SCHERR+KLIMKE AG

Cracks in silo walls

1 Constraints for operation during monitoring
2 Schematic isometric view of a silo
3 Top view of an outlet of an upper 4 x ¼ silo
4 Top view of an outlet of a lower cylindrical silo
5 Damages of the silo from outside
6 Wide cracks in the mechanical room at level +32.40 m to +36.50 m
7 Schematic view of cracks in walls and slabs of the silo in the mechanical room at level +32.40 m to +36.50 m and at cross walls of the upper 4 x ¼ silo cells at level +36.50 m to +63.00 m
8 Assumptions for outlet of upper 4 x ¼ silo
9 Horizontal action on silo wall of upper 4 x ¼ silo
10 FE-model of the silo
11 FE-model showing the stresses and deformations due to horizontal pressure in one of the silo cells of the upper 4 x ¼ silo
12 Monitoring devices
13 Measuring data, e.g. stain of reinforcement and filling degree
The simpler a construction may seem, the more ­challenging the design can be All Scherr+Klimke AG

Is it a must to repair and strengthen or even demolish silos if wide cracks are observed? This question might be best answered by means of an example of a reinforced multi-chamber raw meal silo. In this article a special case will be highlighted which may be of interest for many cement producers.

1 Introduction

In general silos are structurally delicate structures. They consist of shell elements and can carry membrane tension or compression forces very well. However any bending moments or shear forces could lead to problems to the structural stability of the silo. In the given case the owner determined several extremely wide cracks in his unconventional multi-chamber raw meal silo during the regular inspection. A first expert opinion came with the result that the silo is under designed and must be strengthened with a heavy steel construction to regain structural stability. As the...

TEXT Dr.-Ing. Tarek Nasr, Consultant Engineer, Scherr+Klimke AG, Neu-Ulm/Germany

This article appeared in

ZKG 10/2014

This article appeared in

ZKG 10/2014

Ressort:  Engineering
subscription Content

Related articles:

Issue 6/2015 SCHERR+KLIMKE AG

Does it make sense to think about ­extending the design lifetime of ­deteriorating concrete structures?

This question might be best answered by means of an example of two reinforced concrete pre-heater towers, one is located in Europe and the other one in Asia. These cases may at first seem to be special however similarities to ...

more
Issue 5/2014 THORWESTEN

55 meter silo for pulverised lignite for Swiss cement plant

Thorwesten Vent, active in the field of constructional explosion protection, has received a contract for the design and assembly of a large capacity...

more
Issue 12/2014 HANSFORD SENSORS LTD.

Vibration monitoring to boost efficiency

Cement manufacturing is one of the most aggressive of all production processes. The chemicals used to produce Portland and Masonry cement – particu­larly silicates, aluminates and aluminoferrites – can combine to create high levels of very fine particles, creating significant problems for production and handling equipment. Rotating components are at greatest risk, and they are commonly found in the motors, pumps and fans used in crushers, mills, precipitators, kilns and silos. ...

more
Issue 6/2018 WUERTH CONSULTING ENGINEERS

How safe is your silo?

How long does a silo last, and what can we do to lengthen its life span? One way to do so is to ensure timely inspections and good maintenance. How? This contribution provides some answers. 

more