Numerical Simulation Study On Prestress Loss Of Cable-bolt

It is widely used in projects with anchorage cable, it is focus that the prestress fluctuation in response to load in domestic and abroad engineering at all times. Though analyze the theory on prestress loss, the long-term change of prestress can be estimated, then we can forecast service life on anchorage structure in important engineering credibility and the prestress measured data and the creep parameter can also be analyzed, and it is also important in national welfare and people's livelihood.Because the mechanism of prestress anchor is complicated, and it is too much factors which impact the prestress, what's more, the research of cable's reinforcement in long-term is researched shortly because of the time of observation is long and the charge of observation is high, it is the reaserch of the action of cable in long-term action is not enough both here and abroad, So that the develop of anchorage design and theory is either slowly.This paper refer to the geologic condition weather earthquake condition of Guang-he highway slope, Numerical simulation on cable prestress which under the rock creep rainfall dynamic load and temperature is mainly carried on in this paper, in the progress, the parameters are closed though considerated the rock material of slope cable material and the feather of numerical simulation. Then combined with the theory already existed and monitoring data, at last we found some conclusions, such as :(1).in creep analysis, though the numerical simulation curve, we can found that the prestress present the stabilized descent trend, then smooth gradually. The prestress loss achieve to 45% ultimately.(2). in the flow of fluid calculation, we combined the numerical simulation curve with existing engineering data, found that the cable prestress wavely changed , the more rainfull, the more prestress, but the incremental prestress will be dissipated finally because the fliud pore pressure was dissipated. After that, the prestress changed smooth. The prestress loss probably is 0.04% after one day in the rainfall of june.(3). in thermal analyses, we combined the numerical curve and the monitor data, we found that prestress wavely changed also, the curve drop to one value in the early station , then increased with the thermal's raised , and the temperature correspongding to load perfectly. It means that the variation of prestess is effected by thermal. When the temperature change from the average of all the year to the average of the highest temperature month .prestress loss is 0.2% after 10 hours operation.(4). in this dynamic analyses, we consider the sine simpleharmonic, prestress varieted sharply. Drope down at the initial stage, then increased sharply, prestress wavly changed in the early stage. And reached in stable state ultimately.the prestress loss probably is 4.3% under the condition of locally seismic data.