Sains Malaysiana 43(5)(2014): 751-756
Korelasi
Pekali Kekasaran Kekar (JRC) dengan Sudut Geseran Puncak Satah Ketakselanjaran
Batuan Granit, Semenanjung Malaysia
(Correlation of Joint Roughness Coefficient (JRC)
with Peak Friction Angles of Discontinuity Planes of Granites, Peninsular
Malaysia)
T.L. GOH*, A. GHANI RAFEK & M. HARIRI ARIFIN
Program Geologi, Pusat Pengajian Sains Sekitaran dan Sumber
Alam, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi,
Selangor D.E. Malaysia
Diserahkan: 24 Ogos 2012/Diterima: 19 Ogos 2013
ABSTRAK
Kekasaran permukaan satah ketakselanjaran adalah parameter penting
untuk penilaian kestabilan struktur pengorekan dalam jasad batuan kerana ia
mempengaruhi tingkah-laku ricihan dan nilai sudut geseran puncak satah
tersebut. Beberapa kaedah boleh digunakan untuk menentukan kekasaran permukaan
ketakselanjaran. Kertas ini memperkenalkan satu pendekatan yang mudah dalam
bentuk tiga (3) persamaan polinominal untuk mengkorelasikan sudut geseran
puncak ketakselanjaran (øp) batuan granit segar,
terluluhawa sedikit dan terluluhawa sederhana dengan pekali kekasaran kekar, (JRC).
Persamaan polinominal ketakselanjaran batuan granit segar ialah fp1 = -0.071JRC2 + 3.56JRC + 35.6.
Persamaan polinominal ketakselanjaran batuan granit terluluhawa sedikit dan
terluluhawa sederhana masing-masing ialah øp2 = -0.087JRC2 +
4.32JRC + 34.1 dan fp3 = -0.133JRC2 + 5.08JRC + 29.
Hasil kajian ini memberikan satu kaedah alternatif penganggaran nilai øp satah
ketakselanjaran daripada penentuan nilai PKK pada permukaan ketakselanjaran batuan
granit di lapangan.
Kata kunci: Granit; pekali kekasaran kekar; sudut geseran puncak;
ujian kemiringan
ABSTRACT
Surface roughness is an important parameter in the evaluation of
the stability of structures excavated in rock masses as it controls the shear
behaviour and the value of the peak friction angle of a discontinuity plane.
Several approaches can be adopted for the determination of surface roughness of
discontinuities. This paper presents a simple approach in the form of three (3)
polynomial equations to correlate the peak friction angle (øp) with the Joint Roughness
Coefficient (JRC)
for discontinuity planes in fresh, slightly weathered and moderately weathered
granites. For fresh granite discontinuities, the polynomial equation is fp1 =
-0.071JRC2 +
3.56JRC + 35.6. The polynomial equations for slightly and moderately weathered
granite discontinuities are fp2 = -0.087JRC2 + 4.32JRC + 34.1 and øp3 =
-0.133JRC2 +
5.08JRC + 29, respectively. These results offer an alternative method for the
estimation of the øp of the discontinuity planes by measuring
the JRC values of the granite discontinuity planes in the field.
Keywords: Granites; joint roughness coefficient;
peak friction angle; tilt test
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*Pengarang
untuk surat-menyurat; email: gdsbgoh@gmail.com
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