Foundation soil of Ci-Xian section of the main canal in the Middle Route of South-to-North Water Transfer Project has medium liquefaction phenomenon. Canal subsidence and landslide can happen if the foundation soil is not treated properly, which can affect canal safety. The ram-compaction gravel piles can decrease sand ground liquefaction. In-situ pile test needs to be conducted. The effects of different pile spacing on treatment of sand liquefaction were tested to determine the appropriate pile spacing, which can support the design parameters and principle for pile construction in a large area. The ram-compaction gravel piles used heavy hammer impact to form the hole, and then filled in gravel or other replacement materials in each layer to reach the design height. The results showed that ground liquefaction is not shown when the pile spacing is 1.8 m but occurs when the pile spacing is 1.9 m. In addition, the shear wave test of original crosshole showed thatthe shear wave velocity of soil among piles increases after the treatment, which indicated the compaction effect is significant.