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Selected Works

Buddhima Indraratna

Selected Works

2014

Effects

Articles 1 - 5 of 5

Full-Text Articles in Engineering

Effects Of Geosynthetic Reinforcement On Performance Of Ballasted Rail Track, Pongpipat Anantanasakul, Buddhima Indraratna, Sanjay S. Nimbalkar, Tim Neville Mar 2014

Effects Of Geosynthetic Reinforcement On Performance Of Ballasted Rail Track, Pongpipat Anantanasakul, Buddhima Indraratna, Sanjay S. Nimbalkar, Tim Neville

Buddhima Indraratna

The 'field' performance of different geosynthetics to reinforce ballasted rail tracks was investigated. An extensive monitoring program was undertaken on fully instrumented track sections constructed near Singleton, New South Wales. Four types of geosynthetics were installed at the ballast-subballast interface of track sections located on subgrades with three distinctly different values of stiffness. It was found that geogrids could decrease vertical settlements of the ballast layer with obvious benefits of improved track stability and decreased maintenance cost. It was also found that the effectiveness of reinforcing geogrids increased when the subgrade stiffness decreased. Keywords: Geosynthetic, Reinforcement, Rail track, Ballast.


Numerical Solution Of Stone Column Improved Soft Soil Considering Arching, Clogging And Smear Effects, Buddhima Indraratna, Sudip Basack, Cholachat Rujikiatkamjorn Mar 2014

Numerical Solution Of Stone Column Improved Soft Soil Considering Arching, Clogging And Smear Effects, Buddhima Indraratna, Sudip Basack, Cholachat Rujikiatkamjorn

Buddhima Indraratna

Improvement of soft clay deposits by the installation of stone columns is one of the most popular techniques followed worldwide. The stone columns not only act as reinforcingmaterial increasing the overall strength and stiffness of the compressible soft soil, but they also promote consolidation through effective drainage. The analytical and numerical solutions available for ascertaining the response of column-reinforced soil have been developed on the basis of the equal strain hypothesis. For typical surcharge (embankment) loading, the free strain analysis appears to give more realistic results comparable to field data. The paper presents a novel numericalmodel (finite-differencemethod) to analyze the …


Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn Mar 2014

Radial Consolidation Model Incorporating The Effects Of Vacuum Preloading And Non-Darcian Flow, Kourosh Kianfar, Buddhima Indraratna, Cholachat Rujikiatkamjorn

Buddhima Indraratna

A modified 150 mm Rowe cell equipped with pore water pressure measurement was used to capture the flow relationship during vacuum-assisted radial consolidation. Based on the measured data, a radial consolidation model incorporating the effects of vacuum preloading is proposed, based on a non-linear relationship between the flow velocity and hydraulic gradient. The predictions of the proposed consolidation model are then compared with the predictions based on Hansbo’s Darcian and non- Darcian models. The agreement between the proposed model and the measured data is shown, and the advantages of the proposed model compared with the existing models are discussed. An …


Effects Of Normal Stress On Water Flow Through A Single Roughwalled Rock Joint, Z Zhang, B Indraratna, C Kumara, Jan Anton Nemcik, W Gale Mar 2014

Effects Of Normal Stress On Water Flow Through A Single Roughwalled Rock Joint, Z Zhang, B Indraratna, C Kumara, Jan Anton Nemcik, W Gale

Buddhima Indraratna

Water ingress to underground openings is one of the major concerns in mining and tunnelling, because, rock joints provide natural seepage paths for groundwater flow. To study the water flow through deformable rock joints, triaxial tests with water flow were conducted under various confining stress levels (0.7-5.0 MPa). Two tests were performed on fully mated fracture specimens, and three tests were performed on a non-mated specimen where the fractured surfaces were displaced by 2.0 mm at the start of the test. The results show that the volumetric flow rate decreases with the increase in the normal stress, but the decreasing …


Effects Of Fouling On The Stress-Strain-Degradation Behaviour Of Rail Ballast, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn Mar 2014

Effects Of Fouling On The Stress-Strain-Degradation Behaviour Of Rail Ballast, Buddhima Indraratna, Nayoma C. Tennakoon, Sanjay Nimbalkar, Cholachat Rujikiatkamjorn

Buddhima Indraratna

Ballast is most commonly used as a structural component of rail track due to its high load bearing capacity, resiliency and rapid drainage. However, ballast along coal freight corridors often becomes fouled due to spilling of coal from moving wagons, in addition to further track deterioration attributed to particle breakage and pumping of soft subgrade. Highly fouled ballast needs to be cleaned or replaced to maintain the desired track resiliency, load bearing capacity and the track alignment. In order to identify the risk associated with fouling, it is important to accurately assess the amount of fouling. In this paper, the …