A crew is pouring a concrete wall column using a 10-foot tall plywood form. Wet concrete acts as a heavy liquid with an average unit weight ($\gamma$) of $150 \text{ lbs/ft}^3$. If the entire form is filled rapidly before the bottom layer can set, calculate the maximum hydrostatic pressure at the very bottom of the formwork.

According to ACI (American Concrete Institute) guidelines, the pressure on formwork can be significantly reduced if the concrete is poured slowly, allowing the lower layers to begin stiffening (taking their initial set) before the full height is reached. A wall is poured at a rate of 4 feet per hour at $70^\circ \text{F}$. The ACI formula for walls with $R < 7 \text{ ft/hr}$ is $P = 150 + \frac{9000 R}{T}$. Calculate the design pressure.

A 10-inch thick concrete floor slab (125 psf dead load) is being poured on the 5th floor. The formwork is supported by shores resting on the 4th-floor slab, which is only 7 days old and has only reached 60% of its design strength (Design strength = 4,000 psi, Current = 2,400 psi). The 4th-floor slab alone cannot support the combined weight of the wet 5th-floor slab plus construction live loads (50 psf). What engineering control must be utilized?

A worker is walking along a narrow 2x10 wooden plank placed 4 feet above a grid of exposed, vertical #5 rebar dowels waiting for the next column pour. They slip and fall backward off the plank.

A crane is lifting a 30-ton precast concrete wall panel from a horizontal position on the slab into a vertical position (tilt-up construction). A crew member stands directly under the panel to guide the bottom edge into place with a pry bar. The crane's rigging suddenly snaps.