Search results for: Latest H19-461_V1.0 Exam Questions Vce 🏯 H19-461_V1.0 Labs 🐒 H19-461_V1.0 New Study Plan 🙊 Search for ✔ H19-461_V1.0 ️✔️ on 「 www.pdfvce.com 」 immediately to obtain a free download 🧎H19-461_V1.0 Best Vce
-
Geotechnical challenges for development In the Hunter Region – Key Figures 1, 2 and 3
This paper presents an overview of the geology of the wider Hunter Valley and Central Coast regions of New South Wales and a discussion of some of the consequences that present challenges to the geotechnical engineering profession. The contrasting structural styles of the folded and faulted Southern New England Fold Belt and the relatively flat-lying, undeformed Sydney Basin are described and compared. Consideration is given to the potential for instability arising from the combination of competent, blocky conglomerates, low strength claystones and coal seams, particularly within the Newcastle Coal Measures. Of the wide variety of challenges that arise from such a regionally diverse range of geological conditions, three areas of practice are given special discussion due to their local importance. These are the treatment of Quaternary sediments that underlie many of the more intensely developed areas; the distribution, properties and treatment of reactive clay soils that are well developed in all geological environments and the treatment of problems due to the risk of mining-induced subsidence on development.
-
Evaluation of changes of the Thornthwaite Moisture Index in Victoria
Climate change has become one of the most pressing environmental concerns and the greatest challenges to global infrastructure today. It has been demonstrated by many researchers that Victoria along with other Australian States and Territories has been experiencing a drying trend over the last several decades. Numerous lightly-loaded residential buildings constructed on expansive soils are subjected to distortions arising from differential ground movements caused by seasonal soil moisture changes. The climatic parameter, Thornthwaite Moisture Index (TMI) has been widely used by geotechnical engineers and practitioners as a means of classifying climatic zones and estimating the depth of design soil suction changes. The main aim of this paper is to evaluate changes of TMI index in Victoria in the past 60 years. Long-term (1954-2013) meteorological data from 70 weather stations across Victoria were employed to develop TMI isopleth maps for the three 20-year periods (i.e. 1954-1973, 1974-1993 and 1994-2013). The methodology and equations employed for TMI computation are presented and a worked example is provided as well.
-
Working Platforms And Bearing Capacity Assessments Of Sand Overlying Clay Using Finite Element Limit Analysis
The bearing capacity of shallow foundations on layered soils is typically based on empirical models assuming a strip footing. Shape factors are then applied to the strip footing solution to account for the specific geometry of the foundation being considered. A common practical application of this methodology is when the ultimate bearing capacity of a granular working platform constructed over a clay subgrade is estimated using the Working Platforms for Tracked Plant BRE-470 guideline. Previous studies using finite element limit analysis have been undertaken to examine a strip footing on a layered soil and how the resulting bearing capacity compares to that derived from BRE-470. This paper presents an extension of previous work by the authors using finite element limit analysis to investigate the three-dimensional influence on the bearing capacity of square and rectangular footings on sand over clay. The finite element limit analysis solutions are used to produce charts to assist designers with estimating the ultimate bearing capacity of granular working platforms overlying clay. The paper also aims to highlight some important considerations when adopting the BRE-470 guideline to design granular working platforms overlying clay.
-
AGS Sydney Symposium 2023
Sustainable Geotechnics in Design, Materials, Construction and Maintenance
-
The use of early-works embankments in soft soil areas to optimise detailed design: Gateway motorway case study
This paper presents a case study on the use of early-works preload embankments in soft soils areas to provide information to optimise detailed design. The Gateway Upgrade North (GUN) project involved the widening of the existing Gateway motorway from four to six lanes with some areas of re-alignment. Early-works for the motorway upgrade involved construction of sections of embankment located in areas of soft soils. From a geotechnical perspective, the early-works were essentially instrumented trial embankments constructed 9 to 12 months ahead of the main package and therefore provided an opportunity to observe embankment and wick drain performance and back-analyse soft soil consolidation parameters used for the detailed design for the final motorway construction.
