken-back walls subject to static and seismic loading conditions. The effect of wall inertia is also considered in these analyses. The results show that the horizontal thrust and the overturning moment exerted by a backfill soil are largely reduced on a broken-back retaining wall. A parametric study is subsequently carried out for comparing the static and seismic resilience and structural stability of broken-back walls with those of a vertical-back wall. The comparisons demonstrate significantly enhanced bearing capacity and external stability of a broken-back wall. It is determined that a segmental broken-back gravity wall with adequate bearing capacity and sliding stability will be also structurally stable against slippage or toppling of its concrete-block segments. These characteristics can be exploited to design resilient and less voluminous gravity retaining walls to mitigate earthquake damage.