scholarly journals Dynamic Response of Rock Slopes under Obliquely Incident Seismic Waves

2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Biao Liu ◽  
Boyan Zhang
Keyword(s):  
Dynamic Response ◽  
Peak Ground Acceleration ◽  
Rock Slope ◽  
Incident Angle ◽  
Slope Angle ◽  
Amplification Coefficient ◽  
Slope Surface ◽  
Ground Acceleration ◽  
Obliquely Incident ◽  
Acceleration Amplification

In this study, the seismic input model of slope is proposed to investigate the dynamic response of the rock slope under obliquely incident seismic wave on the basis of the time-domain wave analysis method. The model includes viscoelastic boundary considering the infinite foundation radiation damping and the seismic obliquely incident method. The semi-infinite space numerical example is simulated to verify the validity and accuracy of the model. Based on the established model, the effects of the variation of the seismic wave incident angles and slope angles on the dynamic response of a rock slope are analyzed. The results demonstrate that the changes of the incident angle and the slope angle have no discernible effect on the dynamic response of the rock slope when the P wave is obliquely incident. As the SV wave is obliquely incident, the peak ground acceleration amplification coefficient along the slope surface gradually increases with the increase of the incident angle; when the slope angle gradually increases, the peak ground acceleration amplification coefficient along the slope surface will also gradually increase at the upper part of the slope. The research results can provide some basis for the pseudostatic method to determine the seismic action coefficient.

Dynamic Response Differences Between Bedding and Counter-Tilt Rock Slopes with Intercalated Weak Layers

2016 ◽  
Vol 11 (4) ◽  
pp. 681-690
Author(s):  
Song Zhi ◽  
◽  
Liu Yang ◽  
◽  
◽  
...  
Keyword(s):  
Dynamic Response ◽  
Rock Slope ◽  
Surface Displacement ◽  
Amplification Coefficient ◽  
Rock Slopes ◽  
Relative Height ◽  
Slope Surface ◽  
Weak Layer ◽  
Acceleration Amplification ◽  
Bedding Rock Slope

Bedding and counter-tilt rock slope with intercalated weak layers are common geological bodies in west China, the dynamic response research will guide the anti-seismic reinforcement of bedding and counter-tilt rock slope with intercalated weak layer effectively. Two test models of bedding rock slope with intercalated weak layer and counter-tilt rock slope with intercalated weak layer, which are in the same size, have been designed and developed. A large scale shaking table test has been performed to analyze the dynamic response difference of bedding and counter-tilt rock slope with intercalated weak layer. The study results show that the acceleration amplification coefficient inside the bedding slope is smaller than that inside the counter-tilt rock slope; at the middle and upper parts of the slope body (relative height > 0.4), the acceleration amplification coefficient at bedding rock slope surface is larger than that of counter-tilt rock slope. At the lower part of the slope (relative height le 0.4), the acceleration amplification coefficient at bedding rock slope surface is close to that of counter-tilt rock slope. The slope surface displacement of both bedding and counter-tilt rock slopes increases with increasing input seismic wave amplitude. The slope surface displacement of the bedding rock is larger than that of counter-tilt rock slope. The seismic stability of counter-tilt rock slope is stronger than bedding rock slope. The dynamic failure form of bedding rock slope mainly includes vertical tension crack at back edge, bedding sliding along intercalated weak layer and rock collapse at slope crest; whereas the dynamic failure form of counter-tilt slope mainly includes intersection of horizontal and vertical cracks on slope surface, extrusion of intercalated weak layer and shattering of slope crest.

scholarly journals Dynamic Response and Failure Process of a Counter-Bedding Rock Slope under Strong Earthquake Conditions

Symmetry ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 103
Author(s):  
Ming-Zhu Guo ◽  
Kun-Sheng Gu ◽  
Chen Wang
Keyword(s):  
Dynamic Response ◽  
Seismic Wave ◽  
Rock Slope ◽  
Amplification Factor ◽  
Failure Process ◽  
Slope Surface ◽  
Maximum Value ◽  
Acceleration Amplification ◽  
Weak Intercalated Layer ◽  
Bedding Rock Slope

