Bangladesh Chemical Industries Corporation (BCIC) || Assistant Engineer (CE) || (14-02-25) || 2025

All Written Question

Data, 

Q=2000m3/day
B 
SoR 32 m3/m2/day 
L=?   T=?

We know, 

SoR = Q BL 

 32 = 20004×L

 L = 15.625m (Ans) 

T =VQ= =15.625 × 4 × 2.42000= 0.075 day = 1.8 hour (Ans) 

Consolidated angle of shearing resistance, 

Here, 
σ3=100kN/m2
σ1=100+80=180kN/m2
udf=40kN/m2
φ =? : 
φ' =? :

φ=sin-1σ1-σ3σ1+σ3=sin-1 180-100180+100=16.60 (Ans) 

Drained friction angle, 

φ'=sin-1 σ1-σ3σ1+σ3-2udf=sin180-100180+100-2×40 = 23.58° (Ans)

Data, 

φ = 0 
cu=300 psf
γ= 110 pcf 
Zo= ?

Solution: 

ka=(1-sinφ)(1+sinφ)=(1-sin0)(1+sin0)/=1.0

Depth of tensile crack, 

z0=2cuy ka=2×3001101.0=5.45 ft(Ans)

Here, E = Kinetic energy + Potential Energy 

E=12mV2+mgh
pw=1000 kg/m3

Q=50 m3/sec

V= 3m /sec 

h = 90m 

Total mechanical energy per unit mass, 

Em=12×V2+gh=12× 32+9.81×90

= 887.4J / kg(Ans) 

Power generation potential, 

P=Em×Q×ρw=887.4×50×1000

=44.37×106W=44.37MW(Ans)

Here, L = 2000m 

Z1=100m
Z2=20m
V1=0
V2 = 1m /sec
P1=0
Diameter of pipe, d = 20cm = 0.2m 
p = 0.015 
α= 1
 

Solution: Head loss, 

HL=f'LV222gd=0.015×2000×122×9.81×0.2=7.645 m

Now, Bernoulli Equations, 

Z1+αV122g+P1γ=Z2+αV222g+P2γHL

100+0+0=20+1.0×122×9.81+P29.81+7.645 m

P2=709.3 kPa (Ans)

Here, 

A=25km2=25×106m2
V=1.5×106m3
i = 10cm = 0.1m

Solution: 

Effective rainfall  =VA=1.5×10625×106=0.06m=6cm

Runoff coefficient = 610 = 0.6(Ans) 

Data,
ht = 2.4 sec 
V = 60 mph 

Solution:  We know, 

Capacity or flow =  3600 ht =3600 2.4 =1500 veh/hour (Ans) 

And, 
Q = kV 
1500k x 60 
k = 25 Veh/mile (Ans) 

Sd=s12n1+s22n2= 7.52250+7.42280=0.65

Difference in means  = 38.7 - 35.5 = 3.2 > 1.96 × 0.65 

                                        = 3.2 > 1.3mph 

It can be concluded that the difference in mean speeds is significant at the 95% confidence level.

Error between two stations: 

e =6.72 - 5.86+4.96 - 4.182= 0.82m 

A is lower than B so, RL of ARL of B-Error 

= 108.92-0.82= 108.10 m (Ans)

Latitude Correction: 

Correction to latitude of any line =  -Length of that line Total Length ×Total error in latitude 

ClCD =-324.781922.82×-1.19=0.201 

Corrected Length of CD Latitude =L CD +Cl CD =-22.94+0.201=22.739 

CDDA =-477.241922.82 ×-1.93=0.479 

Corrected Length of DA Departure =LDA +CDDA =-25.53+0.479=25.051