To the repeated interaction between the clay layer with poor permeability and the sand layer with good permeability encountered in the vacuum preloading reinforcement of a port project in Bangladesh，there may be problems such as boundary permeability，complex and difficult to predict foundation consolidation laws，and difficult to predict foundation reinforcement effects.Based on the experimental and typical construction blocks of the project，this article focuses on the sealing effect of clay mixing piles on the sealing wall.The influence of permeable layers on the theoretical calculation of consolidation velocity，as well as the changes in physical and mechanical properties of complex interlayered sites after reinforcement are studied.This article mainly uses experimental detection and comparative analysis of experimental measured data and theoretical calculation data to compare and study the surface settlement time history curve，pore water pressure dissipation curve，SPT index before and after reinforcement，compressibility index，etc.The results show that clay sealing walls have good adaptability in silty sand formations，and the presence of permeable sand layers has a much smaller impact on actual site consolidation than experiments under theoretical or ideal boundary conditions.Vacuum preloading has a good reinforcement effect on complex interlayer foundations.It has certain reference significance for guiding the design of vacuum preloading reinforcement on complex interlayer foundations.