Eurocode 7 - geotechnical design

Eurocode 7 - geotechnical design

ETC10 Questionnaire 2.3


	General Q1. Please provide your contact details in case we need to clarify your submission. (These details will be kept strictly confidential.) Name Affiliation Email address Q2. How many structures of this kind have you previously designed? None 1-2 3-6 More than 6 Q3. Having completed your design to Eurocode 7, how confident are you that the design is sound? Very unsure Unsure Confident Very confident Q4. How did you account for the location of boreholes/cone tests relative to the foundation? Did not consider borehole/test location Considered nearest borehole/test only Considered 'average' of all boreholes/tests Considered trend of all boreholes/tests, biased towards nearest Other (specify) Q5. Please explain the reasons for your answer to Q4 Serviceability limit state Q6. Which parameters did you use for the SLS design of the pile foundation? Cone resistance q_c SPT blow count N Corrected SPT blow count (N₁)₆₀ UU triaxial test strength c_u Pressuremeter limit pressure p_lim Undrained Young's modulus of elasticity E_u Drained Young's modulus of elasticity E' Poisson's ratio n Shear modulus of elasticity G Other (specify) Q7. What correlations did you use to derive soil parameter values (if used) for the SLS verification? If more than one, please list others below. Description Author Title Pages Q7a. Any other correlations? (please give same info as above) Q8. What assumptions did you make in choosing these correlations? Q9. How did you account for any variation in parameters with depth? Ignored variation with depth Assumed linear variation with depth Assumed bi-linear variation with depth Assumed stepped variation Other (specify) Q10. Please explain the reasons for your answer to Q9 Q11. (If used) What is the characteristic value of N at these levels? At +17 m, N_k = At +7 m, N_k = At -3 m, N_k = Q12. (If used) What is the characteristic value of q_c at these levels? At +17 m, q_c,k (MPa) = At +7 m, q_c,k (MPa) = At -3 m, q_c,k (MPa) = Q13. (If used) What is the characteristic value of plim at these levels? At +17 m, p_lim,k (MPa) = At +7 m, p_lim,k (MPa) = At -3 m, p_lim,k (MPa) = Q14. (If used) What is the characteristic value of triaxial c_u at these levels? At +17 m, c_u,k (kPa) = At +7 m, c_u,k (kPa) = At -3 m, c_u,k (kPa) = Q15. How did you assess these values? By eye By linear regression By statistical analysis From an existing standard (specify) From a published correlation (specify) Comparison with a previous design From the soil description, not using the data Other (specify) Q16. Which calculation model did you use to determine settlement? Method from national annex (specify) Method from national standard (specify) Finite element analysis Finite difference analysis Other (specify) Q17. What length does the pile need to avoid a serviceability limit state? L_SLS (in m) = Ultimate limit state Q18. Which parameters did you use for the ULS design of the pile foundation? Cone resistance q_c SPT blow count N Corrected SPT blow count (N₁)₆₀ UU triaxial test strength c_u Pressuremeter limit pressure p_lim Other (specify) Q19. What correlations did you use to derive soil parameter values (if used) for the ULS verification? If more than one, please list others under Q29. Description Author Title Pages Q19a. Any other correlations? (please give same info as above) Q20. What assumptions did you make in choosing these correlations? Q21. (If determined) What is the characteristic value of unit shaft resistance q_s at these levels? At +17 m, q_s,k (kPa) = At +7 m, q_s,k (kPa) = At -3 m, q_s,k (kPa) = Q22. (If determined) What is the characteristic value of unit base resistance q_b at these levels? At +17 m, q_b,k (kPa) = At +7 m, q_b,k (kPa) = At -3 m, q_b,k (kPa) = Q23. Which calculation model did you use to determine shaft and base resistance? Annex D.6 from EN 1997-2 Annex D.7 from EN 1997-2 Annex E.3 from EN 1997-2 Alternative given in a national annex (specify) Alternative given in a national standard (specify) Finite element analysis Finite difference analysis Other (specify) Q24. Which country's National Annex did you use to interpret EN 1997-1? Q25. Which Design Approach did you use for verification of the Ultimate Limit State (ULS)? Design Approach 1 Combinations 1 and 2 Design Approach 1 Combination 1 only Design Approach 1 Combination 2 only Design Approach 2 Design Approach 2* Design Approach 3 Other (specify) Q26. What values of partial factors did you use for this ULS verification? g_G g_Q g_f g_c g_cu g_s g_b g_t Q26a. If you used a second combination of partial factors, what values did you use for this second combination? g_G g_Q g_f g_c g_cu g_s g_b g_t Q27. What correlation factors (if any) did you use for this verification? x₃ x₄ Q28. What model factor (if any) did you use for this verification? g_Rd Q29. What length does the pile need to avoid an ultimate limit state? L_ULS (in m) = Q30. What is the design compressive force that the pile must be designed for according to Eurocode 2? Design compressive force, F_cd (in kNm) = Concluding questions Q31. What other assumptions did you need to make to complete your design? Q32. Please specify any other data that you would have liked to have had to design this type of foundation Q33. How conservative do you consider your previous national practice to be for this design example? Very conservative Conservative About right Unconservative Very unconservative Q34. How conservative do you consider Eurocode 7 (with your National Annex) to be for this example? Very conservative Conservative About right Unconservative Very unconservative Q35. How does your Eurocode 7 design compare with your previous national practice? Much more conservative More conservative About the same Less conservative Much less conservative Q36. Please provide any other relevant information needed to understand your solution to this design exercise

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