title: Strata Movement Study Using a 250 m Deep Inclinometer Borehole, Huntly East Coalmine, New Zealand

authors: Du, Zhaodong

subjects: strata movement

abstract: Strata movement has adverse impacts on structures located on the surface and in the subsurface within a subsidence basin or affected area. Damages to a mine shaft may result from lateral movement and/ or vertical subsidence of the strata at a depth when the resultant stress is larger than the strength of the lining.

My study was developed in collaboration with Solid Energy NZ Limited. My research concentrated on monitoring a 250 m deep borehole to assess changes of strata movement that occurred as underground mining approached the inclinometer borehole. The borehole was a simulation of a proposed shaft. The objectives of my research were to study strata movement characteristics above and adjacent to the North 5 coal mining area by monitoring the inclinometer and interpreting the reading data collected from the inclinometer borehole as the underground mining advanced; develop a model of subsidence using Phase2 software; then compare the modelling subsidence with what we have measured to identify any correlation or difference.

The inclinometer borehole was located west of Te Ohaki Road, 300 m from the location of a proposed shaft in the adjacent panel in the Huntly East Mine. A total of 13 sets of inclinometer measurements were undertaken over two years from March 2009. Measurement stopped on 11 March 2011 because the probe could not be lowered through a depth of approximately 38 m in the borehole.
 
My study uses ‘extraction vector’, and ‘movement trajectory of the borehole’ for analysing and interpreting the deep borehole movement in underground mining, and addresses the far field subsidence movement as to its potential impact on structures on the surface or in the subsurface. This thesis also introduces the concept of negative vertical additional friction, developed in China, which is a potentially helpful concept for this study, and the proposed shaft project. 

Three major movement zones were identified, two ‘shear zones’ from 135.0 to 135.5 m and from 166 to 170 m, and one ‘creeping zone’ from the surface to 115 m. The borehole movement was presented by the trajectory of the intersection of the borehole at depths of surface (1 m), 135 m, and 166 m. The two shear zones occurred on the bedding planes in Te Kuiti Group, the creeping zone occurred in the weak strata of the Tauranga Group and upper Te Kuiti Group. The borehole movements were non-linear, and the borehole lateral movement trajectories varied with depth. Three polynomial equations were developed from regression and modelling for indicating the relationship and predication between the nearest extraction distance and the induced lateral movement.

The installation of an inclinometer borehole deeper than 120 m was not found in around 100 literature articles reviewed. No reports of use of inclinometer monitoring of ground movement induced by underground extraction were found in the literature reviewed. According to ASTM (2005), no standards are available yet for evaluation against precision and bias issues arising from use of borehole inclinometer. Therefore, the inclinometer borehole in this study may be one of the most complicated cases for monitoring and measurement of strata movement induced by the underground extraction in New Zealand.

text: Strata Movement Study Using a 250 m Deep Inclinometer Borehole, Huntly East Coalmine, New Zealand Strata movement has adverse impacts on structures located on the surface and in the subsurface within a subsidence basin or affected area. Damages to a mine shaft may result from lateral movement and/ or vertical subsidence of the strata at a depth when the resultant stress is larger than the strength of the lining.

My study was developed in collaboration with Solid Energy NZ Limited. My research concentrated on monitoring a 250 m deep borehole to assess changes of strata movement that occurred as underground mining approached the inclinometer borehole. The borehole was a simulation of a proposed shaft. The objectives of my research were to study strata movement characteristics above and adjacent to the North 5 coal mining area by monitoring the inclinometer and interpreting the reading data collected from the inclinometer borehole as the underground mining advanced; develop a model of subsidence using Phase2 software; then compare the modelling subsidence with what we have measured to identify any correlation or difference.

The inclinometer borehole was located west of Te Ohaki Road, 300 m from the location of a proposed shaft in the adjacent panel in the Huntly East Mine. A total of 13 sets of inclinometer measurements were undertaken over two years from March 2009. Measurement stopped on 11 March 2011 because the probe could not be lowered through a depth of approximately 38 m in the borehole.
 
My study uses ‘extraction vector’, and ‘movement trajectory of the borehole’ for analysing and interpreting the deep borehole movement in underground mining, and addresses the far field subsidence movement as to its potential impact on structures on the surface or in the subsurface. This thesis also introduces the concept of negative vertical additional friction, developed in China, which is a potentially helpful concept for this study, and the proposed shaft project. 

Three major movement zones were identified, two ‘shear zones’ from 135.0 to 135.5 m and from 166 to 170 m, and one ‘creeping zone’ from the surface to 115 m. The borehole movement was presented by the trajectory of the intersection of the borehole at depths of surface (1 m), 135 m, and 166 m. The two shear zones occurred on the bedding planes in Te Kuiti Group, the creeping zone occurred in the weak strata of the Tauranga Group and upper Te Kuiti Group. The borehole movements were non-linear, and the borehole lateral movement trajectories varied with depth. Three polynomial equations were developed from regression and modelling for indicating the relationship and predication between the nearest extraction distance and the induced lateral movement.

