Stiffened walls
1 Walls may be considered as stiffened at a vertical edge if and its stiffening wall is not expected, i.e. - both walls are made of materials with approximately similar deformation behaviour, - are approximately evenly loaded - are erected simultaneously and bonded together - and differential movement between the walls for example, due to shrinkage, loading etc., is not expected, the connection between a wall and its stiffening wall, is designed to resist developed tension and compression...
Effective thickness of walls
where t1 and t2 are the thicknesses of the leaves. 3 When the effective thickness would be overestimated if the loaded leaf of a cavity wall has a higher E value than the other leaf, the relative stiffness should be taken into account when calculating tef. 4 When only one leaf of a cavity wall is loaded, equation 4.17 may be used to calculate the effective thickness, provided that the wall ties have sufficient flexibility such that the loaded leaf is not affected adversely by the unloaded leaf....
Reduction factor for slenderness and eccentricity
I At the top or bottom of the wall. ei is the eccentricity at the top or the bottom of the wall M Mi is the design bending moment at the top or the bottom of the wall resulting from the eccentricity of the floor load at the support, according to 4.4.7 see figure 4.1 , ehi is the eccentricity at the top or bottom of the wall, if any, resulting from horizontal loads for example, wind , ea is the accidental eccentricity see 4.4.7.2 , Figure 4.1 Moments from calculation of eccentricities. Figure...
Insertion
On the background of the semi probabilistic safety concept, looking at only one action S and one resistant value R The difference R - S in an actual case indicates the actual margin of safety. As the distributions of S and R are overlapping, it is possible, that R - S becomes lt 0, which means failure of the structure The safety factors have to be chosen such that the probability of failure is small enough to be tolerated.
Verification of unreinforced masonry walls
1 The design vertical load resistance of a single leaf wall per unit length, NRd, is given by Fim is the capacity reduction factor Fi or Fm, as appropriate, allowing for the effects of slenderness and eccentricity of loading fk is the characteristic compressive strength of masonry gM is the partial safety factor for the material taking into account the depth of recesses in joints greater than 5 mm. 2 The design strength of a wall may be at its lowest - in the middle one fifth of the heigth,...
Modulus of elasticity
1 P The short term secant modulus of elasticity, E, shall be determined by tests in accordance with eN 1052-1 at service load conditions, i.e. at one third of the maximum load determined in accordance with EN 1052-1. 2 In the absence of a value determined by tests in accordance with EN 1052-1, the short term secant modulus of elasticity of masonry, E, under service conditions and for use in the structural analysis, may be taken to be 1 000 f 3 When the modulus of elasticity is used in...
Concrete infill
Concrete used for infill shall be in accordance with EN 206. The characteristic shear strength of concrete infill, fcvk, for the relevant concrete strength classes Table 3.4 Characteristic shear strength, fcvk, of concrete infill. Table 3.4 Characteristic shear strength, fcvk, of concrete infill.
Analysis of shear walls
For the analysis of shear walls, the design horizontal actions and the design vertical loads shall be applied to the overall structure. This causes the following situation of the individual shear wall The most unfavourable combination of vertical load and shear should be considered, as follows - maximum axial load per unit length of the shear wall, due to vertical loads and considering the longitudinal eccentricity due to cantilever bending, or - maximum axial load per unit length in the...
General Nsb
1 P The characteristic compressive strength of unreinforced masonry, fk, shall be determined from the results of tests on masonry. 2 The characteristic compressive strength of unreinforced masonry - may de determined by tests in accordance with EN 1052-1, - or it may be established from an evaluation of test data, based on the relationship between the characteristic compressive strength of unreinforced masonry, and the compressive strengths of the masonry units, and the mortar. In masonry...
Characteristic flexural strength of unreinforced masonry
determinated from the results of tests on masonry - fxk1 failure parallel to the bed joints, - fxk2 failure perpendicular to the bed joints. - only for transient loads for example wind - fxk1 0, where failure of the wall would lead to a major collapse. fxk1 and fxk2 will be given in the NAD's fxk1 Plane of failure fxk2 Plane of failure parallel to bed joints perpendicular to bed joints Determination of the flexural strength by tests Examples of test set-ups and of typical test specimens for W...
Outofplane eccentricity General
The out-of-plane eccentricity of loading on walls - from the material properties given in Section 3, - and from the principles of structural mechanics. A simplified method is given in Annex C - the joint between the wall and the floor may be simplified, by using uncracked cross sections - elastic behaviour of the materials A frame analysis or a single joint analysis may be used. Joint analysis may be simplified as shown in figure C.1 Figure C.1 Simplified frame diagram For less than four...
Design values of actions
1 P The design value Fd of an action is expressed in general terms as Ad gA Ak if Ad is not directly specified where gF, gG, gQ, gA and gp are the partial safety factors for the action. 3 P The upper and lower design values of permanent actions are expressed as follows - where only a single characteristic value Gk is used then Gd ,sup gG,sup Gk Gd ,inf - gG,inf Gk - where upper and lower characteristic values of permanent actions are used then Gd ,sup gG,sup Gk ,sup Gd ,inf gG,inf Gk ,inf
Determination of effective height
1 The effective height hef can be taken as pn is a reduction factor where n 2, 3 or 4 depending on the edge restraint or stiffening of the wall. 2 The reduction factor, pn , may be assumed to be I For walls restrained at the top and bottom by reinforced concrete floors or roofs spanning from both sides at the same level or by a reinforced concrete floor spanning from one side only and having a bearing of at least 2 3 the thickness of the wall but not less than 85 mm 0,75 unless the...
Partial safety factors for actions on building structures
Table 2.2 Partial safety factors for actions in building structures for persistent and transient design situations Table 2.2 Partial safety factors for actions in building structures for persistent and transient design situations For accidental design situations the partial safety factor For accidental design situations the partial safety factor for variable actions is equal to 1,0 3 By adopting the g values given in table 2.2, the following simplified combinations may be used - considering...