scholarly journals Remote monitoring of the snow loads on a roof of buildings

2016 ◽  
Vol 56 (2) ◽  
pp. 246-252
Author(s):  
V. A. Lobkina ◽  
I. A. Kononov ◽  
A. A. Potapov
Keyword(s):  
Remote Monitoring ◽  
Winter Season ◽  
Snow Accumulation ◽  
Snow Melting ◽  
Snow Load ◽  
Load Change ◽  
Load Cells ◽  
Snow Loads ◽  
Flat Roof ◽  
Snow Loading

Obtaining actual data on a change in the value of snow load for a snowfall is an important task the solution of which is usually neglected. The purpose of the work was to obtain a data on dynamics of the snow load change on a roof for a snowfall. A system for remote monitoring of the snow load was developed for this purpose. This system allows continuous gathering and transmission of the data on the snow load change from a unit of area. Obtaining this information gives an indication of the size of snow loading and dynamics of the snow accumulation during snowfall. The developed system provides continuous collection and transmission of data about the changing snow load per unit area. This information makes possible judging values of the snow load and its dynamics during a snowfall. Using of this system allows monitoring of snow accumulation during a snowfall. Discreteness of the system is 1 minute, and the sensitivity to the load change is 50 g. The platform is designed for a load less than 100 kg. When a snowfall ends the platform should be cleaned. In 2015, the system has been just tested, but in future we plan to use the system without cleaning for the whole snow season. In this connection, the more powerful sensors will be used. The system consists of a rectangular platform with an area of 1 m2, and it is equipped with four load cells «TOQUES» BBA at the corners. It was used for two months from late January to mid-March. In total, nine snowfalls were observed. In the winter season of 2014/15, increases of snow loads changed within the range of 10–100 kg/m2. Analysis of the data shows that the maximum snow load exerted on the roof takes place at a snowfall peak, after that it decreases under the influence of external factors. Three main factors influencing formation of the snow loads on a flat roof are as follows: the quantity of solid precipitation, the snow melting, and redistribution of snow by wind. Using of the system allows obtaining actual values of snow load on roofs of buildings instead of data calculated from the snow weight on the ground. These values can be then used to correct standards for the snow loads.

A Probabilistic Approach to the Prediction of Snow Loads

1974 ◽  
Vol 1 (1) ◽  
pp. 28-49 ◽  
Author(s):  
N. Isyumov ◽  
A. G. Davenport
Keyword(s):  
Formation Process ◽  
Extreme Values ◽  
Meteorological Data ◽  
Digital Simulation ◽  
Probabilistic Approach ◽  
Snow Accumulation ◽  
Meteorological Variables ◽  
Snow Load ◽  
Design Values ◽  
Snow Loads

The magnitudes of loads imposed by snow depend upon a number of climatological and meteorological variables and as a result exhibit marked variations geographically, due to local effects within a particular region, and with time. The snowload formation process, which depends both on the macro- and microclimates of such meteorological variables as the depth of the snowfall, the snowfall density, wind speed, air temperature etc., as well as, the size and geometry of particular roofs and the influence of their immediate environment, is discussed.A model of the snow load formation process based on a mass balance approach, which takes into account the deposition of snow by individual snowfalls and the depletion of the snow load by wind action and thermal effects, is introduced. The use of this approach requires the establishment of statistical descriptions of the various meteorological variables, as well as a knowledge of the physical process of snow accumulation and depletion for a particular roof. The statistical properties of some of the more important meteorological variables are discussed. Also presented are some model derived data of snow accumulation and depletion for particular roofs located in different terrain.It is shown that even relatively simple statistical descriptions of the relevant meteorological data and snow accumulation and depletion mechanisms can lead to realistic predictions of roof snow loads. Snow loads on a flat roof are generated by a digital simulation technique and compared with full scale observations. Annual extreme values of the simulated snow load process are presented and compared with currently specified design values. Comments are made regarding the practicability of this approach.

scholarly journals Experimental Study of Interference Effects of a High-Rise Building on the Snow Load on a Low-Rise Building with a Flat Roof

2021 ◽  
Vol 11 (23) ◽  
pp. 11163
Author(s):  
Qingwen Zhang ◽  
Yu Zhang ◽  
Ziang Yin ◽  
Guolong Zhang ◽  
Huamei Mo ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Snow Accumulation ◽  
Interference Effects ◽  
Wind Tunnel Tests ◽  
Snow Load ◽  
Building Roof ◽  
High Rise ◽  
High Rise Building ◽  
Snow Distribution ◽  
Flat Roof