The installation of an inclinometer borehole deeper than 120 m was not found in around 100 literature articles reviewed. No reports of use of inclinometer monitoring of ground movement induced by underground extraction were found in the literature reviewed. According to ASTM (2005), no standards are available yet for evaluation against precision and bias issues arising from use of borehole inclinometer. Therefore, the inclinometer borehole in this study may be one of the most complicated cases for monitoring and measurement of strata movement induced by the underground extraction in New Zealand.

year: 2012

title: The critical role of technical and social principles and values in encryption regulation

authors: Dizon, Michael

abstract: Encryption is a complex and enigmatic technology that poses significant challenges to regulators. While encryption is crucial to preserving the security and privacy of information and communications, it can also be used for illegal purposes and means and impede criminal investigations. Governments around the world have been proposing various ways to regulate this technology since the widespread presence and use of computers and the internet in the 1990s. Legislators have unsurprisingly taken a very law-centred approach to regulating encryption. They assume that the enactment of laws can definitively solve the problems brought about by new or disruptive technologies such as encryption. This regulatory mindset is encapsulated in a statement made by former Austrian Prime Minister Turnbull about how law trumps the underlying mathematics of encryption. He said, “The laws of Australia prevail in Australia, I can assure you of that. The laws of mathematics are very commendable, but the only law that applies in Australia is the law of Australia”. The issue with this exceedingly narrow and one-sided view of the relationship between law and technology is that it neglects to take into account important non-legal factors and considerations that are necessary in order to properly deal with encryption or any technology for that matter. Focusing solely on the laws and legal aspects of encryption without sufficient recognition of its technical and social contexts and conditions can result in the adoption of laws that are either ineffectual or unacceptable to the relevant stakeholders or society as a whole. This presentation will discuss the attendant technical and social principles and values of encryption that must be considered when seeking to develop appropriate laws and policies. Through the examination of the often overlooked technical and social dimensions of encryption, this presentation can provide key insights into how to better regulate encryption and technology more generally.

text: The critical role of technical and social principles and values in encryption regulation Encryption is a complex and enigmatic technology that poses significant challenges to regulators. While encryption is crucial to preserving the security and privacy of information and communications, it can also be used for illegal purposes and means and impede criminal investigations. Governments around the world have been proposing various ways to regulate this technology since the widespread presence and use of computers and the internet in the 1990s. Legislators have unsurprisingly taken a very law-centred approach to regulating encryption. They assume that the enactment of laws can definitively solve the problems brought about by new or disruptive technologies such as encryption. This regulatory mindset is encapsulated in a statement made by former Austrian Prime Minister Turnbull about how law trumps the underlying mathematics of encryption. He said, “The laws of Australia prevail in Australia, I can assure you of that. The laws of mathematics are very commendable, but the only law that applies in Australia is the law of Australia”. The issue with this exceedingly narrow and one-sided view of the relationship between law and technology is that it neglects to take into account important non-legal factors and considerations that are necessary in order to properly deal with encryption or any technology for that matter. Focusing solely on the laws and legal aspects of encryption without sufficient recognition of its technical and social contexts and conditions can result in the adoption of laws that are either ineffectual or unacceptable to the relevant stakeholders or society as a whole. This presentation will discuss the attendant technical and social principles and values of encryption that must be considered when seeking to develop appropriate laws and policies. Through the examination of the often overlooked technical and social dimensions of encryption, this presentation can provide key insights into how to better regulate encryption and technology more generally.

year: 2021-07-21

title: Te tātari i te kaupapa

authors: Ka'ai, Tānia M.

abstract: The primary objective of this thesis focuses on the linking of the National Qualifications Framework and standards-based assessment as an emancipatory mechanism for Māori in Kaupapa Māori schooling and the wider Māori community in New Zealand.

Argued from an eclectic theoretical approach incorporating Kaupapa Māori theory, it espouses a position which rejects structural inequalities that perpetuate the subordinate positioning of Māori people through the development of culturally responsive assessment theories and practices in written language for teachers and children in Kura Kaupapa Māori which purport a culturally responsive pedagogy.

The thesis also links curriculum, assessment and pedagogy using Kaupapa Māori theory which provides insights into Māori views of emancipation in education.

text: Te tātari i te kaupapa The primary objective of this thesis focuses on the linking of the National Qualifications Framework and standards-based assessment as an emancipatory mechanism for Māori in Kaupapa Māori schooling and the wider Māori community in New Zealand.

Argued from an eclectic theoretical approach incorporating Kaupapa Māori theory, it espouses a position which rejects structural inequalities that perpetuate the subordinate positioning of Māori people through the development of culturally responsive assessment theories and practices in written language for teachers and children in Kura Kaupapa Māori which purport a culturally responsive pedagogy.

The thesis also links curriculum, assessment and pedagogy using Kaupapa Māori theory which provides insights into Māori views of emancipation in education.

year: 1995