An elongated sheet piling panel having a length and width, and opposed side edges (30, 32), the panel comprising: a first flange wall segment: a second flange wall segment; and a middle wall segment between said first and second wall segments (20, 24); wherein said first and second flange wall segments (20, 24) and said middle wall segment define a substantially Z-shaped cross section; wherein at least the middle wall segment has elongated voids positioned within an interior of the panel, said voids being oriented in the direction of the length of the panel, and wherein said middle wall segment is comprised of spaced apart front and rear surfaces (46, 48), and wherein said middle wall segment has material between adjacent voids, with the material between adjacent voids linking said front and rear surfaces (46, 48), thereby forming an I-beam configuration; and wherein said side edges (30, 32) of the panel are configured to be connected to the edges of additional similar panels; characterized in that said middle wall segment includes: a first edge portion adjacent the intersection of said middle wall segment and said first flange wall segment, said first edge portion containing no voids; a second edge portion adjacent the intersection of said middle wall segment and said second flange wall segment, said second edge portion containing no voids; and a middle portion between said first and second edge portions, said middle portion containing said voids, the proportion of a width of said middle portion to the entire width of said middle wall segment being within the range of from about 50 percent to about 80 percent, the entire width of said middle wall segment extending between said first and second edge portions. a first flange wall segment: a second flange wall segment; and a middle wall segment between said first and second wall segments (20, 24); wherein said first and second flange wall segments (20, 24) and said middle wall segment define a substantially Z-shaped cross section; wherein at least the middle wall segment has elongated voids positioned within an interior of the panel, said voids being oriented in the direction of the length of the panel, and wherein said middle wall segment is comprised of spaced apart front and rear surfaces (46, 48), and wherein said middle wall segment has material between adjacent voids, with the material between adjacent voids linking said front and rear surfaces (46, 48), thereby forming an I-beam configuration; and wherein said side edges (30, 32) of the panel are configured to be connected to the edges of additional similar panels; characterized in that said middle wall segment includes: a first edge portion adjacent the intersection of said middle wall segment and said first flange wall segment, said first edge portion containing no voids; a second edge portion adjacent the intersection of said middle wall segment and said second flange wall segment, said second edge portion containing no voids; and a middle portion between said first and second edge portions, said middle portion containing said voids, the proportion of a width of said middle portion to the entire width of said middle wall segment being within the range of from about 50 percent to about 80 percent, the entire width of said middle wall segment extending between said first and second edge portions. a second flange wall segment; and a middle wall segment between said first and second wall segments (20, 24); wherein said first and second flange wall segments (20, 24) and said middle wall segment define a substantially Z-shaped cross section; wherein at least the middle wall segment has elongated voids positioned within an interior of the panel, said voids being oriented in the direction of the length of the panel, and wherein said middle wall segment is comprised of spaced apart front and rear surfaces (46, 48), and wherein said middle wall segment has material between adjacent voids, with the material between adjacent voids linking said front and rear surfaces (46, 48), thereby forming an I-beam configuration; and wherein said side edges (30, 32) of the panel are configured to be connected to the edges of additional similar panels; characterized in that said middle wall segment includes: a first edge portion adjacent the intersection of said middle wall segment and said first flange wall segment, said first edge portion containing no voids; a second edge portion adjacent the intersection of said middle wall segment and said second flange wall segment, said second edge portion containing no voids; and a middle portion between said first and second edge portions, said middle portion containing said voids, the proportion of a width of said middle portion to the entire width of said middle wall segment being within the range of from about 50 percent to about 80 percent, the entire width of said middle wall segment extending between said first and second edge portions.