To explore the interference effects of a high-rise building on the snow load on a low-rise building with a flat roof, a series of wind tunnel tests were carried out with fine silica sand as a substitute for snow particles. The effects of the height of the interfering building and the distance between buildings on the snow distribution of the target building under three different wind directions were studied. The snow depth on the target building roof and the mass of particles blown off from the target building were measured during the wind tunnel tests, and the results showed that the snow distribution of the target building roof tends to be uniform when the interfering building is located upstream of the target building due to the shelter effect. When the interfering building is on the side of the target building, the snow distribution of the target building tends to be more uneven, because the interfering building increases the friction velocity on the target building roof near the interfering building. However, when the interfering building is located downstream of the target building, there will be an amplification effect of snow accumulation, and the snow distribution on the target building roof is nearly the same as that of the isolated condition. Under each wind direction, the interference effect of the snow load increases with the increase of the building height and the decrease of the building spacing. Therefore, the influence of the surrounding buildings on the snow distribution of the building roof cannot be ignored and should be considered in the structure design.

scholarly journals Climate change impact on water resource extremes in a headwater region of the Tarim basin in China

2011 ◽  
Vol 15 (11) ◽  
pp. 3511-3527 ◽  
Author(s):  
T. Liu ◽  
P. Willems ◽  
X. L. Pan ◽  
An. M. Bao ◽  
X. Chen ◽  
...  
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
Ground Water ◽  
Climate Change Impact ◽  
Snow Accumulation ◽  
Tarim River Basin ◽  
Hydrological Models ◽  
Snow Melting ◽  
Change Impact ◽  
Ipcc Sres

Abstract. The Tarim river basin in China is a huge inland arid basin, which is expected to be highly vulnerable to climatic changes, given that most water resources originate from the upper mountainous headwater regions. This paper focuses on one of these headwaters: the Kaidu river subbasin. The climate change impact on the surface and ground water resources of that basin and more specifically on the hydrological extremes were studied by using both lumped and spatially distributed hydrological models, after simulation of the IPCC SRES greenhouse gas scenarios till the 2050s. The models include processes of snow and glacier melting. The climate change signals were extracted from the grid-based results of general circulation models (GCMs) and applied on the station-based, observed historical data using a perturbation approach. For precipitation, the time series perturbation involves both a wet-day frequency perturbation and a quantile perturbation to the wet-day rainfall intensities. For temperature and potential evapotranspiration, the climate change signals only involve quantile based changes. The perturbed series were input into the hydrological models and the impacts on the surface and ground water resources studied. The range of impact results (after considering 36 GCM runs) were summarized in high, mean, and low results. It was found that due to increasing precipitation in winter, snow accumulation increases in the upper mountainous areas. Due to temperature rise, snow melting rates increase and the snow melting periods are pushed forward in time. Although the qualitive impact results are highly consistent among the different GCM runs considered, the precise quantitative impact results varied significantly depending on the GCM run and the hydrological model.

scholarly journals Seasonal Variation of Oxygen Isotopic Composition of Firn Cores in the Antarctic Ice Sheet

1990 ◽  
Vol 14 ◽  
pp. 256-260 ◽  
Author(s):  
Kazuhide Satow ◽  
Okitsugu Watanabe
Keyword(s):  
Oxygen Isotopic Composition ◽  
Snow Accumulation ◽  
Snow Melting ◽  
Snow Layer ◽  
Yearly Variation ◽  
Maximum Value ◽  
Power Spectral ◽  
Yearly Change ◽  
Oxygen Isotopic ◽  
The Antarctic

We have investigated two 30 m cores at two different spots in the most heavy snow-accumulation regions on Mizuho Plateau, East Antarctica. Marked seasonal variations periodically appear in oxygen isotope records of the cores. We analyzed one core with no trace of snow melting and found it had a complete record showing a yearly change of annual net snow accumulations from 1920 through 1980. The analysis shows that a yearly variation of annual net accumulation (N.A.) has some relations with that of the annual maximum value (δmax) of δ18O and that of the annual amplitude (Δδ) of the δ18O-change in an annual snow layer. Power spectral analyses with respect to the variation of N.A., δmax and Δδ also indicate that there is commonly a predominant periodicity of about five years.

scholarly journals Snow loads in a changing climate: new risks?

2008 ◽  
Vol 8 (1) ◽  
pp. 1-8 ◽  
Author(s):  
U. Strasser
Keyword(s):  
Snow Cover ◽  
Freezing Point ◽  
Warning System ◽  
Winter Precipitation ◽  
Snow Load ◽  
Time Period ◽  
Sudden Rise ◽  
Trigger Event ◽  
Snow Loads ◽  
Modelling Data

