In the reconstruction of separate drainage systems of old residential districts in Changshu,there were several problems,such as treatment of septic tank,buried depth of pipe,reasonable utilization of existing pipings for combined drainage system and selection of pipe materials and diameters.

The enterprise restructuring and reposition of redundant personnel is very complicated, this reform implies a series of issues such as assets disposal, change of ownership, disposal of financial claims and debts, as well as the arrangement of labor relationship.

Mainly introduced the necessity, the epuipment and the effect of add-strand rebuilding of continuous casting machine No1,No2, and No4 of Steel-making Plant of Changzhi I &S(Group) Co.