The increasing use of integral bridges has been observed worldwide. However, the clear drawback of the integral bridge structure is the integral abutment, which continuously pushes against and then separates from the backfill due to the repeated thermal expansion and contraction of the bridge deck. This makes it challenging to predict lateral pressure, as the dynamic behavior of soil particles during repeated soil–structure interaction leads to the coexistence of both passive and active failure in the backfill. Many previous studies have observed, discussed, and reported this phenomenon, yet few have provided a conclusive method for estimating lateral passive pressure due to the complex and dynamic backfill condition under ongoing cyclic abutment movement. This present study identifies a previously unobserved form of passive pressure failure that lies between active and passive failure states. The found out may provide some new insights into particle movement mechanism under cyclic lateral passive pressure loading and unloading on the integral backfill.