Design of pyongtaek LPG storage terminal underneath the Lake Namyang

Abstract

This paper presents the geo-engineering problems and approaches in the design of the first kind LPG storage terminal underneatha lake in the western part of Korea. The Pyongtaek LPG Terminal was proposed to be constructed underneath the Lake Namyang to facilitate the storage caverns within the limited property boundary complicated with complex geological conditions and potential interference with the neighboring storage caverns L-1 in operation. To precisely characterize the geological feature of the bed rock underneath the lake with very limited information from the outcrops, a new method of geophysical investigation was applied. And to prevent the potential hydrogeological interference with the neighboring L-1 in operation, discreet evaluation of geological data and numerical analyses were carried out. As a result, vertical and horizontal water curtain systems were constructed to prevent the detrimental draw-down of water level nearby the L-1. The depth and geometry of the new cavern were determined based on the in situ stress and operation pressure to have as large capacity as possible to overcome the spatial constraints. The continuous monitoring during the construction of the storage caverns and tunnels, any unfavorable measurement for the final tightness of the storage cavern was not taken. In May 1999, the first LPG supply in the cavern was made after the acceptance test.