Article Per Year (5 Year)
p-Index From 2020 - 2025
0.751
P-Index
This Author published in this journals
All Journal Jurnal Teknik Sipil Journal of the Civil Engineering Forum SAINSTECH: Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Alatas, Idrus M
Institut Sains Dan Teknologi Nasional, Jakarta, INDONESIA
Biochemistry, Genetics & Molecular Biology Civil Engineering, Building, Construction & Architecture Electrical & Electronics Engineering Engineering Mechanical Engineering

Published : 5 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 5 Documents
Search

 1 
Pengaruh Proses Pelapukan Clay Shale terhadap Perubahan Parameter Rasio Disintegritas (DR) Alatas, Idrus M; Simatupang, Pintor T
Jurnal Teknik Sipil Vol 24, No 1 (2017)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2162.422 KB) | DOI: 10.5614/jts.2017.24.1.9

Abstract

Abstrak Penelitian ini dilatarbelakangi oleh sering terjadinya kegagalan desain geoteknik pada clay shale yang disebabkan oleh pelapukan. Rasio disintegritas adalah perbandingan perubahan fisik akibat pelapukan pada waktu tertentu terhadap kondisi awalnya. Perubahan sifat fisik clay shale akibat pelapukan ditentukan dengan rasio disintegritas (DR). Pelapukan clay shale akan lebih cepat terjadi akibat siklus pembasahan dan pengeringan bila dibandingkan dengan proses pengeringan. Manakala akibat bertambah jumlah pembasahan dan pengeringan pada waktu yang sama, menyebabkan pelapukan pada clay shale akan lebih cepat lagi. Sampai hari ke-80 dari waktu pengeringan, DR clay shale Semarang-Bawen dan Hambalang besarnya adalah sama yaitu DR = 0,916 (completelly durable). Sedangkan akibat siklus pembasahan dan pengeringan di hari ke-32, clay shale Semarang-Bawen DR = 0,000 atau completelly non durable, manakala pada clay shale Hambalang DR = antara 0,2117 hingga 0,3344. Pada umumnya clay shale Semarang-Bawen akan lebih lebih cepat melapuk bila dibandingkan clay shale Hambalang. Ini terjadi karena perbedaan kandungan mineralogi. Clay shale Semarang-Bawen didominasi oleh mineral Smectite, sedangkan clay shale Hambalang didominasi mineral Kaolinite dan Illite.Abstract The background of this research because of the frequent occurrence of the failure in the geotechnical design of clay shale caused by weathering. Disintegration ratio is a comparison of physical changes due to weathering at certain times of the initial conditions. Changes in physical properties due to clay shale weathering determined by the disintegration ratio (DR).Clay shale weathering will occur more quickly as a result of wetting and drying cycles when compared with the drying process. While due to the increased number of cycles of wetting at the same time, causing weathering on clay shale will be faster again. Until the 80th day of drying time, the magnitude DRof Semarang-Bawenclay shaleand Hambalang are the same, namely DR = 0.916 (completelly durable). However, due to wetting and drying cycles on day 32, samples of Semarang-Bawenclay shale is DR = 0.000 or non durable completelly, while on Hambalang clay shale in same day DR between 0.2117 to 0.3344. Generally Semarang-Bawen clay shale will be faster weathered than Hambalang clay shale. It is caused by the mineralogy content of Semarang-Bawen clay shale has dominated by Smectite, and Hambalangclay shalehas dominated mineral Kaolinite and Illlite.
Pengaruh Proses Pelapukan Clay Shale terhadap Perubahan Parameter Rasio Disintegritas (DR) Idrus M Alatas; Pintor T Simatupang
Jurnal Teknik Sipil Vol 24 No 1 (2017)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/jts.2017.24.1.9

