Part of the foundation pit of the Zone A2 commercial and residential buildings of Taiyuan Wanda Plaza is composed of coarse sand and gravel stratum， where the deep mixing piles cannot be used effectively for the water cut-off curtain of the foundation pit； therefor， high pressure jet grouting piles were put forward for the water cut-off curtain in coarse sand and gravel stratum. With the jet grout technology， the double casing anchor drill pre-bored the grout hole with the single pipe high pressure jet grout process for grouting to complete the project successfully. Inspection indicated that the jet grouting elements interlocked well with each other with even cement content across the effective pile diameter and free of blocky inclusions； thus， providing good sealing effect.