Each gate of the lock is 6 m high and is supported by two hinges placed on the top and bottom of the gate. When the gates are closed, they make an angle of 120º. The weight of the lock is 5 m. If the water levels are 4 m and 2 m upstream and downstream, respectively, determine the magnitude of forces on hinges due to the water pressure.

Determine the factor of safety against bottom heave for the braced cut described in Problem 15.18. Use Eqs. (15.66) and (15.70). For Eq. (15.70), assume the length of the cut, L = 18 m. 15.18 Refer to Figure 15.51 in which = 17.5 kN/m3, c = 60 kN/m2, and center-to-center spacing of struts is 5 m. Draw the earth pressure envelope and determine the strut loads at levels A, B, and C. FIG. 15.51

A braced cut shown in Figure P19.3 is to be made to a depth of 9.0 m in a saturated clay deposit where the unit weight is 17.65 kN/m3 and the undrained shear strength is 30 kN/m2. The struts are spaced horizontally at 3.0 m center to center. Find the strut loads.