9.4 An exploratory drill hole was made in a stiff saturated clay (see Figure 9.9). The sand layer underlying the clay was observed to be under artesian pressure. Water in the drill hole rose to a height of 4 m above the top of the sand layer. If an open excavation is to be made in the clay, how deep can the excavation proceed before the bottom heaves? Exploratory deill hole G,-2.72 Moisture content w- 35% 6.1m 4 m wnted chu

9.4 An exploratory drill hole was made in a stiff saturated clay (see Figure 9.9). The sand layer underlying the clay was observed to be under artesian pressure. Water in the drill hole rose to a height of 4 m above the top of the sand layer. If an open excavation is to be made in the clay, how deep can the excavation proceed before the bottom heaves? Exploratory deill hole G,-2.72 Moisture content w- 35% 6.1m 4 m wnted chu

Fundamentals of Geotechnical Engineering (MindTap Course List)

5th Edition

ISBN:9781305635180

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter8: Stresses In A Soil Mass

Section: Chapter Questions

Problem 8.16P

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An exploratory drill hole was made in a stiff saturated clay having a moisture content of 29% and Gs = 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. If an open excavation is to be made in the clay, determine the safe depth of excavation before the bottom heaves.
An exploratory drill hole was made in a stiff saturated clay, as shown in Figure 1, having a moisture content of 25% and Gs = 2.56. The sand layer underlying the clay was observed to be under artesian pressure. Water in the drill hole rose to a height of 3 m above the top of sand layer. If an open excavation is to be made in the clay. a.What is the maximum depth of excavation before the bottom heaves? b.What would be the required height of water inside the cut in order to ensure a factor of safety of 1.5?
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A 9.15m thick layer of sandy soil overlies an impervious rock. The groundwater level is at a depth of 1.22m below the top of the soil. Water was pumped out of the soil from a central well at the rate of 5680 kg/min and the drawdown of the water table was noted in two observation wells. These two wells were on a radial line from the centre of the main well at distances of 3.05m and 30.5m. During the pumping the water level in the well nearest to the pump was 4.75m below ground level. In the furthest well was observed to be 2.13m below ground level. Make a sketch of the situation explained in the foregoing and indicate what kind of aquifer is being described. Evaluate the permeability of this aquifer in m/day.