AS 3774-1996

1 - AS 3774-1996 LOADS ON BULK SOLIDS CONTAINERS
4 - PREFACE
5 - CONTENTS
7 - SECTION 1 SCOPE AND GENERAL
7 - 1.1 SCOPE
7 - 1.2 REFERENCED DOCUMENTS
7 - 1.3 DEFINITIONS
7 - 1.3.1 Angle of repose
7 - 1.3.2 Axisymmetric flow
7 - 1.3.3 Bulk solids container
7 - 1.3.4 Coefficient of wall friction
7 - 1.3.5 Coefficient of variation
7 - 1.3.6 Cone
7 - 1.3.7 Cylinder
7 - 1.3.8 Dead zone
7 - 1.3.9 Eccentric flow
8 - 1.3.10 Effective angle of internal friction
8 - 1.3.11 Effective transition
8 - 1.3.12 Expanded flow
8 - 1.3.13 Flow factor
8 - 1.3.14 Flow load
8 - 1.3.15 Funnel flow
8 - 1.3.16 Hopper
8 - 1.3.17 Initial load
8 - 1.3.18 Live storage
8 - 1.3.19 Lower characteristic value
8 - 1.3.20 Mass flow
8 - 1.3.21 Pipe flow
8 - 1.3.22 Planar flow
8 - 1.3.23 Pressure multiplier
8 - 1.3.24 Primary flow zone
8 - 1.3.25 Secondary flow zone
8 - 1.3.26 Traction
8 - 1.3.27 Upper characteristic value
9 - 1.4 NOTATION
15 - SECTION 2 CLASSIFICATION AND GEOMETRIC PARAMETERS OF BULK STORAGE CONTAINERS
15 - 2.1 CLASSIFICATION OF CONTAINERS
15 - 2.1.1 Bases of classification system
15 - 2.1.2 Container geometry
15 - 2.1.3 Flow mode
16 - 2.1.4 Flow geometry
16 - 2.1.5 Roughness of wall surfaces
20 - 2.1.6 Flexibility of walls in the hoop direction
20 - 2.1.7 Continuity of walls in the vertical direction
20 - 2.1.8 Cross-sectional shapes
20 - 2.1.9 Configuration of discharge outlets
20 - 2.1.10 Means of flow promotion
22 - 2.2 GEOMETRIC PARAMETERS OF CONTAINERS
22 - 2.2.1 Basic parameters
22 - 2.2.2 Origin of vertical coordinate
22 - 2.3 CONTAINER CAPACITY
23 - SECTION 3 PROPERTIES OF BULK SOLIDS
23 - 3.1 CLASSIFICATION
23 - 3.2 PROPERTIES FOR LOADING CALCULATION
23 - 3.3 OTHER PROPERTIES
23 - 3.4 REPRESENTATIVE VALUES
23 - 3.4.1 General
24 - 3.4.2 Unit weight
24 - 3.4.3 Effective angle of internal friction
24 - 3.4.4 Angle of wall friction
24 - 3.4.5 Angle of repose
24 - 3.4.6 Effective elastic modulus
24 - 3.5 COMBINATION OF CHARACTERISTIC VALUES
26 - SECTION 4 LOAD CLASSIFICATION, LOAD COMBINATIONS, AND LOAD FACTORS
26 - 4.1 GENERAL
26 - 4.2 LOAD COMBINATIONS
27 - 4.3 LOAD FACTORS
28 - 4.4 CONTAINERS SUBJECT TO REPEATED LOADING
28 - 4.5 CONSTRUCTION TOLERANCES
28 - 4.5.1 Relationship between the loads and wall imperfections
28 - 4.5.2 Permissible deviations
28 - 4.6 ALLOWANCE FOR WEAR AND CORROSION
29 - SECTION 5 DETERMINATION OF PERMANENT LOADS (GROUP A)
29 - 5.1 SELF-WEIGHT OF THE STRUCTURE AND FIXED MECHANICAL PLANT AND EQUIPMENT (LOAD TYPE A.1)
29 - 5.2 LOADS FROM STRUCTURES SUPPORTED BY THE CONTAINER
30 - SECTION 6 DETERMINATION OF NORMAL SERVICE LOADS (GROUP B)
30 - 6.1 RELEVANT PROPERTIES OF STORED BULK SOLID
30 - 6.1.1 General
30 - 6.1.2 Unit weight of bulk solid
30 - 6.1.3 Angle of wall friction
30 - 6.1.4 Effective angle of internal friction
30 - 6.1.5 Consistent material properties
31 - 6.2 INITIAL LOADS ON SYMMETRICALLY FILLED CONTAINER WALLS (LOAD TYPE B.2)
31 - 6.2.1 Initial normal pressures on vertical walls
38 - 6.2.2 Initial frictional forces on vertical walls
40 - 6.2.3 Initial forces on container closures
47 - 6.3 LOADS INDUCED BY FLOW DURING SYMMETRICAL DISCHARGE (LOAD TYPE B.3)
47 - 6.3.1 Method of determining symmetrical flow loadings
47 - 6.3.2 Normal pressures on the vertical walls
49 - 6.3.3 Friction on vertical walls
49 - 6.3.4 Vertical loads on container bottoms
50 - 6.3.5 Normal pressures on hoppers
51 - 6.3.6 Frictional traction on hoppers
52 - 6.3.7 Normal pressures on the vertical end walls of a slot hopper
52 - 6.4 INITIAL LOADS ON ECCENTRICALLY FILLED CONTAINER WALLS (LOAD TYPE B.2)
52 - 6.4.1 Normal pressures on vertical walls
54 - 6.4.2 Frictional tractions on vertical walls
55 - 6.5 FLOW LOADS ON ECCENTRICALLY DISCHARGED CONTAINER WALLS (LOAD TYPE B.3)
55 - 6.5.1 General
55 - 6.5.2 Normal pressures on vertical walls
58 - 6.6 LOADS ASSOCIATED WITH GATES AND FEEDERS
