(a) Using the Mechanism (Upper Bound) Method, determine the collapse load factor from all possible collapse mechanisms for the fixed end beam ABCD shown in Figure 6(a). Plastic moment capacity for the members of the portal frame is Mp = 240 kNm. (6 marks) 10% KN 302 kN B C D 2m 2m >* 1m Figure 6(a) (b) A fixed-base portal frame is subjected to a horizontal load 30a kN at B and two vertical loads, one of 10a kN at C and the other 30a kN at D as shown in Figure 6(b). Plastic moment capacity for the members of the portal frame is Mp = 240 kNm. By using the Mechanism Method, calculate the collapse load factor a from all possible mechanisms. (10 marks) 10 kN 30 KN 2m 2m 1m 30a kN B C D 4m A TITT Figure 6(b) E