{"title":"Geotechnical Considerations Associated With The Poatina Power Station Cavern","authors":"D. Sainsbury, K. Stacey, B. Sainsbury, P. Hills","doi":"10.56295/agj5745","DOIUrl":"https://doi.org/10.56295/agj5745","url":null,"abstract":"The Poatina Power Station Cavern was designed with a focus on the newly emerging rock mechanics theory and principles that were rapidly developing during the 1950’s and 60’s. This included measurement of the in-situ rock mass stress condition and photo-elastic analysis of the induced stress around the planned underground openings. These studies led to the adoption of many ‘firsts’ in rock mechanics that included a trapezoidal roof shape, installation of stress relieving slots and fully encapsulated grouted rebar bolts. Based on historical documentation of the construction of the cavern, a three- dimensional numerical model of the cavern construction sequence has been developed. The model is able to provide an accurate match to the observed and monitored ground conditions during construction that includes observed failure modes and instrumentation data. Based on the calibrated model outcomes, Hydro Tasmania was able to undertake a more informed review of the risks associated with the current and future ground support capacity and were able to reliably assess rehabilitation requirements for the cavern support system.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43128584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jonathon R Griffin, Z. Rice, R. Clayton, Ben Harvey, C. Leek, M. Bondietti, Ross Keeley, G. Cocks
{"title":"Use of Bitumen Stabilised Limestone in Western Australian Road Pavements","authors":"Jonathon R Griffin, Z. Rice, R. Clayton, Ben Harvey, C. Leek, M. Bondietti, Ross Keeley, G. Cocks","doi":"10.56295/agj5732","DOIUrl":"https://doi.org/10.56295/agj5732","url":null,"abstract":"Bitumen emulsion stabilisation of locally available Tamala Limestone was widely used by State and Local Governments from the mid-1960s through the late-1990s, however its use has declined in recent years. This paper aims to substantiate its benefits as a viable alternative material for use on heavily trafficked roads. The benefits provided through stabilisation of crushed limestone with bitumen emulsion include improved workability, reduced ravelling under construction traffic, lower moisture susceptibility and enhanced mechanical properties. Case studies are presented that show that satisfactory performance has been observed where Bitumen Stabilised Limestone (BSL) is used as a basecourse under heavily trafficked roads. The paper provides a construction methodology and discusses barriers and future opportunities. Two structural design approaches are presented for the use of BSL under sprayed seals and thin asphalt surfacings.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48913000","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bulli Pass Landslide Risk Management Part 1 - Hazard Assessment","authors":"Andrew Hunter, P. Flentje, Alan Moon","doi":"10.56295/agj5735","DOIUrl":"https://doi.org/10.56295/agj5735","url":null,"abstract":"The Princes Highway along Bulli Pass is a narrow, heavily trafficked two lane section of the Princes Highway that traverses steep slopes on a grade of 9H:1V on the Illawarra Escarpment, about 11 km north of Wollongong, and 75 km south of Sydney in New South Wales (NSW), Australia. It is an important arterial road for the northern suburbs of Wollongong, connecting Mt Ousley Road (M1 Princes Motorway) at the crest of the escarpment to the suburb of Thirroul on the coastal plain at the base of the escarpment. Bulli Pass has a long history of landslide and rockfall events, some of which were reported as early as 1890. One of the most significant of these events occurred on 17 August 1998 during a 1 in 100 year rainfall event. The 1998 landslide event comprised approximately 38 debris flows and slides and numerous rockfalls which partially inundated a number of cars and trapped about 15 cars on the pass. More recently, in early 2015, a small rockfall penetrated the windscreen of a car travelling up the pass. Transport for New South Wales (TfNSW) commissioned an investigation into slope instability hazards affecting the road in late 2011. This was followed in 2015 by a Risk Mitigation Options study and the detailed design of risk mitigation works in 2016. This paper provides an overview of the methods used to investigate hazards and assess risk at the site over a five year period. This has included research into the landslide history, geomorphological mapping, acquisition and review of airborne laser scanning (ALS) data, review of rainfall data and the development of a landslide volume frequency model. The development of this model allowed hazards to be readily communicated and risks to be assessed. The actual design and construction of the Shallow Landslide Barriers and the Debris Flow Barriers that followed on from these assessments will be discussed in a subsequent companion paper.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46205709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thornthwaite Moisture Index and Climate Zones in the Northern Territory","authors":"Stephen Jackson","doi":"10.56295/agj5733","DOIUrl":"https://doi.org/10.56295/agj5733","url":null,"abstract":"The Thornthwaite Moisture Index (TMI) is an established climate parameter for geotechnical engineers to categorise a site and enable estimation of seasonal ground movements associated with soil moisture changes. TMI assessment and mapping for the Northern Territory are presented, using the TMI calculation method commonly used for similar recent studies elsewhere in Australia. The assessment included the analysis of 17 sites within the Northern Territory and one site in Queensland which has enabled development of Climate Zone classifications. Climate data was obtained from the Australian Bureau of Meteorology to calculate the TMI on a ‘year by year’ basis over a target period of 29 years (1990 to 2019). Related work in Queensland (Fox 2002) and Western Australia (Hu et al, 2016) has guided the development of the Northern Territory Climate Zone Map. Further work is required to characterise the soil moisture behaviour in arid zones. A general lack of guidance in AS2870 (2011) for arid areas, including much of the Northern Territory, could be addressed with further research and development.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41869873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
