ABSTRACT: Initial parameter investigations for earth-cut slope of the Hong Sa coalfield, Laos

Laoprapaipan, Pramote¹ and Krish K. Sappal²
(1) Curtin University of Technology, Bangkok, Thailand
(2) Curtin University of Technology, Perth, Australia

The Hong Sa Coalfield, located in the northeastern part of Laos, is of Tertiary age. Sedimentary deposits in the basin form synclinal and anticlinal structures and bounded by Mesozoic sandstone. A total 585,000,000 metric tonnes of coal resources are estimated. Coal bearing sediments occur as interbedded deposits of various type of sediments. They expose at ground surface and extend to a depth of few hundred meters near the synclinal axis. The sediments forming geological formations are classified as material type succession. They comprise soil-like material, dominantly fine grained. Undisturbed core samples have been collected for geotechnical laboratory test in order to determine basic engineering properties and shear strength parameters. The shear strength parameter tests comprise direct shear and triaxial tests according to the sedimentary structure and mode of failure. A number of typical piezometers are installed into the bore holes to a depth of few hundred meters. The ground water level monitoring indicates high ground water pressure within the basin. Statistical analyses and the derived data are brought to form parameters for earth-cut slope in order to optimise open-pit mining development of the Hong Sa coalfield.

AAPG Search and Discovery Article #90913©2000 AAPG International Conference and Exhibition, Bali, Indonesia