Abstract

Abstrak Penelitian ini dilatarbelakangi oleh sering terjadinya kegagalan desain geoteknik pada clay shale yang disebabkan oleh pelapukan. Rasio disintegritas adalah perbandingan perubahan fisik akibat pelapukan pada waktu tertentu terhadap kondisi awalnya. Perubahan sifat fisik clay shale akibat pelapukan ditentukan dengan rasio disintegritas (DR). Pelapukan clay shale akan lebih cepat terjadi akibat siklus pembasahan dan pengeringan bila dibandingkan dengan proses pengeringan. Manakala akibat bertambah jumlah pembasahan dan pengeringan pada waktu yang sama, menyebabkan pelapukan pada clay shale akan lebih cepat lagi. Sampai hari ke-80 dari waktu pengeringan, DR clay shale Semarang-Bawen dan Hambalang besarnya adalah sama yaitu DR = 0,916 (completelly durable). Sedangkan akibat siklus pembasahan dan pengeringan di hari ke-32, clay shale Semarang-Bawen DR = 0,000 atau completelly non durable, manakala pada clay shale Hambalang DR = antara 0,2117 hingga 0,3344. Pada umumnya clay shale Semarang-Bawen akan lebih lebih cepat melapuk bila dibandingkan clay shale Hambalang. Ini terjadi karena perbedaan kandungan mineralogi. Clay shale Semarang-Bawen didominasi oleh mineral Smectite, sedangkan clay shale Hambalang didominasi mineral Kaolinite dan Illite.Abstract The background of this research because of the frequent occurrence of the failure in the geotechnical design of clay shale caused by weathering. Disintegration ratio is a comparison of physical changes due to weathering at certain times of the initial conditions. Changes in physical properties due to clay shale weathering determined by the disintegration ratio (DR).Clay shale weathering will occur more quickly as a result of wetting and drying cycles when compared with the drying process. While due to the increased number of cycles of wetting at the same time, causing weathering on clay shale will be faster again. Until the 80th day of drying time, the magnitude DRof Semarang-Bawenclay shaleand Hambalang are the same, namely DR = 0.916 (completelly durable). However, due to wetting and drying cycles on day 32, samples of Semarang-Bawenclay shale is DR = 0.000 or non durable completelly, while on Hambalang clay shale in same day DR between 0.2117 to 0.3344. Generally Semarang-Bawen clay shale will be faster weathered than Hambalang clay shale. It is caused by the mineralogy content of Semarang-Bawen clay shale has dominated by Smectite, and Hambalangclay shalehas dominated mineral Kaolinite and Illlite.
Shear Strength and Durability Behaviors of Compacted Weathered Clay Shale Mixture Using Portland Cement Pintor Tua Simatupang; Idrus M. Alatas; Ayu K. Redyananda; Eko A. Purnomo
Journal of the Civil Engineering Forum Vol. 8 No. 2 (May 2022)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2960.818 KB) | DOI: 10.22146/jcef.3491

Abstract

The use of weathered clay shale often has the potential to cause geotechnical problems as an embankment material, especially slope failures. In order for weathered clay shale to be used as embankment material, the weathered clay shale must be mixed with other materials. An example of a widely used mix is a mix with a Portland cement (PC). In general, this mixture will increase the shear strength of the embankment material. In addition to shear strength, it is very important to investigate whether the material mixture is susceptible to durability. Therefore, this study aims to evaluate the shear strength and durability behaviors of weathered clay shale mixture, using PC. The percentage of this cement was varied and did not exceed 20%, with the mixing material also compacted based on Proctor Standard procedure. This test included the determination of shear strength and durability index at the smaller and larger (dry and wet sides) than optimum moisture content (OMC). Shear strength and durability index were determined by Triaxial and slake durability index tests, respectively. The results showed that the weathered clay mixture with 10% PC and 8% larger OMC led to an increase in the normalized shear strength (∆σ/σ) and durability index at approximately 300% and 24%, respectively, compared to the original clay shale. This indicated that the optimum shear strength and durability of this shale mixture were highly observed at 10% PC and 8% larger OMC (wet side). This verified also although the durability index increased by 97% with the addition of 20% PC, whose utilization was found to be unrealistic
Durabilitas Clay Shale Hambalang Lapuk Distabilisasi dengan Semen Portland dan Energi Pemadatan Berlebih Ega Yogaswara; Idrus M. Alatas
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 32 No 4 (2022): Sainstech : Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v32i4.1450

