Setting of subgrade width of Haite culvert

Hello, I seem to be a colleague. Hite company people don't answer, I will answer. This must be your culvert profile input error. In other words, your culvert bottom elevation is wrong. Hite's default altitude is above 300. If your design elevation is 600, then the height difference is 300 meters. The subgrade slope 1: 1.5 will be calculated automatically after it is laid down. Ha ha. Specifically, 173368 159qq.