There are massive landslides and potential landslides along the Three Rivers Basin in the Qinghai–Tibet Plateau, which pose a serious threat to the Sichuan–Tibet Railway. A normal shaking table model test was conducted to study the dynamic characteristics and dynamic response of a symmetrical counter-bedding rock slope based on the Zongrong Village landslide. The influences of the dynamic parameters, seismic wave type, and a weak intercalated layer on the slope’s dynamic response were considered. The results showed symmetry between the growth trend of the acceleration amplification factor and other research results. When the input wave amplitude was constant, the acceleration amplification factor increased at first and then decreased as the frequency increased. When the input frequency was near the slope’s natural frequency, the acceleration amplification factor increased at first and then decreased with an increase in the input amplitude and reached the maximum value at 0.3 g. The acceleration amplification factor increased linearly with height in the vertical direction inside the slope but increased slowly at first and then sharply along the slope surface, reaching the maximum value at the slope’s top and exhibiting an obvious “elevation effect”. When sinusoidal waves, Wolong waves, and Maoxian waves with the same amplitude were input, the slope’s amplification effect on the bedrock wave was more obvious. The weak intercalated layer showed the phenomenon of “thin layer amplification” and “thick layer attenuation” in response to the input seismic wave. The slope’s failure process can be roughly divided into three stages: (1) the formation of tensile cracks at the top and shear cracks at the toe; (2) the extension of cracks and the sliding of the slope-surface block; (3) the formation of the main sliding surface.

scholarly journals Dynamic response and damage character of road embankment under strong earthquake

2018 ◽  
Vol 14 (9) ◽  
pp. 155014771879461 ◽  
Author(s):  
Jian Wang ◽  
Qimin Li ◽  
Changwei Yang ◽  
Caizhi Zhou
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Strong Earthquake ◽  
Spectral Characteristics ◽  
Shaking Table ◽  
Ground Acceleration ◽  
Critical Acceleration ◽  
Embankment Height ◽  
Logarithmic Relationship

Dynamic response of road embankment under strong earthquake was explored by site investigation, shaking table tests, and discrete element method simulations, which shows that the distribution of responded accelerations strongly depends on the amplitude of input ground motion and the height of road embankment. When the peak ground acceleration of ground motion is small, peak ground acceleration amplification factors will linearly increase from the toe to the top of the slope; then, it will step into non-linear amplification; when the peak ground acceleration of ground motion is large enough, it will transform from amplification to attenuation. There is a logarithmic relationship between the magnitude of acceleration and the slope amplification factor, and the critical acceleration making the peak ground acceleration transform from amplification to attenuation increases with the raise of embankment height and connects with spectral characteristics of ground motion. There is a logarithmic relationship between the input ground acceleration and the amplification ratio of slope top to toe, and the critical acceleration making the peak ground acceleration transform from amplification to attenuation increases with the raise of embankment height and connects with spectral characteristics of ground motion. The results found should be useful for aseismic of road embankment as well as railway subgrade.

scholarly journals Time-Frequency Energy Distribution of Ground Motion and Its Effect on the Dynamic Response of Nonlinear Structures

2019 ◽  
Vol 11 (3) ◽  
pp. 702 ◽  
Author(s):  
Dongwang Tao ◽  
Jiali Lin ◽  
Zheng Lu
Keyword(s):  
Dynamic Response ◽  
Energy Distribution ◽  
Ground Motion ◽  
Peak Ground Acceleration ◽  
Structural Response ◽  
Ground Acceleration ◽  
Time Frequency ◽  
Plastic Structure ◽  
Perfectly Plastic ◽  
Frequency Components

The ground motion characteristics are essential for understanding the structural seismic response. In this paper, the time-frequency analytical method is used to analyze the time-frequency energy distribution of ground motion, and its effect on the dynamic response of nonlinear structure is studied and discussed. The time-frequency energy distribution of ground motion is obtained by the matching pursuit decomposition algorithm, which not only effectively reflects the energy distribution of different frequency components in time, but also reflects the main frequency components existing near the peak ground acceleration occurrence time. A series of artificial ground motions with the same peak ground acceleration, Fourier amplitude spectrum, and duration are generated and chosen as the earthquake input of the structural response. By analyzing the response of the elasto-perfectly-plastic structure excited by artificial seismic waves, it can be found that the time-frequency energy distribution has a great influence on the structural ductility. Especially if there are even multiple frequency components in the same ground motion phrase, the plastic deformation of the elasto-perfectly-plastic structure will continuously accumulate in a certain direction, resulting in a large nonlinear displacement. This paper reveals that the time-frequency energy distribution of a strong ground motion has a vital influence on the structural response.

