An example can be found in Annex E of EN 1997-1:2004.
The use of experience and testing to determine SLS parameters that will also satisfy ULS requirements is generally done. Q ult = c’N cs c + q’N qs q + 0.5γ’BN γs γĬombination 1: q ult = (10 × 15.84 × 1.419) + (16.2 × 7.07 × 1.358) + (0.5 × 18.0 × 4.66 × 1.0 × 0.7) = 409.66 kN/m 2Ĭombination 2: q ult = (8 × 12.28 × 1.369) + (16.2 × 4.77 × 1.292) + (0.5 × 18.0 × 2.305 × 1.0 × 0.7) = 248 kN/m 2įor sizing of the foundation, Combination 2 allowable bearing capacity should be used (no other factor of safety is to be applied).įor the semi-empirical (indirect) method, a commonly recognized semi-empirical method such as bearing resistance estimation using pressuremeter test should be used. Q ult = c’N cs cd ci cg cb c + q’N qs qd qi qg qb q + γ’BN γs γd γi γg γb γ/2įor this calculation, all inclination factors have been ignored. The unit weight of soil is 18 kN/m 3 and the safety factor γ γ = 1 Step 4: Calculate the overburden pressure, q. Step 3: Calculate the design shape factors. Use the equations in section D.4 of Annex D of Eurocode 7. Step 2: Calculate design bearing capacity factors. UPL: Failure due to uplift of the foundation due to water pressure GEO: Failure due to excessive deformation of the ground supporting the structure STR: Internal failure or excessive deformation of the structure itself These limit states are ĮQU: Loss of equilibrium of the structure For the design of pad foundation using Design Approach 1, three limit states with their appropriate load combination shall be satisfied for the structure. However, the UK National Annex to Eurocode 7 permits only Design Approach 1 (DA1).
The three approaches can give very different results when applied in design. Eurocode 7 gives three approaches for the geotechnical design of foundations and they are as follows ĭesign Approach 1 (DA1): In this approach, partial factors are applied to actions and to ground strength parameters.ĭesign Approach 2 (DA2): In this approach, partial factors are applied to actions or to the effects of actions and to ground resistances.ĭesign Approach 3 (DA3): In this approach, partial factors are applied to actions or to the effects of actions from the structure and to ground strength parameters. The geotechnical design of a pad foundation can be carried out according to the requirements of EN 1997-1:2004 (Eurocode 7).
0 kommentar(er)
