Large spoil heaps formed during construction projects have caused serious soil erosion and threatened ecological security. The recent researches on soil erosion of spoil heaps are based on one or several soil types, which can only represent the soil texture category within the limited area, but cannot be used in other larger scale areas. Soil texture and gravel are the main factors affecting infiltration and erosion processes of spoil heaps.

The runoff plot dimensions were 5.0 m?×?1.0 m?×?0.5 m (length × width × depth). A series of rainfall experiments with a constant rainfall intensity of 1.0 mm min^?1 and a slope gradient of 25° were conducted to investigate the effects of soil texture (sandy, loam, and clay) and gravel mass content (GC, 0%, 10%, 20%, and 30%) on the infiltration and erosion processes. The gravels are divided into 3 classes according to particle size 2–14 mm (small), 14–25 mm (medium), 25–50 mm (large), and the mass ratios were 30%, 50%, and 20%. The duration of each rainfall event was 45 min after runoff out of the plot.

Results showed that there was a critical GC (10%) improving or controlling infiltration and soil loss. Infiltration rate of sandy spoil heap (SSH) decreased within 45 min, but it decreased first and then stabilized for loam spoil heap (LSH) and clay spoil heap (CSH). Soil loss rate (SLR) of SSH stabilized first and then increased, while it decreased and then stabilized for LSH and CSH. SLR at early stage (0–18 min) was 0.08–0.23 times than it was at later stage (18–45 min) for SSH, but it was 2.06–5.06 times and 1.46–1.95 times for LSH and CSH, respectively. The soil texture had a more significant effect on SLR (P?< 0.05) than GC did. The effects of gravel on SLRs were dependent on soil texture.

The greater the GC was, the lower the SLR was for the spoil heaps. Special attention should be paid to the later stage during rainfall events for SSHs and the early stage for LSHs and CSHs when considering erosion protection measures.