2877
Deep Basement Construction of Bank of Thailand Along Chao Phraya River closed
to Tewavej Palace and Bangkhumphrom Palace
Construction du sous-sol profond de la Banque de Thaïlande le long de la Chao Phraya près des
palais de Bangkhumphrom et Tewavej
Teparaksa W.
Associate Professor, Department of Civil Engineering, Chulalongkorn University, Bangkok, 10330, Thailand
ABSTRACT: The Bank of Thailand (BOT) head office is a large building constructed in the inner Ratanakosin Island of Bangkok
along Chao Phraya River, a main river of Bangkok, where high-rise building construction with more than three stories is not
permitted. The BOT building consists of five basements with excavation depth of 15.8 meters and only three stories of super structure.
The basement construction was constructed only five meters away from Tewavej Palace and ten meters away from Bangkhunphrom
Palace. The damage assessment by means of Finite Element Method (FEM) with simulation of basement construction method was
carried out to predict the influence on both palaces. Finally, the top-down construction method was selected for basement construction
with one meter thick and 20 meters long of diaphragm wall which was designed together with the 50 meters long bored pile to support
the whole building. The full set of instrumentation was installed at the palaces, diaphragm wall and ground surface for monitoring the
field performances during and after basement construction. The field measurement and FEM prediction will be compared and the time
dependent of lateral wall movement will be discussed. The construction was completed without any damage or effect to both palaces.
RÉSUMÉ : Le siège social de la Banque de Thaïlande (BDT) est un grand édifice construit sur l île intérieure de Rattanakosin dans
Bangkok le long de la Chao Phraya, un fleuve principal de Bangkok, ou la construction de bâtiments haut de plus de trois étages est
interdite. La BDT est constituée de cinq niveaux de sous sols avec excavation jusqu'à 15.8 mètres de profondeur et seulement trois
étages de superstructure. La construction du sous-sol a été effectuée seulement à cinq mètres du Palais de Tewavej and à dix mètres
du Palais de Bangkhunphrom. L’évaluation des dégâts par simulation de la construction du sous-sol par méthode des éléments finis
(MEF) a été effectuée afin de prédire l’impact sur les deux palais. Enfin, la méthode de construction ‘du haut vers le bas’ a été
sélectionnée pour la construction du sous-sol ainsi qu’une paroi moulée d’un mètre d’épaisseur et 20 mètres de long qui a été
dimensionnée avec des pieux forés de 50 mètres de long pour supporter l’intégrité du bâtiment. Les mesures sur le terrain ainsi que les
prédictions par MEF sont comparées et la dépendance en temps du mouvement latéral du mur est discutée. La construction a été
effectuée sans qu’il n y ait de dégâts ou d’impacts sur les deux palais.
KEYWORDS: Deep Basement, FEM Analysis, Deep Excavation, Historical Building, Palace.
1 INTRODUCTION
The demand for deep underground basement construction is
increasing in Bangkok city especially in the inner zone due to
the optimized land use for underground car park and retail of
the department store. The design and construction of deep
basement in the large city have to take the impact of the nearby
structure as well as public utilities into account. The designs of
the deep basement in Bangkok subsoil done by the author are
the Bai Yok II tower with 12 m. deep (Teparaksa, 1992),
Library of Thammasat University with 14 m. deep (Teparaksa,
1999a), Central World with 9 - 14 m. deep and Millennium
Sukhumvit hotel next to Bangkok Mass Rapid Transit (MRT)
Tunnel with 14 m. deep (Teparaksa, 2007).
The head office, Bank of Thailand (BOT) is located in the
inner Ratanakosin Island where high-rise building construction
more than three stories is not allowed. The location of the new
head office of BOT is planned along Chao Phraya riverbank and
closed to two historical palaces; Tewavej Palace and
Bangkhunphrom Palace as shown in Fig. 1.
The design and construction of the deep basement for head
office of the BOT consists of five basements for underground
car park with 15.8 m deep excavation and three floors of head
office above ground surface.
The analysis and the diaphragm wall design as well as the
impacted assessment of two palaces were carried out by Finite
Element Method (FEM) analysis by simulating the full method
of excavation and construction in the model. The
instrumentation was installed in both diaphragm wall and at the
palaces to monitor the safety and stability of the palaces. The
behavior of diaphragm wall movement will also be discussed
and compared with FEM prediction.
Figure 1. The location of new head office, Bank of Thailand (BOT) and
the surrounding palaces.
2 SOIL CONDITIONS
The soil conditions at BOT site based on nine boreholes soil
investigation consists of 12.5 m. thick soft dark grey clay and
followed by medium stiff clay and stiff to hard clay until
