A 2.75-m-Ø wood-stave pipe has 9 m³/s of water entering through a horizontal 30⁰ reducing bend where the other end is 1.82 m in diameter. The curved portion is made of steel plate to resist rupture and the bend is embedded in concrete block weighing 2400 kg/m³. The pressure at entrance of the bend is 138 kPa. The combined weight of the bend and its content is 268 kN. Neglecting friction in the flow, compute the minimum volume of concrete block holding the bend that can withstand the thrust of water on the bend assuming the coefficient of friction between the concrete and its foundation is 0.30.