Based on Twerskys theory, with the multiple scattering of plane acoustic or electromagnetic waves by an arbitrary configuration of parallel cylinders, a new method differing from the conventional ones is developed to figure out the plane SH waves scattered by rigid piles to solve the problem of the environmental vibration isolated by pile rows. This new method eliminates the disadvantages of the single scattering hypothesis which does not consider the coherent phase relations between the waves. Also, the influence factors on screening effectiveness including the orders of scattering, the space between pilerows and separations between the adjacent piles are investigated.