### Use a numerical method to estimate the excess pore pressure

Assignment Help Civil Engineering
##### Reference no: EM13544557

At the site of a large scale land reclamation project 2 m of sand overlie a silty clay layer 5 m thick, which overlies highly fractured permeable rock. The project involved rapidly placing 5 m of fill over a large area that applied a stress of 100 kPa to the underlying soil. It was initially expected that after 2 years consolidation would be complete. However, after 2 years the excess pore pressures in the silty clay layer were still significant and had the values shown in the table below.

Depth below

top of clay layer (m)   Excess pore pressure(kPa)

0                                         0

1                                         25

2                                         40

3                                         50

4                                         40

5                                         25

6                                         0

To speed up consolidation it is proposed to place additional fill, starting at t = 2 years, so that the stress on the clay increases at a rate of 10kPa/month for 6 months, at which time all the additional load will be removed.

a.Assuming that consolidation is occurring under 1-Dimensional conditions show that the pore pressures measured at 2 years are consistent with a cv of approximately 1.7 m2/yr.

b.Use a numerical method to estimate the excess pore pressure distribution in the clay layer between 2 years and 2.5 years from the start of the land reclamation, and hence determine the settlement at 2.5 years. Use ?t = 2 months, ?z = 1 m, and take mv = 0.0001 m2/kN.

#### Questions Cloud

 Find the stress in the steel and the stress in the concrete : A 14-in. square concrete post is 6ft tall and reinforced by nine 3/4" diameter steel rods. Assume that the materials are high-strength concrete and ASTM-A36 structural steel. What is the difference in water levels between reservoirs : A wrought iron water line connecting two reservoirs at 20°C has a length of 1500 m, a diameter of 75 cm, two elbows (90º, long-radius, flanged), a fully open gate valve, and a reentrant pipe entrance. Find the magnitude of the velocity and acceleration for the : Sketch the flow field defined by u=3y, v=2 and derive expressions for the x and y components of acceleration. Find the magnitude of the velocity and acceleration for the point having the coordinates (3,4). Specify units in terms of L and T. Parallel and perpendicular lines : Write an equation in slope-intercept form of the line that passes through the given point and is perpendicular to the given line - Write an equation in slope-intercept form of the line. Use a numerical method to estimate the excess pore pressure : At the site of a large scale land reclamation project 2 m of sand overlie a silty clay layer 5 m thick, which overlies highly fractured permeable rock. Find the steady state concentration if the air in the box : Consider the air over a city to be a box 100km on a side that reaches up to an altitude of 1.0 km. The air is blowing into the box along one of its sides with a speed of 4 m/s Determine the force p that must be applied to the cylinder : The brass tube AB (E=105 GPa) has a cross-sectional area of 140 mm^2 and is fitted with a plug at A. The tube is attached at B to a rigid plate that is itself attached at C to the bottom of an aluminum cylinder Determine the required do concentration in the treatment : Given the following information, determine the required DO concentration in the treatment plant effluent discharge in order to ensure that at no point downstream the DO in the river drops below 4 mg/L: Determine the required diameter of the thread : A nylon thread is to be subjected to a 10-N tension. Knowing that E=3.2 GPa, that the maximum allowable normal stress is 40 MPA, and that the length of the thread must not increase by more than 1%, determine the required diameter of the thread.

### Write a Review

#### Determine the filtration rate at the depth of the layer

The absolute viscosity and density of water are 1.4X10^-3 Pa-s and 998 kg/m^3, respectively. For a head loss of 0.1 m, determine the filtration rate (m/d) if the depth of this layer of sane is 0.1m

#### Determine what is speed of the car as it passes the light

If the motorist wishes to pass the light just as it turns green without having to stop, what is the required uniform deceleration of the car and what is the speed of the car as it passes the light

#### Determine the increase in the temperature of the river

A power plant operates at steady-state. It receives energy from a hot source (combustion of fuel) at a temperature of 420 oC. The plant discharges this energy to a nearby river that acts as a cold source.

#### Determine the worked deeloped in kj per kg of air

air enters a turbine operating at steady state at 8 bar, 1127 C and exits at 1.5 bar, 347 C. The heat transfer from the turbine to its surroundings is 10 kJ/kg of air flowing through the turbine.

#### Determine what is flexural rigidity ei of the diving board

Consider a diver weighing 200 lb at the end of a diving board that cantilevers out over 3 ft. The diver oscillates at a frequency of 2 Hz. What is the flexural rigidity EI of the diving board

#### Determine the force required to lift the block of stone

Determine the force required to lift the block of stone that weighs 200 lb. The rollers are frictionless and the static coefficient between all other surfaces is 0.3. Neglect the size and weight of the wedges.

#### Determine the approximate dimensions of each carbon bed

A two-bed carbon adsorption system is to be designed to handle 8000 acfm of air containing 700 ppm of hexane. Laboratory studies indicate that carbon can adsorb 8lb hexane per 100 lb carbon under the conditions

#### Determine how the steam is extracted from the turbine

During a regeneration process, some steam is extracted from the turbine and is used to heat the liquid water leaving the pump. This does not seem like a smart thing to do since the extracted steam could produce

A rectangular copper specimen (Table 1--> E=120GPa) is loaded in tension of 300MPa and then the load is removed. The total plastic strain in the unloaded specimen is e=0.25.

#### What is the total lenth ac and its standard deviation

A line AC was observed in 2 sections AB and BC, with lengthsand standard deviations listed below. What is the total lenth AC and its standard deviation?

#### Determine maximum tensile and compressive bending stresses

A rectangular tube has an outside dimensions that are 2in wide and 4in deep and a wall thickness of 0.25in. The tube is acted on by a bending moment of 12,000lb-in.

#### Determine the approximate flow rate in a conduit

Water at 20 C flows in a conduit with a cross-section shaped in the form of an equilateral triangle. The cross-sectional area of the conduit is 100 sqaure meters and e=0.045 mm.