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FOUNDATION ENGINEERING
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159 views15 pagesBFC 43103
FOUNDATION ENGINEERING
Uploaded by
znyaphotmail.comCopyright
© © All Rights Reserved
We take content rights seriously. If you suspect this is your content, claim it here.
Available Formats
Download as PDF or read online on Scribd
/ 15
.CONFIDENTIAL
UTHM
Universiti Tun Hussein Onn Malaysia
UNIVERSITI TUN HUSSEIN ONN MALAYSIA
FINAL EXAMINATION
SEMESTER I
SESSION 2018/2019
COURSE NAME : FOUNDATION ENGINEERING
COURSE CODE : BFC 43103
PROGRAMME CODE : BEF
EXAMINATION DATE : DECEMBER 2018 / JANUARI 2019
DURATION : 3 HOURS
INSTRUCTION : ANSWER ALL QUESTIONS IN
SECTION A, AND ANY THREE (3)
QUESTIONS IN SECTION B
THIS QUESTION PAPER CONSISTS OF FIFTEEN (15)
CONFIDENTIAL BFC 43103
CONFIDENTIAL
SECTION A
Qi (@)_Briefly, discuss ONE (1) mechanical modification and ONE (1) hydraulic
(b)
©)
modification technique for ground improvement.
(4 marks)
The in situ void ratio, ¢ of a borrow pit is 0.72. The borrow pit soil is to be excavated
and transported to fill a construction site where it will be compacted to a void ratio of
0.42. The construction project requires 10,000 m? of compacted soil fill. Determine
the volume of soil that must be excavated from the borrow pit to provide the required
volume of fill.
(4 marks)
Refer to Figure Q4(e) and Table QU(¢) for a large fill operation, the average
permanent load (A’(p) on the clay layer will increase by about 57.5 KN/m?. The
average effective overburden pressure on the clay before the fill operation is 71.88
kN/m?, For the clay layer, which is normally consolidated and drained from top and
bottom, it is also given that He = 4.57 m, Ce = 0.30, e0 = 1.0, ey = 9.68 x 10 em*/min,
Determine the followings:
(i) The primary consolidation settlement of the clay layer caused by the addition of
the permanent load, Ao" p.
(2 marks)
(ii) The time required for 80% of primary consolidation settlement under the
addition permanent load only.
(4 marks)
(iii) The temporary surcharge, Ao’, that will be required to eliminate the entire
primary consolidation settlement in 12 months by the precompression technique.
(6 marks)
CONFIDENTIAL BFC 43103
CONFIDENTIAL
SECTION
Q2 —(@)__ Site investigation is one of the important process in foundation works. Explain in
detail the purposes of doing site investigation or subsurface exploration.
(6 marks)
(b) Table Q2(b) shows results of a seismic refraction field work at a Batu Pahat
residual soil for proposed new building project.
(Sketch of graph distance against time of first arrival
(6 marks)
(ii) Calculate the seismic velocity and thickness of the material encountered from
the survey.
(8 marks)
Q3_—_(@)_ Explain types of bearing capacity failure.
(6 marks)
(b) The square footing is 1.5 m x 1.5 m in plan, The soil supporting foundation has a
friction angle 29° and cohesive value 92 kN/m?. The unit weight of soil is 19 KN/m*,
Assume the depth of foundation is 1.8 m depth. The column was located 0.3 m
away from the centre of footing in X-axis but remain in the centre for Y-axis,
calculate:
i, The ultimate bearing capacity of soil using Meyerhof’s method (refer Table
Q3(b)@).
(9 marks)
ii, The ultimate bearing capacity of soil using Prakash & Saran’s method ( refer
Figure Q3(b)(ii)).