Data from settlement plates, vibrating wire piezometers and inclinometers was used in conjunction with site investigation and laboratory data to assess consolidation parameters of highly compressible Holocene-age alluvial clays. Asaoka’s method and Terzaghi’s theory of one-dimensional consolidation were used in the back analysis of primary consolidation parameters. Secondary settlement was also observed allowing back analysis of secondary compression parameters. Using consolidation parameters derived from the back analysis, design parameters were allocated to relevant geological units which were then applied in settlement modelling for critical sections in the detailed design.
Assessment of the early-works embankment monitoring data enabled a more robust prediction of embankment behaviour during and post-construction. This resulted in a more cost-effective and optimised embankment design with higher confidence in predicted post-construction settlements.
The term preloading is used in this paper to refer to both ‘preloading’ and ‘surcharging’. The former is the application of a temporary load, usually via fill, equivalent to the future fill plus in-service load, for inducing a substantial fraction of the expected settlement prior to construction. The latter refers to applying extra load to enhance preloading.
-
Resilience And Vulnerability To Climate Change Through The Prism Of Soil-Water Interactions: Challenges Of Temporal And Geographical Scales For Geotechnical Engineering
The interaction between water and soil particles lies at the heart of the work of geotechnical and geo-environmental engineers. The water content of the subsurface is an important state variable influencing soil behaviour in relation to strength and stability, hydrologic and chemical insulation, sediment budgets and transport, and support for biological life. The capacity of many soils to maintain high shear strength and withstand loads applied to them without significant deformation, crushing or erosion; their ability to insulate contaminated sites and filter heavy metals and organic chemicals out of polluted water; and their effectiveness in supporting healthy biological life for food production and other ecosystem services, are all examples of vital, and sometimes conflicting services, that soils provide and which are critically dependent on water content.
Three major sources of ecological and social change are reasonably certain in the 21st century:
- increased urbanisation with more demands placed on subsurface systems and structures, by the energy, transport, mining and environmental sectors;
- increased frequencies, magnitude and duration of droughts and floods as a result of anthropogenic climate change, with likely changes to patterns of precipitation and water retention; and
- significant rise in sea levels as a result of thermal expansion and melting of glaciers, leading to higher risks of erosion of coastal land and weakening of coastal foundations with possible damage to private properties and critical water, wastewater, telecommunications and transport infrastructure.
The paper‘s goal is threefold. First, different pathways for the impacts of climate change on subsurface systems are described through the lens of soil-water and land-ocean interactions. Second, a case study from Callala beach in Shoalhaven is presented to illustrate the complexity of making adaptation choices at the interface between land and water, especially as a result of uncertainty and unusual temporal and geographical scales of the problems. Third, the readiness of geotechnical education and practice to deal with these problems is discussed in the context of the difference between risk and vulnerability and the emerging distinction between incremental and transformational adaptation. The paper calls on the geotechnical community to engage more fully in the debate on adaptation to climate futures, going beyond the technical assessment of the integrity of infrastructure systems, and identifying long-term strategies for the conflicting demands we place on the subsurface. This will require innovations and possibly some extension of the spatial and temporal scopes of our experimental, analytical and theoretical methodologies.
-
Resilience and vulnerability to Climate Change: Challenges of temporal and geographical scales for geotechnical engineering
The interaction between water and soil particles lies at the heart of the work of geotechnical and geo-environmental engineers. The water content of the subsurface is an important state variable influencing soil behaviour in relation to strength and stability, hydrologic and chemical insulation, sediment budgets and transport and support for biological life. The capacity of many soils to maintain high shear strength and withstand loads applied to them without significant deformation, crushing or erosion, their ability to insulate contaminated sites and filter heavy metals and organic chemicals out of polluted water and their effectiveness in supporting healthy biological life for food production and other ecosystem services, are all examples of vital, and sometimes conflicting services, that soils provide and which are critically dependent on water content.
Three major sources of ecological and social change are reasonably certain in the 21st century:
- increased urbanisation with more demands placed on subsurface systems and structures, by the energy, transport, mining and environmental sectors
- increased frequencies, magnitude and duration of droughts and floods as a result of anthropogenic climate change, with likely changes to patterns of precipitation and water retention and
- significant rise in sea levels as a result of thermal expansion and melting of glaciers, leading to higher risks of erosion of coastal land and weakening of coastal foundations with possible damage to private properties and critical water, wastewater, telecommunications and transport infrastructure.
