Abstract: Taking the irregular developed anhydrock in dolomite layer of Yi-Ba section which located in Hangzhou-Lanzhou highway as research object, and adopting test methods such as X-ray diffraction experiment, ion-chromatographic analysis, environmental scanning electron microscopy and energy spectrum analysis tests, it is mainly quantitatively analyzed the damage of anhydrock to the tunnel structure. The result shows that the damage to the tunnel structure mainly displayed in hydration-swelling action, sulfate erosion generated by corrosion and the aggravation of dolomite corrosion by acid environment. On this basis, combining with regional engineering geological condition of this area, this paper proposes the deterioration mechanism of the tunnel concrete protective structure under anhydrock and the coupled corrosion action of the anhydrock and dolomite. Finally, it gives treatment suggestions for the similar engineering, mainly by lowering the groundwater level and improving the performance of the concrete.

Key words: anhydrock, dolomite, sulfate, expansibility, causticity