Principle involved in the relationship between submerged unit weight and saturated weight of a soil is based on

A beam with a rectangular cross section of size $$250$$ $$mm$$ wide and $$350$$ $$mm$$ deep is prestressed by a force of $$400$$ $$kN$$ using $$8$$ numbers $$7$$ $$mm$$ $$\phi $$ steel cables located at an eccentricity of $$75$$ $$mm.$$ Determine the loss of prestress due to creep of concrete. Grade of concrete is $$M40;$$ Coefficient of creep is $$2;$$ stress at transfer is $$80\% $$, Modulus of elasticity of steel $$\left( {{E_s}} \right)$$ is $$2.0 \times {10^5}\,\,MPa.$$

In reinforced concrete, pedestal is defined as compression member, whose effective length does not exceed its dimension by

The width and effective depth of a reinforced concrete beam is $$250$$ $$mm$$ and $$440$$ $$mm$$ respectively. The beam is provided with $$4$$ number of $$20$$ $$mm$$ bars in the tension zone. The beam is subjected to a shear force of $$150$$ $$kN$$ (Factored). Check the requirement of shear reinforcement and provide if required. Grade of concrete is $$M20$$ and that of steel is $$Fe415.$$ The shear strength of concrete for different percentage of tensile steel are as below $$8$$ $$mm$$ diameter vertical stirrups are available.
$$\left[ {{V_{us}} = 0.87\,\,{f_y}{A_{sv}}\,\,d/{S_v}} \right.$$ and $${\left( {{A_{sv}}/{S_v}} \right) \ge 0.4b/{f_y}}$$ with the terms having usual meaning $$\left. \, \right]$$