Ignatius Tommy Pratama
Universitas Katolik Parahyangan

Published : 6 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 6 Documents
Search

Studi Parametrik Pengaruh Spasi, Panjang, dan Kuat Tarik Geogrid Terhadap Mechanically Stabilized Earth Wall di Boyolali Budijanto Widjaja; Ignatius Tommy Pratama; Daniel Sutanto
Jurnal Aplikasi Teknik Sipil Vol 21, No 4 (2023)
Publisher : Departemen Teknik Infrastruktur Sipil Institut Teknologi Sepuluh Nopember Surabaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j2579-891X.v21i4.16297

Abstract

Kegagalan dinding penahan tanah yang distabilkan secara mekanis (mechanically stabilized earth retaining wall, dinding MSE) dapat terjadi karena kesalahan desain dan kurangnya referensi terkait penggunaan tanah kohesif sebagai bahan timbunan. Maka, serangkaian studi parametrik dilakukan pada studi ini untuk menyelidiki efek jarak vertikal, panjang, dan kekuatan tarik geogrid biaksial, masing-masing divariasikan dalam tiga nilai, pada stabilitas global dinding MSE dengan ketinggian material timbunan tanah kohesif 15 m di Boyolali. Metode elemen hingga dan metode kesetimbangan batas digunakan dalam penelitian ini untuk mendapatkan faktor keamanan global dinding dan lokasi bidang gelincir terlemah. Selain itu, model material Mohr-Coulomb digunakan untuk memodelkan respon tegangan-regangan pada tanah. Hasil penelitian menunjukkan bahwa pengurangan jarak vertikal geogrid dan peningkatan panjang geogrid dan kekuatan tarik meningkatkan nilai faktor keamanan global dinding MSE. Selain itu, jarak yang lebih pendek, panjang yang lebih panjang, dan kekuatan tarik geogrid yang lebih tinggi juga memengaruhi lokasi bidang gelincir terlemah.
Numerical Study on the Shear Failure and Load Transfer Mechanism of Helical Piles in Cohesionless Soils under Axial Compressive Loading Pratama, Ignatius Tommy; Lestari, Anastasia Sri; Oktavianus, Ivan
Journal of the Civil Engineering Forum Vol. 10 No. 2 (May 2024)
Publisher : Department of Civil and Environmental Engineering, Faculty of Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jcef.7791

Abstract

The methods employed to calculate the axial bearing capacity of a helical pile depends on the shear failure model around the pile, which is also influenced by the spacing and diameter of the helical plates. However, studies on the transition of the failure mode and the load transfer mechanism with the change of helical plate spacing and diameter in cohesionless soil subjected to axial compressive load have been limited. Thus, this paper investigated the effects of helix diameter and spacing on the axial compressive load-bearing capacity, shear failure model, and load transfer mechanism of helical piles with two helical plates embedded in the homogeneous medium and dense sands, as well as in the stratified medium to very dense sand. Axial loading tests on helical piles with various helix diameters and spacings were simulated using a two-dimensional finite element program with axisymmetric modeling to obtain the load-settlement curve, which was later used to estimate the ultimate bearing capacity of the helical piles. The ultimate bearing capacity of the helical piles was also computed using the conventional methods, i.e., the individual bearing and cylindrical shear methods, and then compared to the numerical-based axial bearing capacity. The stress-strain behaviors of pile and soil were modeled using the Linear Elastic and Mohr-Coulomb material models, respectively. The results show that the numerical-based ultimate bearing capacity of a helical pile increased with increasing the diameter and spacing of the helix. However, the ultimate bearing capacity computed using conventional methods did not show this trend. Then, the transition from the cylindrical shear to the individual bearing failure mechanism occurred at a spacing ratio (i.e., helical plate spacing divided by its diameter) of about two. Ultimately, the load transfer curves indicate that the helical plates mainly supported the applied load.
Effects of EPS Beads on the Unconfined Compressive Strength and Stiffness of Bentonite Soil-Cement Mixture Lim, Aswin; Pratama, Ignatius Tommy; Verguson, Yoghi Jo
Jurnal Teknik Sipil dan Perencanaan Vol 25, No 1 (2023)
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jtsp.v25i1.38056

