# EN 1997-1 2004 AC2009

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 1997-1:2004/AC February 2009 Février 2009 Februar 2009 ICS 93.020; 91.010.30 English version Version Française Deutsche Fassung Eurocode 7: Geotechnical design - Part 1: General rules Eurocode 7: Calcul géotechnique - Partie 1: Règles générales Eurocode 7 - Entwurf, Berechnung und Bemessung in der Geotechnik - Teil 1: Allgemeine Regeln This corrigendum becomes effective on 18 February 2009 for incorporation in the three official language versions of the EN. Ce corrigendum prendra effet le 18 février 2009 pour incorporation dans les trois versions linguistiques officielles de la EN. Die Berichtigung tritt am 18.Februar 2009 zur Einarbeitung in die drei offiziellen Sprachfassungen der EN in Kraft. EUROPEAN COMMITTEE FOR STANDARDIZATION COMITÉ EUROPÉEN DE NORMALISATION EUROPÄISCHES KOMITEE FÜR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels © 2009 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Tous droits d exploitation sous quelque forme et de quelque manière que ce soit réservés dans le monde entier aux membres nationaux du CEN. Alle Rechte der Verwertung, gleich in welcher Form und in welchem Verfahren, sind weltweit den nationalen Mitgliedern von CEN vorbehalten. Ref. No.:EN 1997-1:2004/AC:2009 D/E/FEN 1997-1:2004/AC:2009 (E) 2 1 Modification to Foreword Last subpart “National Annex for EN 1997-1“, last paragraph including the list of national choice, add between “2.4.7.1(3)“ and “2.4.7.2(2)P“: “2.4.7.1(4), 2.4.7.1(5), 2.4.7.1(6)“ and between “8.6(4)“ and “11.5.1(1)P“: “10.2 (3)“. 2 Modification to Subclause 1.1.2 Part (3), 1 stindent, replace: “partial safety factor“ with “partial factor“. 3 Modifications to Subclause 1.6 Part “Latin letters“: Read the explanation of the following symbols as follows: “A’ effective base area (A’= B’ × L’)“ “q b;kcharacteristic value of unit base resistance“ “q s;i;kcharacteristic value of unit shaft resistance in stratum i“. Replace as symbol for “width of a foundation“: “b“ with “B“. Replace in the explanation of “C d “: “effect of an action” with “relevant serviceability criterion”. Replace as symbol for “foundation length“: “l“ with “L“. Insert the following symbol in the list after “q s;r;k “: “q uunconfined compressive strength“. Part “Greek letters“: Read the explanation of the following symbols as follows: “γ R;e partial factor for passive earth resistance“ “γ Q;dstpartial factor for a variable destabilising action“ “γ Q;stbpartial factor for a variable stabilising action“. 4 Modification to Subclause 2.1 Part (17), replace: “soil” with “ground”. EN 1997-1:2004/AC:2009 (E) 3 5 Modification to Subclause 2.4.2 Part (4), 3rd dash, delete: “and ground-water pressure”. 6 Modifications to Subclause 2.4.7.1 Part (4), add the following note: “NOTE The values of partial factors may be set by the National Annex.” Part (5), add the following note: “NOTE The values of partial factors may be set by the National Annex.” Part (6), add the following note: “NOTE The values of model factors may be set by the National Annex.” 7 Modification to Subclause 6.5.3 Part (11)P, replace in formulas (6.4a) and (6.4b): “A c “ with “A’ “. 8 Modification to Subclause 7.1 Part (3)P, delete the “NOTE“ and add: “ — EN 14199:2005, for micropiles“. 9 Modification to Subclause 7.6.2.1 Part (13), 2nd dash, replace: “cross-sectional” with “gross cross-sectional”. 10 Modification to Subclause 7.6.3.3 Part (6), “NOTE“, replace: “from“ with “in“. 11 Modifications to Subclause 7.6.4.2 Part (1)P, replace: “partial safety factors“ with “partial factors“. Part (4), replace: “assessed on“ with “assessed on the basis of”. 12 Modifications to Subclause 7.8 Part (4)P, replace: “very weak” with “extremely low strength fine”. Part (5), replace: “representative, undrained” with “characteristic”. EN 1997-1:2004/AC:2009 (E) 4 13 Modification to Subclause 7.9 Part (4), add after “EN 12699:2000,“: “EN 14199:2005,“; and delete the final “NOTE“. 14 Modifications to Subclause 8.1.1 Part (3): Replace: “(3)“ with “(3)P“. Replace the sentence: “This Section should not be applied to soil nails.“ with the following: “This Section does not apply to soil nails.“ 15 Modification to Subclause 8.1.2 “8.2.1.7 Tendon free length“, renumber “8.2.1.7“ into “8.1.2.7“. 16 Modification to Subclause 8.8 Part (1)P, replace: “It shall be specified in the design that all” with “All”. 17 Modification to Subclause 9.3.1.5 Part (1)P, delete: “forces“ after “ice”. 18 Modification to Subclause 9.3.2.2 Part (3), replace: ‘’execution period’’ with “design situation”. 19 Modification to Subclause 9.5.3 Part (2), replace: “high angles of internal friction” with “high angles of shearing resistance”. 20 Modifications to Subclause 9.6 Part (3)P: Replace: “(3)P“ with “(3)“. Replace the two occurrences of: “shall” with “should normally”. EN 1997-1:2004/AC:2009 (E) 5 21 Modification to Subclause 9.7.5 Part (5)P, replace: “Section 6” with “Section 7”. 