P. Flentje, Connor Larkin, Damian Mulcahy, Larissa Hettiarachchi, Daniel M. Horan, James Cox, Stuart Milling, Peter Tobin, Kevin Bogie
{"title":"A Photographic Essay on Landslides Across Southeastern New South Wales Triggered by the Rainfull Events of 2022","authors":"P. Flentje, Connor Larkin, Damian Mulcahy, Larissa Hettiarachchi, Daniel M. Horan, James Cox, Stuart Milling, Peter Tobin, Kevin Bogie","doi":"10.56295/agj5736","DOIUrl":"https://doi.org/10.56295/agj5736","url":null,"abstract":"Eastern Australia has experienced a significant magnitude rainfall event of extended duration in the first 7 months of 2022. Across the east coast of New South Wales (NSW) a series of troughs and East Coast Lows occurred during a La Nina weather cycle bringing above average rainfall to the region. As this first half of 2022 La Nina event was drawing to a close the Indian Ocean Dipole entered a negative phase which coincided with another intense East Coast Low in early July 2022 impacting the Illawarra region of NSW. These events caused widespread flooding and significant landslide damage to road and rail infrastructure across the state networks and local government infrastructure across NSW. During this extended wet period in the first 7 months of 2022 more than 200 landslides have been recorded across the Illawarra, Southern Highlands and Blue Mountains regions of NSW whilst many more have occurred across the north coast region. This paper presents a brief and albeit preliminary summary of the rainfall and provides a series of photographs with very brief descriptions of some of these landslide events within southeastern NSW. The intent of the paper is to provide early guidance to AGS members of the nature and form of landslides that have occurred across the Illawarra region. This paper does not discuss the dual fatality resulting from the Wentworth Falls area rockfall of the 5th April.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47720581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Moisture Movement Analyses for Coal Stockpiles","authors":"J. Eckersley","doi":"10.56295/agj5731","DOIUrl":"https://doi.org/10.56295/agj5731","url":null,"abstract":"Flowslides and stability issues have occurred periodically within stockpiles of coking (metallurgical) coal at coal processing plants and export terminals in Queensland’s Bowen Basin, and to a lesser degree in New South Wales, since the early 1970s. A description of the issue and summary of research at James Cook University from 1973 to 2000 was published in ACARP Report C4057. Despite this work, coal stockpile flowslides remain a significant risk at mine and port stockpiles due to their initiation without warning and dramatic consequences. To be able to adequately model the redistribution of moisture that leads to collapse of a stockpile and then conduct realistic stability analyses for design of preventative measures remains an elusive prospect. This paper therefore updates the previous work with results from SEEP/W transient seepage modelling within a 12m high 14,700 tonne coal stockpile constructed at Hay Point in late 1991 for which initial moisture content, pore pressures at the stockpile base, outflows from subsoil drains and final density and moisture profiles were measured. The model was based on results of laboratory permeability and column drainage tests on specimens taken from a composite bulk sample obtained at the time of stockpile construction. The coking coal product was from an operation with a known history of stockpile instability. Results were found to correspond well with pore pressures measured at the stockpile base and the stockpile’s final moisture profile provided account was taken of a thin higher permeability zone just above the subgrade. The approach adopted and parameters developed provide a significant advance in modelling of moisture movements within production coal stockpiles, with a view to subsequent slope stability analyses.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46330692","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Soil-Structure Interaction of Battered Minipile Groups in Sandy Soil","authors":"Sanchari Mondal, M. Disfani","doi":"10.56295/agj5738","DOIUrl":"https://doi.org/10.56295/agj5738","url":null,"abstract":"Battered minipile groups mimicking tree root networks have been gaining popularity as a footing solution for light structural applications in residential, commercial and infrastructure sectors, recently. Battered minipile group configurations are recently in the limelight due to advantages such as ease of installation and environmentally friendly nature. The lateral load resistance of battered minipile groups is investigated in this paper through a combination of physical and numerical modelling. Two-unconventional battered minipile groups with configurations representing the root network of trees with the capacity of engaging a larger volume of soil compared to conventional battered minipile group configurations are studied. A conventional battered minipile group is also included in the study to draw a direct comparison with the new minipile group configurations introduced in this paper. The conventional battered minipile group has two positively and two negatively 25° battered minipiles. The second type of group has one 25° perpendicularly battered minipile in the leading and trailing row each. Another unique orientation of the battered minipile group is also introduced in this study which has four diagonally outward 25° battered minipiles. The third type of minipile group with four diagonally outward battered minipiles offered the highest lateral resistance among the three groups. This better performance capability was attributed to the engagement of a larger volume of soil in resisting lateral load applied at the minipile head. Through this study, the industrial application of the unconventional minipile group configuration with better performance capability in terms of lateral load resistance can be advocated more confidently.