Exercise A certain site is underlain by clay. A proposed building for this site having a 500 kN column load (including the weight of foundation) is designed to be supported on a surface square footing. A field plate loading test was performed using a square plate of size 30 cm, Figure 1 displays the pressure- settlement curve, from which the ultimate capacity of the plate was 180 kN/m2. Answer the following questions: According to the plate loading test result, considering a factor of safety of 2 against vertical bearing capacity and the allowable settlement of 2.5 cm for design requirements, determine the minimum footing size to meet the requirements and the condition which governs the design (bearing capacity or settlement). Pressure (kN/m2) 200 180 180 180 160 140 120 120 100 100 80 60 40 20 0. 10 15 20 25 30 Settlement (mm) Figure 1. Load-settlement curve of the plate loading test 2.

A thin circular pipe with a mean radius of 39 mm is subject to an external compressive pressurepof 4 N/mm?. If the thickness of the pipe wall is 1 mm, determine the circumferential or hoop stress due to the external pipe pressure in N/mm?. Round off your answer to the nearest N/mm?. If the answer is negative remember to include the "-" sign.

C36000 Brass Load (lbs) Cycles to failure (N) Stress (S) in (ksi) 60 21925 45.28 45 62333 33.96 40 162745 30.18 35 274145 26.40 4130CF Steel Load (lbs) Cycles to failure (N) Stress (S) in (ksi) 100 4444 75.46 80 223126 60.35 70 611424 52.80 67 2191170 50.55 Plot S-N curves for both metals using log scale and showing appropriate axes limits and labels and compare the fatigue characteristics.