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Sarkari MCQs Government Exam Question Bank
Question no. 18620

If ‘D’ represents the tunnel diameter in meters, the lining thickness in mm, derived from the empirical formula, is expressed as_________________?

Select your answer for: If ‘D’ represents the tunnel diameter in meters, the lining thickness in mm, derived from the empirical formula, is expressed as_________________?
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Answer: B. 82 D

Explanation

Empirical tunnel design formulas correlate concrete lining thickness directly with excavated tunnel diameter. Standard engineering practice for specific ground conditions yields the multiplier factor eighty-two in millimeters. Multiplying tunnel diameter D in meters by eighty-two gives the required preliminary lining thickness estimate. Tunnel lining thickness must resist external earth loads and internal service pressures safely. Empirical formulas provide rapid preliminary sizing estimates before detailed finite element analysis. Larger diameter tunnels require thicker concrete linings to prevent structural bending and buckling failures.

Civil engineers use empirical rules of thumb during early feasibility studies for major metro projects. Water conveyance tunnels apply similar thickness formulas to withstand internal hydrostatic bursting pressures. Final lining designs are always verified using detailed numerical stress modeling and geotechnical testing. Option A uses a smaller factor of forty-two, which results in dangerously thin lining dimensions. Option C applies a higher factor of one hundred four, leading to overly conservative concrete quantities. Option D suggests a factor of one hundred twenty-four, exceeding standard empirical thickness guidelines.

Subject
Engineering
Category
Civil Engineering
Topic
—
Difficulty
medium

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