.5 A layer of sand extends from ground level to a depth of 9 m 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 kN/m' and that of the clay 20 kN/m'; the unit weight of the sand above the water table is 16 kN/m³. Over a short period of time the water table rises by 3 m and is expected to remain permanently at this new level. Determine the effective vertical stress at depths of

.5 A layer of sand extends from ground level to a depth of 9 m 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 kN/m' and that of the clay 20 kN/m'; the unit weight of the sand above the water table is 16 kN/m³. Over a short period of time the water table rises by 3 m and is expected to remain permanently at this new level. Determine the effective vertical stress at depths of

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 2.15P

See similar textbooks

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.
A dense silt layer has the following properties: e=0.30, D10=10µm and capillary constant = 0.20cm2 Free ground water level is 8m below the ground surface. Determine the vertical effective stress (kPa) at 5m depth (point A). Assume unit weight of solids = 26.5 KN/m3 and that the soil above the capillary rise and ground surface is partially saturated at 50%.
A layer of sand extends from group level at 9m and overlies a layer of clay of very Low permeability 6m. The water table is 6m below the surface of the sand the saturated unit weight of the sand is 19kn/m3.and that of the clay 20kn/m3.the unit weight of the sand above the ? table is 17kn/m3 .over a short period of time the water table lower by 3m. And expected to remain permanently at that Level. Determine the effective vertical stress at depth of 8 and 12m. Below the ground level.(a) immediately after the lowering of water table (b) several years after the lowering of the water table. Explain your answer for each step.
A dense silt layer has the following properties: void ratio e = 0.50, effective Diameter D10 = 10 μm, capillary constant C = 0.20 cm2. The free groundwater level is 8m below the ground surface. Assume unit weight of solids y= 26.50kN/m3. Find the vertical effective stress at 10m depth. Assume that the soil above the capillary zone is partially saturated at 50%.
A dense silt layer has the following properties: e =0.406 D10= 10.1 um Capillary constant = 0.209 sq.cm Free ground water level is 8m below the ground surface. 1.) Find the height of capillary rise in the siltin meters. 2) Find the vertical effective stress at 6m depth. Assume ys = 26.51 kn/m3 and the soil above capillary action rise and ground surface is partially saturated at 79%.
A dense silt has the following properties: Void ratio (e) = 0.40, SpecificGravity (Gs) = 2.70, Effective diameter d10 = 1x10^-6 m, Capillary constant (C) = 0.20 cm^2. Free ground water level is 8.0 m below the ground surface. a. Find the height of capillary rise in the silt. b. Find the vertical effective stress in kPa at 5m depth. Assume that the soil abovethe capillary zone or capillary action rise to be dry soil and the soil within thecapillary action be partially saturated (degree of saturation, S) at 50%. c. Find the vertical effective stress at 10m depth. Assume that the soil above thecapillary zone or capillary action rise to be dry soil and the soil within the capillaryaction be partially saturated (degree of saturation, S) at 50%.
A dense silt layer has the following properties.void ratio = 0.30eff. Diameter ?10 = 10??capillary constant (c)=0.20 cm²Groundwater level is 8.0m below the ground surface 1. Calculate the height of capillary rise in the silt. 2. Calculate the vertical effective stress in kpa at 5m depth, assume ?? = 26.5 ??/?³and that the soil above the capillary action rise and ground surface is partially saturated at 50%. 3. Calculate the effective vertical stress at 10m depth assuming ?? = 26.5 ??/?³and that the soil above the capillary action rise and ground surface is partially saturated at 50%.
The profile at a site consists of 5m of sand overlying 10m of compressible clay, which in turn overlies a dense sand. The water table is at the top of the profile. The total unit weight of the top sand is 19kN/m3 and that of the clay is 18kN/m3. The Cv of the clay is estimated to be 5x 10-3 cm2/sec. Initially the clay is normally consolidated. It is planned to place a temporary fill that will exert a vertical load of 200kPa over the entire site. How long must the fill be in place so that, after it is removed, the maximum past pressure at every point in the clay is at least 50kPa larger than the vertical effective stress that existed before the fill was placed?
The subsoil strata at a site consist of fine sand 3.0 m thick overlying a stratum of clay 2.8 m thick. Under the clay stratum lies a deposit of coarse sand extending to a considerable depth. The water table is 2.8 m below the ground surface. Assuming the top fine sand to be saturated by capillary water, calculate the effective pressures at ground surface and at depths of 3.0 m, 5.8 m and 8.0 m below the ground surface. Assume for fine sand G = 2.65, e = 0.83 and for coarse sand G = 2.79, e = 0.53. What will be the change in effective pressure at depth 3.74 m, if no capillary water is assumed to be present in the fine sand and its bulk unit weight is assumed to be 16.88 kN/m3 . The unit weight of clay may be assumed as 19.75 kN/m3. Comment on the effect of the present of groundwater on design of earth structures?
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 sea is 15 m deep. The seabed consists of a depth of sand of saturated unit weight 20 kN/m3 .The shear strength parameters of the sand are c'=0, and '=35. Calculate the shear strength of soil and lateral earth pressure 5m below the seabed.
50 ft thick sand is underlain by 25 ft clay. The ground water table, initially at the ground surface, was lowered to a depth of 25 ft below the ground. After such lowering, the degree of saturation of the sand above water table was lowered to 20%. Saturated and dry unit weight of sand are 135 pcf and 116 pcf respectively. The saturated unit weight of clay is 120 pcf. a. what is the unit weight of the sand above the water table after lowering in pcf? b. What is the vertical effective pressure at the midheight of the clay layer when the water table is lowered 50 ft. Below the ground in psf?