Hasbullah Nawir, Hasbullah
Kelompok Keahlian Rekayasa Geoteknik, Program studi Teknik Sipil, Fakultas Teknik Sipil dan Lingkungan Institut Teknologi Bandung, Jl. Ganesa No. 10 Bandung 40132.

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Journal : Journal of Engineering and Technological Sciences

Axial and Lateral Small Strain Measurement of Soils in Compression Test using Local Deformation Transducer Nawir, Hasbullah; Apoji, Dayu; Ekawita, Riska; Khairurrijal, Khairurrijal
Journal of Engineering and Technological Sciences Vol 50, No 1 (2018)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (634.837 KB) | DOI: 10.5614/j.eng.technol.sci.2018.50.1.4

Abstract

This paper presents the development of a method using local deformation transducers (LDTs) to locally and sensitively measure small axial and lateral strains in soil in a compression test. A local strain measurement system comprising of axial and lateral LDTs was developed referring to the original LDT system and the cantilever LDT system, respectively. The LDTs were calibrated both in air and under water. Their insensitivity to pressurized water was confirmed. The calibration factors for the axial and lateral LDTs were found to be 1.695 mm/volt and 1.001 mm/volt, respectively. The performance in terms of repeatability and stability of the LDT system was evaluated. The repeatability test showed that the average standard deviation of the lateral LDT was 0.015 volt, while the stability test showed that the average standard error of the axial and lateral LDT were 3.13 × 10-5 volt and 2.65 × 10-5 volt, respectively. Unconfined compression tests were conducted on three reconstituted clay samples to examine the proposed axial and lateral LDT system. The stress-strain relationship indicates a nonlinear relationship between the axial and lateral strain of soil instead of the conventionally assumed constant relationship. The results demonstrate this nonlinear behavior even at small strain levels, which were successfully measured using a domestically built axial and lateral LDT system.
Axial and Lateral Small Strain Measurement of Soils in Compression Test using Local Deformation Transducer Hasbullah Nawir; Dayu Apoji; Riska Ekawita; Khairurrijal Khairurrijal
Journal of Engineering and Technological Sciences Vol. 50 No. 1 (2018)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2018.50.1.4

Abstract

This paper presents the development of a method using local deformation transducers (LDTs) to locally and sensitively measure small axial and lateral strains in soil in a compression test. A local strain measurement system comprising of axial and lateral LDTs was developed referring to the original LDT system and the cantilever LDT system, respectively. The LDTs were calibrated both in air and under water. Their insensitivity to pressurized water was confirmed. The calibration factors for the axial and lateral LDTs were found to be 1.695 mm/volt and 1.001 mm/volt, respectively. The performance in terms of repeatability and stability of the LDT system was evaluated. The repeatability test showed that the average standard deviation of the lateral LDT was 0.015 volt, while the stability test showed that the average standard error of the axial and lateral LDT were 3.13 × 10-5 volt and 2.65 × 10-5 volt, respectively. Unconfined compression tests were conducted on three reconstituted clay samples to examine the proposed axial and lateral LDT system. The stress-strain relationship indicates a nonlinear relationship between the axial and lateral strain of soil instead of the conventionally assumed constant relationship. The results demonstrate this nonlinear behavior even at small strain levels, which were successfully measured using a domestically built axial and lateral LDT system.
Strength and Deformation Characteristics of Reconstituted Sand under Different Stress Paths in True Triaxial Tests Hasbullah Nawir; Bagus Eko Prasetyo; Andhika Sahadewa
Journal of Engineering and Technological Sciences Vol. 52 No. 6 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.6.10

Abstract

To improve the geotechnical stress"“strain analysis, the stress"“strain behavior of geomaterial under general three-dimensional stress conditions prevailing in the field need to be captured. The true triaxial apparatus is an enhanced version of the conventional triaxial apparatus, which allows to simulate stresses by applying loadings independently in 3 orthogonal directions. This study evaluated the strength and deformation behavior of Bangka sand under true triaxial test conditions. The test specimens were prepared by means of the multi-sieve sand pluviation method. Various true triaxial test stress paths were applied under axial compression, lateral extension, axial extension, and lateral compression with the objective of understanding and developing the empirical correlation of coarse-grained soil strength parameters in axial compression stress paths related to other stress paths. The test results showed that an increase in the value of b, the parameter used to quantify the relative magnitude of the intermediate principal stress to the other principal stresses, resulted in an increase of the internal friction angle and a decrease of the peak stress ratio. In addition it was observed that the Lade-Duncan failure criterion fitted the results of this study better than other failure criteria, namely the extended von Mises, Mohr-Coulomb, and Matsuoka-Nakai failure criteria.
Compaction Control Using Degree of Saturation and Plasticity Index on Tropical Soil Hasbullah Nawir; Laras Dipa Pramudita; Tita Kartika Dewi; Dayu Apoji; Sugeng Krisnanto
Journal of Engineering and Technological Sciences Vol. 55 No. 3 (2023)
Publisher : Directorate for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2023.55.3.5

Abstract

Soil compaction in the field is conventionally controlled using maximum dry density, (ρd)max, and optimum moisture content, (w)opt, as the target properties. However, achieving accurate control of these target properties can be difficult due to variation of compaction energy level (CEL) and soil type. Recently, a novel soil compaction control approach using optimum degree of saturation, (Sr)opt, as the target properties has been proposed. It was argued that (Sr)opt can be a better compaction control property as the value is less sensitive to the variation of CEL and soil type. This paper presents an investigation of the compaction characteristics of tropical soils from several locations in Indonesia based on both primary and secondary data. This study was performed by exploring the relationships between (i) dry density (ρd) and Sr, (ii) (ρd) and plasticity index (PI), (iii) (ρd) and CBR, as well as (iv) (ρd) and permeability. This study showed that the (Sr)opt of the soils was 91.2%, with variation between 81.2% and 96.5%. This study also showed that (ρd)max can be related to PI at a given CEL. It is expected that the proposed relationships can be better references for field compaction control practices in Indonesia.