Final $($Case Study$)-$ Foundation Engineering

CIVE $424$

Name:

ID #:

Time: $120$ minutes

Instructor: Dr$.$ Riad Al Wardany

Date: April ${28}^{th},2021$

$01$:

Consider the soil profile below. The piles used are driven pipe piles with a flat driving point; they will be filled with concrete once in$-$place. The water table was observed at $5m$ depth from the natural ground level. Investigation boreholes were drilled and undisturbed soil samples were taken from the different layers using Shelby tubes. The soil samples were used to determine the soil unit weight and the unconfined compressive strength of the different encountered layers.

a$)$ Calculate the undrained cohesion $(c_n)$ for each soil layer

b$)$ Use Meyerhof's method to calculate the point bearing capacity of each individual pile

c$)$ Draw the variation of the effective vertical stress ${}_0{?}_0$ with respect to depth

d$)$ Calculate the skin resistance of each individual pile $($Qs$)$ by $1)$ the a method, $2)$ the $$ method and $3)$ the $$ method; assume OCR $=3$ for the bottom layer

e$)$ Estimate the total allowable bearing capacity of each individual pile

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Final $($Case Study$)-$ Foundation Engineering

CIVE $424$

f$)$ The pile group consists of $4$ piles arranged as follows. Determine the allowable load bearing capacity of the pile group

g$)$ The result of the consolidation test on a sample retrieved from the middle of the bottom layer. Deduce from the graph the compression index, swelling index and over consolidation ratio of the tested soil. Indicate whether this layer is over$-$consolidated or not. Justify your answer.

h$)$ In service, the group of piles is assumed to bear a total load equal to $1200kN.$ Determine the consolidation settlement of the piles.

Take:

Atmospheric pressure $P_A=100$kPa

Unit weight of water ${}_w=10k\frac{N}{m^3}$

Spring $2021$

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