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Full-Text Articles in Engineering
Shear Behaviour Of Rock Joints Under Cyclic Loading, Buddhima Indraratna, Ali Mirzaghorbanali, David Oliveira, Wuditha N. Premadasa
Shear Behaviour Of Rock Joints Under Cyclic Loading, Buddhima Indraratna, Ali Mirzaghorbanali, David Oliveira, Wuditha N. Premadasa
Buddhima Indraratna
For the design of civil and mining engineering geo-structures, it is often necessary to investigate the behaviour and the role of discontinuities on the rock mass performance. In many cases, failure is governed by the shear behaviour of discontinuities in excavations. In this context, evaluation of the effects of small repetitive earthquakes on the shear strength parameters of rock joints especially in tunnels and dam foundations is also important. This paper presents the results of a systematic study carried out on the cyclic shear behaviour of artificial rock joints under constant normal stiffness (CNS) conditions, as many of the previous …
Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng
Experimental Study On The Effectiveness Of Prefabricated Vertical Drains Under Cyclic Loading, Cholachat Rujikiatkamjorn, Buddhima Indraratna, Guanghui Meng
Buddhima Indraratna
This study is an attempt to investigate the effectiveness of a prefabricated vertical drain (PVD) installed in remoulded soft clay, where a large-scale cyclic triaxial process simulation rig was employed to simulate cyclic loading representing a track environment. The experimental data show that PVD successfully prevents excessive accumulation of pore water pressure during cyclic loading, and their dissipation continues to occur after the load is removed. The findings of this study have direct significance to rail track environments, e.g. in coastal Australia, where PVD installation beneath rail tracks constructed on low-lying estuarine soils has been recently adopted.
Cyclic Behaviour Of Soft Soil Subgrade Improved By Prefabricated Vertical Drains, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jing Ni
Cyclic Behaviour Of Soft Soil Subgrade Improved By Prefabricated Vertical Drains, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jing Ni
Buddhima Indraratna
The behaviour of saturated soft clays subjected to cyclic loading is of considerable importance in the design of railway subgrades. Soft clays can be extensively found in many coastal regions of Australia up to significant depths, including the coastal belt and the central part of NSW. These soft clay deposits are characterised by very low bearing capacity and excessive settlement. The increase in generated excess pore pressures due to heavy freight trains significantly reduces the bearing capacity and causes serious damage to the rail infrastructure such as clay pumping underneath railway tracks and excessive subsidence. The use of prefabricated vertical …
Deformation Of Coal Fouled Ballast Stabilized With Geogrid Under Cyclic Load, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn
Deformation Of Coal Fouled Ballast Stabilized With Geogrid Under Cyclic Load, Buddhima Indraratna, Ngoc Trung Ngo, Cholachat Rujikiatkamjorn
Buddhima Indraratna
This paper presents the results of laboratory investigations into the deformation of coal fouled ballast stabilized with geogrid at various degrees of fouling. A novel track process simulation apparatus was used to simulate realistic rail track conditions subjected to cyclic loading, and the void contamination index (VCI) was used to evaluate the level of ballast fouling. The experimental results show that coal fines act as a lubricant, causing grains of ballast to displace and rotate, and as a result, accelerate its deformation. However, coal fines also reduce ballast breakage because of a cushioning effect, that is, by reducing interparticle attrition. …
Experimental Investigations Into Subballast Filtrations Behaviour Under Cyclic Conditions, Laricar Dominic Ortega Trani, Buddhima Indraratna
Experimental Investigations Into Subballast Filtrations Behaviour Under Cyclic Conditions, Laricar Dominic Ortega Trani, Buddhima Indraratna
Buddhima Indraratna
In rail track environments the loading system is cyclic unlike the monotonic seepage force that usually occurs in embankment dams. The mechanisms of filtration, interface behaviour and time-dependent changes of the drainage and filtration properties occurring within the filter medium require further research to improve the design guidelines. A novel cyclic process simulation filtration apparatus was designed and commissioned at the University of Wollongong, and a standard testing procedure was established. The test apparatus was designed to simulate heavy haul train operations. Key parameters that influence the change in porosity and pore water pressure within the sub ballast layer under …
Physical And Chemical Ground Improvement For Sustainable Transportation Infrastructure Under Cyclic Loads, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jayan S. Vinod, Sanjay Nimbalkar
Physical And Chemical Ground Improvement For Sustainable Transportation Infrastructure Under Cyclic Loads, Buddhima Indraratna, Cholachat Rujikiatkamjorn, Jayan S. Vinod, Sanjay Nimbalkar
Buddhima Indraratna
Railways form one of the major worldwide transportation networks and they continue to provide quick and safe public and freight transportation. In order to compete with other modes of transportation and to meet the ever growing demand of public and freight transport, railway industries face challenges to improve their efficiency and decrease the costs of maintenance and infrastructure. Large cyclic loading from heavy haul and passenger trains often leads to progressive deterioration of the track. The excessive deformations and degradations of the ballast layer and unacceptable differential settlement or pumping of underlying soft and compressible subgrade soils necessitate frequent costly …
Investigation On Effectiveness Of A Prefabricated Vertical Drain During Cyclic Loading, Buddhima Indraratna, Jing Ni, Cholachat Rujikiatkamjorn
Investigation On Effectiveness Of A Prefabricated Vertical Drain During Cyclic Loading, Buddhima Indraratna, Jing Ni, Cholachat Rujikiatkamjorn
Buddhima Indraratna
The effectiveness of prefabricated vertical drains (PVDs) in enhancing the stability of soft soils during cyclic loading was investigated using triaxial cyclic loading tests. Both undrained and with PVD tests were employed to study the associated excess pore pressure and accumulated strain under the repeated loading condition. The loading frequency and cyclic stress ratio have been chosen to be the variables which influence the performance of soft clays. The experimental results illustrate that with PVDs, the excess pore water pressure generation during cyclic loading decreases significantly. It is found that the excess pore water pressure build up depends on both …