自50年代以来,由于土壤力学理论、土工试验、抗震设计和大型施工机械的不断改进和完善,以及坝址地质条件日趋复杂,修建土石坝的技术有很大发展。由于土石坝具有适应性强、可就地取材、能节约水泥和便于机械化施工等优点,在一般情况下,特别是在边远地区,修建土石坝的造价要比混凝土坝便宜。但是,在一些流量季节性变化较大的大型河流 Since the 1950s, due to the soil mechanics theory, the geotechnical test, the aseismic design and the continuous improvement and improvement of the large-scale construction machinery, and the increasingly complicated geological conditions at the dam site, great efforts have been devoted to the construction of earth-rock dam technology. Due to the adaptability of earth-rock dams, the availability of materials, the saving of cement and the advantages of mechanized construction, under normal circumstances, especially in remote areas, the cost of constructing earth-rock dams is cheaper than that of concrete dams. However, in some large rivers with seasonal changes in their flow rates