Horizontal to vertical pressure ratio Ksm
1 The horizontal to vertical pressure ratio Ks,m shall be determined at a vertical stress level corresponding to the maximum vertical pressure in the silo. The test specimen shall be confined laterally. The vertical pressure may be assessed by using expression 5.4 . 2 A test method is given in Annex B. 3 An alternative test method based on the measurement of the internal angle of friction is also given. Max pv for Ks 0,9Ksm and 0,9 m Max pw for Ks 1,15Ksm and 1,15 , 4 The conversion factors...
Scope of ENV Actions on silos and tanks
1 P This part provides general principles and actions for the structural design of tanks and silos including some geotechnical aspects and shall be used in conjunction with ENV 1991-1 Basis of Design, other parts of ENV 1991 and ENV 1992-1999. 2 This part may also be used as a basis for the design of structures not covered in ENV 1992-1999 and where other materials or other structural design actions are involved. 3 The following limitations apply to the design rules for silos The silo cross...
Distinction between principles and application rules
1 Depending on the character of the individual clauses, distinction is made in this part between principles and application rules. general statements and definitions for which there is no alternative, as well as requirements and analytical models for which no alternative is permitted unless specifically stated. 3 The principles are identified by the letter P following the paragraph number. 4 The application rules are generally recognized rules which follow the principles and satisfy their...
Simplified method for filling and discharge
1 For silos, where dc is less than 5m a simplified method for considering filling and discharge processes may be applied. In this procedure, the patch loads according to 5.2.1 and 5.2.2 may be adjusted by increasing the horizontal pressures. 2 For concrete silos, silos with stiffeners and silos with non circular cross-sections shapes the increased horizontal pressures for filling Phf,s and discharge Phe,s are Phf is calculated from expression 5.3 Phe is calculated from expression 5.21 b is...
B Coefficient of wall friction pm for the determination of pressures
A sample of the particulate material is sheared along a surface representing the silo wall a sample with corrugation in the case of corrugated steel silos and the friction force at the sheared surface is measured. The test apparatus is shown in Figure B1. The diameter of the box shall be at least 40 times the maximum particle size and the compacted height H of the sample shall be between 0,15D and 0,20D. In the case of wall samples with irregularities such as corrugations the box size shall be...
Coefficient of wall friction
1 Two values should be measured. One shall be used for the determination of flow patterns and the other for the calculation of wall loads. 2 Tests to determine for the evaluation of flow patterns should be carried out at a low stress level corresponding to the stress level found during flow in the lower part of the hopper. 3 Tests to determine for the calculation of loads should be carried out at a stress level corresponding to the maximum horizontal pressure phf in the vertical part of the...
Section Loads on silos due to particulate materials
1 Loads due to particulate materials depend on the range of particulate material properties the variation in the surface friction conditions the methods of filling and discharge. 2 The flow pattern mass flow or funnel flow should be determined from Figure 5.1. 3 For the determination of the flow pattern, the angle of wall friction may be obtained either by testing as described in 5.5.2 or by using the approximate values of coefficient of wall friction given in Table 7.1 and shall be calculated...
reference stress
stress levels at which the measurements of stored material properties are carried out. The reference stress is selected to correspond to the stress level in the silo after filling B6 Sampling and preparation of samples 1 Testing shall be carried out on representative samples of the particulate material. The mean value for each material property shall be determined making proper allowance for variation of secondary parameters. 2 The following method of sample preparation shall be used for the...
Normative references
This European Prestandard incorporates by dated or undated reference, provisions from other standards. These normative references are cited in the appropriate places in the text and publications listed hereafter. ISO 3898 1987, Basis of design for structures Notations. General symbols. NOTE The following European Prestandards which are published or in preparation are cited at the appropriate places in the text and publications listed hereafter. ENV 1991-1, Eurocode 1 Basis of design and actions...
Flat bottoms
1 Vertical loads acting on fiat or shallow silo bottoms inclinations a lt 20 shall be calculated as follows pvt Cb pv 5.13 pv is calculated using expression 5.4 Cb is a bottom load magnifier to account for the uneven load distribution calculated using expression 5.14 Figure 5.2 Side elevation and plan view of the patch load Figure 5.2 Side elevation and plan view of the patch load 1 P When a gt 20 see Figure 5.3 the pressure normal to the inclined hopper wall pn is calculated as follows x is a...
Eurocode programme
7 Work is in hand on the following Structural Eurocodes, each generally consisting of a number of parts EN 1991 Eurocode 1 Basis of design and actions on structures EN 1992 Eurocode 2 Design of concrete structures EN 1993 Eurocode 3 Design of steel structures EN 1994 Eurocode 4 Design of composite steel and concrete structures EN 1995 Eurocode 5 Design of timber structures EN 1996 Eurocode 6 Design of masonry structures EN 1997 Eurocode 7 Geotechnical design EN 1998 Eurocode 8 Design of...
Scope of ENV Eurocode
1 P ENV 1991 provides general principles and actions for the structural design of buildings and civil engineering works including some geotechnical aspects and shall be used in conjunction with 2 It may also be used as a basis for the design of structures not covered in ENV 1992-1999 and where other materials or other structural design actions are involved. 3 ENV 1991 also covers structural design during execution and structural design for temporary structures. It relates to all circumstances...