Dr Jubert Pineda
School of Engineering
- Phone:(02) 4921 7034
Jubert Pineda is Civil Engineer from the Santo Tomas University (Bogotá, Colombia). He received a Master Degree in Geotechnical Engineering from the National University of Colombia (2004) and also a PhD in Geotechnical Engineering from the Technical University of Catalonia (UPC, Barcelona) in 2012. At present he is Research Academic at the ARC Centre of Excellence for Geotechnical Science and Engineering in the University of Newcastle Australia.Research Expertise
Most of my research experience has been focused on studying the hydro-mechanical behaviour of geomaterials (soils and rocks) when subjected to the actions of civil engineering structures (dams, tunnels, slopes) and well as their interaction with the environment (i.e., mechanical and hydraulic loads). It is worth noted the particular emphasis on studying the influence of environmental effects (i.e., relative humidity or total suction effects) on the progressive degradation of argillaceous rocks and their consequences on the stability of civil engineering structures (slopes, dams and tunnels). The mechanical behaviour of compacted soils has been another of my research interest due to the key role played by compacted soils in most civil engineering structures (embankments, dams, roads). In this field, the research has been focussed on the influence of suction on the soil shear strength. The influence of sampling on the induced disturbance in soft soils is another of my research fields due to the main role played by sampling in the determination of geotechnical parameters (obtained from laboratory tests). A comprehensive study focused on the quantification of sample disturbance induced by sampling in soft soils from Barcelona region (Spain) was carried out for this purpose.
I've been occasional Lecturer for the undergraduate course Geomechanics 2 (Principal Lecturer: Prof. Daichao Sheng)
Dr. Jubert Pineda has been involved in different research and consulting projects related with unsaturated soil mechanics, stability analysis of dams founded on argillaceous rocks as well as with high-quality sampling in soft soils at Universitat Politécnica de Catalunya (UPC). His current research interests include unsaturated soils and rocks, mechanics of natural soft clays and more recently Geo-Engineering problems related to Energy and Sustainability.
- PhD (Geotechnical Engineering), Universitat Politecnica de Catalunya - Spain
- Bachelor of Science (Civil Engineering), Universidad Santo Tomas - Columbia
- Master of Civil Engineering (Geotechnics), National University of Columbia - Bogota -Columbia
- Bender elements
- Development of laboratory devices for soil/rock testing
- Geomechanics 2
- Hydro-mechanical behaviour of argillaceous rocks
- Sampling and laboratory testing of soft soils
- Soil/rock microstructure
- Unsaturated soil/rock mechanics
- Spanish (Fluent)
Fields of Research
|050399||Soil Sciences not elsewhere classified||15|
|091599||Interdisciplinary Engineering not elsewhere classified||15|
|090599||Civil Engineering not elsewhere classified||70|
|Dates||Title||Organisation / Department|
|13/04/2015 - 12/04/2017||Research Academic||University of Newcastle|
School of Engineering
For publications that are currently unpublished or in-press, details are shown in italics.
Journal article (11 outputs)
|2015||Burton GJ, Pineda JA, Sheng D, Airey D, 'Microstructural changes of an undisturbed, reconstituted and compacted high plasticity clay subjected to wetting and drying', Engineering Geology, (2015)|
The behaviour of soil, and in particular compacted clay fill, can have significant implications on the safe and reliable operation of man-made infrastructure. The mechanical behaviour of soil (e.g. volume change and shear strength) is widely recognised as being associated with the microstructural arrangement (fabric/structure). In the case of high plasticity clays, despite the large amount of research carried out, soil microstructure and its evolution along mechanical and hydraulic paths are still not well understood. This makes incorporation of microstructural analysis difficult in engineering practice and highlights the need for further research. A comprehensive microstructural analysis of Maryland clay, a high plasticity residual soil, based on mercury intrusion porosimetry tests, is presented in this paper. Experimental results obtained from undisturbed, reconstituted and compacted specimens subjected to different hydraulic and mechanical paths are described. As with mechanical investigations, the reconstituted state is proposed to be used routinely as a reference state for comparison of undisturbed and compacted soil. The microstructural evolution of the compacted clay, prepared on the wet side of standard Proctor optimum water content, with an initially high void ratio, is examined along the main drying path. Importantly, a monotonic suction increase from the as-compacted state is shown to have negligible effect on the distribution of macro-pores. However, a new insight is provided based on the evolution of the dominant micro-pore entrance diameter which is shown to reduce with increased suction. This micro-pore entrance diameter is shown to correspond with the theoretical suction back-calculated from a simple capillary tube model, up to a limit. It is observed that, under oedometric conditions, the as-compacted microstructure is erased during saturation (soaking) and resembles the reconstituted microstructure. For this particular material and preparation conditions, it is demonstrated that a bimodal microstructure is not recovered on drying from a saturated state.