(S marks)
CONFIDENTIAL BFC 43103,
CONFIDENTIAL
Qa
as
@)
(b)
(a)
(b)
A pile is a slender structural member that is installed in the ground to transfer the
structural loads to the foundation soil. Outline how piles are classified according to
the type of material, cross sectional geometry, method of installation and load transfer
‘mechanism,
(5 marks)
A building was constructed with conerete piles used for its foundation that is
embedded in sand. The building imposed an allowable working load of 338 kN of.
point load and 280 KN of frictional resistant load on a 0.305 x 0.305 m cross section
piles. Site investigation has shown that the sand has a unit weight of (y) 17 KN/m? and
a frictional resistance () of 38°. It is also given that Ep = 21 x 106 kN/m?, ,000
kNim?, 1s = 0.3, and & = 0.62. Calculate the elastic settlement of the pile.
(7 marks)
A group of piles has a section of 3 x 4 with each having a diameter of 500 mm are
embedded in clay. The length of the piles is 12 m and the spacing between the piles
(@) is 1.2 m. The dry unit weight of the clay is 18 kN/m?. The water table is located
at a depth of 2 m and the saturated unit weight of the clay is 20 KN/m’. The recorded
undrained shear strength (C,) profile for the ground is shown in Table Q4(c).
Evaluate the allowable load bearing capacity of the pile with a factor safety of (FS)
of 25.
(8 marks)
Propose and explain the suitable materials used as a backfill of retaining wall,
(2 marks)
A cantilever sheet pile wall penetrating 3.0 m into the sandy soil. The ground water
table is 3 m below the ground surface. The soil properties at site is shown in Figure
Q5(b). For design purposes, the factor of safety of 1.5 was applied on the passive
earth pressure coefficient.
(Determine the stability of the sheet pile wall as shown in Figure Q5(b).
(15 marks)
(ii) According to the answer in Q5(b)(i), if the wall is not stable, propose and explain
briefly the conventional and economical method in the construction of sheet pile.
(G marks)
-END OF QUESTIONS-
CONFIDENTIAL BFC 43103,
» CONFIDENTIAL
FINAL EXAMINATION
SEMESTER / SESSION: SEM1/2018/2019 PROGRAMME CODE: BFF
FOUNDATION ENGINEERING COURSE CODE, + BFC 43103
Table Q1(c): Variation of time factor with degree of consolidation
ue ui 7. ue) Tr vem T
0 o 6 ‘083i 3 O22 8 0539
1 0.00008 2 00372 3 oz ~ os
2 0.0003 2 0.0618 3 0330 0 0367
3 00071 2» 0.0660 3s 0239 a 0588
4 0.00126 x0 0707 36 0288 2 0610
5 0.00196, 31 ors 37 0287 8 0633
6 ‘0.00283, 2 803 58 0287 i 0.688
7 ‘0038s 3 0.0855 59 0276 88 084
8 ‘0.00502 a 0.0907 o 0286 86 om2
9 0.00635, 35 0.0962 6 0297 87 07a
0 0.00785 % oor 2 0307 88 om
us E ue % veo a ui tn
ir ‘0095 7 107 @ rey ‘0305
2 ons 8 ons 6 0329 °0 oss
5 00133 x” on 68 0308 ot sot
4 iss 0 0.126 6 0352 2 0938
15 0177 4 032 67 0364 3 0993
16 ooo 2 0.18 68 ox 34 ss
0 oon? 8 os 0 0300 95 129
is ars 4 ose 70 0.03 % 1219
» 0.0083 45 0.139 n oat 7 1336
» 0514 46 0.166 2 0.31 98 1500
2 0.0346 Po 0173 B 0.46 * 181
2 0.0380, 4 oust 1 0.61 100 *
2 oss ” o.i88 15 0.77
ey 10882, 50 ous %6 0493
as 0.0491 3H 208 n asi
Table Q2(b): Result of a seismic refraction field survey
Distance from the source Time of first arrival of P-wave
of disturbance (m) (sec x 103)
5 10
10 20
15 30
20 40
30, 50
40 60
45 65
60 nT
70 76
80 80
e .
