STUDY ON PRESTRESS LOSS LAW OF ANCHOR CABLES IN DEEP UNLOADING DEFORMED RIPPED BLOCKS
ZHANG Jinlong1，2，XU Weiya1，2，XU Fei1，2，CAI Dewen3
(1. Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering，Hohai University，Nanjing， Jiangsu 210098，China；2. Institute of Geotechnical Research，Hohai University，Nanjing，Jiangsu 210098，China； 3. Chengdu Hydroelectric Investigation and Design Institute，China Hydropower Engineering Consulting Group Corporation，Chengdu，Sichuan 610072，China)
Abstract：According to the construction process of prestressed anchor cable，the total prestress loss is divided into three parts，that is，tensioning prestress loss，locking prestress loss and time-dependent prestress loss. The definition and calculation formula of each part are specified. The monitoring data of prestressed anchor cables of left bank excavation slope in Jinping first stage hydropower station are analyzed systematically，and the distribution features of prestress loss are obtained. The analysis result shows that the tensioning prestress loss is the maximum component of total prestress loss of anchor cable，and the time-dependent prestress loss is the intermediate one and the locking prestress loss is the minimum one. A comparison is made between the law of cable prestress loss of left bank excavation slope in Jinping first stage hydropower station and those of some other hydropower engineering slopes. The result shows that the tensioning prestress losses of anchor cables of left bank excavation slope in Jinping first stage hydropower station are greater than those of some other hydropower engineering slopes remarkably. Based on the engineering geology of left bank excavation slope of Jinping first stage hydropower station，the factors resulting in large tensioning prestress loss are analyzed，and some measures to reduce the tensioning prestress loss are put forward. At last，the present load of anchor cables is evaluated. It is shown that the present load of anchor cables can meet the requirement of design. This result can provide references to other similar engineering.
ZHANG Jinlong1，2，XU Weiya1，2，XU Fei1，2，CAI Dewen3. STUDY ON PRESTRESS LOSS LAW OF ANCHOR CABLES IN DEEP UNLOADING DEFORMED RIPPED BLOCKS. , 2009, 28(S2): 3965-3970.
