Underground pipeline damping from the action of rayleigh waves

Abstract

The question of the depth of laying occupies a special place in the seismic protection of underground structures. With a seismic shock, different waves appear in the ground. Upon impact on the surface of the half-space, surface waves arise that have a destructive force for underground structures. Waves with longitudinal and transverse components of displacement, called Rayleigh waves, can occur on the surface. Rayleigh waves have a maximum effect on the surface and quickly fade with depth. To protect against the action of such waves, underground structures are laid deep on the ground. Reducing the depth of laying allows you to reduce costs and facilitates the maintenance of the structure. It will be possible to reduce the influence of Rayleigh waves at a shallower depth using dynamic dampers installed on the structure. The analysis of the work of a dynamic damper to reduce the displacement of an underground cylindrical structure allows us to conclude that the damping effect can be achieved both in terms of displacement amplitude and in the frequency zone width.

Damping of longitudinal vibrations of a cylindrical rod

“…Dynamic influences can create unfavorable vibrational states with large displacements. To create acceptable values of the vibration amplitudes of an underground structure, dynamic vibration dampers are used [3,4]. In [3], the possibility of reducing the amplitude of oscillations of a hard disk in an elastic medium with the help of a multi-mass dynamic absorber was studied.…”

“…In [3], the possibility of reducing the amplitude of oscillations of a hard disk in an elastic medium with the help of a multi-mass dynamic absorber was studied. The possibility of damping the oscillation amplitude of an underground cylindrical structure from the action of Rayleigh surface waves was considered in [4].…”

“…Previous studies [3,4] show the effectiveness of using absorbers to identify the likelihood of occurrence of underground phenomena. At the same time, a previously used single-mass absorber [4] is required to extinguish the accumulation of an underground structure, and to achieve a greater result, the use of a multi-mass absorber.…”

Transverse vibrations of underground pipeline with pinched ends

“…Surface waves are dangerous for not deeply laid structures. In [2], the oscillation of an elastic half-space with a cylindrical cavity under the influence of Rayleigh (surface) waves was studied, and in [3], the possibility of damping the oscillations of a cylindrical structure not deeply embedded in the elastic halfspace using a single-mass dynamic vibration damper was considered. The damping of vibrations of an underground cylindrical structure using a multi-mass dynamic vibration damper was considered [4], and the effectiveness of this approach was proved.…”

Longitudinal vibrations of a cylindrical bar from the action of harmonic forces

“…To reduce the movement of structures, dynamic vibration dampers are used. The possibility of damping vibrations of underground pipelines from the action of Rayleigh waves using a single-mass damper and damping of vibrations of an underground structure using a three-mass damper is considered in [4,5].…”