n exploratory drill hole was made in a stiff saturated clay having a moisture content of 29% and G, = 2.68 (Figure 9.27). The sand layer underlying the clay was observed to be under artesian pressure. Water in the drill hole rose to a height of 6 m above the top of the sand layer.  a. If an open excavation is to be made in the clay, determine the safe depth of excavation before the bottom heaves.  b. How much is the pressure at the interface of the clay and sand? c. If a factor of safety of 2.0 is to be ensured, how deep should be the excavation from the ground surface?

gerotechnical engineering question

A storage tank of diameter of 30 m and gross (total)weight 105 kN is to be constructed on site shown below. To construct the tank 5 m of the dense sand layer will be excavated and the tank will be built as shown .a) Calculate the increase in stress in the clay layer under the center of the tank . b) Calcuate the final consolidation settlement due to the tank. C) how much settlement that would be expected to occure 1 year, 5 years and 20 years after the tank is completed. d)- Assume that the silty clay were originally overconsolidated (OCR=1.4), how would be the ultimate consolidations settlements be different? Given c 0.03 %3D Dense Sand, G,-2.80; e=0.55 10m 0.95 Saturated nomially consolidated silty clay C43 10" m day 20 m G267: Drained permicable sandstone

Please solve this problem and explain each step clearly, Please explain the theory and show your work clearly, I really want to understand. Thank you