Table 4. Result of drilling investigation.

Number	Stratum division	Depth (GL.-m)	Thickness (m)	Geological composition	N value (TCR/RQD)
BH-1	Colluvium	0.0~1.5	1.5	Argillaceous gravel, Sand, mixed complex	-
	Colluvium	1.5~4.5	3.0	Slity clay, sand and gravel mixed complex	7/30~12/30
	Sedentary deposit	4.5~29.0	24.5	Sandy slit, Silty sand, Fine textured soils	9/30~50/16
	Weathered rock	29.0~29.8	0.8	Silty sand, Fine textured soils	50/10
	Weathered rock	29.8~38.0	8.2	Syenite, Complete~High weathering state	20~94/0
	Soft rock	38.0~41.0	3.0	Syenite, Normal weathering state	100/49
BH-2	Colluvium	0.0~0.6	0.6	Argillaceous gravel, Sand mixed complex	-
	Colluvium	0.6~2.0	1.4	Slity clay, gravel and Cobble stone mixed complex	3/30
	sedentary deposit	2.0~28.0	26.0	Slity clay, Slity sand, Fine textured soils	4/30~50/11
	weathered rock	28.0~32.0	4.0	Silty sand, Fine textured soils	50/10~50/8
	sedentary deposit	32.0~38.0	6.0	Silty sand, Fine textured soils	50/19~50/13
	weathered rock	38.0~39.5	1.5	Silty sand, Granule~Medium texture	50/9~50/7
	weathered rock	39.5~55.8	16.3	Syenite Complete~High weathering state	12~96/0
	Soft rock	55.8~56.5	0.7	Syenite, Little weathering state	100~33
BH-3	Colluvium	0.0~1.4	1.4	Argillaceous gravel, Sand mixed complex	3/30
	Colluvium	1.4~7.5	6.1	Slity clay, gravel and Cobble stone mixed complex	6/30~11/30
	sedentary deposit	7.5~33.0	25.5	Sandy slit, Slity sand, Fine textured soils	16/30~50/17
	weathered rock	33.0~36.5	3.5	Slity sand, Granule~Medium texture	50/10~50/6
	Soft rock	36.5~39.0	2.5	Syenite, Normal~little weathering state	84/22