scholarly journals Dynamical similarity of multi-block catenary arches and rocking blocks subjected to horizontal base excitation

2021 ◽  
Author(s):  
Tamás Ther ◽  
László P. Kollár
Keyword(s):  
Dynamic Response ◽  
Peak Ground Acceleration ◽  
Response Spectra ◽  
Frequency Parameter ◽  
Base Excitation ◽  
Acceleration Response ◽  
Ground Acceleration ◽  
Acceleration Response Spectra ◽  
Basic Hypothesis ◽  
Two Parameters

AbstractIn this paper, the dynamical similarity of multi-block catenary arches and columns is discussed, which can be used for the simplified design of rocking arches. The basic hypothesis is that the dynamic response of multi-block arches and columns is similar when the shape of the arch follows the thrust line, i.e. it is a catenary arch. It is validated numerically that the responses of slender catenary arches are safe and reliable approximations of those of not slender arches and then that the overturning acceleration (response) spectra of rigid, slender monolithic blocks can be directly applied for catenary arches. The similarity is based on two parameters, on the limit peak ground acceleration (under which the structure will not move at all) and on the frequency parameter (defined by Housner for rigid blocks).

scholarly journals Seismic Response of Rock Slopes with the Anchor Cable in Centrifuge Modeling Tests

2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Yong Nie ◽  
Yufei Zhao ◽  
Xiaogang Wang ◽  
Linhao Li ◽  
Hongtao Zhang
Keyword(s):  
Seismic Response ◽  
Rock Slope ◽  
Centrifuge Modeling ◽  
Amplification Coefficient ◽  
Rock Slopes ◽  
Acceleration Response ◽  
Structural Plane ◽  
Horizontal Acceleration ◽  
Anchor Cable ◽  
Acceleration Amplification

In order to study the seismic response of the rock slopes with the anchor cable, centrifuge modeling tests were performed on concrete slope models. Different seismic loadings were performed to investigate the horizontal acceleration response, the rock slope displacement, and the stress of anchor cables. The results show that the horizontal acceleration response is obviously amplified by a rock slope. Under the same conditions, the higher the seismic intensity is, the larger the acceleration amplification coefficient will be. Anchor cable can effectively reduce the acceleration amplification effect of the slope. For the slope with a structural plane, the anchor cable at the structural plane is stressed greatly during the seismic action, and the strength of anchor cables near the expected structural plane is important.

scholarly journals Methodology to evaluate rock slope stability under seismic conditions at Solà de Santa Coloma, Andorra

2009 ◽  
Vol 9 (6) ◽  
pp. 1763-1773 ◽  
Author(s):  
O. Mavrouli ◽  
J. Corominas ◽  
J. Wartman
Keyword(s):  
Slope Stability ◽  
Rock Slope ◽  
Limit Equilibrium ◽  
Water Pressure ◽  
Slope Angle ◽  
Water Levels ◽  
Equilibrium Analysis ◽  
Rock Slope Stability ◽  
Ground Acceleration ◽  
Moderate Seismicity

Abstract. An analytical methodology is presented to evaluate rock slope stability under seismic conditions by considering the geomechanical and topographic properties of a slope. The objective is to locate potential rockfall source areas and evaluate their susceptibility in terms of probability of failure. For this purpose, the slope face of a study area is discretized into cells having homogenous aspect, slope angle, rock properties and joint set orientations. A pseudostatic limit equilibrium analysis is performed for each cell, whereby the destabilizing effect of an earthquake is represented by a horizontal force. The value of this force is calculated by linear interpolation between the peak horizontal ground acceleration PGA at the base and the top of the slope. The ground acceleration at the top of the slope is increased by 50% to account for topographic amplification. The uncertainty associated with the joint dip is taken into account using the Monte Carlo method. The proposed methodology was applied to a study site with moderate seismicity in Solà de Santa Coloma, located in the Principality of Andorra. The results of the analysis are consistent with the spatial distribution of historical rockfalls that have occurred since 1997. Moreover, the results indicate that for the studied area, 1) the most important factor controlling the rockfall susceptibility of the slope is water pressure in joints and 2) earthquake shaking with PGA of ≤0.16 g will cause a significant increase in rockfall activity only if water levels in joints are greater than 50% of the joint height.

scholarly journals Investigation into a Homogenous Rock Slope Response Under Wide Frequency Seismic Loads Using a Large-Scale Shaking Table

