CONFIDENTIAL
UNIVERSITI TUN HUSSEIN ONN MALAYSIA
TEST 1 SEMESTER II SESSION 2016/2017
COURSE NAME
:
GEOTECHNICS 1
COURSE CODE
:
BFC21702
PROGRAMME CODE
:
BACHELOR OF CIVIL BFF ENGINEERING WITH HONOURS
EXAMINATION DATE
:
31 MARCH 2017 / MARCH 2017
DURATION
:
1 HOUR 30 MINUTES
INSTRUCTIONS
:
1. ANSWER ALL QUESTIONS 2. WRITE DOWN YOUR ANSWERS IN THE ANSWER BOOKLET 3. ATTACH TTACH ALL A LL YOUR YOU R ANSWERS ANS WERS IN GRAPH PAPERS TO THE ANSWER BOOKLET
THIS QUESTION PAPER CONSISTS OF SIX (6) PAGES
1
CONFIDENTIAL
Q1
(a)
BFC21702
Atterberg limit is a basis measurement of the critical water contents for fine-grained soil. Illustrate and explain the atterberg limit boundary by consider the liquid limit (LL), plastic limit (PL) and shrinkage limit (SL). (5 marks)
(b)
(c)
Grain size distribution curves of samples A and B are given in Figure Q1(b-1). Based on this figure; (i)
Determine the percentages of gravel, sand, silt and clay of both soil types according to AASHTO classification system as shown in Figure Q1 (b-2). (4 marks)
(ii)
On the basis of the gravel, sand, silt and clay percentages, classify the types of soil sample A and B. (1 marks)
Soil investigations were carried on four different samples designated as W, X, Y and Z that collected in several locations in Malaysia. The results were recorded in Table 1 and analyzed in Figure Q1(c). (i)
Determine the Plastic Limit (PL) of sample W, X, Y and Z. (2 marks)
(ii)
Classify the soils type of each sample by the AASHTO classification system as shown in Table 2. (5 marks)
(iii)
If F is the percentage of particles passing sieve No. 200, calculate the Group Index (GI) of Sample W, X, Y and Z using Equation 1 and/or Equation 2 (Refer page 6). (6 marks)
(iv)
According to the AASHTO classification system on sample W, X, Y and Z, which sample would make the best highway subgrade? Why? (2 marks)
2
CONFIDENTIAL Q2
(a)
Explain the following components of soil based on weight-volume relationships. (i) (ii) (iii) (iv)
Void ratio Porosity Degree of saturation Unit weight (4 marks)
(b)
Soil mass consist of three main phases including fully saturated, partially saturated and dry soil. Illustrate and indicate the phase diagram of : (i)
Partially saturated soil with volume of soil solids equal to one. (3 marks)
(ii)
Fully saturated soil with volume of soil solids equal to one. (3 marks)
(c)
If ρ sat = M/ V , where M is the mass of saturated soil and demontrate that ρ sat is equal to ρw(G s + e)/ 1+e .
V is
the volume of the soil, (5 marks)
(d)
A soil sample collected in Ulu Tiram, Johor has a volume of 0.28 m 3 and weighs 5450 N. The oven dry weight of the soil is 4928 N. If G s = 2.73, calculate: (i)
The moisture content and moist unit weight. (2 marks)
(ii)
Dry unit weight and void ratio. (4 marks)
(iii)
Porosity and degree of saturation. (4 marks)
END OF QUESTIONS
3
CONFIDENTIAL
TEST 1 SEMESTER/SESSION COURSE NAME
: SEM II / 2016/2017 : GEOTECHNICS I
PROGRAMME CODE : 2 BFC COURSE CODE : BFC21702
`
A B
FIGURE Q1(b-1) : Particle-size distribution curves of sample A and B
FIGURE Q1(b-2) : Grain size of various classification systems
4
CONFIDENTIAL TEST 1 SEMESTER/SESSION COURSE NAME
: SEM II / 2016/2017 : GEOTECHNICS I
PROGRAMME CODE : 2 BFC COURSE CODE : BFC21702
TABLE 1: Result of Sample W, X, Y and Z. Percentage Passing (%) Soil Type
Liquid Limit
Plasticity Index
No. 4 (4.75 mm)
No.10 (2.00 mm)
No.40 (0.075 mm)
No. 200 (0.075 mm)
W
80
72
62
38
28
10
X
100
90
68
30
30
9
Y
100
100
96
72
58
23
Z
94
80
51
15
26
12
X
Y
W
Z
FIGURE Q1(c) : Grain size distribution of sample W, X, Y and Z.
5
CONFIDENTIAL
BFC21702
TEST 1 SEMESTER/SESSION COURSE NAME
: SEM II / 2016/2017 : GEOTECHNICS I
PROGRAMME CODE : 2 BFC COURSE CODE : BFC21702
TABLE 2: AASHTO Classification System (AASHTO M-145) General Classification Group classification Sieve analysis (% passing) No.10 (2.0 mm) No.40 (425µm) No.200 (75µm) Characteristics of fraction passing No. 40 (425µm)
Granular Material (35% or less passing 0.075 mm (Sieve No. 200) A-1 A-2 A-3 A-1-a A-1-b A-2-4 A-2-5 A-2-6
50 max 30 max 15 max
50 max 25 max
51 min 10 max
35 max
35 max
35 max
A-2-7
Fine Grained Soils (>35% passing 0.075 min (No. 200) A-7 A-4 A-5 A-6 A-7-5* A-7-6ψ
35 max
36 min
36 min
36 min
36 min
Liquid Limit 40 max 41 min 40 max 41 min Plasticity Index 6 max N.P 10 max 10 max 11 min 11 max Usual types of significant Stone fragments, Fine Silty or clayey gravel and sand constituent gravel and sands sand materials General rating Excellent to good as subgrade * For A-7-5, PI ≤ LL-30 @ PL ≥ 30 Ψ For A-7-6, PI > LL – 30 @ PL < 30
40 max 10 max
41 min 10 max
40 max 11 min
41 min 11 min
Silty soils
Fair to poor
EQUATION - 1
= ሺ − 35ሻሾ0.2 + 0.005ሺ − 40ሻሿ + 0.01ሺ − 15ሻሺ − 10ሻ EQUATION - 2
= 0.01ሺ − 15ሻሺ − 10ሻ
6
Clayey soils
