A multi-well pad for fracturing a subterranean formation can include a valve assembly that includes a shuttle valve, an inlet, a first outlet, and a second outlet, where the inlet is coupled to a fracturing pump, where the first outlet is coupled to a first well, where the second outlet is coupled to a second well, where first shuttle valve has a first position and a second position. The fracturing pump and the first well can form a continuous first path through the valve assembly while closing off a second path between the fracturing pump and the second well when the shuttle valve is in the first position. The fracturing pump and the second well can form a continuous second path through the valve assembly while closing off the first path between the fracturing pump and the first well when the shuttle valve is in the second position.