CONFIDENTIAL BRC 43103
» CONFIDENTIAL
FINAL EXAMINATION
EMESTER / SESSION: SEM 1/ 2018/2019 PROGRAMME CODE: BFF
POURSE NAME, FOUNDATION ENGINEERING COURSE CODE, BEC 43103
‘Table Q3(b)(i): Meyerhof’s Bearing Capacity factors for general equation
OTN [TN] N [oO] N Ny Ny
0 | 344 | 1.00 | 0.00 [26 | 22.25 | i1as | 1254
1} 338 | 109 | 007 | 27 | 2394 | 1320 | 1447
2| 563 | 120 | o1s | 28 | 2580 | 1472 | 16.72
3 | 590 | 131 | 024 | 29 | 2786 | 1644 | 1934
4| 619 | 143 | 034 | 30 | 30.14 | 1840 | 2240
s | 649 | 137 | oas | 31 | 3267 | 2067 | 2599
6 | 681 | 172 | os7 | 32 | 3549 | 2318 | 3022
7 35.19
8 41.06
9 48.03
116 | 188 | o71 | 33 | 3864
733 | 2.06 | 086 | 34 | 42.16
792 | 225 | 103 | 35 | 462
10} 835 | 247 | 122 | 36 | 5059 56.31
uf} sso | 2m | 144 | 37 | ss.63 66.19
12 | 928 | 297 | 169 | 38 | 613s 78.03
13 | 981 | 326 | 197 | 39 | 677 92.25
4 | 1037 | 339 | 229 | 40 | 7531 109.41
15 | 1098 | 394 | 265 | 41 | s3.86 130.22
16 | 1163 | 434 | 3.06 | 42 | 93.71 155.55
17 | 1234 | 477 | 3.53 | 43 | 105.11 186.54
18 | 13.10 | 526 | 407 | 44 | 11837 224.64
19 | 13.93 | 580 | 468 | 45 | 133.88 211.76
20| 1483 | 640 | 539 | 46 | 152.10 33035
21 | 1382 | 707 | 620 | 47 | 173.68 403.67
22 | 168s | 782 | 713 | 48 | 199.26 496.01
23 | 1805 | 8.66 | 820 | 49 | 229.93 613.16
24 | 1932 | 9.60 | 944 | 50 | 266.89 762.89
25 | 2072 | 10.66 | 10.88
‘Table Q4(c): Variation of Cu with pile embedment length
Depth (m) 0-4 | 4-7 | 7-13
Undrained shear strength, Cu (KNim?) [70 85 100
CONFIDENTIAL BFC 43103
CONFIDENTIAL
FINAL EXAMINATION
SEMESTER / SESSION. : SEM 1/2018/2019 PROGRAMME CODE: BFE
‘OURSE NAME, FOUNDATION ENGINEERING ‘COURSE CODE BFC 43103,
Surcharge
‘
Surcharge per unit area
a
Aoi) + Ae
Y
Settlement (b)
Figure QI (c)
CONFIDENTIAL BFC 43103
CONFIDENTIAL
FINAL EXAMINATION
EMESTER / SESSION. : SEM 1/ 2018/2019 PROGRAMME CODE: BFF
SOURSE NAME : FOUNDATION ENGINEERING ‘COURSE CODE BFC 43103
Figure Q3(b)(ii
ariation of Nee) , Nae and Nyo With soil friction angle 6
8g
CONFIDENTIA BFC 43103,
» CONFIDENTIAL
FINAL EXAMINATION
ESTER / SESSION : SEM1/ 2018/2019 PROGRAMME CODE: BFF
"OURSE NAME FOUNDATION ENGINEERING COURSE CODE : BFC 43103
Rao wOaRN
Note: pq = atmospheric pressure
>= 100 KN/m? or 2000 Ib/ft?
Figure Q4(i): Variation of a
CONFIDENTIAL BFC 43103,
» CONFIDENTIAL
‘FINAL EXAMINATION
SEMESTER / SESSION. : SEM 1/ 2018/2019 PROGRAMME CODE: BFF
OURSE NAME : FOUNDATION ENGINEERING COURSE CODE BFC 43103
631 kg/m?