Abstract

Expanded Polystyrene Beads (EPS Beads) have characteristics that are lightweight and low density. However, EPS is waste that does not pollute the soil, but has hundreds of years to decompose, thereby reducing the landfill area. Therefore, alternative disposal is to use EPS for soil improvement. The effects of different EPS beads size on the mechanical behavior of bentonite soil-cement mixture were studied using the unconfined compression test. The curing time of the mixture also varied from 7 to 28 days. The results indicate that adding EPS beads to the soil-EPS beads-cement mixture changed the behavior of the material to be more ductile. The samples could also support larger stresses at a lower strain level, less than 1 %. Furthermore, the unconfined compressive strength of the mixture of bentonite, EPS, and cement increased with increasing curing time and decreased with increasing EPS beads size. Then, adding EPS beads to the soil-cement mixture regardless of its size also promoted a larger stiffness of the samples compared to the sample with no EPS beads in the mixture.
Landslide Treatment in the Al-Husainiyyah Junior High School Area using Cantilever-Geofoam Wall: Penanganan Longsor di Lingkungan SMP Al-Husainiyyah dengan Menggunakan Dinding Kantilever-Geofoam Aswin Lim; Ignatius Tommy Pratama; Budijanto Widjaja; Helmy Hermawan Tjahjanto; Johannes Adhijoso Tjondro; Obaja Triputera Wijaya; Bobby Minola Ginting; Theresita Herni Setiawan; Yohanes Lim Dwi Adianto; Felix Hidayat; Patricia Hartieni; Octavianus William; Tabitha Aldrianita; Imam Ahmad Fadhil
Dinamisia : Jurnal Pengabdian Kepada Masyarakat Vol. 8 No. 4 (2024): Dinamisia: Jurnal Pengabdian Kepada Masyarakat
Publisher : Universitas Lancang Kuning

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31849/dinamisia.v8i4.19519

Abstract

A landslide triggered by heavy rainfall occurred in the Al-Husainiyyah Junior High School area on April 26th, 2023. The landslide damaged the nearby access roads, the existing retaining wall, and a futsal court threatening the safety of the teachers and students in conducting the learning activities that especially require open areas. Thus, this community service aims to provide a cantilever wall design with geofoam as an innovative lightweight backfill material to reinforce the slope and repair the damaged structures. Field surveying and numerical analysis were then conducted to understand the current slope and soil conditions and to analyze the stability of the slope and retaining wall. The results show that a cantilever wall with a total height of 1.8 m supported by a strauss pile row with a diameter of 0.4 m, 4 m in length, and 2.5 m in spacing could increase the stability of the slope.
Laboratory Study on Vallejo and Scovazzo’s Methods in Estimating the Rheology Parameters of Bentonite and Kaolinite Muds Budijanto Widjaja; Ignatius Tommy Pratama; Ian Hartono; Boby Limowa
Civil Engineering Dimension Vol. 26 No. 1 (2024): MARCH 2024
Publisher : Institute of Research and Community Outreach - Petra Christian University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9744/ced.26.1.51-62

Abstract

The mud undrained shear strength and viscosity are the essential parameters in understanding the behavior of mudflow. One of the laboratory test methods to estimate the undrained shear strength and viscosity is Vallejo and Scovazzo’s cylinder strength meter test (CSMT) and flume channel test, respectively. This paper compares the undrained shear strength of kaolin and bentonite muds obtained from the CMST to those obtained using the fall cone and mini vane shear tests and also studies the scale effects in the flume channel test in measuring the mud viscosity at a 20o to 40o slope angles and at various liquidity indexes. The results exhibit that CMST could estimate the undrained strength of mud as low as 0.45 kN/m2 with a liquidity index of up to 5.93. Then, the reduction of the size of the flume channel by half resulted in a mud viscosity of about 2.3 times higher.
Studi Stabilitas Lereng Clay Shale di Kalimantan dengan Menggunakan Metode Kesetimbangan Batas dan Pendekatan Probabilistik dan Deterministik Pratama, Ignatius Tommy
Jurnal Rekayasa Konstruksi Mekanika Sipil Vol 4 No 2 (2021): Volume 4 Nomor 2 Tahun 2021
Publisher : Fakultas Teknik Universitas Katolik Santo Thomas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.54367/jrkms.v4i2.1366

Abstract

Analisis deterministik dan probabilistik kestabilan lereng tanah clay shale di Kalimantan dilakukan di dalam studi ini dengan menggunakan metode kesetimbangan batas untuk mengestimasikan nilai faktor keamanan dan probabilitas kegagalan lereng sebelum dan sesudah pemasangan perkuatan lereng. Hasil analisis balik mengindikasikan bahwa longsoran translasi terjadi pada tanah clay shale dengan nilai kohesi efektif sebesar 1,5 kN/m2 dan nilai rata-rata sudut geser residu efektif berkisar antara 8,5o hingga 10,3o. Kemudian, penggunaan perkuatan lereng berupa barisan tiang pancang pipa baja dan cerucuk kayu dan penggalian sedalam 3 m dari permukaan tanah eksisting dapat meningkatkan faktor keamanan lereng menjadi 1,25. Hasil analisis probabilistik berbasis simulasi Monte-Carlo dengan jumlah simulasi yang bervariasi antara 2.000 hingga 20.000 simulasi menunjukkan bahwa penggunaan struktur perkuatan lereng dapat menurunkan nilai probabilitas kegagalan hingga ke nilai 0,05%-0,28%. Berdasarkan hasil analisis sensitivitas, elevasi muka air tanah memiliki pengaruh paling signifikan di dalam perhitungan faktor keamanan lereng clay shale.