A STUDY ON 33 YEARS CORROSION BEHAVIOUR OF MATERIALS IN SOIL AT THREE GORGES AREA
三峡地区材料33年土壤腐蚀行为研究

A comprehensive survey of the soil corroded samples is made.which have been bu-ried in a site located at the place on the south bank of Yangzi River near the underconstructing Three Gorges Dam for 33 years.The sample were made of 4 kinds of materials,including plate and pipe of plain carbon steels and polyvinychloride,reinforced concrete block and cement asbestos pipe etc. The examination results reveal that the base steels suffered obviously from un-uniform corrosion.Typical pitting corrosion,selectively weldment corrosion,even perforation corrosion were observed.However, the pitch coating provided effective protection for steels from soil corro-sion;The reinforced concrete made of silicate cement also suffered from severe corrosion resulting in significantly decreasing of its compressive strength to an extent 38-83%;In general,cement as-bestos pipe showed good corrosion resistance in normal soil there;And the products of polyvinychloride showed not obvious change of their mechanical and electrical properties,still, an extent of 7-13% decrease of their compressive strength may be observed.The features of the mate-rials corrosion in soil are characterized and theirs regularities are also discussed in term of the soil corrosivities. And than some suggestions are proposed, concening the materials selection and the propriety protective measures needed for the underground structures, which may be established in the very area.