3.2　Geotechnical Investigation

3.2.1　Geotechnical investigation and analysis shall be carried out meticulously according to the requirements of different investigation stages，and investigation reports with complete data and correct evaluation shall be developed.

3.2.2　Geotechnical investigation shall be carried out by stage and the following sites should be subject to geotechnical investigation when poles or towers are constructed:

1　Sites in karst areas；

2　Goaf；

3　Sites in fill areas；

4　Sites where underground works is located；

5　Sites located in dyke and globular weathered body of granite area；

6　Other areas where the construction investigation is necessary.

3.2.3　Special investigation shall be carried out according to the requirements of construction when lines pass through the following areas:

1　Where goaf and ground surface depression basin moves are active；

2　Where the karst strongly develops；

3　Landslide areas；

4　Deserts for which no sufficient construction experience is available；

5　Where the debris flow develops；

6　Where permafrost soil exists；

7　Other areas for which special investigation is required.

3.2.4　The complexity of sites where poles or towers are located and their foundations shall be classified in accordance with the provisions in the current national standard GB 50021 Code for Investigation of Geotechnical Engineering.

3.2.5　The classification and identification of rock and soil shall be in compliance with the current national standard GB 50021 Code for Investigation of Geotechnical Engineering.