3095
Proceedings of the 18
th
International Conference on Soil Mechanics and Geotechnical Engineering, Paris 2013
Reconstitution of foundation platform of Prasat Suor Prat by compaction of original
soil with slaked lime, Angkor Ruins, Cambodia
Reconstitution de la plate-forme de la fondation de Prasat Suor Prat par compactage du sol
d’origine
additionné de chaux éteinte,
sur les ruines d’Angkor
, au Cambodge
“+Corr BOULON”
Y. Akazawa
Japan Cultural Heritage Consultancy Co. Ltd.
M. Fukuda
Taisei Geo-Tech Co. Ltd.
Y. Iwasaki
Geo-Research Institute
J. Nakazawa
Tokyo Engineering Consultants Co. Ltd.
ABSTRACT: Angkor ruins are situated at Siem Reap in Cambodia and are composed of many masonry structures of temples, moats
and large earth embankment for a reservoir. They were constructed from the 9th to the 15th centuries. These cultural heritages in
ancient Angkor have been in dangerous states that have resulted in collapse from various severe natural forces. The individual
masonry towers of Prasat Suor Prat at Angkor Thom were studied and investigated. The N1 Tower was deemed as the most dangerous
tower among them for restoration work. It has inclined 6.6 degrees towards a nearby pond with a northwest direction. The compacted
sandy formation was found from -1.5m from the original ground surface and to +3.5m above the ground. The safety factor for the
ground bearing capacity in rainy season was calculated with S.F=1.1. When its bearing strata were reconstituted, it was designed to
have a sufficient safety factor value of S.F>1.5. To achieve this purpose, the original sandy soils were mixed with slaked lime and
compacted by tamping with Geo-textile. The material soil used for the platform was a mixture of different soils of original sandy soil,
clayey soil and lateritic soil at weight ratios of 70%, 15% and 15%. Slaked lime was added to the mixed soil 1 at a rate of 0.1.
RÉSUMÉ: Les ruines
d’
Angkor sont situées à Siem Reap au Cambodge et sont composées de nombreux temples à structure en
maçonnerie, de fossés et
d’une
grande digue autour
d’
un réservoir. Ils ont été construits entre les 9e et 15e siècles. Ces héritages
culturels de l'ancien Angkor sont dans un état dangereux résultant
d’écroulements résultant de
forces naturelles sévères. La
maçonnerie particulière des tours de Prasat Suor Prat à Angkor Thom a été
l’objet d’
études et
d’investigations
. La Tour N1 a été jugée
la plus dangereuse parmi celles-ci, justifiant un travail de restauration. Elle est inclinée de 6.6 degrés en direction
d’
un étang proche,
vers le nord-ouest. Une formation sablonneuse compactée a été identifiée de -1.5m de la surface originelle
jusqu’
à 3.5m au-dessus. Le
facteur de sécurité en terme de capacité portante en saison des pluies a été évalué à S.F =1.1. Quand les couches portantes ont été
reconstituées, le facteur de sécurité
a été amélioré jusqu’à la valeur
S.F >1.5 considérée comme suffisante. Pour parvenir à ce but, les
sols sablonneux originaux ont été mélangés avec de la chaux éteinte, compactés et renforcés avec du géo-textile. Le sol utilisé pour la
plate-forme était un mélange de différents sols, constitué du sol sablonneux original, de sol argileux et lateritique selon des ratios en
poids de 70%, 15% et 15%. La chaux éteinte a été ajoutée au mélange à raison de 0.1 pour 1.
KEYWORDS: Angkor ruins, cultural heritage, reconstitution, foundation, soil improvement, slaked lime,
1 INTRODUCTION
Angkor ruins are situated at Siem Reap in Cambodia and are
composed of many masonry structures of temples, moats and
large embankment for reservoir, that were constructed from the
9th to the 15th centuries. These ruins were registered as Cultural
Heritages Sites by UNESCO in 1992. At the same time these
were listed as Endanger World Heritages Site. Afterwards, in
2004 these were removed the list by many conservation
activities around groups from the world. However they are still
under dangerous states resulting in collapse by human activities
and natural forces that sometimes may cause collapses, etc.
In 1993, Japanese Government team for Safeguarding
Angkor was organized and has been working at on investigating
and conserving them (Nakagawa 1996-2005).
This paper reports on a conservation project was carried out
(Nakagawa 2005, Akazawa et al. 2009).
2OUTLINE OF OBJECTIVE STRUCTURE
Prasat Suor Prat in Angkor Thom is composed of 12 towers and
terraces. The towers are masonry structures. They are
constructed materials out of laterite blocks. They are designed
to look like three stories. Each tower constructed differently and
has different structure problems, for example, openings of wall
joints and leaning of towers etc...
Photo. 1. N1 tower (Before reconstitution)
N1 tower was selected as the most dangerous tower among
them for restoration work (Photo. 1). This tower had inclined
6.6 degrees towards a nearby pond in a northwest direction. The
dimensions of the tower are 21m in height and 9.2m×10.5m in
width and length at base level.
3RESULTS OF INVESTIGATION
To advance the design of N1 tower’s restoration, case histories
were collected of restoration of similar building. The existing
states of N1 tower structure and investigations of ground under
it were carried out (Iwasaki et al. 2013).
Based on these results, principals, guidelines and methods
for the N1 tower’s restoration project were decided.
Reconstitution of foundation platform of Prasat Suor Prat by compaction of
original soil with slake lime, Angkor Ruins, C mbodia
Reconstitution de la plate-forme de la fondation de Prasat Suor Prat par compactage du sol
d’origine additionné de chaux éteinte, sur les ruines d’Angkor, au Cambodge
Akazawa Y.
Japan Cultural Heritage Consultancy Co. Ltd.
Fukuda M.
Taisei Geo-Tech Co. Ltd.
Iwasaki Y.
Geo-Research Institute
Nakazawa J.
Tokyo Engineering Consultants Co. Ltd.