|2014||Pineda JA, Alonso EE, Romero E, 'Environmental degradation of claystones', Geotechnique, 64 64-82 (2014) [C1]|
The paper presents the results of a comprehensive experimental programme carried out to study the effects of relative humidity cycling on the degradation of argillaceous rocks. Lilla claystone, a low-porosity Tertiary rock, was used for this purpose. Four aspects were analysed: (a) the influence of the number of relative humidity cycles; (b) the amplitude of relative humidity cycles; (c) the stress level; and (d) the effects of using liquid water or vapour during wetting paths. The application of relative humidity cycles induced a progressive degradation of the rock in terms of accumulative irreversible volumetric swelling, irreversible reduction in rock stiffness, and tensile strength. The irreversible expansion increased with the amplitude of the relative humidity change. However, it reduced with increase of the confining pressure. This irreversible behaviour accelerated when liquid water was used during the wetting paths. Microstructural analysis has shown that the degradation pattern of Lilla claystone was associated mainly with fissuring, as a consequence of non-uniform deformations of the clayey matrix. This phenomenon leads to the opening of fissures at the weaker interfaces of the clayey matrix with detrital, non-active minerals. A damage law derived in terms of the accumulated volumetric irreversible strain has been proposed to represent the progressive loss in volumetric and shear stiffness as well as the tensile strength.
|2014||Pineda J, Romero E, Alonso EE, Pérez T, 'A New High-Pressure Triaxial Apparatus for Inducing and Tracking Hydro-Mechanical Degradation of Clayey Rocks', Geotechnical Testing Journal, 37 20130163-20130163 (2014) [C1]|
|2014||Pineda J, Suwal LP, Kelly R, 'Sampling and laboratory testing of Ballina clay', Australian Geomechanics Journal, 49 29-40 (2014) [C1]|
This paper discusses some topics related to the sampling and laboratory testing currently ongoing on Ballina clay (NSW). Emphasis is made on particular aspects of natural soft clays frequently neglected in laboratory procedures that may affect its mechanical response. Preliminary results are shown to highlight the importance of sample disturbance, salinity and rate effects in Ballina clay. Ongoing research as well as future activities are discussed in the last section of the paper. Implications for the current state of practice as well as the development of new constitutive models for soft clays are highlighted.
|2014||Lloret-Cabot M, Wheeler SJ, Pineda JA, Sheng D, Gens A, 'Relative performance of two unsaturated soil models using different constitutive variables', CANADIAN GEOTECHNICAL JOURNAL, 51 1423-1437 (2014) [C1]|
|2014||Pineda JA, Romero E, De Gracia M, Sheng D, 'Shear strength degradation in claystones due to environmental effects', Geotechnique, 64 493-501 (2014) [C1]|
This note explores the influence of environmental effects, as those induced by cyclic changes in relative humidity, on the degradation of the shear strength parameters in Lilla claystone, a low-porosity clayey rock from northern Spain. The results of a comprehensive experimental programme, combining long-term relative humidity cycling tests with saturated direct shear tests, are described. A continuous monitoring of the evolution of volumetric strain during the previous relative humidity cycling is used to evaluate the swelling behaviour of the rock. Both undisturbed and degraded specimens are subjected to shearing at saturated conditions to determine the peak and post-rupture shear strength envelopes. The effects on rock brittleness and dilation angle are also analysed. Shear strength shows a strong dependence on the history of relative humidity cycling. In particular, the evolution of the peak shear strength parameters (c' and ø) seem to be related to the accumulated irreversible strains developed during each cycle. A damage law, recently proposed by the authors, is used to represent the progressive degradation of the shear strength parameters as a function of the accumulated irreversible strains.
