A steel mono-pile needs to be constructed to hold a monitoring station. The monitoring station should be 20 feet above the still water level, SWL, of 55 feet. The superstructure including the building and equipment will weigh 55,000 lb. The building will be 13 ft x 13 ft x 20 ft high. It will be subjected to a wind force where the design wind speed is 100 mph (including the gust factor). Assume this speed to be constant with height. Also neglect the wind force on the pile. The pile will be subjected to a wave force where the design wave length, L, is 400 feet and wave height, H, is 16 feet. Assume the wind force and wave forces are in the same direction. There is no significant current at the location. The customer wants to save money and use an existing steel pile. This pile has an outer diameter of 36 inches, a thickness of 1 inch, and is sufficiently long. The steel has a yield stress of 36,000 psi and modulus of elasticity of 29*106 psi. Determine if the existing pile is suitable given the wind load, axial compressive load, and wave forces. For the wave force, use determine that resultant force and its location along the wetted length of the pile. Use the API Design Guidelines to determine the suitability of the design. Complete all checks including shear, bending, axial, hoop, and combined stresses even if all or one fails. State if each check fails or passes. State if the mono-pile design passes or fails overall. Monitoring Station: Solid Structure 13' x 13' x 20' Wind: v = 100 mph Wave: H = 16 ft L = 400 ft d = 55 ft w = 1 = 13 ft +Z -Z +X h = 20 ft D = 36 in D = 34 in Steel Mono-Pile F, = 36,000 psi E = 29* 106 psi 20 ft SWL d = 55 ft Forces on a Monopile Due to Waves Time*, t = X= MLLW(ft)= Surge(ft)= Tide(ft)= z+d 55.00 1 0.95 52.25 0.9 49.50 0.85 46.75 0.8 44.00 0.75 41.25 0.7 38.50 0.65 35.75 0.6 33.00 0.55 30.25 0.5 27.50 0.45 24.75 0.4 22.00 0.35 19.25 0.3 16.50 0.25 13.75 0.2 11.00 0.15 8.25 0.1 5.50 0.05 2.75 0 0.00 Current(kts) = g (ft/s)= depth (ft)= H (ft)= L(ft)= k (rad/ft)= w (rad/s)= T(s)= 10 secs 0.000 ft C_building= Vwind (mph) = A (ft) = Fwind (lb)= 55 0 O O O 0 0 32.2 55 16 400 1.5 100 u eqn. 3.29 6.4184 6.2307 6.0547 5.8899 5.7362 5.5931 5.4605 5.3381 5.1230 5.0298 4.9461 4.8715 4.8061 4.7496 4.7020 4.6632 4.6331 4.6116 4.5987 4.5944 (calculate) (calculate) (calculate) (calculate) (calculate) wt= Current Velocity 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Speed_conv(ft/s/kts)= 0 0 0 Total Moment (lb ft)= C_D= C_M= Spec Wt of SW (pcf)= Az (ft) = P (lb)= 0 0 Centroid* (ft) = 5.942963 Pile Diameter = Total Velocity Total Force* (lb) = 6,147 (*NEXT optimize using solver by varying time, MAX FORCE with constraints time>=0, time 3. Hand calculations of wind force a. Include calculation of equivalent force and moment when the wind force is translated to the top of the piling