Civil Engineering - UPSC Civil Service Exam Questions - Discussion
Discussion Forum : UPSC Civil Service Exam Questions - Section 1 (Q.No. 38)
38.
If the pressure carried by a CBR specimen at 2.5 mm penetration is 3.5 N/mm2, the CBR of the soil is
Discussion:
8 comments Page 1 of 1.
Pawan sharma said:
4 years ago
Here pressure given is 3.5 N/mm^2 for 2.5 mm penetration and we have to find load in kg so
pressure = load / area , p=l/a and plunger dia =50 mm so,
area = 1964mm^2,
So 3.5= P /1964 so P = 6875 N,
P = 6875/9.81 = 700 kg.
Standard value of CBR for 2.5mm penetration is 1370 kg,and for 5.mm is 2055 kg
% CBR =700/1370 = 50%.
pressure = load / area , p=l/a and plunger dia =50 mm so,
area = 1964mm^2,
So 3.5= P /1964 so P = 6875 N,
P = 6875/9.81 = 700 kg.
Standard value of CBR for 2.5mm penetration is 1370 kg,and for 5.mm is 2055 kg
% CBR =700/1370 = 50%.
Shishir said:
8 years ago
The standard plunger size is 50mm, and the load for 2.5mm penetration is 1370 kg. So, the stress.
Ps= applied load / area .. Ps= 1370*9.8/ area = 6.84 N/mm2,
So, CBR= P/PS *100 = 3.5/6.84 * 100= 51% = 50%.
Ps= applied load / area .. Ps= 1370*9.8/ area = 6.84 N/mm2,
So, CBR= P/PS *100 = 3.5/6.84 * 100= 51% = 50%.
(1)
Subha Annadurai said:
7 years ago
CBR=P/PS.
p- measured pressure for site soils in N/mm2,
PS - pressure to achieve equal Penetration on the standard soil in N/mm2.
p- measured pressure for site soils in N/mm2,
PS - pressure to achieve equal Penetration on the standard soil in N/mm2.
Adnan said:
6 years ago
@Shishir.
Sir, please explain how you get 1730 kg for 2.5 mm penetration and secondly how you calculate area? Please explain.
Sir, please explain how you get 1730 kg for 2.5 mm penetration and secondly how you calculate area? Please explain.
R. Balaji said:
6 years ago
@Adnan it is a standard load for 2.5mm penetration and for 5mm it is 2055 kg.
Kamal said:
5 years ago
Area=π*r^2.
Where r is the radius of the plunger which is (50/2).
Where r is the radius of the plunger which is (50/2).
(2)
Priya said:
8 years ago
CBR =3.5/70=0.05,
0.05*100=5.
0.05*100=5.
(1)
Dolly said:
7 years ago
Please, anyone explain it.
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