Mechanical response of saturated and unsaturated gravels of different sizes in drained triaxial testing

  • PDF / 6,809,700 Bytes
  • 19 Pages / 595.276 x 790.866 pts Page_size
  • 89 Downloads / 204 Views

DOWNLOAD

REPORT


(0123456789().,-volV)(0123456789(). ,- volV)

RESEARCH PAPER

Mechanical response of saturated and unsaturated gravels of different sizes in drained triaxial testing Israa Jamal Alhani1 • Mohd Jamaludin bin Md Noor1 • Mohammed Ali Mohammed Al-Bared2 Indra Sati Hamonangan Harahap2 • Wael Mahmood Albadri1



Received: 15 August 2019 / Accepted: 8 March 2020 Ó Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract During the construction of pavements, gravelly soil is used as the main material in the base and sub-base layers. Predicting the deformation behaviour of gravelly soil has been increasingly important, and this may require comprehensive knowledge about both the mechanical and microstructural behaviours of gravelly materials. This study evaluates the saturated and unsaturated behaviours of 200-mm-high remoulded gravelly soil samples under a large-scale consolidated drained triaxial test. The laboratory tests included physical, mechanical, and microstructural testing on gravelly soil and different sizes of gravel. A series of drained triaxial tests were conducted on gravelly soil under both saturated and unsaturated conditions and on 5 mm, 10 mm, 14 mm, 20 mm, and 25 mm sizes of gravel. The results indicated an increase in the mechanical properties with increasing gravel size. The shear strength parameters were also improved with increasing gravel size. When comparing the results of the gravelly soil under both saturated and unsaturated conditions, the soil had an apparent shear strength that decreased beyond the residual suction during the unsaturated condition. The deviator stress and axial and volumetric strains were significantly dependent on the confining pressure. The microstructural studies confirmed the presence of calcite minerals with granular structures and crystalline textures as the main mineral in the gravelly soil. Therefore, the particle breakage when confining pressure is applied will be minimal, which enables the use of this soil in the base and sub-base layers of the pavement. Keywords Chemical tests  Consolidated drained triaxial test  Gravelly soil  Gravel size

1 Introduction Soil deposits that are mainly composed of boulders, gravels, sands, and fine particles can be described as gravelly soil. The friction angle of gravelly soils is usually found to be high due to the interlocking between the large gravel particles and the small particles existing within the soil [15]. Soil is considered gravelly when the amount of course fragments retained on a sieve with 4.75-mm-wide openings

& Mohammed Ali Mohammed Al-Bared [email protected]; [email protected] 1

Faculty of Civil Engineering, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Malaysia

2

Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, 32610 Bandar Seri Iskandar, Malaysia

is more than 50%. Meanwhile, gravelly soil is distributed widely in the tropical and subtropical regions of the world as material on slopes formed by complex conditions such as the accumulation of r