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The Alpine Fault in western South Island ruptures every 300±100 years in large magnitude (7.8 ± 3) earthquakes and presents a major seismic hazard to New Zealand. The Deep Alpine Fault Drilling Project (DFDP) aims to drill, sample, and monitor the Alpine Fault in order to investigate the processes of earthquake genesis, rock deformation, and fault gouge formation for a tectonically active fault late in the seismic cycle. Rapid dextral reverse movements and exhumation rates on the central section of the Alpine Fault at Whataroa Valley make this a geologically favourable setting to drill and sample fault rocks at depth that can be correlated with surface exposures. The suitability of a site for stationing a major drilling operation depends upon practical issues such as the engineering geological characteristics of the proposed site, possible geohazards, and drilling logistics. This thesis presents new engineering geological, geophysical, and geomorphic investigations of the Whataroa Valley for the DFDP-2 drill site in order to provide a framework for proposed future operations. MASW, GPR and basic geotechnical methods such as test pits and face logs were conducted at various locations at the site to gain geotechnical properties and attempt to find depth to bedrock. Results showed bedrock is at least 25m deep as it was not seen in any of the GPR surveys. Correlation of the MASW and GPR profiles with freshly eroded and face logged outcrops permitted assignment of s-wave velocities to each of the gravels present and confirmation of features seen in the geophysical surveys. Vs30 values gained from the MASW classed the gravels as a soft soil in Site Class D in NZS 1170.5. Expected peak ground accelerations at the study site during an Alpine Fault earthquake are estimated at ≥0.8g. The Whataroa River is actively eroding the southern edge of the investigation area. Comparison of historic aerial photos and newly obtained LiDAR showed the river bank has moved a total of 165 m since 1948, a majority of that occurring in the past decade, 35 m of erosion occurring over a few days during early January 2011. Little correlation between heavy rainfall periods and increased erosion rates suggest changing channel dynamics play a major part in the channel migration. Modelling of the threshold discharges required to overtop the Whataroa terraces results in return periods several orders of magnitude larger than Alpine Fault earthquake recurrence intervals that result in major sediment pulses, implying that inundation from river flooding under current channel conditions is highly unlikely. Debris flows originating from the west valley wall have been identified as a possible hazard to drilling operations. Recent debris flows were easily mapped due to the changes in vegetation, whereas the remnants of historic debris flows were able to be mapped using the LiDAR. Studies of these show that they have a minimal run out distance (<100 m), and can be easily avoided by ensuring the drill site is located outside the proposed debris flow risk zone plus a 50 m buffer that has been added for caution. Current uncertainty of the fault dip and target depth of the hole causes large variation in proposed drill rig locations at the surface. All of the investigations are summarised on a hazard map used to suggest a range of favoured drill sites based on varied angle dips and drilling depths, minimizing flood, erosion and sediment inundation hazards, and specifying access routes.

This thesis aims to create a specific and robust geotechnical data set for the Lyttelton Volcanic Group, and investigate the effect of emplacement and post-emplacement mechanisms on geotechnical characteristics. The thesis provides an engineering geological model of a representative section of the Lyttelton Volcanic Complex, which, in conjunction with field observations, informed the subdivision of the main lithological groups into geotechnical sub-units. The sub-units account for the geological variations within the rock types of this study. Eighteen geotechnical sub-units were identified, sampled and characterised: 1trachytic dykes, 2trachytic domes, 3trachytic lava, 4brecciated basaltic ignimbrite, 5moderately welded basaltic ignimbrite, 6highly welded basaltic ignimbrite, 7red ash, 8crystal dominated tuff, 9lithic dominated tuff, 10rubbly basaltic breccia, 11unweathered basaltic lava, 12slightly to moderately weathered basaltic lava, 13highly to completely weathered basaltic lava, 14highly vesicular basaltic lava bomb, 15basaltic dyke, 16blocky basaltic lava, 17volcanogenic conglomerate and 18volcanogenic tuffaceous sandstone. Thirteen units were able geotechnically tested. Sample preparation and geotechnical testing followed ASTM and ISRM guidelines respectively. Geotechnical testing included: uniaxial compressive strength (σci), point load strength index (Is(50)), porosity (n), density (ρd), P and S wave velocities (Vp and Vs), slake durability (Id2), Young’s Modulus (E), Poisson’s Ratio (υ), shear modulus (G) and bulk modulus (K). The igneous lithologies included in this study have been