A normally consolidated deposit of clay extends to a depth of 20m from ground surface. The groundwater table is 8m below ground surface. If the plasticity index of clay is 70% determine the unconfined compressive strength of clay sample taken from a depth 15m from the ground surface. γsat=19.5kN/m2 and γd=14kN/m2
Profile of a weir on permeable foundation is shown in figure I and an elementary profile of 'upstream pile only case' according to Khosla's theory is shown in figure II. The uplift pressure heads at key points Q, R and S are 3.14 m, 2.75 m and 0 m, respectively (refer figure II). What is the uplift pressure head at point P downstream of the weir (junction of floor and pile as shown in the figure I)?
A 4 m thick layer of normally consolidated clay has an average void ratio of 1.30. Its compression index is 0.6 and coefficient of consolidation is 1 m2/yr. If the increase in vertical pressure due to foundation load on the clay layer is equal to the existing effective overburden pressure, the change in the thickness of the clay layer is ______ mm.
An aquifer of 25 m average thickness is overlain by an impermeable layer of 30 m thickness. A test well of 0.5 m diameter and two observation wells at a distance of 18 m and 65 m from the test well were drilled through the aquifer. After pumping at a rate of 0.2 m3/s for a long time, the following drawdown were stabilized in these wells (i) First observation well = 4 m (ii) Second observation well = 3 m The drawdown (in m) in the test well is
Yield of a well is 10lit/sec under a depression head of 4m. The value of specific capacity per unit area is 0.6/hr. The bottom diameter of the dug well (in m) is ____
10 m below sea water is the bed of sea. Take unit weight of water = 9.81 kN/m2. Take the specific gravity of soil solids and that of sea water as 2.67 and 1.03 respectively. Relative density of soil is 20%. Maximum void ratio is 1 and minimum void ratio is 0.5. By how much amount the effective stress will change if water level rises by 8 m from initial.
The relationship between water content (w%) and number of blows (N) in soils as obtained from Casagrande’s liquid limit device, is given by W = 21 – log10 N The liquid limit (in %) of soil is
The laboratory tests on a soil sample gave the following results: 1). Natural water content, wn = 25% 2). Liquid limit, wL = 60% 3). Plastic limit, wp = 35% 4). Percentage of particle less than 2μ = 20% The value of activity number is
The Factor of Safety of an infinite slope in a sand deposit is found to be 1.732. The angle of shearing resistance of the sand is 30o. The average slope of the sand deposit is given by
From the following type of foundation given below which one of the following foundation can be adopted for following situation. Consider the soil as a low allowable bearing capacity and the soil deposit contains compressible loess. The foundation is provided for a structure carrying heavy loads.