Foundation Engineering Exam Questions

2

Question-1:  The soil supporting the foundation has afriction angle of Φ= 25 and c=20 kN/m . The unit weight of soil, γ, is 16.5 3

kN/m .A square foundation measuring B measuring  Bx x B will be subjected to an allowable gross load of 1000 kN with FS=3 and  Df = 1 m. Determine the size B size  B of the foundation.

 Bx B) has to be constructed as shown in Question-2: A square foundation ( Bx B 3 3 Figure. Assume that γ=17 kN/m , γ sat = 20 kN/m , Φ=34, Df= 34, Df= 2  2 m, and D and  D1 1=1 m. The gross allowableload, Qall, with FS = 3 is 700 kN. Determine the size of the foundation.

Given: Df = 1.5 m, γ=15.9 Question-3:  A square column foundation has to carry a gros s allowable load of 1805 kN (FS=3 ). Given: Df kN/m3, Φ= 34, and c= 0. UseTerzaghi’ UseTerzaghi ’s equation to determine the size of the foundation ( B ( B). ). Assume general shear failure.

Question-4:  A column foundation (see Figure) is 3m x 2m in plan. Given:  Df =1.5 m, Φ= 25, c= 70 kN/m2 and FS= 3. Determine the net allowable load, the foundation could carry.

Question-5:  For a square foundation that is  B x B in plan, Df plan, Df = 2 m; vertical gross allowable load, Qall =3330 kN, γ=16.5 kN/m3; Φ=30; c= 0; and FS= 4. Determine the size of t he foundation.

Question-6:  A load of 425 kN/m is carried on a strip footing 2m wide at a depth of 1m in a stiff clay of saturated unit weight 21

kN/m3, the water table being at ground level. Determine the factor of safety with respect t o shear failure (a) when c u = 105 kN/m2 and Φu= 0 and (b) when c=10 kN/m2 and Φ= 28.

Question-7:  A strip footing 1.5m wide is located at a depth of 0.75m in a sand of unit weight 18 kN/m3, the water table being

well below foundation level. The characteristic shear strength parameters are c=0 and Φ=38. The footing supports a design load of 500 kN/m. Determine the factor of safety with respect to shear failure.

Question-8:  A 400 kN vertical downward column load acts at the centroid of 1.5 m square footing. The bottom of this footing is

0.4 m below the ground surface and the top is flush with the ground surface. The groundwater table is at a depth of 3 m below the ground surface. The soil type is unifor m dense sand that has a friction angle Φ of 31 31°. The total unit weight of the soil i s equal to 18.7 kN/m3.Compute the bearing pressure. Question-9: A square footing of 1 m is located at a depth of 15 m below the ground surface. The soil properties are: c=0 Φ=38 γ=16.5 kN/m3 γ sat =16.5 kN/m3

a)  b)

The water table is well below the foundation level, The water table is at the ground surface.

Question-10: A square footiong; 3,75x3,75m, is to be constructed as shown at le ft. The groundwater table is at depth of 1.5 meter

 below the ground surface. Compute the ultimate ultimate bearing capacity and the the column load required to produce a bearing capacity failure. The unit weigth of the soil is 20,5 kN/m 3. Depth of the foundation is 1.0 m. Soil, has a firiction angle of 28 °, and cohesion 2 of 20 kNm  B1= 4m, B 4m, B2= 2= 6m, L 6m, L1= 1= 12m, and L and  L2= 2= 18m. If the area is subjected to a uniform Question-11:  A flexible rectangular area. Given:  B1= 2

load of 3000 kN/m . Determine the stress increase at a depth of 1 2 meter located immediately below point O. (Çözebilmek için Çözebilmek için ekte verilen EXAMPLE 6.2’ye 6.2 ’ye bakınız) bakını z)

Question-12:  A flexible foundation measuring 1.5 m 3 3 m is supported by a saturated clay. Given:  Df= 1.2  Df= 1.2 m, H= m, H=3 3 m, Es m, Es

(clay)= 600 kN/m2, and qo =150 kN/m2. Determine the average elastic settlement of the foundation. ( Çözebilmek Çözebilmek için ekte ekte verilen EXAMPLE 7.1’ye 7.1’ye bakınız) bakınız)

Eğer birden fazla Ic değeri var ise topla sonra verilen yük ile çarp…