A layer of sand extends from ground level to a depth of 9m and overlies a layer of clay, of very low permeability, 6m thick. The water table is 6m below the surface of the sand. The saturated unit weight of the sand is 19.5 kN/m³ and that of the clay 20 kN/m³; the unit weight of the sand above the water table is 17 kN/m³. Over a short period of time the water table rises by 3m and is expected to remain permanently at this new level. Determine the effective vertical stress at depths of 8 and 12m below ground level (a) immediately after the rise of the water table and (b) several years after the rise of the water table.. WT(2) SAND 3m WT(1) CLAY 12 m

A layer of sand extends from ground level to a depth of 9m and overlies a layer of clay, of very low permeability, 6m thick. The water table is 6m below the surface of the sand. The saturated unit weight of the sand is 19.5 kN/m³ and that of the clay 20 kN/m³; the unit weight of the sand above the water table is 17 kN/m³. Over a short period of time the water table rises by 3m and is expected to remain permanently at this new level. Determine the effective vertical stress at depths of 8 and 12m below ground level (a) immediately after the rise of the water table and (b) several years after the rise of the water table.. WT(2) SAND 3m WT(1) CLAY 12 m

Principles of Foundation Engineering (MindTap Course List)

9th Edition

ISBN:9781337705028

Author:Braja M. Das, Nagaratnam Sivakugan

Publisher:Braja M. Das, Nagaratnam Sivakugan

Chapter2: Geotechnical Properties Of Soil

Section: Chapter Questions

Problem 2.8P

See similar textbooks

Related questions

Q: A silty sand fill 4.5 meters thick and an estimated density of 20 kN/m³ is to be placed over 4.0 m…

A: eo = 1.255Cc = 0.29Cr = 0.035Cv = 0.79 m2/yrNOTE : As per guidelines, first 3 parts are solved.…

Q: (b) A layer of saturated clay with 4 m thick is overlain by sand with thickness of 5 m deep, the…

Q: A cubic meter of dry (no water) quartz sand (G, = 2.65) with a porosity of 60% is immersed in an oil…

A: Vt = 1 m3Gs = 2.65n = 60% or 0.60 = 0.92 g/cm3 or 920 kg/m3 Vair = 0.27 m3

Q: when flowing through the same rock at 20°C? want weight = 8.44 kN/m³) 6.10 The maximum dry unit…

A: Given data - Relative compaction = 90% Max. dry unit weight in lab = 16 KN/m3 Gs = 2.7 k1 = 0.03…

Q: The soil profile consists of a 15 m layer of sand underldin by a 25 m layer of clay. The location of…

A: From the above figure water will rise at 10 m+ effective pressure at bottom of the sand(81.9…

Q: 1. (30 pts) The soil profile shown below consists of 10 meters of sandy silt overlying gravel. The…

A: Step 1:Step 2: Step 3: Step 4:

Q: Q3. A soil in its natural state is partially saturated having a water content of 17.5% and a void…

Q: A layer of silt 3.5 m thick underlain by 3 m thick tay layer. The water table is located at 2.5 m…

Q: A bed of sand consists of three horizontal layers 10.0 of equal thickness. The value of Darcy's 'K'…

Q: Calculate the saturated density from void ratio 0.8.

A: The saturated density of soil is defined as the bulk density of soil when the soil is below water…

Q: Effective and Neutral Stress Question 2: The saturated unit weight of sand in the bed of a pond 20 m…

A: Sand in the bed of a pond-Depth h=20 mSaturated unit weight of sand = Unit weight of water Effective…

Q: The relationship between the specific gravity of sand (G) and the hydraulic gradient (i) to initiate…

Concept explainers

Calculation of Settlement

The vertical displacement of the structural foundation due to the loading from the superstructure is known as settlement. It is due to the reduction of air voids present in the soil. The amount of vertical displacement depends on the bearing capacity of the soil on which the foundation is laid. The effect of the settlement depends on the magnitude of settlement, uniformity, and the structural design of the structure. The maximum allowable settlement for residential and office buildings should be less than 18 mm, for industrial buildings, it is 38 mm and for commercial buildings, it is 25 mm.

Question

A layer of sand extends from ground level to a depth of 9m and overlies a layer of clay, of
very low permeability, 6m thick. The water table is 6m below the surface of the sand. The saturated
unit weight of the sand is 19.5 kN/m³ and that of the clay 20 kN/m³; the unit weight of the sand above
the water table is 17 kN/m³. Over a short period of time the water table rises by 3m and is expected to
remain permanently at this new level. Determine the effective vertical stress at depths of 8 and 12m
below ground level (a) immediately after the rise of the water table and (b) several years after the rise
of the water table..
WT(2)
SAND 3m
WT(1)
CLAY
8 m
12 m
6m

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1

VIEW

Step 2

VIEW

Step 3

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 3 steps with 3 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, civil-engineering and related others by exploring similar questions and additional content below.