Water table
‘Sand
‘you = 20 KN/m?
om o=32
Dred line
Sand Sand
‘Your = 22 KN/m? ysat = 22 KN/m>
7s
o=37 6-32
Figure Q5(b): Sheet Pile Wall
CONFIDENTIAL BEC 4:
CONFIDENTIAL
13103
FINAL EXAMINATION
|SEMESTER / SESSION
‘OURSE NAME
: SEM 1/2018/2019
FOUNDATION ENGINEERING
PROGRAMME CODE
COURSE CODE,
BFF
BFC 43103
List of formula
SOIL IMPROVEMENT AND G
+A.)
wel
y=——t_% _]
in) FAG)
6, +Aq,
log|
RAO enn
For U%: 0% to 60%; 7, ==
100
For U% > 60%:
1.781-0.93 log (100-U%)
|
a
Ac
o =
6
field conditions
Hammer Effiency (%)
Correction for borehole diameter
Sampler correction
Correction for rod length
1
Ts
ne
Variation of ns
Diameter (mi)
60 — 120
1
200
[a
| Variation of ns
Rod lenght (mm) Te
Standard sampler 10
With liner for dense sand and clay | 0.8
With liner for loose sand 09”
op) = D2 —D? vy
4,00) =P)
—_ Nanmenste ‘Schmertmann’s (1975) theory
Neo = “Gq 0.34
where eer Neo
Neo= Standard penetration number, conected for | © 722203(2)
where, of effective overburden pressure
(kPa) = yH
Pa = atmospheric pressure
CONFIDENTIAL BFC 43103
» CONFIDENTIAL
FINAL EXAMINATION
ESTER / SESSION. : SEM 1/ 2018/2019 PROGRAMME CODE: BFF
COURSE NAME, FOUNDATION ENGINEERING COURSE CODE + BPC 43103
ee Modification of Bearing Capacity Equations for Water Table
Case II for water within 0 B, the
= DP ay + Di (You Fe) aed) water will have no effect on
aes 7=7+5(tw-7) | the ultimate bearing capacity.
= ONE Fgh, + GN, FegFy Fy + 4YBN,F, FraF,
Shape Factor
B
F, =1+21an
ia mde tang
_ Depth Factor
D,/B <1,forp=0
Fa =1
Ply <1,forp>0
D
Faq = 1+ 2tang'(1 — sing")? a Fa
D;/B> 1, forp=0
Fat = Fra
D;/B> 1, forp>0
Fa Fa=i
Faq = 1+ 2tan p' (1 — sing’)tai
7 ins
where L is the length of the foundation and L>B
Inclination Factor
Fea = Fat ~ Weta
90°,
Bis the inclination of the load on the foundation with respect to vertical
Eccentric Loading in Shallow Foundations
6M
CONFIDENTIAL CONFIDENTIAL a
FINAL EXAMINATION
sEMESTER / SESSION: SEM 1/ 2018/2019 PROGRAMME CODE: BFF
"OURSE NAME, FOUNDATION ENGINEERING COURSE CODE : BEC 43103
Ge = ON FoFoaFg + INFpFeahy + 27 BNF Fahy
‘One Way Eccentric Loading in Shallow Foundations
Method 2:
Qu = Ale My +0 $770]
1
Quy = 21 eof + AN gaFo +F7PN Fu
$= ON EaR, + ON FoFoka | pot 2-005
+ 7 BNF Fak a
Q,,=4,BL' Fue) = 1.00
26 B 3\(e\(By
Fy ~10+(2-o08)8[oas-(3)(5)](2)
Method 3: -
Gece)
uicenrne)
Gascoe) = Geter) (I= Ry)
eoure) = ING Fa + 2 BN Fog
Qar = BA yecsoic)
Primary Consolidation Settlement for Normally Consolidated Clays.
&
for 2:1 method dof = <= ——
area
Primary Consolidation Settlement for OverConsolidated Clays
foro +A0?,