|2014||Kouretzis G, Ansari Y, Pineda J, Sheng D, 'Experimental and numerical investigation of rate and softening effects on the undrained shear strength of Ballina clay', Australian Geomechanics Journal, 49 51-57 (2014) [C1]|
|2013||Kelly RB, Mayne P, Pineda JA, 'In situ and laboratory testing of soft clays', Australian Geomechanics, 48 61-72 (2013) [C1]|
|Show 8 more journal articles|
Conference (27 outputs)
|2015||Sau N, Arroyo M, Pérez N, Pineda JA, 'Using CAT to obtain density maps in Sherbrooke specimens of silty soils', Geomechanics from Micro to Macro - Proceedings of the TC105 ISSMGE International Symposium on Geomechanics from Micro to Macro, IS-Cambridge 2014 (2015)|
CAT (Computed Axial Tomography) has been sometimes used to obtain density maps of small core specimens of soft soil. Here it is applied to do the same with a Sherbrooke-type block sample recovered at depth from a silt layer. Sherbrooke block samples are considered as the one more closely related to the material 'in situ', because the sampling method excludes practically any other alteration process apart from deviatoric stress relief. Sherbrooke samples are large typically 25 cm in diameter and 35 in height. Because of this large specimen size the standard medical scanner used for the CAT test presented several artifacts (noise, rings, outliers) that made difficult the quantitative interpretation of the resulting images. The procedures employed to remove those artifacts from the images and obtain a map of density of the block sample are described here. Validation with independent laboratory measurements of density is shown to result in a good agreement. © 2015 Taylor & Francis Group.
|2014||Yang C, Sheng D, Carter JP, Pineda J, Kelly R, 'From compression behavior to plastic anisotropy of reconstituted soft soils', Geotechnical Special Publication (2014) [E1]|
The plastic anisotropy of reconstituted soft soils is described from the compression behaviour observed during radial loading paths in stress space. A unique relationship is established between the orientation of the yield surface and the corresponding normal compression line, which indicates that a stabilized fabric is maintained under continuous loading along radial stress paths. The equilibrium orientation angle of the plastic potential surface is obtained explicitly. A new rotational hardening law is proposed by considering the dependence of the evolution of anisotropic fabric with the current stress condition and plastic strain. An elastoplastic constitutive model for anisotropic soil is formulated within the framework of Critical State Soil Mechanics. Validation with experimental data and predictions from other models demonstrate the feasibility of the basic concept and the capacity of the proposed new model. © 2014 American Society of Civil Engineers.
|2014||Sheng D, Kelly RB, Pineda JA, Bates L, 'Numerical study of rate effects in cone penetration test', CPT 14, Las Vegas, USA (2014) [E1]|
|2014||Pineda JA, McConnell A, Kelly RB, 'Performance of an innovative direct-push piston sampler in soft clay', CPT14, Las Vegas, USA (2014) [E1]|
|2013||Pineda JA, Romero E, Tarragó D, Tauler E, Alonso EE, 'Microstructural evaluation of the water sensitivity of clayey rocks.', American Society of Civil Engineers, Viena-Austria (2013) [E2]|
|2013||Pineda JA, Kelly R, Bates L, Sheng D, Sloan S, 'Effects of pore fluid salinity on the shear strength of a soft clay', Poromechanics V - Proceedings of the 5th Biot Conference on Poromechanics, Vienna, Austria (2013) [E2]|
|Show 24 more conferences|
Report (1 outputs)
|2013||Pineda JA, Sheng D, 'Subsidence: an overview of causes, risks and future developments for Coal Seam Gas production', Office of the NSW Chief Scientist and Engineer (2013) [R1]|
Grants and Funding
|Number of grants||3|
Click on a grant title below to expand the full details for that specific grant.
20151 grants / $782,600
Funding body: ARC (Australian Research Council)
20132 grants / $16,896
Funding body: NSW Trade & Investment
Hydro-Mechanical coupling in unsaturated soils: experimental observations and constitutive modelling$5,000
Funding body: University of Newcastle
|Commenced||Research Title / Program / Supervisor Type|
|2015||Experimental and Numerical Modelling of Soft Soil Testing Techniques|
Civil Engineering, Faculty of Engineering and Built Environment
|2014||Stress Path-Dependency of Soil Moduli|
Civil Engineering, Faculty of Engineering and Built Environment
November 21, 2014
Professor Daichao Sheng and Dr Jubert Pineda have been awarded more than $782,000 in ARC Discovery Project funding commencing in 2015 for their research project Mechanics of Hard Soils and Soft Rocks.