title: Monotonic and cyclic undrained behaviour and liquefaction resistance of pumiceous, non-plastic sandy silt

authors: Chaneva, Jordanka

subjects: Hamilton lowlands

abstract: Experimental data related to the mechanical behaviour of crushable pumiceous soils are limited compared with those for hard-grained soils. The main focus of previous studies has been on pumiceous sands, whereas pumiceous silts have not been investigated to date. In this paper, several series of monotonic and cyclic triaxial tests were performed to investigate the undrained behaviour and liquefaction resistance of a natural volcanic-ash derived, non-plastic pumiceous silt from northern New Zealand. Particle crushing due to sample reconstitution and triaxial testing was analysed by quantifying the changes in grain-size parameters and pumice contents. The main results can be summarized as follows. (1) The pumiceous silt showed a contractive response, even at medium to high relative densities, leading to high flow liquefaction susceptibility. (2) When subjected to cyclic undrained loading, the silt exhibited similar trends in terms of excess pore water pressure and axial strain accumulation to those established for hard-grained soils as opposed to those for pumiceous sands. (3) The liquefaction resistance of both medium-dense and dense samples was within the lower range compared to published cyclic resistance curves of both hard-grained soils and pumiceous sands. (4) The material did not undergo significant particle crushing after testing. Result (4) was considered to be the main factor that contributed to the fact that, in general, the cyclic undrained behaviour of the pumiceous silt was close to the trends established for those of hard-grained soils.

text: Monotonic and cyclic undrained behaviour and liquefaction resistance of pumiceous, non-plastic sandy silt Experimental data related to the mechanical behaviour of crushable pumiceous soils are limited compared with those for hard-grained soils. The main focus of previous studies has been on pumiceous sands, whereas pumiceous silts have not been investigated to date. In this paper, several series of monotonic and cyclic triaxial tests were performed to investigate the undrained behaviour and liquefaction resistance of a natural volcanic-ash derived, non-plastic pumiceous silt from northern New Zealand. Particle crushing due to sample reconstitution and triaxial testing was analysed by quantifying the changes in grain-size parameters and pumice contents. The main results can be summarized as follows. (1) The pumiceous silt showed a contractive response, even at medium to high relative densities, leading to high flow liquefaction susceptibility. (2) When subjected to cyclic undrained loading, the silt exhibited similar trends in terms of excess pore water pressure and axial strain accumulation to those established for hard-grained soils as opposed to those for pumiceous sands. (3) The liquefaction resistance of both medium-dense and dense samples was within the lower range compared to published cyclic resistance curves of both hard-grained soils and pumiceous sands. (4) The material did not undergo significant particle crushing after testing. Result (4) was considered to be the main factor that contributed to the fact that, in general, the cyclic undrained behaviour of the pumiceous silt was close to the trends established for those of hard-grained soils.

year: 2023-05

title: Prevalence of gestational diabetes in the Waikato region of New Zealand

authors: Chepulis, Lynne Merran

subjects: Science & Technology

abstract: Gestational diabetes mellitus (GDM) during pregnancy is associated with health complications for both mother and infant, but patient numbers in the Waikato District Health Board region of New Zealand have not been well characterised. This study reviewed the full 2018 cohort of Waikato District Health Board hospital births (n = 4970) to report on GDM prevalence by ethnicity and age. The overall prevalence of GDM was 5.7% and is more likely to affect Asian, Pacific and Māori women as well as those of advanced maternal age.

text: Prevalence of gestational diabetes in the Waikato region of New Zealand Gestational diabetes mellitus (GDM) during pregnancy is associated with health complications for both mother and infant, but patient numbers in the Waikato District Health Board region of New Zealand have not been well characterised. This study reviewed the full 2018 cohort of Waikato District Health Board hospital births (n = 4970) to report on GDM prevalence by ethnicity and age. The overall prevalence of GDM was 5.7% and is more likely to affect Asian, Pacific and Māori women as well as those of advanced maternal age.

year: 2022

title: Development and care of pā harakeke in 19th century New Zealand: Voices from the past

authors: McAllum, Priscilla M

subjects: Raranga

abstract: Māori weaving is experiencing a resurgence. Some weavers are involved in the planting of pā harakeke so that they have a high quality resource on hand ready for use.  A number of recent scientific publications, undertaken jointly with weavers, have explored the unique fibre qualities of different harakeke varieties along with specific aspects of Māori use of these varieties. In this paper, I examine Māori planting practices of pā harakeke and other aspects of resource management as revealed in literature sources from the late 18th to the early 20th centuries.  Although some of the practices outlined here may have fallen into disuse over time, they may, nevertheless, continue to be appropriate for contemporary pā harakeke. It is hoped, therefore, that the information provided here will be of interest to contemporary weavers.

text: Development and care of pā harakeke in 19th century New Zealand: Voices from the past Māori weaving is experiencing a resurgence. Some weavers are involved in the planting of pā harakeke so that they have a high quality resource on hand ready for use.  A number of recent scientific publications, undertaken jointly with weavers, have explored the unique fibre qualities of different harakeke varieties along with specific aspects of Māori use of these varieties. In this paper, I examine Māori planting practices of pā harakeke and other aspects of resource management as revealed in literature sources from the late 18th to the early 20th centuries.  Although some of the practices outlined here may have fallen into disuse over time, they may, nevertheless, continue to be appropriate for contemporary pā harakeke. It is hoped, therefore, that the information provided here will be of interest to contemporary weavers.

year: 2005-02