Analytical Study for Stress Wave Interaction with Rock Joints Having Unequally Close–Open Behavior

A rock mass often contains joints filled with a viscoelastic medium of which seismic response is significant to geophysical exploration and seismic engineering design. Using the propagator matrix method, an analytical model was established to characterize the seismic response of viscoelastic filled joints. Stress wave propagation through a single joint highly depended on the water content and thickness of the filling as well as the frequency and incident angle of the incident wave. The increase in the water content enhanced the viscosity (depicted by quality factor) of the filled joint, which could promote equivalent joint stiffness and energy dissipation with double effects on stress wave propagation. There existed multiple reflections when the stress wave propagated through a set of filled joints. The dimensionless joint spacing was the main controlling factor in the seismic response of the multiple filled joints. As it increased, the transmission coefficient first increased, then it decreased instead, and at last it basically kept invariant. The effect of multiple reflections was weakened by increasing the water content, which further influenced the variation of the transmission coefficient. The water content of the joint filling should be paid more attention in practical applications.

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Semi-analytical study on regular sea wave interaction with circular elastic floaters of aquaculture fish cages

Aquacultural Engineering ◽

10.1016/j.aquaeng.2020.102125 ◽

2020 ◽

Vol 91 ◽

pp. 102125

Author(s):

Ataollah Gharechae ◽

Mohammad Javad Ketabdari

Keyword(s):

Analytical Study ◽

Wave Interaction ◽

Aquaculture Fish ◽

Fish Cages ◽

Sea Wave

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Experimental and theoretical study on the propagation characteristics of stress wave in filled jointed rock mass

PLoS ONE ◽

10.1371/journal.pone.0253392 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0253392

Author(s):

Shuailong Jia ◽

Zhiliang Wang ◽

Jianguo Wang ◽

Zhitang Lu ◽

Haochen Wang

Keyword(s):

Rock Mass ◽

Transmission Coefficient ◽

Stress Wave ◽

Loading Rate ◽

Theoretical Calculations ◽

Rock Joints ◽

P Wave ◽

Specific Stiffness ◽

Filling Materials ◽

Filled Joint

This study is to theoretically and experimentally investigate the propagation of stress waves in the filled joint set. The time-domain recursive method is used to derive the propagation equations in the filled joint set, and the filled joints are further simplified into structural planes without joint thickness. The split-Hopkinson rock bar is modified to simulate P wave propagation normally across the parallel filled joints. The relationship among stress-closure curve, joint specific stiffness, transmission coefficient and loading rate is analyzed. The results show that, for the rock mass with a single joint, both the joint specific stiffness and transmission coefficient of different filling materials increase with loading rate. More serious particle breakage of the filling materials leads to lower joint specific stiffness and transmission coefficient. For the rock mass with two joints, the joint specific stiffness of each joint affects the transmission coefficient of the filled joint set. It is found that our theoretical calculations are basically consistent with the experimental ones, and the joint specific stiffness can well characterize the propagation behavior of stress wave in the filled parallel rock joints.

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