6.2　Determination of Design Elevation

6.2.1　Design elevation of the site shall meet the following requirements:

1　If the plant area is beside the river（including estuary）or sea，the design elevation of the site shall meet the following requirements:

1）When there is no embankment，the design elevation of the site must be higher than the calculation water level（or tide level）by 0.5m or more.

2）When there is no embankment，the design elevation of the site shall enable main water drain outlet of the plant area to be higher than the calculation water level（or tide level）by 0.5m or more as far as the condition permits and reasonable technoeconomic indexes can be achieved.

3）When there is embankment，the design elevation of the site must be higher than the highest water level of waterlogging in past years.

4）When there is embankment，the design elevation of the site must be higher than the flood level（or average high tide level）in normal year as far as the condition permits and reasonable techno-economic indexes are achieved.

2　In the flat area，the design elevation of the site should be slightly higher than the elevation of the natural terrain.

3　In the area with high groundwater level，no cut work should be carried out，and where necessary fill work may be performed.In the filled area，efforts shall be made to prevent from increasing the buried depth of the foundation of buildings，and if such an attempt fails the increase shall be kept to the minimum.

6.2.2　Elevation difference between the indoor floor of buildings and the outdoor ground should be 0.15m-0.3m.Where the building is located in an area with big precipitation but poor drainage condition，or where the building foundation may settle，the elevation difference between indoor floor and outdoor ground shall be increased as the case may be.For the buildings with approach road，the height difference between indoor floor and outdoor ground should not be lager than 0.5m.For the buildings into which standard-gauge railway is extended，the height difference between indoor floor and outdoor ground should be 0.5m.