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Design criteria for structural design of silage silo walls.

Von Wachenfelt, Hans and Nilsson, Christer (2012). Design criteria for structural design of silage silo walls. I/In: International Conference of Agricultural Engineering, CIGR-Ageng2012, 8 - 12 July, Valencia.
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Official URL: http://cigr.ageng2012.org/comunicaciones-online/ht...

Abstract

The national guidelines for design of silage bunker silo walls are not available today. The present calculation and design is based on previously issued guidelines. These were elaborated to be used in designing silo wall heights of maximum 3 m. There are reasons to believe that these guidelines overestimate the forces and pressures, mainly from silage juice, that are occurring especially for silo walls > 3 m. This could result in over-sizing, material waste and increased investment costs. The aim of the project is to determine silage physical properties of importance for the horizontal wall pressure and evaluate maximum silage juice level of silos with a wall height of 3 m or more. The data will form a basis for new national design guidelines and a revised Swedish Standard. The ultimate goal is to lower the investment costs for silage bunker silos. A pressure profile was acquired by means of transducers mounted on a “ladder rack” placed vertically along the inside silo wall. The pressure on the transducers was recorded by a data acquisition system displaying static and total load (pressures imposed by silage matter and compacting tractor). The silage juice levels were measured by slotted 16 mm steel pipes placed vertically along the silo walls. The level inside the pipe was determined by a measuring stick. Additionally the juice level could be registered in one of the legs of the “ladder rack”. Silage juice level measurement were carried out during two seasons, all together in 24 silos, while pressure profiles were measured during 10 grass and maize harvests in one season, with approximately 400 pressure profiles at each harvest. The static loads were recorded with no tractor present and total loads as a tractor was passing in front of the transducer racks. The difference between the static and the total load was defined as the dynamic load. Preliminary results show that the silage juice level can vary considerably between harvests within the farm due to weather conditions and geographic location in Sweden. Mean of peak levels was approximately 40% of the silage height. A direct relation was found between grass silage juice level and silage total solid content. The silage juice level tends to remain stable during the storage but can be radically redistributed between layers within the silo. Tentative pressure profile results show that the dynamic pressure created by the compacting tractor is largely concentrated to the first half metre below the vehicle when driving 0.1-0.5 m from the silo wall. Pressure measurements after filling the silo show an increase in wall pressure. The pressure profile results are presently under evaluation.
Key words: Silo, wall, silage, pressure, force.

Authors/Creators:Von Wachenfelt, Hans and Nilsson, Christer
Title:Design criteria for structural design of silage silo walls.
Year of publishing :2012
Number:P1754
Page range:1-5
Number of Pages:5
Place of Publication:Sopporo
Publisher:CIGR-AgEng
ISBN for printed version:978-84-615-9928-8
Language:English
Publication Type:Conference Paper (Paper)
Refereed:No
Article category:Scientific peer reviewed
Version:Published version
Full Text Status:Public
Agris subject categories.:N Machinery and buildings > N01 Agricultural engineering
Subjects:(A) Swedish standard research categories 2011 > 2 Engineering and Technology > 201 Civil Engineering > Building Technologies
Keywords:Silo, Wall, Silage, Pressure, Force
URN:NBN:urn:nbn:se:slu:epsilon-e-1900
Permanent URL:
http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-1900
ID Code:10674
Faculty:LTJ - Faculty of Landscape Planning, Horticulture and Agricultural Science (until 2013)
Department:(LTJ, LTV) > Rural Buildings and Animal Husbandry (until 121231)
Deposited By: SLUpub Connector
Deposited On:16 May 2014 12:43
Metadata Last Modified:02 Dec 2014 11:02

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