downstream apron是什么意思

用法例句

A design risk model for the downstream slope for overtopped rockfill cofferdam during flood;

过水土石围堰下游护坡的溢流设计风险率模型

Mechanism of apron protection against local scour on bridge pier and abutment;

桥梁墩台的护坦防护局部冲刷深度计算

Combination of spur-dike and apron for scour protection to highway subgrade by river side;

沿河公路冲刷防护中丁坝与护坦的配合使用

Rxperimental research on the apron protection for riverside subgrade;

沿河路基的护坦冲刷防护试验研究