Model tests for time-dependent evolutionary behavior of anchored bedding slope in corrosion environment
LI Cong1，ZHU Jiebing1，WANG Bin1，LIU Zhijun2，JIANG Yuzhou1，LIU Xiaohong1，ZENG Ping1
(1. Key Laboratory of Geotechnical Mechanics and Engineering of Ministry of Water Resources，Yangtze River Scientific Research Institute，Wuhan，Hubei 430010，China；2. Guangzhou Baiyun International Airport Co.，Ltd.， Guangzhou，Guangdong 510406，China)
For better understanding time-dependent evolutionary behavior of anchored bedding slope in corrosion environment，a prestressed anchored slope model test systems which can simulate complex corrosive environment was developed. Using the test systems，an anchor bedding slope geomechanical model test was carried out，in which the corrosion of the free section of anchoring is simulated. Based on test results，the electrochemical corrosion process of pre-stressed anchor bar，anchorage loss laws and long-term deformation characteristics of anchored slope were analyzed. It was found that：(1) The anchor bar enter activation corrosion state rapidly as contacting with the etching solution. The corrosion rate of anchor bar is high in initial stage，with the increase of immersion time，the corrosion rate decreases gradually，and the corrosion rate stabilized after about 30–60 days. (2) Cl－，O2 in the environment and pre-stress will significantly increase the corrosion rate of anchor bar. (3) Corrosive effects did not significantly accelerate loss of prestress when both ends are anchored well，and prestress losses of anchorage are mainly influenced by the initial anchoring force and rock deformation after corrosion of free section. (4) Deformation of different parts of anchored slope is mainly related to rock mass structure，gravity stress and anchor force，and reinforcement corrosion in free section doesnot directly affect the slope deformation. Anchoring force drastically reducing caused by corrosion of anchoring section or the failure of anchor bar caused by corrosion could significantly affect the deformation and stability of the slope. Test results can provide scientific basis for long-term safety assessment of anchored bedding slope.
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2018, Vol. 37 
