Abstract:In view of the wide application of double row piles under complex surrounding environment and the complex mechanical behavior of double row piles, based on the principle of similar material model test, a laboratory test model for double row piles of deep foundation pit was built. The bearing characteristics of double-row piles under four kinds of working conditions, including inter-pile soil, passive zone at pile side, soil at pile end and un-reinforcement, were analyzed and studied. The results show that the maximum positive and negative bending moments of front row piles are 32.4% and 38.5% lower than those without reinforcement measures, while the maximum positive and negative bending moments of back row piles are 76.8% and 55.4% lower respectively, while the horizontal displacement of top piles is 57.5% lower. The bearing capacity of double-row piles can be effectively improved by soil reinforcement between piles, passive zone at pile side and soil reinforcement at pile end, but the effect of soil reinforcement between piles is the most significant. The main reason is that soil reinforcement between piles can significantly improve the deformation modulus of soil between piles, thereby enhancing the overall flexural rigidity of the cross-section of pile-soil composite bearing body, then improving the bearing capacity of double-row piles.