Similar questions

Q A layer of sand extends from ground level to a depth of 9 m and overlies a layer of clay, of very low permeability, 6 m thick. The water table is 6 m below the surface of the sand. The saturated unit weight of the sand is 19 kN/m3 and that of the clay 20 kN/ m3; the unit weight of the sand above the water table is 17 kN/m3. Over a short period of time the water table lowers by 3 m and is expected to remain permanently at this new level. Determine the effective vertical stress at depths of 8 and 12 m below ground level (a)immediately after the lowering of water table and (b)Several years after the lowering of the water table. Explain your answer for each part.
Soil Mechanics - ANSWER URGENTLY
3.3 A layer of clay 4 m thick lies between two layers of sand each 4m thick, the top of the upper layer of sand being ground level. The water table is 2 m below ground level but the lower layer of sand is under artesian pressure, the piezo- metric surface being 4 m above ground level. The saturated unit weight of the clay is 20 kN/m³ and that of the sand 19 kN/m³; above the water table the unit weight of the sand is 16.5 kN/m³. Calculate the effective vertical stresses at the top and bottom of the clay layer.
A 5 m thick clay layer lies between two layers of sand each 4 m thick, the top of the upper layer of sand being at ground level. The water table is 2 m below the ground level but the lower layer of sand is under artesian pressure, the piezometric surface being 4m above ground level. The 27 saturated unit weight of clay is 20 kN/m³ and that of sand is 19 kN/m³. Above the water table unit weight of sand is 16.5 kN/m³. Calculate the effective vertical stresses at the top and bottom of the clay layer. Also draw the total vertical stress diagram in the given soil layers.
A stratum of normally consolidated clay 7 m thick is located at a depth 12m below ground level. The natural moisture content of the clay is 40.5 per cent and its liquid limit is 48 per cent. The specific gravity of the solid particles is 2.76. The water table is located at a depth 5 m below ground surface. The soil is sand above the clay stratum. The submerged unit weight of the sand is 1 1 kN/m3 and the same weighs 18 kN/m3 above the water table. The average increase in pressure at the center of the clay stratum is 120 kN/m2 due to the weight of a building that will be constructed on the sand above the clay stratum. Estimate the expected settlement of the structure in cm. a. 9.55 b. 4.96 c. 4.83 d. 23.3
A 5 m thick clay layer lies between two layers of sand each of 3 m thick, the top layer being at ground level. The water table is 1 m below the ground level, but the lower layer of sand is under artesian pressure, the piezometric surface being 2 m above ground level. The saturated unit weight of clay is 20 kN/m² and that of sand is 19 kN/m³. Above the water table, the unit weight of sandy soil 17 kN/m³, Calculate the effective stress just below the clayey Layer (in kN/m², up to two decimal places).
A sand has Gs = 2.66. Calculate the hydraulic gradient that will cause boiling for e = 0.35, 0.45, 0.55, 0.7, and 0.8.
Calculate the final settlement of the clay layer shown in figure due to an increase of pressure of 3 ton/m? at mid-height of the layer. Also calculate the settlement when the water table rises to the surface. Sand 4m Y=2 ton/m3 1.25m _2.5m Clay LL = 34.45% eo = 1.3 y=1.8 ton/m³ 1.25m
A layer of silt 3.5 m thick underlain by 3 m thick tay layer. The water table is located at 2.5 m below the ground surface. The capillary rise that layer is 1.5 m. Assuming that the sit and clay layer has the following parameters Sile layer: Depth 0-1 m:G-2.7, e-0.6: 5-0% Depth 1-3 G-27; -0.6 5-6 Depth 25-33 G-2.7; e-0.6: 5-100% Clay layer: G-2.69; -0.807; S-100% (Full (1) Calculate the total and effective stresses and pure water pressure at points A, B, C, D and Eat 0, 1,25,3.5 and 6.5 m respectively Auming no capillary rise. 145 Marks) (1) Repeat (1), this time with capillary rise of 15m 145 Marks) (i) Comment on the effect of capillary rise 12
A layer of sand, 4m thick, overlies a layer of low permeability clay, 5mthick. The bulk unit weight of the sand is 16.5 kN/m3 and its saturatedunit weight is 18 kN/m3 . The saturated unit weight of the clay is 21kN/m3 . The water table exists initially at 1.0m below ground level butpumping will permanently and rapidly lower the water table to 3.0mbelow ground level.Determine the variation of total stress and porewater pressure at depthh in the clay and the long-term variation in effective stress.Calculate the initial (before pumping) and the long-term (afterpumping) effective stress at the middle of the clay layer.
A clay stratum 8.0 m thick is located at a depth of 6 m from the ground surface. The natural moisture content of the clay is 56% and G, = 2.75 The soil stratum between the ground surface and the clay consists of fine sand. The water table is located at a depth of 2 m below the ground surface. The submerged unit weight of fine sand is 10.5 kN/m² and its moist unit weight above the water table is 18.68 kN/m? Calculate the effective stress at the center of the clay layer. 6 m -8 m- Sand Clay Figure Ex. 5.11 2 m 4 m 4 m
A cubic meter of dry (no water) quartz sand (G, = 2.65) with a porosity of 60% is immersed in an oil bath having a unit weight of 0.92 g/cm³. How much force in addition to the upthrust (buoyant force) is required to prevent the sand from sinking if the soil contains 0.27m³ of entrapped air after submergence?