scholarly journals POTENSI LIKUIFAKSI DI PESISIR BARAT SUMATERA MENGGUNAKAN SONDIR

Sebatik ◽  
2021 ◽  
Vol 25 (2) ◽  
pp. 704-714
Author(s):  
Herdiana Mutmainah
Keyword(s):  
Cone Penetration Test ◽  
Penetration Test ◽  
Cone Penetration

  Peristiwa gempa umumnya diikuti oleh serangkaian guncangan dan sesar tanah di permukaan. Gempa rawan terjadi pada lokasi yang dilalui jalur patahan dan tumbukan lempeng tektonik aktif. Pantai barat Sumatera berada di jalur patahan Semangko dan perbatasan lempeng tektonik aktif Eurasia dan Australia-Hindia. Gempa di atas skala 5,5 SR memicu likuifaksi pada tanah granuler dan muka air tanah dangkal. Kabupaten Agam dan Kabupaten Pasaman Barat di pesisir barat Provinsi Sumatera Barat merupakan lokasi yang rawan likuifaksi. Gempa Padang pada tahun 2009 (7,9 SR) berdampak memicu likuifaksi di kedua kabupaten tersebut. Penelitian ini bertujuan untuk menganalisa potensi likuifaksi di Kabupaten Agam dan Kabupaten Pasaman Barat. Penelitian dilakukan pada Oktober 2019 berdasarkan metode faktor aman menggunakan sondir (Cone Penetration Test/CPT) di 3 (tiga) desa yaitu Desa Tiku (Kabupaten Agam), Desa Air Bangis dan Desa Sasak (Kabupaten Pasaman Barat). Hasil penelitian menunjukkan Gempa 7 SR sudah mampu memicu likuifaksi (SF<1,0) di Desa Air Bangis dan Desa Sasak sedangkan simulasi Gempa Padang tahun 2009 (7,9 SR) menunjukkan potensi likuifaksi di Desa Tiku adalah SF = 0,53 – 0,95; Desa Air Bangis SF = 0,51 – 0,97 dan Desa Sasak SF = 0,45 – 0,95.

Seismic cone penetration test and seismic tomography in permafrost

2004 ◽  
Vol 41 (5) ◽  
pp. 796-813 ◽  
Author(s):  
Anne-Marie LeBlanc ◽  
Richard Fortier ◽  
Michel Allard ◽  
Calin Cosma ◽  
Sylvie Buteau
Keyword(s):  
Seismic Tomography ◽  
Dynamic Properties ◽  
Cone Penetration Test ◽  
The Body ◽  
Body Waves ◽  
Reconstruction Technique ◽  
Seismic Velocities ◽  
Penetration Test ◽  
Cone Penetration ◽  
Seismic Cone Penetration Test

Two high-resolution multi-offset vertical seismic profile (VSP) surveys were carried out in a permafrost mound near Umiujaq in northern Quebec, Canada, while performing seismic cone penetration tests (SCPT) to study the cryostratigraphy and assess the body waves velocities and the dynamic properties of warm permafrost. Penetrometer-mounted triaxial accelerometers were used as the VSP receivers, and a swept impact seismic technique (SIST) source generating both compressional and shear waves was moved near the surface following a cross configuration of 40 seismic shot-point locations surrounding each of the two SCPTs. The inversion of travel times based on a simultaneous iterative reconstruction technique (SIRT) provided tomographic images of the distribution of seismic velocities in permafrost. The Young's and shear moduli at low strains were then calculated from the seismic velocities and the permafrost density measured on core samples. The combination of multi-offset VSP survey, SCPT, SIST, and SIRT for tomographic imaging led to new insights in the dynamic properties of permafrost at temperatures close to 0 °C. The P- and S-wave velocities in permafrost vary from 2400 to 3200 m/s and from 900 to 1750 m/s, respectively, for a temperature range between –0.2 and –2.0 °C. The Young's modulus varies from 2.15 to 13.65 GPa, and the shear modulus varies from 1.00 to 4.75 GPa over the same range of temperature.Key words: permafrost, seismic cone penetration test, vertical seismic profiling, seismic tomography, dynamic properties.

Computerized Cone Penetration Test for Soil Classification

2008 ◽  
Vol 2053 (1) ◽  
pp. 47-64 ◽  
Author(s):  
Murad Y. Abu-Farsakh ◽  
Zhongjie Zhang ◽  
Mehmet Tumay ◽  
Mark Morvant
Keyword(s):  
Classification System ◽  
Soil Classification ◽  
Cone Penetration Test ◽  
Classification Systems ◽  
Fuzzy Classification ◽  
Classification Methods ◽  
Penetration Test ◽  
Cone Penetration ◽  
Cone Tip Resistance ◽  
Tip Resistance

Computerized MS-Windows Visual Basic software of a cone penetration test (CPT) for soil classification was developed as part of an extensive effort to facilitate the implementation of CPT technology in many geotechnical engineering applications. Five CPT soil engineering classification systems were implemented as a handy, user-friendly, software tool for geotechnical engineers. In the probabilistic region estimation and fuzzy classification methods, a conformal transformation is first applied to determine the profile of soil classification index (U) with depth from cone tip resistance (qc) and friction ratio (Rf). A statistical correlation was established in the probabilistic region estimation method between the U index and the compositional soil type given by the Unified Soil Classification System. Conversely, the CPT fuzzy classification emphasizes the certainty of soil behavior. The Schmertmann and Douglas and Olsen methods provide soil classification charts based on cone tip resistance and friction ratio. However, Robertson et al. proposed a three-dimensional classification system that is presented in two charts: one chart uses corrected tip resistance (qt) and friction ratio (Rf); the other chart uses qt and pore pressure parameter (Bq) as input data. Five sites in Louisiana were selected for this study. For each site, CPT tests and the corresponding soil boring results were correlated. The soil classification results obtained using the five different CPT soil classification methods were compared.

Sign in / Sign up

Export Citation Format

Share Document