58 - 6.6.1 Loads on gates and feeders from the stored solid
59 - 6.6.2 Increased gate and feeder loads due to large drop heights and rapid fill rates
60 - 6.6.3 Horizontal loads on containers due to unattached feeders
60 - 6.7 LIVE LOADS ON PLATFORMS AND ROOFS (LOAD TYPE B.5)
60 - 6.8 LOADS DUE TO DIFFERENTIAL GAS PRESSURE (LOAD TYPE B.6)
60 - 6.8.1 Negative gas pressure due to dust control equipment
60 - 6.8.2 Adiabatic pressure drop due to temperature drop
61 - 6.8.3 Internal pressure due to pneumatic discharge
61 - 6.8.4 Rapid discharge of solids of low permeability
61 - 6.9 FORCES FROM LATERAL RESTRAINTS (LOAD TYPE B.7)
61 - 6.9.1 Loads in lateral restraints
61 - 6.9.2 Loads due to the container being used as a restraint
62 - 6.10 LOADS ON INTERNAL STRUCTURAL ELEMENTS WITHIN THE STORED SOLID (LOAD TYPE B.8)
62 - 6.10.1 General
62 - 6.10.2 Vertical pressures on internal structural elements
62 - 6.10.3 Horizontal pressures and internal structural elements
62 - 6.10.4 Frictional tractions on internal structural elements
62 - 6.10.5 Vertical forces on internal structural elements
63 - 6.11 LOADS TRANSMITTED TO SUPPORTS
63 - 6.12 LOADS DUE TO BULK SOLIDS ON CONTAINER ROOFS
64 - SECTION 7 DETERMINATION OF ENVIRONMENTAL LOADS (GROUP C)
64 - 7.1 WIND LOADS (LOAD TYPE C.1)
64 - 7.1.1 General
64 - 7.1.2 Negative internal air pressure
64 - 7.2 LOADS DUE TO DIFFERENTIAL SETTLEMENT OF FOUNDATIONS (LOAD TYPE C.2)
64 - 7.2.1 Assessment of differential settlements
64 - 7.2.2 Differential settlement under column-supported containers
65 - 7.2.3 Differential settlement under ground-supported containers
65 - 7.3 LOADS DUE TO DIFFERENTIAL TEMPERATURE (LOAD TYPE C.3)
65 - 7.3.1 Assessment of differential temperature
65 - 7.3.2 Temperature decrease in container walls
66 - 7.3.3 Temperature differentials in supporting columns
67 - 7.3.4 Storage of hot bulk solids
67 - 7.4 SEISMIC LOADS (LOAD TYPE C.4)
67 - 7.4.1 General
68 - 7.4.2 Elevated containers and supporting structures
68 - 7.4.3 Ground-supported structures
70 - 7.5 LOADS DUE TO SWELLING OF STORED BULK SOLIDS (LOAD TYPE C.5)
72 - SECTION 8 DETERMINATION OF ACCIDENTAL LOADS (GROUP D)
72 - 8.1 VEHICLE IMPACT LOADS (LOAD TYPE D.1)
72 - 8.2 PRESSURE CAUSED BY INTERNAL EXPLOSION (LOAD TYPE D.2)
72 - 8.3 FORCES DUE TO CONTAINED WATER (LOAD TYPE D.3)
73 - APPENDIX A - BULK SOLIDS CONTAINER SPECIFICATION DATA SHEETING
74 - APPENDIX B - PROPERTIES OF BULK SOLIDS
74 - B1 PROPERTIES FOR LOADING CALCULATIONS
75 - B2 DETERMINATION OF UPPER AND LOWER CHARACTERISTIC VALUES
75 - B3 DETERMINATION OF EFFECTIVE ANGLE OF WALL FRICTION FOR SURFACE ROUGHNESS CATEGORY
75 - B4 EFFECTIVE ANGLE OF WALL FRICTION FOR COARSE SPHERICAL GRAINS
78 - APPENDIX C - TESTING TO DETERMINE PROPERTIES OF BULK SOLIDS
78 - C1 THE METHOD OF TESTING
79 - C2 FACTORS WHICH CAN MODIFY FLOW PROPERTIES
79 - C2.1 Particle size and distribution
79 - C2.2 Moisture content
79 - C2.3 Aeration
81 - C2.4 Particle cohesion
82 - C2.5 Vibration
82 - C2.6 Slip-stick properties
82 - C2.7 Other factors
82 - C3 UNCERTAINTY AND VARIABILITY
83 - APPENDIX D - PRESSURE CAUSED BY INTERNAL EXPLOSION

Specifies requirements for the determination of loads for the design of containment structures for the mass storage of bulk solids. The loads include permanent loads, normal service loads, environmental loads, and accidental loads. Does not apply to containers for the storage of silage.

This Standard specifies requirements for the determination of loads for the design of containment structures, including bins, silos, bunkers, and dump hoppers, for the mass storage of granular bulk solids.This Standard does not apply to containers for the storage of silage or containers with parameters not complying with Section 2.NOTE: A typical bulk solids container specification data sheet is shown in Appendix A.

Originated as AS 3774-1990.
Second edition 1996.
Incorporating: Amdt 1-1998 Amdt 2-1998