characterised using the Detailed Engineering Geological Igneous Descriptive Scheme, developed purposely for the needs of the thesis. The results of laboratory testing showed many strong trends with geological characteristics and relationships between geotechnical parameters. Parameters such as porosity, density, P-wave velocities, Young’s Modulus and point load strength showed very strong correlations with uniaxial compressive strength. Variability in the physical and mechanical properties is attributed to the geological factors, which dictate the material behaviour. These include texture, grain size, composition, welding, lithification, flow banding, percentage and size of phenocrysts/clasts/lithics. Geological factors affecting geotechnical behaviour are a function of emplacement mechanism. Four distinct emplacement mechanisms were identified in this study: lava flows, pyroclastic density currents, intrusions (dykes) and airfall deposits. Typically, lava flows and intrusions have higher strength, durability, density and lower porosity than pyroclastics and airfall deposits. Importantly, the data illustrates a considerable variability in some geotechnical parameters within the same unit (e.g. 58-193 MPa strength variation in the unweathered basaltic lava). Variability within rocks with similar emplacement mechanisms is attributed to the effects of post-emplacement mechanisms and processes (e.g. weathering, alteration and micro/macro fracturing leading to lower strength). Evaluation of engineering geological and geotechnical parameters of rock and soil materials are required for engineering purposes, specifically when any form of design is required. This study has highlighted the importance and necessity to identify volcanic lithologies and features correctly as there are consequences for geotechnical behaviour, and that volcanic data from literature data should not be used without the correct degree of ground-truthing and geological context. Location-specific engineering geological data are necessary for the quantitation of variability in engineering geological characterisation for engineering geological models, designs and simulations in the Port Hills Volcanics.

Drilling bit optimization is one the key concepts in drilling engineering.It is considered as one f the economical factors in an overall well budget.Computers are strictly used as decision-making systems in the optimization calculations.Formation parameters are easily processed according to drilling bit selection criteria by the help of computer programs.Although computer program is an interface by which user makes computer some jobs,database is another important part of this necessary decision-making systems.Data is stored and can be modified in the database.Also necessary calculations can be accomplished by database so that results of these calculations and data can be reached by the computer programs.In this study,a database,holding field data is designed and a computer program calculating necessary parameters and related excel file holding output are prepared.Although mostly lowest costper foot is preferred and there isn&#039 / t an absolute method for choosing optimum bit,this design can be helpful in selection period.

The site investigation phase plays a vital role in any foundation design where inadequate characterisation of the subsurface conditions may lead to either a significantly over designed foundation that is not cost-effective, or an under-designed foundation, which may result in foundation failure. As such, the scope of an investigation should be dependent on the conditions at the site and the importance of the structure. However, it is common for the expense dedicated to the site investigation to be a fraction of the total cost of the project, and is typically determined by budget and time constraints, and the experience and judgement of the geotechnical engineer. However, additional site investigation expenditure or sampling is expected to reduce the financial risk of the design by reducing the uncertainties in the geotechnical system and protecting against possible foundation failures. This research has quantified the relative benefits of undertaking site investigations of increased and differing scope. This has been achieved by simulating the design process to yield a foundation design based on the results of a site investigation. Such a design has been compared to an optimal design that utilises the complete knowledge of the soil, which has only been possible due to the use of simulated soils. Comparisons between these two design types indicate the performance of the site investigation to accurately or adequately characterise the site conditions. Furthermore, the design based on the results of the site investigation have been analysed using the complete knowledge of the soil. This yields a probability of failure and, therefore, has been included in a risk analysis where the costs associated with the site investigation have been measured against the financial risk of the design. As such, potential savings in financial risk for increased site investigation expenditure have been subsequently