robustness
 

robustness
hi
please i want any body to clear my doubts about the robusness and accidental load as the following:
1- i consider as bs8110 part1 sec 2.2.2.2 we should to creat&design a "tieing system" as sec 3.12.3 by calculate ft and check the the tie element reinforcement > as=ft/(.95fy), is that correct ?
2- in bs8110 part2 sec 2.6 mentioned a "key elements", what exactly the key element is ? is it option if the tieing is nit exist ?
3- 34kn/m2 load due to accidental applying into the key elements , how can i apply this load? .
4- is the 34 kn/m2 laod replacing the "notional horizontal load" mentioned in part1 sec 3.1.4.2?
i which from the people who's involving in that case to help.
my best regards and thanx to all in advance.
ahmed