Abstract

Abstrak The mechanical properties of clay shale are very unique. When dry it will shrink and harden, but when it absorbs water, it swells and to some extent loses its shear strength so that falling forces can occur suddenly even with its own weight. Due to its swell-shrink nature which is strongly influenced by climate and weather, the durability of clay shale can decrease over time when it comes into direct contact with air and water. Clay shale research was carried out in Hambalang, Bogor - West Java, Indonesia in the Jatiluhur formation, using weather stabilization stabilized with portland cement and excess compaction energy. with dynamic slaking (slake durability test). The dynamic slacking test was carried out three times, namely after sampling, 10, 20, and 30 blows/layer compaction were performed. With a low plasticity index, the durability research in Hambalang is classified as moderate to medium-high durability. Then, a test of excess compaction energy was carried out on variations in the stabilization of portland cement by increasing additional pressure. To determine the effect of the stabilization of portland cement with a composition of 5%, 10%, and 15% on clay shale, it showed an increase in the slake durability index, with the highest value in a mixture of 10% PC. The sample with an additional 15% PC and with an energy of 30 blow + pressure shows the highest Slake Durability Index value of 93.52%. However, this behavior cannot return to the original condition of clay shale (fresh clay shale). Keywords: Clay shale, durability, Slaking index, portland cement
Pengembangan Metode Audio Frequency Magnetotelluric untuk Keperluan Geoteknik Idrus M. Alatas; Ribka Sherry Tania Dethan
SAINSTECH: JURNAL PENELITIAN DAN PENGKAJIAN SAINS DAN TEKNOLOGI Vol 35 No 1 (2025): Sainstech : Jurnal Penelitian dan Pengkajian Sains dan Teknologi
Publisher : Institut Sains dan Teknologi Nasional

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37277/stch.v35i1.2325

Abstract

Metode audio frequency magnetotelluric (ADMT) adalah suatu metode geofisika yang bekerja berdasarkan gelombang elektromagnetik domain frekuensi sebagai sumber gelombang atau energi untuk mengetahui struktur tahanan jenis bawah permukaan. Metode ADMT adalah metode yang non-destruktif, tidak invasif, portabel, dan ramah lingkungan, sehingga dapat digunakan dalam berbagai bidang teknik, dan geologi. Penelitian ini mengembangkan metode ADMT dalam keperluan geoteknik, khususnya untuk penentuan stratigrafi tanah berdasarkan nilai impedansi. Pengukuran dilakukan di dua lokasi, yaitu Kantor HATTI, Ciracas dan Duren Tiga, Jakarta Selatan, dengan analisis impedansi pada tanah clay, silt, dan sand. Metode yang digunakan untuk mendapatkan data geoteknik adalah dengan pengujian SPT dan pengujian laboratorium. Sedangkan untuk mendapatkan nilai impedansi, dilakukan pengukuran pada lintasan sepanjang 30 titik (Ciracas) dan 7 titik (Duren Tiga) dengan interval 1 meter, menggunakan ADMT tipe 300 HT3. Karena keterbatasan alat yang hanya dapat membaca nilai impedansi dengan interval 5 meter, maka dilakukan pengujian ADMT pada elevasi yang beragam, yaitu elevasi 0 sampai elevasi +4 meter. Analisis korelasi menunjukkan bahwa hubungan antara nilai N-SPT dan impedansi tergolong rendah di kedua lokasi. Selain itu, hasil korelasi impedansi terhadap stratigrafi tanah tidak dapat langsung diterapkan di lokasi lain karena dipengaruhi oleh faktor seperti kandungan mineral logam. Penerapan hasil korelasi dari Kantor HATTI ke Duren Tiga memiliki tingkat kecocokan 70,83%, dengan ketidaksesuaian 29,17%, terutama pada tanah kohesif. Oleh karena itu, metode ADMT dapat digunakan dalam tahap awal penyelidikan tanah, tetapi tetap memerlukan verifikasi melalui pemboran dan deskripsi visual minimal satu titik untuk kalibrasi. Kata Kunci: Audio Frequency Magnetotelluric, Impedansi, Stratigrafi Tanah, Geoteknik, Korelasi N-SPT.
Co-Authors Ayu K. Redyananda Ega Yogaswara Eko A. Purnomo Pintor T Simatupang Pintor Tua Simatupang Ribka Sherry Tania Dethan Simatupang, Pintor T