identified. A Monte Carlo analysis has been used in this research to incorporate the uncertainties in the foundation design process. Uncertainties have been included due to soil variability; sampling errors; measurement and transformation model errors; and errors related to the use of a simplified foundation response prediction method. The Monte Carlo analysis has also provided the means to obtain results in a probabilistic framework to enable reliability and risk analyses. Computer code has been specifically developed with an aim to: generate a simulated soil that conforms to the variability of soil properties; simulate a site investigation to estimate data for a foundation design; simulate the design of a foundation and conduct a reliability and risk analysis of such a design. Results indicate that there are significant benefits to be derived from increasing the scope of a site investigation in terms of the risk and reliability of the foundation design. However, it also appears that an optimal site investigation scope or expenditure exists where additional expenditure leads to a design with a higher financial risk due to the increased cost of the site investigation. The expected savings in terms of financial risk are significant when compared to the increased investigation cost. These results will assist geotechnical engineers in planning a site investigation in a more rational manner with knowledge of the associated risks. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1255275 / Thesis(Ph.D.) -- School of Civil and Environmental Engineering, 2006

The Patonga Claystone, a red bed facies in the Narrabeen Group of the Sydney Basin, is one of the most unfavorable rock units in the basin from a geotechnical point of view. This rock unit is composed of sandstone, siltstone, mudstone and claystone. One of the unfavorable characteristics is the low shear strength, which causes instability of cut slopes; another is its slaking-prone behaviour. Numerous measurements of geotechnical properties, along with extensive mineralogical and geochemical determinations, were carried out to identify cause of this slaking behaviour. Key techniques were the use of quantitative X-ray diffractometry for mineralogical analysis, and the determination of slake durability index and related properties to evaluate the slaking behaviour under both standard and more extended conditions. Standard (two cycle) slake durability test results indicate a range from low to high slake durability index values, with some mudstone samples having very low durability and some sandstones having very high slake durability indices. Jar slake test results indicate that the rock samples break rapidly and/or develop several fractures (Ij = 4) in an as-received state, but degrade to a pile of flakes or mud (Ij = 1) if the samples are oven dried before testing. The results for jar slake testing of oven-dried material are comparable, for individual samples, to those obtained from the more comprehensive slake durability tests. The mineralogy of the samples was evaluated by quantitative X-ray diffraction techniques using the Rietveld-based Siroquant processing system. Comparison to independent chemical data show a generally good level of agreement, suggesting that the mineralogical analysis results are consistent with the chemical composition of the individual rock samples. Good correlations were also obtained between clay mineralogy determined from orientedaggregate XRD analysis of the &lt2 micron fraction and the results from powder diffractometry and Siroquant analysis of the whole-rock samples. Evaluation of the slake durability characteristics and other geotechnical properties in relation to the quantitative mineralogy suggests that quartz and feldspar form a rigid framework in the rocks that resists the disruptive pressures that cause slaking. Expansion of the clay minerals by various processes, including the incorporation of water into the interlayer spaces of illite/smectite as well as changes in pore pressures associated with entry of water into micro-fractures in the clay matrix, are thought to produce the disruptions that cause slaking and degradation. An abundant clay matrix also reduces the strength of the rock materials, probably because of the less rigid nature of the clay minerals relative to the quartz and feldspar particles. As well as the mineralogy, the loss on ignition (LOI) and water absorption percentage were found to provide good indicators of longer-term slaking behaviour. Both properties are also related to the overall clay content. Rock samples with water absorption values of &lt10, 10-15 and &gt15% behave as highly durable, intermediate and less durable materials respectively. Rocks with LOI values of greater than 5% by weight behave as less durable rock materials, at least for the strata encompassed by the present study. The water absorption and LOI values were also used to develop a predictive model of slake durability characteristics for the different rock materials in the Patonga Claystone, providing a relatively simple basis for predicting longer-term stability in a range of geotechnical studies.