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42030393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Digital Twin for Underground Stations : Improving Decision Making for Construction Lifecycle","authors":"Mengqi Huang, J. Ninić, Qianbing Zhang","doi":"10.56295/agj5737","DOIUrl":"https://doi.org/10.56295/agj5737","url":null,"abstract":"Challenges in the extraction and use of earth resources and spaces are encountered given a growing worldwide population, rising infrastructures development, and widespread climate change. In Australia, mining and construction are two major bases for economic growth while both being traditional hazardous and heavy industries. A nation-wide infrastructure upgrade featuring large-scale underground development is underway, the geological uncertainties and localisation difficulties of already laid infrastructure are associated with challenges not seen in building construction. A safer and competent subterranean transport solution is yet proposed in the context of sustainable developments. In light of this, geotechnical analysis as a fundamental subject for developing and maintaining safe and sustainable use of underground space has huge potential to be undertaken more intuitively considering the advancements in information management and visualisation. The PhD work examines the state-of-the-art applications, limitations and future opportunities of Building Information Modelling (BIM) and other computational techniques in the digitisation of tunnelling and underground construction. The visualisation and interoperability facilitated by data-driven processes are especially important to underground construction that engages interdisciplinary and multi-environment interaction.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45910765","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amir Tophel, Jeffrey M. Walker, Ye Lu, J. Kodikara
{"title":"Proximal Sensing of Density During Soil Compaction by Instrumented Roller","authors":"Amir Tophel, Jeffrey M. Walker, Ye Lu, J. Kodikara","doi":"10.56295/agj5739","DOIUrl":"https://doi.org/10.56295/agj5739","url":null,"abstract":"The measurement of density or void ratio during the compaction of geomaterials (soils and unbound granular materials) in the field during road construction is essential for superior performance. The specifications adopted by the road authorities worldwide are exclusively based on density. However, estimating density evolution proximally or non-destructively is challenging. Conventional field-based density measurement techniques are hazardous, slow to use and are point-based measurements. This study developed a novel methodology to estimate the density of geomaterials non-destructively in real-time during the compaction process. The methodology included measuring the surface deformation using Light Detection and Ranging (LiDAR) systems attached to rollers and developing physics-based 1-Dimensional and machine learning (ML) based constitutive models to relate the measured parameters to the density. The developed methodology was validated in an indoor environment where a large soil box (dimensions: 7.5 m×4 m×0.8 m) was fabricated and a well-graded sand in 5 layers of 100 mm was compacted using a 1.5-tonne instrumented roller. The measurement of deformation provided an opportunity to estimate the density in real-time. The estimated density using 1-D model and a ML based classification model had an error of 20% and 16% respectively when compared to density measured from Nuclear Density Gauge (NDG). This novel instrumentation allowed the density to be measured during compaction with high accuracy, which presents an unprecedented advantage over other conventional approaches, which are intrusive and pointwise, thereby ensuring that the road will be constructed expediently and will function satisfactorily, minimising the occurrence of premature failures. The continual measurement of density during compaction will also facilitate maintaining uniformity of the density, thereby reducing the potential for excessive differential deformations.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44348196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Arsham Mazaheri, M. Hajiazizi, R. Orense, M. Veiskarami, M. Biglari
{"title":"Prediction Of Force Exerted On Stabilizing Sheet Piles In The Sliding Slope","authors":"Arsham Mazaheri, M. Hajiazizi, R. Orense, M. Veiskarami, M. Biglari","doi":"10.56295/agj5727","DOIUrl":"https://doi.org/10.56295/agj5727","url":null,"abstract":"This paper attempts to investigate the concept of forces acting on sheet pile installed in sliding slope. A new analytical formulation is proposed to reinforce the sliding slope. The equilibrium equation is formulated, and a new relationship is proposed to calculate the force exerted on the sheet pile. When the slope is stable the minimum force and moment are exerted on the sheet pile; however, when the slope starts to move the moment and force exerted on the sheet pile are increased. A reduction of 5 kPa in cohesion increases the force exerted on the sheet pile by about 180 kN/m. By reducing the friction angle by 5 degrees, the force exerted on the sheet pile is increased by about 50 kN/m. The proposed analytical formulation is shown good agreement with numerical analysis.","PeriodicalId":43619,"journal":{"name":"Australian Geomechanics Journal","volume":" ","pages":""},"PeriodicalIF":0.2,"publicationDate":"2022-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43940531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}