We found geological cracks at bottom during Head Race Tunnel excavation in Dikchu- 96 MW, Hydro Electric Project in Sikkim, India. Expert team has decided to apply treatment by trench cutting followed by RCC application. Further we appreciate your helpful suggestions to over come such phenomenon in future for safe and successful construction practices.

D-SHAPE TUNNEL CROSS-SECTION AREA CALCULATION TECHNIQUE

As presented earlier, the short-cut technique for Area calculation of tunnels cross-section, the calculation for Area of D-Shape tunnels has been specified this time.

For calculating the cross-sectional area, most of the time we depend on Auto Cad, as well as various hectic calculations.

From my past experiences and as per knowledge, the short-cut calculation has been developed, called as AREA CBS FACTOR, the calculation has been shown below……..

C/S AREA OF D-SHAPE TUNNEL =  d2 X CBS FACTOR

Where,

d = Dia. Of D-Shape tunnel

CBS FACTOR = 0.8927

From above formula, we can calculate Area instantly with simple multiplication.

For example….

For a 6mt. dia tunnel, the Area has been calculated…

Area = d² X 0.8927

   6² x 0.8927  ->   32.13 m²

The above calculation can be verified using Auto-Cad or any mathematical technique

area   32.1372 m2          perimeter   21.4248 m

Horse shoe shape tunnel Cross-section Area with CBS Factor by Er. C B Singh : For calculating the cross-sectional area, most of...

Please go through www.cbsinghhydro.blogspot.in for Horse shoe-shaped tunnel cross-section:
For calculating the cross-sectional area, most of... For calculating the cross-sectional area, most of the time we depend on AutoCAD, as well as various hectic calculations. From my past... https://www.youtube.com/watch?v=nO9D-ub84BY

Area Calculation of Horse Shoe Shape Tunnel with CBS Factor by Er. C B Singh

For calculating the cross-sectional area, most of the time we depend on AutoCAD, as well as various hectic calculations.

From my past experiences and as per knowledge, the shortcut calculation has been developed, called the AREA CBS FACTOR; the calculation has been shown below…….

C/S AREA OF HORSE SHOE SHAPE TUNNEL =  d2 X CBS FACTOR

Where,

d = Dia. Of horse-shoe-shaped tunnels

CBS FACTOR = 0.829323611

From the above formula, we can calculate the area instantly with simple multiplication.

For example….

For a 6 m dia tunnel, the area has been calculated…

Area = d² x 0.829323611

             6² x 0.829323611 ->   29.85 m²

The above calculation can be verified using AutoCAD or any mathematical technique

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