The Stored Material Load Factor in Steel Silo Design

Silo Types

Silo System

Steel silo design shall take the following load into consideration:

  1. Permanent load: structural self-weight, other components and fixed equipment load;
  2. Variable load: material storage load, floor live load, roof live load, snow load, wind load, mobile devices load and fix devices live load and the equipment installation load, dust load and the positive and negative pressure caused by the pipeline;
  3. Temperature effect;
  4. Earthquake effect.

Stored Material Load

When calculating the stored material load during silo design, should adopted the parameters of the storage material that has the most adverse effect on the structure. The internal friction Angle of the storage material should be taken when calculating the friction of silo wall.Calculation of gravity flow pressure of deep silo shall meet the following requirements:Below the top of the material or the center of gravity of material cone which we call the place of S, the stored material load is acting on silo wall.The horizontal pressure standard value Phk per unit area shall be calculated according to the following formula:

Phk=Chrρ , (1 –e-μk /ρ ) / μ

k=tan2 (45°- φ /2)

P hk- the horizontal pressure standard value (N/mm2) in the area of material to silo wall

Ch -The horizontal pressure correction factor of the deep silo storage

r - gravity density of stored material (N/mm3 ) ;

ρ- The hydraulic radius (mm) of the horizontal net section of steel silo;

μ-The friction coefficient of material and silo wall

k - lateral pressure coefficient;

e - the base of the natural log;

s一The distance (mm) of the the top of the material or the center of gravity of material cone to the Calculated cross section

φ- The material internal friction angle