Abstract: A simplified mechanical model of dangerous soil mass-anchor bolt-stabilized soil mass anchorage system is established against the background of instability of rammed earth sites caused by wide vertical cracks. In this model, friction between the anchor bolt and the soil mass is simplified into a parallel mechanism of a linear spring together with a speed-related damper, and the connect effect of anchor bolt in crack section is simplified as a linear spring. Dynamic equilibrium equations for the anchoring system are established based on the theory of elastodynamics, and analytic solutions of dynamic response of bolt axial forces and displacement are deduced. Finally, the analytic method proposed by this paper is applied to the anchorage engineering of the southern wall of the Gaochang Ancient City in Xinjiang to analyze the axial force response characteristics and distribution law of the anchor bolt. The rationality of the procedure is verified by numerical analysis. The results show that the axial force response of the anchor bolt at the same position under dynamic action fluctuates around the static equilibrium position, the position of the maximum axial force is near the crack and gradually decreases exponentially toward the free end and the anchor end. And after considering the amplification effect of the seismic acceleration along the height of the site, a more accurate axial force response of anchor bolt can be obtained.

Key words: rammed earth sites, wholly grouted anchor bolt, anchorage system, simplified mechanical model, dynamic response