Abstract：By geomechanical model tests，the variation characteristics of tension in non-bonded prestressed anchor cable and fully grouted anchor cable during the underground opening excavation and overloading are given. Based on the analysis of the developed charts of the variation of tension in cables，it is found that the tension in the two types of cables generally decreases and the average range is 15%–22% during the underground opening excavation. The variation magnitude of tension decreases and the corresponding position of each anchor cable in different places obviously show randomness. In overloading process of the model test，the tension generally increases and the position where the tension increases is relevant to the coefficient of horizontal pressure of the model. The tension in anchor cables installed in the arch ends increases more and that in anchor cables installed in the arch crown and the floor increases less when the coefficient of horizontal pressure is less than 1(N＜1 . Whether the tension in anchor cables decreases during the opening excavation or increases during the opening overloading，the relative increment of tension is more for anchor cables with low initial tension，otherwise，the relative increment of tension is less. Consequently，the different ratio of tension in anchor cables should be taken for anchor cables with different initial tension load. A low ratio should be taken for anchor cables with high initial tension and a high ratio should be taken for anchor cables with low initial tension load. Several suggestions are provided for the design and field construction of anchor cable.