The paper’s goal is threefold. First, different pathways for the impacts of climate change on subsurface systems are described through the lens of soil-water and land-ocean interactions. Second, a case study from Callala beach in Shoalhaven is presented to illustrate the complexity of making adaptation choices at the interface between land and water, especially as a result of uncertainty and unusual temporal and geographical scales of the problems. Third, the readiness of geotechnical education and practice to deal with these problems is discussed in the context of the difference between risk and vulnerability and the emerging distinction between incremental and transformational adaptation. The paper calls on the geotechnical community to engage more fully in the debate on adaptation to climate futures, going beyond the technical assessment of the integrity of infrastructure systems, and identifying long-term strategies for the conflicting demands we place on the subsurface. This will require innovations and possibly some extension of the spatial and temporal scopes of our experimental, analytical and theoretical methodologies.
-
Finite Element Modelling Of An Embankment Seated On Pervious Concrete-Stone Composite Column
Embankments rested on soft soils reinforced with stone columns cannot provide enough support. In such soils, to increase their bearing capacity, pervious concrete can be applied to upper portion of the stone column forms a composite column to restrain bulging collapse. Pervious concrete is a type of concrete made without adding fine aggregate and having permeability comparable with stone column materials. The current research work carried out to study the behaviour of embankment rested on composite column through a parametric study using finite element analysis. The parameters; soft clay elastic modulus, embankment fill elastic modulus, stone column material elastic modulus, pervious concrete column elastic modulus, spacing of column, length of pervious concrete column in composite column, permeability of soft clay, and construction rate are considered for the parametric study. The influence of these parameters are compared and rated in terms of the degree of importance.
-
Assessment of capillary ingress of water in stabilised pavement materials
Geomaterials such as pavement materials and soils are commonly stabilised with cementitious or other binders when it is necessary to upgrade the performance characteristics of the original material for a particular engineering application. Typical examples include construction or in situ rehabilitation of road pavements, formation of stabilised bases in soft or reactive soils and deep-mixing of soils. When these layers are placed at or close to the ground surface (or generally above the water table), they mostly operate under unsaturated conditions. When free water becomes available at or close to the edges of these layers, water ingress will take place predominantly by capillary action. A typical field situation idealizing the pathways for capillary water ingress with reference to a pavement layer is shown in Figure 1.
-
An Innovative Geotechnical Monitoring System For Soft Ground Treatment On W2B Pacific Highway Upgrade Project
This paper presents an innovative geotechnical monitoring system for soft ground treatment for the on-going Woolgoolga to Ballina (W2B) Pacific Highway Upgrade project. This $4.3 billion project is Australia‟s largest regional infrastructure project and will upgrade about 155 kilometers of highway to four lane, divided road. The project starts about six kilometers north of Woolgoolga (north of Coffs Harbour) and ends approximately six kilometers south of Ballina.
One of the major challenges on this project is the construction of road and structures over soft compressible ground with a total length of over 25 kilometers in 1 to 2 years‟ time. During construction, the short term slope stability and settlement performance will be monitored by a total of 1500 instruments taking up to 10 million measurements. This will enable the team to take early preventive actions to maintain slope stability, to protect public safety and existing structures during construction, and to ensure that the projected long term settlement is within acceptable limits.
Following the standard file based approach, the instrumentation data was estimated to produce up to 80,000 files to be manually handled. To efficiently process the data, limit the potential for manual errors and reduce the turnaround time, Pacific Complete developed an instrumentation and monitoring (I&M) system using its project integration platform, automatically warehousing the data on the project servers and presenting real-time dashboard to the team using Qlik Sense and its GIS extension. In addition to providing high availability, transparency and reliability of the information, this system is expected to realize savings of $2.5M in manual handling of the information alone. The system can be progressively extended to support direct data download from automated instruments, more instrument types, single and multiple instruments alerts, and refined graphs to suit the requirements of linear infrastructure geotechnical monitoring.
Compared to the traditional copy and paste method using Excel, the benefits of this I&M system include fast processing of massive data on a daily basis, automatic integration with GIS maps, chainage, instrument type and locations, lateral displacement plots, settlement plots (both predicted and measured) in longitudinal sections, ratios of lateral to vertical displacement and fill height plots, pore pressure plots and existing road/structure movement plots.