Structural assessment of underground utility services pit using Bayesian inference

ABSTRACT

Ageing infrastructure is becoming an increasing challenge as a result of deterioration and greater loading demands. Modern cities were built on top of complex underground infrastructure networks many of which are still in-service beyond their design life. The safety assessment of underground structures is of utmost importance to avoid catastrophic failures and develop cost-effective renewal and rehabilitation strategies. However, the lack of design documentation and absence of data on the level of structural deterioration make determination of current structural capacity a challenge. This paper presents a probabilistic based assessment framework for underground utility service pits using Bayesian updating technique, which is used to refine the probabilistic distribution of material properties from the prior distribution constructed using published data. A case study of an underground pit located in Central Melbourne is provided. Extensive experimental testing was conducted to characterise the material properties and a full-scale masonry wall was tested to understand the failure mode due to earth pressure and traffic load. The test data was used in strength prediction models to achieve a more accurate estimate for wall capacity. Further, the strength degradation models were integrated to develop the time-dependent material models, which were eventually used to compute reliability index.

KEYWORDS:

• Underground infrastructure
• Bayesian updating
• reliability analysis
• deterioration

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Hendrik Wijaya

Dr. Hendrik Wijaya is a PhD researcher at Swinburne University of Technology. He has been involved in various research and industrial projects in various sectors including structural design, seismic assessment, soil-structure interaction, infrastructure monitoring and pipeline engineering which enables him to master unique multidisciplinary skills involving structural, mechanical, geotechnical, and computer science engineering.

Pathmanathan Rajeev

Prof. Patmanathan Rajeev joined the Department of Civil and Construction Engineering at Swinburne University of Technology (SUT) as a Senior Lecturer in November 2013. Prior to joining SUT, he worked as a research fellow at Monash University from 2009 to 2013. His work at Monash focused in the areas of failure management of pipeline (both onshore and offshore), numerical modelling of pipe-soil interaction, and sensor technology for pipeline monitoring. His research interests include earthquake-resistant design and analysis of structures, pipeline engineering, soil-foundation-structure interaction (SFSI), advanced sensor technology and structural reliability and risk analysis. His research projects have been funded by the Australian Research Council, Department of State government Victoria, CRC for Low Carbon Living, Australian Building Codes Board, Italian Civil Protection Agency, European Union, non-profit institutions, and private industry.

Robin Kalfat

Dr. Robin Kalfat is currently appointed as a Senior Lecturer in Civil and Construction Engineering at Swinburne University of Technology. In addition to academic career, he was employed with SRG limited from the year 2004 to 2009 as a Senior Design Engineer in Melbourne, UK and Dubai and gained extensive experience in design of multi-storey buildings, prestressed concrete, bridge design, concrete repair and strengthening. In 2010, he was engaged by the West Gate Bridge strengthening alliance and designed the strengthening applied to the concrete box girder viaducts which utilized fiber reinforced polymers. His research interests include: strengthening and rehabilitation of structures, sustainable construction materials, fire performance of FRP strengthened structures, the use of nano materials such as graphene to improve the strength and durability of concrete and advanced numerical techniques for structural analysis. He is a recipient of 2018 Research Impact Award for strengthening bridges with carbon fibre reinforced polymers, presented by Australian Road Research Board (ARRB). The shear-torsion retrofit system and patch anchor developed as part of his PhD project was implemented on the West Gate Bridge Strengthening Project in Melbourne, Australia.

Emad Gad

Prof. Emad Gad is the Dean of Engineering, School of Engineering within the Faculty of Science, Engineering and Technology. Emad is a civil engineer with extensive experience in structural dynamics, residential construction, structural connections, experimental techniques and finite element modelling. His applied research has contributed to the development of several standards and codes of practice. In addition to his teaching and research contributions, he has completed numerous consulting contracts for local and multinational clients. He is Chair of the Board of the Australian Engineered Fasteners and Anchors Council (AEFAC), Co-Editor of the Australian Journal of Structural Engineering, appointment member of the Victorian Building Practitioners Board (BPC), Director on the Board of the Australian Steel Institute (ASI) and Fellow of Engineers Australia.

Kamiran Abdouka

Dr. Kamiran Abdouka is a part-time Senior Lecturer in Structural Engineering at the Faculty of Engineering and Industrial Sciences - Swinburne University of Technology in Melbourne. He received his BSc in Civil Engineering in1984 and MSc in Structural Engineering from the University Baghdad-Iraq in 1989 and PhD in Civil Engineering in 2003 from the University of Melbourne. He is a member of Engineers Australia and a registered building practitioner in Victoria as a Civil Engineer. His areas of expertise are Reinforced and Prestressed Concrete Design, Assessment of deterioration in buildings, strengthening of concrete structures and Seismic design of structures.