Bulletin of the Geological Society of Malaysia, Volume 44, July 2000, pp. 83 – 89

Rakaman seismos dalam lubang gerudi bagi penyiasatan tanah runtuh: kajian kes tapak Stesen Pemancar Gelombang Mikro Telekom, Jalan Temerloh-Mentakab, Pahang

(Downhole seismic logging for landslide investigations: case study at the Microwave Transmission Station, Temerloh-Mentakab Road, Pahang)

Abdul Ghani Rafek¹, Rahman bin Yaccup¹, Abdul Rahim Samsudin¹, Khairul Anuar Mohd. Nayan² and Umar Hamzah¹

¹ Program Geologi, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selanger D.E.

²Jabatan Kejuruteraan Awam dan Struktur, Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selanger D.E.

Abstrak: Rakaman seismos dalam lubang gerudi dengan penentuan halaju gelombang P, Vp dan gelombang S, Vs dapat mengesan kedudukan satah lemah di suatu tanah runtuh di bukit pemancar gelombang mikro di km 7, Jalan Temerloh-Mentakab. Hasil rakaman seismos lubang gerudi dikorelasikan dengan hasil ujian penusukan piawai. Kedudukan satah lemah dicirikan oleh penyusutan dan peningkatan nilai halaju kedua-dua gelombang P, Vp dan gelombang S, Vs pada satu kedalaman yang sama. Rakaman ini dilakukan dalam tiga lubang gerudi dan dua hingga tiga satah lemah dikesan. Satah lemah ini kemungkinan besar merupakan satah gelinciran. Korelasi dengan hasil ujian penusukan piawai yang dilakukan dalam lubang yang berdekatan menunjukkan perubahan tren yang selari pada kedalaman yang hampir sama (±10%). Keputusan ini menunjukkan keberkesanan kaedah rakaman seismos dalam lubang gerudi untuk mengesan kedudukan satah-satah lemah dalam sesuatu kawasan tanah runtuh.

Abstract: Downhole seismic logging with the determination of P-wave and S-wave velocities, Vp and Vs enabled the detection of weak planes in a landslide at the microwave transmission station hill at km 7, Temerloh-Mentakab road. The results of downhole logging were correlated with standard penetration test results. The location of a weak plane was characterised by reduction and subsequent increase in the values of both the P-wave and S-wave velocities, Vp and Vs at the same depth. Logging was conducted in three boreholes and two to three weak planes were detected. These weak planes are possibly failure or slide planes. Correlation with standard penetration test results in adjacent boreholes shows a parallel trend in the change of values at approximately the same depths (± 10%). This result shows the effectiveness of downhole seismic logging for the detection of weak planes within a landslide area.

https://doi.org/10.7186/bgsm44200011