Modellering av extrema istryck.
(2005)Division of Structural Engineering
- Abstract
- Today, the knowledge about ice forces in Sweden is uncertain. Certain guidelines have been developed according to RIDAS to determine ice forces when constructing dams, piers etc. In this thesis an environmental model has been developed to predict thermal ice pressures. The inputs for the model are;
a) the mean daily air temperature for each day of the year;
b) the snow cover depth.
The mean daily air temperature is based on measured data, from SMHI (The Swedish Meteorology and Hydrology Institute). These input data are then simulated over 1000 years using an Autoregressive Moving Average-model.
Besides this, the model has been produced on assumptions and limitations. The most important assumptions and limitations are;
a) the ice is... (More) - Today, the knowledge about ice forces in Sweden is uncertain. Certain guidelines have been developed according to RIDAS to determine ice forces when constructing dams, piers etc. In this thesis an environmental model has been developed to predict thermal ice pressures. The inputs for the model are;
a) the mean daily air temperature for each day of the year;
b) the snow cover depth.
The mean daily air temperature is based on measured data, from SMHI (The Swedish Meteorology and Hydrology Institute). These input data are then simulated over 1000 years using an Autoregressive Moving Average-model.
Besides this, the model has been produced on assumptions and limitations. The most important assumptions and limitations are;
a) the ice is formed in a static way;
b) freeze-up of the ice;
c) no cracks in the ice;
d) the ice is divided into layers.
Further the ice thickness and the temperature profiles in the ice are analyzed using specific heat transfer equations and approximated by linear equation systems. Thermal ice loads are generated by short and long term temperature changes.
Short term load is the force that´s calculated from the largest positive temperature-change during one day under a season. Long term load is the force that´s calculated from the lowest average temperature in the ice to zero under a season. The ice pressures are calculated according to four cases:
1. Short term load; without snow cover.
2. Long term load; without snow cover.
3. Short term load; with snow cover.
4. Long term load; with snow cover.
The analysis shows that predicted short term load with snow gives ice pressures of the same order of magnitude as RIDAS. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/3172307
- author
- Fredrikson, Magnus and Persson, Johan
- supervisor
- organization
- year
- 2005
- type
- H3 - Professional qualifications (4 Years - )
- subject
- report number
- TVBK-5131
- ISSN
- 0349-4969
- language
- Swedish
- id
- 3172307
- date added to LUP
- 2012-12-04 14:43:26
- date last changed
- 2014-06-12 14:40:37
@misc{3172307,
abstract = {{Today, the knowledge about ice forces in Sweden is uncertain. Certain guidelines have been developed according to RIDAS to determine ice forces when constructing dams, piers etc. In this thesis an environmental model has been developed to predict thermal ice pressures. The inputs for the model are;
a) the mean daily air temperature for each day of the year;
b) the snow cover depth.
The mean daily air temperature is based on measured data, from SMHI (The Swedish Meteorology and Hydrology Institute). These input data are then simulated over 1000 years using an Autoregressive Moving Average-model.
Besides this, the model has been produced on assumptions and limitations. The most important assumptions and limitations are;
a) the ice is formed in a static way;
b) freeze-up of the ice;
c) no cracks in the ice;
d) the ice is divided into layers.
Further the ice thickness and the temperature profiles in the ice are analyzed using specific heat transfer equations and approximated by linear equation systems. Thermal ice loads are generated by short and long term temperature changes.
Short term load is the force that´s calculated from the largest positive temperature-change during one day under a season. Long term load is the force that´s calculated from the lowest average temperature in the ice to zero under a season. The ice pressures are calculated according to four cases:
1. Short term load; without snow cover.
2. Long term load; without snow cover.
3. Short term load; with snow cover.
4. Long term load; with snow cover.
The analysis shows that predicted short term load with snow gives ice pressures of the same order of magnitude as RIDAS.}},
author = {{Fredrikson, Magnus and Persson, Johan}},
issn = {{0349-4969}},
language = {{swe}},
note = {{Student Paper}},
title = {{Modellering av extrema istryck.}},
year = {{2005}},
}