UC Research Repository
Nau mai, haere mai, welcome to the UC Research Repository
The UC Research Repository collects, stores and makes available original research from postgraduate students, researchers and academics based at the University of Canterbury.
Communities
Select a community to browse its collections.
- Items from Journals and Conferences hosted by the University of Canterbury
- University of Canterbury Research Centres
Recent Submissions
Hyperpartisanship in Taiwan Media and Electorate
(2022) Ho K; Clark C; Tan, Alex
Reading the tea leaves: Taiwan's November 2022 ‘midterm’ elections
(9DashLine, 2023) Tan, Alex; Kumar M
The application of the slope stability probability classification system to opencast mining in the Waikato Coal Measures, New Zealand
(2000) Campbell, Richard Nathan
A major factor in successful and economic opencast coal production is the ability to develop an understanding of the engineering behaviour of the overburden rock that must be removed to expose the economic material. The Waikato Coal Region is New Zealand's largest coal producing area, the majority of which is extracted by opencast methods.
The Slope Stability Probability Classification (SSPC) system of Hack (1998) has been applied to the problem of slope stability assessment within the Waikato Coal Measures, which are the basal formation of the predominantly transgressive Te Kuiti Group, of which the economic coal commonly occurs at the base of the coal measure Ethologies. The research undertaken concentated on the Rotowaro and Maramarua Coalfields, which are located in the central and northern sectors of the Waikato Coal Region respectively.
Many of the best known and well documented rock mass classification systems were originally designed for the classification of rock masses in which civil engineering tunnels and caverns are to be excavated, and are thus not well suited to the classification of surface excavations and opencast mining applications. Many of the geotechnical classifications that have been applied to the engineering of slopes in opencast mines (i.e. SMR and MRMR) are adapted versions of Bieniawski's (1973) original RMR system and as such contain input parameters that may not be applicable to slope stability. The SSPC system is one of the few geotechnical classification systems that has been developed specifically for the application to slope engineering.
The engineering geological field data was collected from 22 scanline surveys in the Township and Gunclub Pits and along the Township Northern Highwall in the Rotowaro Coalfield and the Kopuku Pit in the Maramarua Coalfield. Laboratory testing data was collected to characterise the Waikato Coal Measure lithologies, in terms of strength (UCS), triaxial, durability, swelling and sonic velocity. The resultant data has been applied to the SSPC system and the rock mass cohesion, friction angle and rock mass strength output results have been compared to those of the SMR, MRMR and Modified Hoek-Brown Failure Criterion in an effort to test the previously untrialed (in the mining environment) SSPC system against the results obtained from these better known and evaluated classification systems. The SSPC system produced comparable design rock mass values (cohesion, friction angle and rock mass strength) to the other classification systems with the additional feasibility design tools of the orientation-independent and orientation-dependent stability analysis. The orientation-independent stability function of the SSPC has proved to be a useful design tool for identifying the maximum stable batter height for a particular batter angle in terms of probability of failure. The orientation dependent stability analysis has also proven to be a powerful tool for identifying which batter orientations (dip-directions) are preferable in terms of acceptable probability of failure for both the sliding and toppling failure mechanisms.
After assessing the applicability of the SSPC system to coal mining in the Waikato Coal Measures the SSPC system was applied to a orientated and geotechnically logged drill hole as a test of its use as a feasibility assessment tool. The drill hole case study illustrated the usefulness of the SSPC as a feasibility design tool, and provided a similar estimation of the rock mass cohesion friction angle and rock mass strength parameters as complex and time consuming numerical analysis. The stability probability functions determined the maximum stable batter heights and dip angles based on the acceptable probability of failure. The orientation dependent stability analysis identified which of the proposed batter orientations had a higher than acceptable probability of failure and thus should be avoided.
Can free shared e bikes enhance wellbeing among social housing residents
(2024) Kingham, Simon; Curl A; Fitt H; Cushla D; Els R; Christina M; James B; Jonathan W; Banwell K