The corrosion of steel bar, which is mainly due to the presence of chloride anion, is the main reason to lead the destruction of reinforced concrete structure． The influence of chloride anion content on the corrosion of steel bar in concrete was studied． The results showed that the higher chloride content, the earlier corrosion of steel bar happened． At the beginning of corrosion time and stable corrosion time, the more chloride anion content, the quicker corrosion rate and destruction rate was． Once the concrete cracked, the corrosion rate of steel bar will speed up． In addition, the mechanism of chloride anion on heavy corrosion and the reason for stable corrosion maintaining were further explored．

Three－dimensional quarry software Surpac in cement quarry designing was introduced here． The 3D space characteristics and actual position of ore body can be seen clearly after using digital terrain models and geological database have been established by Surpac． By using 3D model, the ore body border is confirmed and open pit design is finished． The reserves calculation and ore body grade determination can be made easily by building the block model． It provides scientific basis for rational developing and utilizing mine resources． 

Energy saving technology of hydraulic system is introduced in this paper． Basic energy saving method and hydraulic control system are discussed． The basic energy saving is determined by hydraulic components selection and system improvement． In regulation control, several saving methods and equipment are introduced here． Besides, the working principle and energy saving effect are compared．