Research And Numerical Simulation Of Anchoring Composite Support System In Layered Rocks Based On Mechanics Of Composite Materials

Rockbolts which can make full use of the self-strength of rocks and soils around and enhance the load-supporting of rocks and soils and save the engineering materials are wildly used in the support of adjacent rocks of tunnels and reinforcement of roadbed and slopes, to be one of the most effective and economic support method in geotechnical engineering. Because of the complexity of geological condition and multiplicity of anchoring mode, the theory usually cannot guide the engineering practice. Nowadays lots of projects in the west of China are built in layered rocks, and more problems of how to analyze this kind of rocks in the design part will be encountered.In order to guide the engineering practice better it's of great importance and meaning to build an equivalent mechanics model and analysis method of anchored layered rocks which can consider the effect rockbolts to rocks quantitatively.In this paper, the composite support system of anchoring layered rocks is seen as a kind of composite materials including layered rocks (base material), rockbolt(strength material), mortar(bond material). According to the theory and method of mechanics of composite materials, the equivalent mechanics model of composite fiber materials made up by rockbolt and mortar is established using Whitney—Riley model. The equivalent mechanics model of the composite support system of anchoring layered rocks reinforced by the composite fiber is deduced and established, in which the cross section of fiber is changed from round to rectangular. And then the effects of the Young's module of rocks, the diameter of rockbolt, and the interval of rockbolt and the Young's module of mortar to the composite support system are analyzed using Matlab programs.The uniaxial and triaxial compression tests of the composite support system of anchoring layered rocks with different Young's module of rocks, the diameters of rockbolts, the intervals of rockbolt and the Young's module of mortar are numerical simulated using MSC.Marc subroutine, to analyzed the effect of these parameters to c, φ of composite support system.The Young's module E_1m of samples in the model test of anchoring rock oftunnels are got using the equivalent mechanics model of composite materials and the c,q> of samples are got using MSC.Marc subroutine. The computing results are anastomotic well to that of the model test, which prove the rationality and reliability of the equivalent mechanics model and numerical analysis method.