ABSTRACT:
The purpose of this Guide is to assist the designers, manufacturers and owners of solids storage facilities to design and assess their silos using relatively simple rules that are compatible with the latest developments in regulatory standards. It provides explanations and advice where the standards may not do so and it should thus be a useful aid when designers use these standards. In addition, it addresses several important problems which lie outside the scope of other design guidance but which recent research provides the knowledge base to tackle with confidence.
The aim of the Guide is to improve current practice to achieve more efficient circular metal silo structures. Because the majority of competitive silo structures are circular in plan, this Guide is restricted to circular silos.
This Guide is, in some senses, a successor to the Draft Design Code produced by the British Materials Handling Board (BMHB) and published in 1987 by BSI in association with the BMHB. It therefore addresses British conditions for silo construction and aims to assist the improvement of British practice in silo design and assessment.
The period in which this Guide is drafted is one of great change and formalisation of the rules for the design of silos. Whilst many national standards on silo pressures have been in existence for over a decade, no standard concerned with the structural design of metal silos of significant size has existed in any country. The national standards on silo pressures have been remarkable by the diversity of their provisions, both in terms of load magnitudes and in philosophy of design.
The advent of the European Standards for structural design of silos therefore changes the picture greatly. The European Standard on silo pressures was developed as a draft for comment in the years up to 1994, and is currently about to be transformed from a draft (ENV) into a normative (EN) document. The European Standard on the structural design of steel silos has recently been published as a standard for trial usage (ENV) over the next five years. This Guide follows the provisions of these European standards in almost all respects, so that users of the Guide may have confidence that their designs will meet their provisions.
The Guide therefore now incorporates many of the provisions established within these draft European documents, but retains additional helpful material from other sources and occasionally uses a better or simpler description of some phenomena, where the change makes a useful improvement to the economy, safety or simplicity of the design. In addition, this Guide addresses a much broader scope than the standards, and provides extensive background information to give some understanding of the basis of these provisions.
Many other standards, guides, texts and technical papers have been exploited in the development of this Guide. In particular, a strong relationship with the draft BMHB/BSI standard of 1987, as well as a certain debt to the Australian Standard AS3774 will be recognised by those who are familiar with the provisions of these documents.
