目录简介 | 3.1.5 Pipeline aerial crossing site shall be selected according to the following provisions:
1 Connection between the pipeline aerial crossing site and oil and gas transportation pipeline engineering, and correlation between the site and railway, highway, river, city and water plan shall be properly managed.
2 Pipeline aerial crossing site shall comply with the general trend of pipeline and the partial trend of pipeline may be adjusted according to the site.
3 Pipeline aerial crossing site and scheme shall be selected according to the environmental impact assessment report of the pipeline engineering, the disastrous geology evaluation report, the earthquake safety evaluation report, flood control safety evaluation report and other relevant requirements involved in the engineering.
4 Pipeline aerial crossing site in different terrain under different geologic conditions shall be determined according to the following provisions:
1) Pipeline aerial crossing site should be selected over narrow river with counterfort or highland on side banks based on good and stable strata, where small scale lateral scouring and corrosion. If there is bending orbit in the river, straight and level section at upper river of the bending orbit should be taken as the crossing site.
2) Pipeline aerial crossing site shall be selected at upper river of gate dam or out of influence area of other water constructional works.
3) Pipeline aerial crossing site shall sheer off development section of gully head.
4) Pipeline aerial crossing site shall sheer off sections of poor geologic conditions such as active seismic fracture zone, landslide, mudflow and karst.
5 Pipeline aerial crossing site shall sheer off the ground or underground sections with critical facilities.
6 There shall be definite construction and installation field and convenient transportation and communication conditions near the pipeline aerial crossing site. |