Abstract. In January/February 2006, heavy snowfalls in Bavaria (Germany) lead to a series of infrastructural damage of catastrophic nature. Since on many collapsed roofs the total snow load was not exceptional, serious engineering deficiencies in roof construction and a sudden rise in the total snow load were considered to be the trigger of the events. An analysis of the then meteorological conditions reveals, that the early winter of 2005/2006 was characterised by an exceptional continuous snow cover, temperatures remained around the freezing point and no significant snowmelt was evident. The frequent freezing/thawing cycles were followed by a general compaction of the snow load. This resulted in a re-distribution and a new concentration of the snow load on specific locations on roofs. With respect to climate change, the question arises as to whether the risks relating to snow loads will increase. The future probability of a continuous snow cover occurrence with frequent freezing/thawing cycles will probably decline due to predicted higher temperatures. However, where temperatures remain low, an increase in winter precipitation will result in increased snow loads. Furthermore, the variability of extremes is predicted to increase. If heavy snowfall events are more frequent, the risk of a trigger event will likely increase. Finally, an attempt will be made here in this paper to outline a concept for an operational warning system for the Bavarian region. This system envisages to predict the development and risk of critical snow loads for a 3-day time period, utilising a combination of climate and snow modelling data and using this together with a snow pillow device (located on roofs) and the results of which.

Development of a Snow Load Alert System, “YukioroSignal” for Aiding Roof Snow Removal Decisions in Snowy Areas in Japan

2020 ◽  
Vol 15 (6) ◽  
pp. 688-697
Author(s):  
Hiroyuki Hirashima ◽  
Tsutomu Iyobe ◽  
Katsuhisa Kawashima ◽  
Hiroaki Sano ◽  
◽  
...  
Keyword(s):  
Snow Depth ◽  
Load Distribution ◽  
Snow Water Equivalent ◽  
Snow Accumulation ◽  
Risk Level ◽  
Residential Areas ◽  
Alert System ◽  
Snow Removal ◽  
Snow Load ◽  
Snow Water

This study developed a snow load alert system, known as the “YukioroSignal”; this system aims to provide a widespread area for assessing snow load distribution and the information necessary for aiding house roof snow removal decisions in snowy areas of Japan. The system was released in January 2018 in Niigata Prefecture, Japan, and later, it was expanded to Yamagata and Toyama prefectures in January 2019. The YukioroSignal contains two elements: the “Quasi-Real-Time Snow Depth Monitoring System,” which collects snow depth data, and the numerical model known as SNOWPACK, which can calculate the snow water equivalent (SWE). The snow load per unit area is estimated to be equivalent to SWE. Based on the house damage risk level, snow load distribution was indicated by colors following the ISO 22324. The system can also calculate post-snow removal snow loads. The calculated snow load was validated by using the data collected through snow pillows. The simulated snow load had a root mean square error (RMSE) of 21.3%, which was relative to the observed snow load. With regard to residential areas during the snow accumulation period, the RMSE was 13.2%. YukioroSignal received more than 56,000 pageviews in the snowheavy 2018 period and 26,000 pageviews in the less snow-heavy 2019 period.

scholarly journals Snow melting bias in microwave mapping of Antarctic snow accumulation

2008 ◽  
Vol 2 (2) ◽  
pp. 255-273
Author(s):  
O. Magand ◽  
G. Picard ◽  
L. Brucker ◽  
M. Fily ◽  
C. Genthon
Keyword(s):  
Reasonable Agreement ◽  
Snow Accumulation ◽  
Snow Melting ◽  
Surface Mass ◽  
Surface Emission ◽  
Continental Scale ◽  
Antarctic Snow ◽  
In Situ Observations ◽  
Microwave Sensors

Abstract. Satellite records of microwave surface emission have been used to interpolate in-situ observations of Antarctic surface mass balance (SMB) and build continental-scale maps of accumulation. Using a carefully screened subset of accumulation measurements in the 90°–180° E sector, we show a reasonable agreement with microwave-based accumulation map in the dry-snow regions, but large discrepancies in the coastal regions where melt occurs during summer. Using an emission microwave model, we explain the failure of microwave sensors to retrieve accumulation by the presence of layers created by melt/re-freeze cycles. We conclude that regions potentially affected by melting should be masked-out in microwave-based interpolation schemes.

scholarly journals STRESS-STRAIN STATE OF FRAME STRUCTURES AT THE DIFFERENT SNOW PRESSURE

2019 ◽  
Vol 7 (2) ◽  
pp. 5-9
Author(s):  
Галина Кравченко ◽  
Galina Kravchenko ◽  
Елена Труфанова ◽  
Elena Trufanova ◽  
Денис Суслопаров ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Strain State ◽  
Element Model ◽  
Frame Structures ◽  
Stress Strain ◽  
Snow Load ◽  
Stress Strain State ◽  
Snow Pressure ◽  
Snow Loading

The multi-variant loading of the large-span unique steel covering of the stadium under snow load is considered. The spatial finite element model is developed using LIRA software. The analysis of the existing schemes application of snow loading is carried out according to the codes. Four snow load cases on the stadium's covering are assumed for analysis. The analysis of the stress-strain state of the stadium structures, the selection and verification of sections of the steel covering are performed. The results show that it is necessary to simulate behaviour of a structure under all possible load cases.

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