Seismic Wave Propagation Characteristics and Their Effects on the Dynamic Response of Layered Rock Sites

Abstract

To investigate the seismic response of layered rock sites, a multidomain analysis method was proposed. Three finite element models with infinite element boundaries for layered sites were analysed. The results of this multidomain analysis show that stratum properties and elevation have an impact on wave propagation characteristics and the dynamic response of layered sites. Compared with the rock mass, the overlying gravel soil has a greater dynamic amplification effect at the sites. A time domain analysis parameter PGA(IMF) was proposed to analyse the effects of different strata on the seismic magnification effect of layered sites, and its application was also discussed in comparison with PGA. According to the frequency domain analysis, the interface of the rock mass strata has a low impact on the Fourier spectrum characteristics of the sites, but gravel soil has a great magnification effect on the spectrum amplitude in the high-frequency band (≥30 Hz) of waves. Moreover, the stratum properties have a great influence on the shape and peak value of the Hilbert energy and marginal spectrum at layered sites. When waves propagate from hard rock to soft rock, the peak value of the Hilbert energy spectrum changes from single to multiple peaks; then, in gravelly soil, the Hilbert energy spectral peak, its nearby amplitude and the amplitude in the high-frequency band (28–36 Hz) are obviously amplified. The frequency components and amplitude of the marginal spectrum become more abundant and larger from rock to gravelly soil in the high-frequency band (28–35 Hz).

Early Detection of Earthquakes Using IoT and Cloud Infrastructure: A Survey

“…One of the most widely used signal processing techniques in seismic wave analysis is the Fourier transform, which is used to transform time-domain signals into frequency-domain signals [109,110]. In earthquake early warning systems, the Fourier transform is often used to analyze the spectral content of seismic waves, which can provide important information about the location, magnitude, and duration of an earthquake [111]. The Fourier transform is also used to filter out noise and unwanted signals from seismic data, improving the accuracy of earthquake detection and analysis [112].…”

Investigation of Quantitative Evaluation Method and Engineering Application of Shallow Buried Tunnel Face Stability

“…The soil body is a homogeneous and isotropic rigid-plastic material and the weighted average method can be used for the multi-layer soil body. 1 The soil material obeys the Mohr-Coulomb failure criterion (τ = c + σtanϕ, c is the cohesion, σ is the normal stress), and the influence of groundwater is not considered. 2 The damage range of excavation section is composed of wedge sliding body (ABC-abc) and prismatic body (DCcd-EFfe).…”

“…With the gradual implementation of deep exploitation strategy, the geotechnical engineering field requires more space resources from deep rock mass [1][2][3][4][5], and the underground traffic engineering shows a strong momentum of development [6][7][8][9]. As early as 1991, the Tokyo Declaration, adopted by the International Academic Conference on the Utilization of Urban Underground Space held in Tokyo, proposed that the 21st century would be the century for the development and utilization of underground spaces [10][11][12].…”

Investigation on Disaster Mechanism of Diversion Tunnel Induced by Gripper TBM in Hydrokarst Erosion Stratum and Engineering Measures

“…In recent years, the tunnel boring machine (TBM) has been widely used in tunnel construction for its advantages of excavation speed, engineering quality, tunneling safety, low carbon emission, and economic benefits, and has become the primary construction method for long railway tunnels and water diversion tunnels [1][2][3]. However, in unfavorable geology such as high ground stress, squeezing rocks, and fault-fracture zones, TBM encounters significant challenges, making it easy for destructive accidents like water-gushing, mud inflowing, collapses, and shield jamming [4][5][6]. These incidents not only lead to project delays and economic losses but also jeopardize tunneling safety [7,8].…”