Question

At the base of a gravity dam section, the vertical stress at toe was found to be 3.6 MPa. If the downstream face of dam has slope of 0.707 H : 1 V and if there is no tail water, then the maximum principal stress at the toe of the dam is

• A. 3 MPa
• B. 4.5 MPa
• C. 3.5 MPa
• D. 5.4 MPa

Answer 1

The correct option is D 5.4 MPa


$tan\alpha =\frac{B}{H}=0.707$

$ta{n}^2\alpha =0.5$

$(p_{max}{)}_{toe}=3.6MPa$

${\alpha }_{max}=(p_{max}{)}_{toe}\times se{c}^2\alpha$

$=\left(p_{max}{)}_{toe}\right(1+ta{n}^2\alpha )$

$=3.6(1+0.5)$

$=5.4MPa$