Shear box test

1. Shear box
Tests

2. Introduction
Shear box test is a test to determine the shear strength of soils.
In principle, this test is to determine the failure strength on a
surface that has been set. This apparatus contains a copper
box, horizontally in the middle of the soil samples. Land
gripped the bars of metal, porous discs can be placed on his
back if necessary to allow the sample drain. Usually the size
of the sample size of 60 mm x 60 mm. To test granular
materials such as gravel or rocky clay, the larger box is
needed, which is 300mm x 300 mm. However, sometimes a
larger dimension is used also
box in
external box
skru motorized
loading
loading screw
motor
hanger load
load
dial gauge
Yoke
pressure plate

3. OBJECTIVE
Student should be able to:
 describes the shear box tests and determine the soil shear
strength parameters

4. Theory
The strength of a soil depends of its resistance to shearing stresses. It
is made up of basically the
Components;
1. Frictional – due to friction between individual particles.
2. Cohesive - due to adhesion between the soil particles
The two components are combined in Coulomb’s shear strength
equation,
τf = c + σf tan ø
Where τf = shearing resistance of soil at failure
c = apparent cohesion of soil
σf = total normal stress on failure plane
ø = angle of shearing resistance of soil (angle of internal friction)
This equation can also be written in terms of effective stresses.
1. Assemble the shear box
2. Compact the soil sample in mould after bringing it to optimum
moisture condition
3. Carefully transfer the sample into shear box
τf = c’ + σ’f tan ø’
Where c’ = apparent cohesion of soil in terms of effective stresses
σ'f = effective normal stress on failure plane
ø’ = angle of shearing resistance of soil in terms of effective stresses
σ'f = σf – uf
uf = pore water pressure on failure plane

5. Equipment
Shear Box Apparatus with ADU
Dial gauge.
Load
Pan Balance – sensitive to 0.1 gram

6. DATA AND ANALYSIS
DEFORMATION
DIAL
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1050
1100
1150
1200
1250
ΔL (mm) x
0.01
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
PROVING RING
DIAL
0
9
14
18
21
25
28
31
31
32
35
37
39
41
42
45
46
47
48
48
49
49
49
49
49
49
LOAD, P
(kN)
0
0.01845
0.0287
0.0369
0.04305
0.05125
0.0574
0.06355
0.06355
0.0656
0.07175
0.07585
0.07995
0.08405
0.0861
0.09225
0.0943
0.09635
0.0984
0.0984
0.10045
0.10045
0.10045
0.10045
0.10045
0.10045
SHEAR
STRESS
P/A
(kN/m2)
0
5.13
7.97
10.25
11.96
14.34
15.94
17.65
17.65
18.20
19.93
21.07
22.21
23.35
23.92
25.63
26.20
26.76
27.30
27.30
27.90
27.90
27.90
27.90
27.90
27.90
STRAIN
ε = ΔL/LO
0
8.33
16.67
25.00
33.33
41.67
50.00
58.33
66.67
75.00
83.33
91.67
100.00
108.33
116.67
125.00
133.33
141.67
150.00
158.33
166.67
175.00
183.33
191.67
200.00
208.33

7. DEFORMATION
DIAL
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1050
1100
ΔL (mm) x
0.01
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
PROVING RING
DIAL
0
5
13
15
16
23
28
33
37
40
43
46
48
50
52
54
55
56
57
58
58
58
58
LOAD, P
(kN)
0
0.01025
0.02665
0.03075
0.0328
0.04715
0.0574
0.06765
0.07585
0.082
0.08815
0.0943
0.0984
0.1025
0.1066
0.1107
0.11275
0.1148
0.11685
0.1189
0.1189
0.1189
0.1189
SHEAR
STRESS
P/A
(kN/m2)
0
2.85
7.40
8.54
9.11
13.10
15.94
18.79
21.07
22.78
24.49
26.19
27.33
28.47
29.61
30.75
31.32
31.89
32.46
33.03
33.03
33.03
33.03
STRAIN
ε = ΔL/LO
0
8.33
16.67
25.00
33.33
41.67
50.00
58.33
66.67
75.00
83.33
91.67
100.00
108.33
116.67
125.00
133.33
141.67
150.00
158.33
166.67
175.00
183.33

8. DEFORMATION
DIAL
0
50
100
150
200
250
300
350
400
450
500
550
600
650
700
750
800
850
900
950
1000
1050
1100
1150
1200
1250
1300
ΔL (mm) x
0.01
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
10.0
10.5
11.0
11.5
12.0
12.5
13.0
PROVING RING
DIAL
0
8
12
18
25
31
36
41
46
50
54
58
60
65
67
69
71
72
75
76
78
78
79
80
80
80
80
LOAD, P
(kN)
0
0.0164
0.0246
0.0369
0.05125
0.06355
0.0738
0.08405
0.0943
0.1025
0.1107
0.1189
0.123
0.13325
0.13735
0.14145
0.14555
0.1476
0.15375
0.1558
0.1599
0.1599
0.16195
0.164
0.164
0.164
0.164
SHEAR
STRESS
P/A
(kN/m2)
0
4.56
6.83
10.25
14.24
17.65
20.50
23.35
26.19
28.47
30.75
33.03
34.17
37.01
38.15
39.29
40.43
41.00
42.71
43.28
44.42
44.42
45.00
45.56
45.56
45.56
45.56
STRAIN
ε = ΔL/LO
0
8.33
16.67
25.00
33.33
41.67
50.00
58.33
66.67
75.00
83.33
91.67
100.00
108.33
116.67
125.00
133.33
141.67
150.00
158.33
166.67
175.00
183.33
191.67
200.00
208.33
216.67

9. Table Maximum Value For Load
Load, P (kg)
Load, σ (kN)
(normal stress)
Maximum Shear
Stress, Ґ
У = mx + C
Ґ = tan θσ + C
5
5 x 10
1000
= 0.05 kN
10
10 x 10
1000
= 0.1 kN
15
15 x 10
1000
= 0.15 kN
28.00
33.00
46.00

10. CONCLUTION
The conclusion is, shear box test is an example test used to
determine the shear strength of soils. In principle, this test is
to determine the failure strength on a surface that has been set.
However, the importance of shear box test is to determine the
shear strength of soil on the surface and it can be test by other
test that can determine the failure strength,

11. Reference
1. Donald Mcglinchey, , Characterisation of bulk solids, 2005, CRC
Press DT Afrika.
2. Mazlan Mohammad Abdul Hamid, Standard aggregate sieve
analysis TEST, ASTM International - Standards Worldwide, (July
2008) ASTM C136-06, retrived from http://www.astm.org/
3. Norliza Muhammad, concrete laboratory,(2006). Gradation Test.
(2007), NorlizaMuhammad,FajarBaktiSdn. Bhd.