Dismantling and Reconstitution of Prasat Suor Prat, Angkor Thom, Cambodia

Abstract

This paper presents geotechnical aspects of dismantling process of one of masonry towers named Prasat Suor Prat that had been constructed in the end of the 12^th century during the Angkor Period in Cambodia. A series of 12 towers had been constructed from south to north along the east side of Royal Plaza in Angkor Thom.

One of the towers, named as N1 Tower, was found badly displaced with inclination of about 5 degrees to the north-west and horizontal spreading at the foundation level. The Tower was dismantled before restoration work by JSA (Japanese Government Team for Safeguarding Angkor) to study possible mechanism that had caused inclination of the Tower and horizontal spreading of stair stones. Dismantling upper structures as well as foundation mound were performed by archaeological trench. The trench revealed the mechanism of deformation of the structure as well as foundation. Before the dismantling, the inclination was believed to be caused by tilting of the foundation mound caused by general sliding failure of the foundation towards adjacent pond. However, it was revealed that the mound was not tilted but kept horizontal under yielded state causing only horizontal spreading. It was found that the inclination was caused by slip down of the sidestep cut stones that had covered the side slopes of the mound.