Pseudo-static scaled-down experiments on dry stone retaining walls: preliminary implications for the seismic design
Résumé
Dry stone retaining walls (DSRWs) are vernacular structures which can be found all over the world. Most of them have been built in the 19 th century but they can be as old as two hundred years. Because of decades of neglect, many of these walls are highly damaged; however, in the absence of national rules for this peculiar heritage, any intervention on these constructions is made difficult. A number of former studies in France have tried to settle the bases for a standard aimed at designing slope DSRWs. This paper complement those works in order to give clues for a seismic design of slope DSRWs following the simplified approach proposed by the Eurocode 8 and denoted pseudo-static approach. Firstly, scaled-down experiments have been carried out using a mock-up composed of a wall made of clay bricks retaining a sandy backfill. This mock-up was then tilted and the characteristics of the system at failure were reported and analysed. A particularity of failure in DSRWs is that the failure surface crosses the wall leaving a part of it intact. Secondly, an analytic method based on the limit equilibrium using the Coulomb wedge theory has been designed to predict the tilting angle and validated on the basis of these experimental results. Finally, some preliminary implications for the seismic design of DSRWs have been proposed for walls built in moderate seismicity areas which is typical of mainland France. In low seismicity zones, the extra width required to bear the seismic motion does not exceed 25% of the width identified through the static design. Results are also given for more critical cases associated to zones of higher seismicity as well as for different wall configurations.
Domaines
Géotechnique
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