Lecture (2)

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Stress And Displacements in a Soil Mass

Sheet (1)

Problem 1 A rectangular foundation ABCD cast at ground level of plan dimensions (5m × 3m), the foundation exerts a uniform vertical load of 1600 KN. Use the Newmark chart to estimate the increase in vertical stress at depths of 2m beneath point (E)4m beneath the center of the foundation3m beneath point (F) (Answer = 43.7, 32.5, 19.2 KN/m2)

Problem 2 The figure shows a new building which exerts a stress of 2 kg/cm2 at foundation level. Calculate the increase of stress due to the new construction at the center line of the shown clay layer under points A,B,C and D. Assume that the soil is semi-infinite homogenous isotropic elastic media.( Answer = 0.87, 0.4, 0.3, 0.22 kg/cm2 )

Problem 3A concentrated load of 8.5 tons acts on ground surface. Use Boussinesq’s equation to calculate the depths z1 and z2 below the point of application of the load at which the values of stress increases due to the load are 1 and 0.5 t/m2 , respectively.

(Answer = 2m , 2.85m)

Problem 4Draw the variation of vertical stress due to point load , and the horizontal variation at constant Z.