Sains Malaysiana 36(1): 1-8 (2007)

Beberapa Sifat Fizik dan Mekanik Batuan Granit Berbutir

Kasar Kuala Kubu Bharu, Selangor

(Some Physical and Mechanical Properties of Coarse Grained

Granite of Kuala Kubu Bharu, Selangor)

Umar Hamzah, Lee Chun Rhen & Abd. Ghani Rafek

Program Geologi, Pusat Pengajian Sains Sekitaran & Sumber Alam

Fakulti Sains & Teknologi, Universiti Kebangsaan Malaysia

43600 UKM Bangi, Selangor D.E. Malaysia

Abstrak 

Empat puluh sampel batuan granit berbutir kasar daripada Kuala Kubu Bharu telah dikumpulkan daripada 14 lokaliti di sepanjang singkapan jalan daripada Taman Bukit Bunga hingga ke kampung Pertak. Sampel-sampel teras selinder dan blok empatsegi telah disediakan daripada sampel lapangan tersebut untuk menjalani ujian halaju sonik dan mekanik setelah pengukuran beberapa sifat fizik. Nilai purata porositi berkesan sampel-sampel tersebut ialah 1.33 % manakala purata ketumpatan kering dan tepu adalah 2542 dan 2555 kg/m³. Graviti spesifik yang dihitung berjulat 2.1-2.9. Halaju denyut ultrasonik min gelombang P dan S yang melalui bahan batuan yang diuji ialah 5359 m/s dan 2890 m/s. Ujian-ujian mampatan sepaksi menunjukkan purata kekuatan mampatan sepaksi sampel yang bernilai 138.6 MPa. Nilai purata bagi indeks kekuatan beban titik Is(50) pula ialah 5.63. Oleh itu perkaitan kekuatan mampatan sepaksi dengan kekuatan beban titik ialah dengan faktor multiplikasi 25.

Kata kunci: sifat fizik; halaju ultrasonik; sifat mekanik; kekuatan batuan

Abstract 

Forty samples of coarse grained granite from Kuala Kubu Bharu were collected at 14 localities of outcrops exposed along the road between Taman Bukit Bunga to Kampung Pertak. Cylindrical cores and rectangular blocks were prepared from the field samples for the ultrasonic velocity and the mechanical tests after measurements of few physical properties of the samples were carried out. Average effective porosity of the samples was 1.33% while the dry and saturated average densities were 2542 and 2555 kg/m³ respectively. Measured specific gravity of the samples were in the range of 2.1-2.9. Mean ultrasonic pulse velocity of  P and S-waves through the rock specimens tested was in between 5359 m/s and 2890 m/s. Uniaxial compression tests showed that the average value of the uniaxial compressive strength was 138.6 MPa. The average value of Is(50) Point Load Strength Index was 5.63. Therefore the uniaxial compression strength is related to the point load strength index by a multiplification factor of 25.

Keywords: Physical properties; ultrasonic velocity; mechanical properties; rock strength 

RUJUKAN/REFERENCES

ASTM, 1976. Suggested method for laboratory determination of pulse velocities and Ultrasonic elastic constants of rock. American Society for Testing and Materials, ANSI/ASTM D2845-69, ASTM Standards, 341-348.

Broch, E. & Fanklin, J.A. 1972. The point load strenght test. Int. J. Rock Mech. Min. Sci. & Geomech. 6: 669-697.

Farmer, I.W., 1968. Engineering Properties of Rocks. London: E & F.N. Spon Ltd., 180 p.

ISRM, 1981. Basic geotechnical description of rock masses. ISRM Commission on Standardization of laboratory and field tests. Int. J. Rock Mech. Min. Sci. 18:85-110.

Ng, T.F., 1992. Ultrasonic investigation of the Kuala Lumpur Granite, Peninsular Malaysia. Warta Geologi 18(5): 182-196.

Obert, L. & Duvall, W.I., 1976. Rock Mechanics and The Design of Structures in Rocks. New York. John Wiley & Sons Inc., 650 p.

Raj, J.K., 1996. Ultrasonic pulse velocities and elastic moduli of igneous rock material From Ajil, Terengganu. Warta Geologi 22(1):1-10

Raj, J.K. and Ali, A.N.M., 1994. Point load strength of a coarsed grained porphyritic Biotite-hornblende granite from the Pergau area, Kelantan. Warta Geologi 20(3): 177-182.

Richard, E.G., 1989. Introduction to Rock Mechanics. Ed. Ke-2. New York: John Wiley & Sons.

Sjorgen B, Ofsthus, A. & Sandberg, J., 1979. Seismic classification of rock mass Geophysical Prospecting 27: 409-442

Umar Hamzah dan Ibrahim Komoo, 1997. Cirian halaju dan ultrasonik profil luluhaw granit km 39.9 Lebuhraya Kuala Lumpur-Karak  Sains Malaysiana 26(1): 19-31.