3.2　Design Scheme of Ground

3.2.1　The design scheme of ground for metallurgical equipment foundations shall be based on the following considerations:

1　Category and types of foundations；

2　Nature and magnitude of loads and actions；

3　Complexity of the site ground and subsoil，stratum distribution，geotechnical properties，ground water distribution and characteristics；

4　Effects exerted by surcharge loads from adjacent ground，interaction with adjacent buildings（structures）and their foundations，underground works and underground pipelines；

5　The ground bearing capacity shall meet the design requirements；

6　The foundation deformation shall meet the requirements for normal operation.

3.2.2　Natural foundations should be employed for metallurgical equipment when the geological conditions are simple，the stratum distribution is uniform and the groundbearing capacity and foundation deformation can meet the design requirements.Anyhow，metallurgical equipment foundations shall by no meanssit directly on untreated under-consolidatedsoil，liquefied soil（in seismic area）and disturbed soil.In case weak underlying strata are found in the supporting layers，the ground bearing capacities and foundation deformation shall be checked in accordance with the current national standard Code for Design of Building Foundations（GB 50007），and ground improvement or use of piled foundations shall be preferred if the natural foundations cannot meet the requirements.

3.2.3　Foundations of metallurgical equipment inthe same process line should be located on soils of the same type or featuring similar behaviors.In case of piled foundations，the same type of soil/rock strata should be used as the supporting layers for pile tips.For piled foundations which are leveled according to variable rigidity and aimed to reduce the differential settlements and internal forces of foundations，relevant requirements in the current industrial standard Technical Code for Building Pile Foundations（JGJ 94）shall apply.

3.2.4　Foundations of metallurgical equipment in the same continuous production line should be constructed with the same design scheme of ground.In case there is local weak underlying stratum，weak soil stratum or bedrock outcrop in the natural foundation of the same production line，the ground may be partially improved，provided that the foundation deformation meets the requirements for the production process，equipment and works.

3.2.5　For structures such as pit type or box type foundations and basements whose bottoms are below the ground water level，if the anti-floating calculations do not meet the requirements，uplift piles or anti-floating anchors may be applied，in addition to solutions such as increasing the dead weight of the foundations and structures or increasing the weight of soil on the foundations.

3.2.6　For metallurgical equipment foundations to be built atop a side slope，the stability of the slope shall comply with the current national standard Code for Design of Building Foundations（GB 50007）.In case of a complex side slope，the stability shall be evaluated specifically and the design scheme of ground shall not be implemented unless verified extensively.