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In the blasting construction of new tunnels adjacent to existing tunnels, it is important to properly evaluate and control the influence of blasting vibration. In this study, the peak particle velocity of the lining structure of the Huanglongshan highway tunnel (i.e. the existing tunnel) in Wuhan, China, which was adjacent to a tunnel under construction by blasting, was monitored and analyzed. The numerical model of the existing tunnel was established by the dynamic finite element software LS-DYNA, and the reliability of the model and parameter selections were verified based on the field monitoring data. The relationship between peak particle velocity and effective tensile stress of the tunnel lining structure was proposed based on the combination of measured peak particle velocity, dynamic stress distribution characteristics, and numerical simulations under different blasting conditions. Based on the maximum tensile stress criterion and considering the dynamic tensile strength increase factor of lining material, the safety threshold of peak particle velocity for existing tunnel lining structure and the maximum charge weight for new tunnel blasting were suggested.

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As for the slope with fault fracture zone, the fault fracture zone is the main sliding surface, whose shear strength parameter is the main calculation parameter of landslide occurrence. In this paper, shaking table model tests and damage theory were used to study the change of shear strength and mechanical cumulative damage model of fault fracture zone under the blasting vibration cyclic load. At first, the slope of Daye Iron Mine is selected as a case to study the shear strength weakening law of fault fracture zone by the similarity theory and the principle of the orthogonal test, in which the influence of the characteristics of vibration loading on the shear strength parameters of fault fracture zone with different thicknesses was studied. Secondly, by the assumption of Lemaitre strain equivalence and according to the extreme value characteristics of the normal stress-shear stress curve, the damage theory model of the fault fracture zone was reconstructed, and the microelement of fault was selected for analysis and divided into two parts, including damaged and undamaged materials. Finally, the results of the shaking table model tests were compared with the results of the shear cumulative damage model to verify the rationality of the theoretical model. Moreover, the predicted results of the theoretical model can better reflect the degradation trend of the fault fracture zone with the loading amplitude, normal stress, and loading times. It can be used as a reference for slope stability prediction under the action of cumulative static and dynamic loads.

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