The Construction of a Zoned Embankment Dam in Indonesia

This paper documents the construction of a 30m high water storage dam at the Bukit Sentul Project in West Java, Indonesia. The author was extensively involved in the design phase of Dam L2 and spent a subsequent six month period in Indonesia for the construction of the embankment. This paper discusses the major technical and engineering issues which arose, as well as focusing on the more practical aspects of living, working and managing a project in a foreign country.

Introduction

Dam L2 is an “off-stream” storage, and carries a curved road alignment on its crest, which dictated the final dam location. The L2 embankment was designed as a zoned earth/soft rockfill embankment with a central clay core. Geotechnical investigation and design were carried out through the latter part of 1994, with construction taking place from April to December 1995.

During the design phase the author undertook stability, seepage and seismic risk analysis, before travelling to Indonesia to take up the position of Laboratory Manager late in June 1995. This position provided much experience in construction supervision, and in September a reduction in site personnel resulted in the author’s duties being extended to include the role of Site Engineer.

The specific aspects of engineering supervision included the excavation of foundations which exhibited unusually rapid deterioration upon exposure, the construction and placement of the extensive filter /seepage collection system and the quality control of material selection , compaction and testing for the ten separate zones incorporated into the embankment.

Some of the more practical issues encountered centred on the problems inherent with understanding and adapting to a different culture and working environment, such as the initial training of laboratory staff, the establishment of satisfactory standards and practices, and the continual liaison with the client and contractors.