The Patonga Claystone, a red bed facies in the Narrabeen Group of the Sydney Basin, is one of the most unfavorable rock units in the basin from a geotechnical point of view. This rock unit is composed of sandstone, siltstone, mudstone and claystone. One of the unfavorable characteristics is the low shear strength, which causes instability of cut slopes; another is its slaking-prone behaviour. Numerous measurements of geotechnical properties, along with extensive mineralogical and geochemical determinations, were carried out to identify cause of this slaking behaviour. Key techniques were the use of quantitative X-ray diffractometry for mineralogical analysis, and the determination of slake durability index and related properties to evaluate the slaking behaviour under both standard and more extended conditions. Standard (two cycle) slake durability test results indicate a range from low to high slake durability index values, with some mudstone samples having very low durability and some sandstones having very high slake durability indices. Jar slake test results indicate that the rock samples break rapidly and/or develop several fractures (Ij = 4) in an as-received state, but degrade to a pile of flakes or mud (Ij = 1) if the samples are oven dried before testing. The results for jar slake testing of oven-dried material are comparable, for individual samples, to those obtained from the more comprehensive slake durability tests. The mineralogy of the samples was evaluated by quantitative X-ray diffraction techniques using the Rietveld-based Siroquant processing system. Comparison to independent chemical data show a generally good level of agreement, suggesting that the mineralogical analysis results are consistent with the chemical composition of the individual rock samples. Good correlations were also obtained between clay mineralogy determined from orientedaggregate XRD analysis of the &lt2 micron fraction and the results from powder diffractometry and Siroquant analysis of the whole-rock samples. Evaluation of the slake durability characteristics and other geotechnical properties in relation to the quantitative mineralogy suggests that quartz and feldspar form a rigid framework in the rocks that resists the disruptive pressures that cause slaking. Expansion of the clay minerals by various processes, including the incorporation of water into the interlayer spaces of illite/smectite as well as changes in pore pressures associated with entry of water into micro-fractures in the clay matrix, are thought to produce the disruptions that cause slaking and degradation. An abundant clay matrix also reduces the strength of the rock materials, probably because of the less rigid nature of the clay minerals relative to the quartz and feldspar particles. As well as the mineralogy, the loss on ignition (LOI) and water absorption percentage were found to provide good indicators of longer-term slaking behaviour. Both properties are also related to the overall clay content. Rock samples with water absorption values of &lt10, 10-15 and &gt15% behave as highly durable, intermediate and less durable materials respectively. Rocks with LOI values of greater than 5% by weight behave as less durable rock materials, at least for the strata encompassed by the present study. The water absorption and LOI values were also used to develop a predictive model of slake durability characteristics for the different rock materials in the Patonga Claystone, providing a relatively simple basis for predicting longer-term stability in a range of geotechnical studies.

The Patonga Claystone, a red bed facies in the Narrabeen Group of the Sydney Basin, is one of the most unfavorable rock units in the basin from a geotechnical point of view. This rock unit is composed of sandstone, siltstone, mudstone and claystone. One of the unfavorable characteristics is the low shear strength, which causes instability of cut slopes; another is its slaking-prone behaviour. Numerous measurements of geotechnical properties, along with extensive mineralogical and geochemical determinations, were carried out to identify cause of this slaking behaviour. Key techniques were the use of quantitative X-ray diffractometry for mineralogical analysis, and the determination of slake durability index and related properties to evaluate the slaking behaviour under both standard and more extended conditions. Standard (two cycle) slake durability test results indicate a range from low to high slake durability index values, with some mudstone samples having very low durability and some sandstones having very high slake durability indices. Jar slake test results indicate that the rock samples break rapidly and/or develop several fractures (Ij = 4) in an as-received state, but degrade to a pile of flakes or mud (Ij = 1) if the samples are oven dried before testing. The results for jar slake testing of oven-dried material are comparable, for individual samples, to those obtained from the more comprehensive slake durability tests. The mineralogy of the samples was evaluated by quantitative X-ray diffraction techniques using the Rietveld-based Siroquant processing system. Comparison to independent chemical data show a generally good level of agreement, suggesting that the mineralogical analysis results are consistent with the chemical composition of the individual rock samples. Good correlations were also obtained between clay mineralogy determined from orientedaggregate XRD analysis of the &lt2 micron fraction and the results from powder diffractometry and Siroquant analysis of the whole-rock samples. Evaluation of the slake durability characteristics and other geotechnical properties in relation to the quantitative mineralogy suggests that quartz and feldspar form a rigid framework in the rocks that resists the disruptive pressures that cause slaking. Expansion of the clay minerals by various processes, including the incorporation of water into the interlayer spaces of illite/smectite as well as changes in pore pressures associated with entry of water into micro-fractures in the clay matrix, are thought to produce the disruptions that cause slaking and degradation. An abundant clay matrix also reduces the strength of the rock materials, probably because of the less rigid nature of the clay minerals relative to the quartz and feldspar particles. As well as the mineralogy, the loss on ignition (LOI) and water absorption percentage were found to provide good indicators of longer-term slaking behaviour. Both properties are also related to the overall clay content. Rock samples with water absorption values of &lt10, 10-15 and &gt15% behave as highly durable, intermediate and less durable materials respectively. Rocks with LOI values of greater than 5% by weight behave as less durable rock materials, at least for the strata encompassed by the present study. The water absorption and LOI values were also used to develop a predictive model of slake durability characteristics for the different rock materials in the Patonga Claystone, providing a relatively simple basis for predicting longer-term stability in a range of geotechnical studies.