22 Modifications to Subclause 9.8.1 Delete full text of parts (2)P and (3)P. Renumber part (4) into (2) and part (5) into (3). In paragraph (3) (renumbered), replace: “may” with “need”. 23 Modifications to Subclause 10.2 Part (2)P: Insert: “while“ between “ground layers,” and “the design resistance”. Part (3): Replace the entire 1 stparagraph with the following: “ If allowed by the National Annex, resistance to uplift by friction or anchor forces may also be treated as a stabilising permanent vertical action (G stb;d ). NOTE The values of the partial factors may be set by the National Annex. ” Figures 10.1 a) to e), key element 1, replace four times: “(ground)-water table” with “groundwater table”, Replace Figures 10.1 c), 10.1 d) and 10.1 e) with the following new Figures 10.1 c), 10.1 d) and 10.1 e): Figure 10.1 c) EN 1997-1:2004/AC:2009 (E) 6 Figure 10.1 d) Figure 10.1 e) Figure 10.1 c), add the key element: “10 groundwater level before the excavation”. Figures 10.1 c) and d), add the key element: “11 groundwater level in the excavation”. In Figure 10.1 c), add the key element: ”12 piezometric level at the base of the clay layer”. In Figure 10.1 d), delete the key element: “6 sand”. 24 Modification to Subclause 10.3 Figure 10.2, replace key element 1: “excavation level (left); water table (right)“ with “excavation level (left); free-water level (right)”. EN 1997-1:2004/AC:2009 (E) 7 25 Modification to Subclause 10.4 Part (5)P, replace the current paragraph with: “If the filter criteria are not satisfied, it shall be verified that the design value of the hydraulic gradient is well below the critical hydraulic gradient at which soil particles begin to move.” 26 Modifications to Subclause 10.5 Part (1)P: Figure 10.3, replace key element 1: “free water table“ with “free-water level”. “NOTE“, 2nd dash, delete underlining of “the”. 27 Modifications to Subclause 11.5.1 Part (10), replace the 2nd sentence with: “If a method of slices is used and horizontal equilibrium is not checked, the inter-slices forces should be assumed to be horizontal.” Part (11)P, delete the final “NOTE“. 28 Modification to Subclause A.5 Part (1)P, NOTE, replace: “EN 1990:2002” with “this standard”. 29 Modifications to Subclause B.2 Part (4): Replace: “Equation (2.6) includes” with “Equations (2.6a) and (2.6b) include”. Part (5):, 2nd paragraph, replace: “equation (2.6)” with “equations (2.6a) and (2.6b)”. 5 thparagraph, replace: “equation (2.6) reduces to” with “equation (2.6a) applies”. Part (6): 2 ndparagraph replace: “equation (2.6) reduces to:” with “equations (2.6a) and (2.6b) reduce to:”. Part (7): Replace: “equation (2.6) remains:” with “equations (2.6a) and (2.6b) remain:”. 30 Modifications to Subclause B.3 Part (1): 1 stline, replace: “equation (2.7)” with “equation (2.7c)”. EN 1997-1:2004/AC:2009 (E) 8 Equation (B.5.2), replace: “equation (2.7)” with “equation (2.7c)”. Part (2): Replace: “equation (2.7)” with “equations (2.7a), (2.7b) and (2.7c)”. Part (5): 2nd paragraph, replace: “equation (2.7)” with “equation (2.7c)”. 31 Modification to Subclause F.2 Equation (F.1), replace: “b“ with “B“. 32 Modification to Annex C Replace the full Annex C with the following new Annex C: EN 1997-1:2004/AC:2009 (E) 9 Annex C (informative) Sample procedures to determine earth pressures C.1 Limit values of earth pressure (1) The limit values of earth pressure on a vertical wall, caused by soil of weight density (γ), uniform vertical surface load (q), angle of shearing resistance (ϕ) and cohesion (c) should be calculated as follows: — active limit state: σ a (z) = K a[ ∫γdz + q − u ] + u − c K ac(C.1) where the integration is taken from ground surface to depth z K ac= 2√[K a(1+a/c)], limited to 2,56√K a— passive limit state: σ p (z) = K p[ ∫γdz +q − u ] + u + cK pc(C.2) where the integration is taken from ground surface to depth z K pc= 2√[K p (1+a/c)], limited to 2,56√K pwhere: a is the adhesion (between ground and wall) c is the cohesion K ais the coefficient of effective horizontal active earth pressure K pis the coefficient of effective horizontal passive earth pressure q is the vertical surface load z is the distance down the face of the wall β is the slope angle of the ground behind the wall (upward positive) δ is the angle of shearing resistance between ground and wall γ is the total weight density of retained ground σ a (z) is the total stress normal to the wall at depth z (active limit state) σ p (z) is the total stress normal to the wall at depth z (passive limit state) (2) For drained soil, K aand K pare functions of angle of shearing resistance ϕ′, and c = c′, the effective cohesion. For undrained soil, K a = K p= 1 and c = c u , the undrained shear strength. EN 1997-1:2004/AC:2009 (E) 10 (3) Values of the effective earth pressure coefficients may be taken from Figures C.1.1 to C.1.4 for K aand C.2.1 to C.2.4 for K p . (4) Alternatively, the analytical procedure described in C.2 may be used. (5) In layered soils, the coefficients K should normally be determined by the shear strength parameters at depth z only, independent of the values at other depths. Figure C.1.1 — Coefficients K aof effective active earth pressure (horizontal component): with horizontal retained surface (β β β β = 0) EN 1997-1:2004/AC:2009 (E) 11 Figure C.1.2 — Coefficients K aof effective active earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 0 and δ δ δ δ = 0) EN 1997-1:2004/AC:2009 (E) 12 Figure C.1.3 — Coefficients K aof effective active earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 0,66) EN 1997-1:2004/AC:2009 (E) 13 Figure C.1.4 — Coefficients K aof effective active earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 1) EN 1997-1:2004/AC:2009 (E) 14 Figure C.2.1 — Coefficients K pof effective passive earth pressure (horizontal component): with horizontal retained surface (β β β β = 0) EN 1997-1:2004/AC:2009 (E) 15 Figure C.2.2 — Coefficients K pof effective passive earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 0 and δ δ δ δ = 0) EN 1997-1:2004/AC:2009 (E) 16 Figure C.2.3 — Coefficients K pof effective passive earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 0,66) EN 1997-1:2004/AC:2009 (E) 17 Figure C.2.4 — Coefficients K pof effective passive earth pressure (horizontal component): with inclined retained surface (δ δ δ δ/ϕ ϕ ϕ ϕ’ = 1) EN 1997-1:2004/AC:2009 (E) 18 C.2 Analytical procedure for obtaining limiting active and passive earth pressures (1) The following procedure, which includes certain approximations, may be used in all cases. (2) The procedure is stated for passive pressures with the strength parameters (represented in the following by ϕ, c, δ, a) inserted as positive values, see Figure C.3. (3) For active pressures the same algorithm is used, with the following changes: — the strength parameters ϕ, c, δ and a are inserted as negative values; — the value of the angle of incidence of the equivalent surface load β 0is β, mainly because of the approximations used for K γ . (4) The following symbols are used (some are also given in 1.6): a is the adhesion between wall and ground c is the cohesion K cis the coefficient for cohesion K nis the coefficient for normal loading on the surface K qis the coefficient for vertical loading K γis the coefficient for the soil weight m tis the angle from the soil surface direction, pointing away from the wall, to the tangent direction of the intersecting slip line that bounds the moving soil mass, pointing out from the soil surface m wis the angle from the wall normal to the tangent direction at the wall of the exterior slip line, positive when the tangent points upwards behind the wall β is the angle from the horizontal to the soil surface direction, positive when the soil surface rises away from the wall δ is the angle of wall friction, with sign convention as defined in Figure C.4 when computing passive resistance ϕ is the angle of shearing resistance θ is the angle between the vertical and the wall direction, positive when the soil overhangs the wall ν is the tangent rotation along the exterior slip line, positive when the soil mass above this slip line is of a convex shape q is the general uniform surcharge pressure, per unit area of the actual surface p is the vertical uniform surcharge pressure, per unit area in a horizontal projection EN 1997-1:2004/AC:2009 (E) 19 Figure C.3 — Definitions concerning wall and backfill inclination, surcharges and slipline geometry (5) The interface parameters δ and a must be chosen so that: ϕ tan tan δ c a = (6) The boundary condition at the soil surface involves β 0 , which is the angle of incidence of an equivalent surface load. With this concept the angle is defined from the vectorial sum of two terms: - actual distributed surface loading q, per unit of surface area, uniform but not necessarily vertical, and; - c cotϕ acting as normal load. The angle β 0is positive when the tangential component of q points toward the wall while the normal component is directed toward the soil. If c = 0 while the surface load is vertical or zero, and for active pressures generally, β 0= β. (7) The angle m tis determined by the boundary condition at the soil surface: () ϕ β β ϕ sin 0 sin 0 t 2 cos − = + + m (C.3) (8) The boundary condition at the wall determines m wby: () ϕ δ δ ϕ sin sin w 2 cos = + + m (C.4) The angle m wis negative for passive pressures (ϕ 0) if the ratio sin δ /sin ϕ is sufficiently large. (9) The total tangent rotation along the exterior slip line of the moving soil mass, is determined by the angle v to be computed by the expression: EN 1997-1:2004/AC:2009 (E) 20 θ β − − + = w t m m v (C.5) (10) The coefficient K nfor normal loading on the surface (i.e. the normal earth pressure on the wall from a unit pressure normal to the surface) is then determine