Scribd
Upload
282 views2 pages

Pile Load Capacity

This document provides information and calculations to determine the vertical load carrying capacity of a bored pile group. It specifies details of the pile group including the number of piles, their diameter and spacing. It also gives soil properties from borehole data. The calculations determine the ultimate tip capacity, skin friction capacity along the pile shaft, and group efficiency factor to arrive at the final vertical load capacity of the pile group. The factors of safety against failure both including and excluding the pile tip capacity are then calculated.

Uploaded by

Aziz ul Hakeem
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as XLS, PDF, TXT or read online on Scribd
282 views2 pages

Pile Load Capacity

This document provides information and calculations to determine the vertical load carrying capacity of a bored pile group. It specifies details of the pile group including the number of piles, their diameter and spacing. It also gives soil properties from borehole data. The calculations determine the ultimate tip capacity, skin friction capacity along the pile shaft, and group efficiency factor to arrive at the final vertical load capacity of the pile group. The factors of safety against failure both including and excluding the pile tip capacity are then calculated.

Uploaded by

Aziz ul Hakeem
Copyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as XLS, PDF, TXT or read online on Scribd
You are on page 1/ 2

VERTICAL LOAD CARRYING CAPACITY OF BORED PILES

General Information
Method given in the book "FOUNDATION ANALYSIS AND DESIGN" by J.E.Bowles

Design load applied on a single pile (KN) 1200 KN


Diameter of the Pile, D (m) 0.75 m
No. of piles in the group, Np 6
Rows of piles, Nrow 2
Columns of piles, Ncol. 3
Center to distance between the rows, Srow (m) 2.8 m
Center to distance between the columns, Scol (m) 2.8 m
Scour depth (m) 1.5 m

Bore Log Information / Effective Soil Layers after Scouring:

Layer Wall Fr.


Layer No. Unit. Wt.
Soil Type Thickness. ' K
From NSL Angle (KN/m3)
(m)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16

Load Carrying of Piles, P u = P pu + P s


Where Ppu is the tip or point capcity and Ps is skin friction capacity.

A. POINT/TIP CAPACITY OF THE PILE

Ultimate bearing capacity of the soil at pile tip/point, qult. 800 KN/m2.

Point/Tip capacity of the pile, Pp = Ap * qult. 353.4292 KN


B. SKIN FRICTION CAPACITY OF PILE
Ps = As f s

f s = K q tan
Where As is shaft area in contact with soil, fs is skin friction, K is coefficient of lateral earth
pressure ranging from K0 to 1.75 (values close to K0 are generally recommended due to long
term soil creep effect.), q is effective vertical stress, and is wall friction angle between pile
and soil material.

K0 = 1-Sin'
Where ' is drained angle of internal friction (for clays see fig. 229 J.E.Bowles)

Skin Friction capacity of the pile, Ps 4116.077 KN

C. GROUP EFFICIENCY OF PILES


(n1) m + ( m1) n
Eg = 1
90 n m
Where Eg, is group efficiency of piles, n is no. of columns in pile group, m is no. of rows
in pile group.

= Tan1 ( D/ S avg ) in deg rees


Where D is diameter of pile, Savg is the average distance between rows and columns of piles.

Group Efficiency, Eg 80.561 %

Factor of Safey against failure, including Point Capacity, 0.00


Factor of Safey against failure, Excluding Point Capacity, 0.00

You might also like