2021 ◽  
Author(s):  
Jianxian He ◽  
Zhifa Zhan ◽  
Shengwen Qi ◽  
Chunlei Li ◽  
Bowen Zheng ◽  
...  
Keyword(s):  
Seismic Response ◽  
Peak Ground Acceleration ◽  
Large Scale ◽  
Rock Slope ◽  
Amplification Factor ◽  
Damping Ratio ◽  
Excitation Amplitude ◽  
Shaking Table ◽  
Ground Acceleration ◽  
Slope Structure

Abstract The main objective of this study was to investigate the effect of input earthquake characteristics on the seismic response of a homogenous step-like rock slope. A sequence of shaking table tests was performed in a large-scale physical model with a size of 3.50 m, 0.68 m and 1.20 m in length, width and height, respectively. Results showed that the absolute peak ground acceleration motion amplification factor in horizontal direction (AAF-X) of upper part of the slope was amplified comparison with that at the slope toe while the absolute peak ground acceleration motion amplification factor (AAF-Z) acquired maximum value at the lower position of the slope. With the increasing of the excitation frequencies, the AAF-X around the slope crest increased firstly and then deceased, while the AAF-Z increased continuously. Seismic response of the slope showed strongest amplification when the normalized height of the slope H/λ (ratio of slope height to wavelength) was around 0.2 and AAF-X exhibited a decrease trend when H/λ was larger than 0.2. The AAF showed nonlinear tendency with the increases of the input amplitudes, especially near the shoulder of the slope. This phenomenon can be revealed by the relationship between the calculated resonance frequency or damping ratio of the slope and the amplitude of the input motion. The excitation amplitude has a “double-effect” on the seismic response of a step-like homogeneous rock slope. That is on the one hand, the larger the excitation amplitude, the stronger the acceleration intensity, the greater deterioration of rock slope structure or material and the larger damping ratio of the slope; on the other hand, more energy will be dissipated due to plastic deformation or particle friction of high damping ratio and weaker slope structure. These results could attribute to reveal the dynamic instability mechanism of the homogeneous slope.

Analisis Percepatan Tanah Puncak Akibat Gempa Pada Kota Sorong Sebagai Upaya Mitigasi Bencana

2018 ◽  
Vol 4 (2) ◽  
pp. 14
Author(s):  
Imam Trianggoro Saputro ◽  
Mohammad Aris
Keyword(s):  
Peak Ground Acceleration ◽  
Ground Acceleration ◽  
Papua Barat

Sorong merupakan salah satu kota yang terletak di Provinsi Papua Barat. Daerah ini memiliki tingkat kerentanan yang tinggi terhadap ancaman bahaya gempa bumi karena lokasinya terletak di antara pertemuan lempengan tektonik dan beberapa sesar aktif. Tingkat kerawanan terhadap gempa pada daerah ini cukup tinggi. Pada September 2016, BMKG mencatat bahwa terjadi gempa bumi dengan skala magnitudo sebesar 6,8 SR (Skala Ritcher) dengan kedalaman 10 meter dari permukaan laut dan berjarak 31 km arah timur laut kota Sorong. Gempa ini bersifat merusak. Akibat gempa ini, sebanyak 62 orang terluka dan 257 rumah rusak. Untuk itu diperlukan suatu analisis terhadap percepatan tanah puncak (Peak Ground Acceleration) terbaru sebagai langkah mitigasi yang nantinya dapat digunakan untuk perencanaan gedung tahan gempa.Pengumpulan data gempa pada peneltian ini yaitu data gempa yang terjadi sekitar kota Sorong pada rentang waktu 1900-2017. Data gempa yang diambil adalah yang berpotensi merusak struktur yaitu dengan magnitudo (Mw) ≥ 5 dengan radius gempa 500 km dari kota Sorong dan memiliki kedalaman antara 0 - 300 km. Setelah diperoleh data gempa maka dibuat peta sebaran gempa di wilayah kota Sorong. Percepatan tanah puncak dihitung berdasarkan fungsi atenuasi matuscha (1980) dan menggunakan pendekatan metode Gumbel.Hasil penelitian menunjukkan bahwa nilai percepatan tanah puncak (PGA) di wilayah kota Sorong pada periode ulang 2500 tahun atau menggunakan probabilitas terlampaui 2% dalam 50 tahun umur rencana bangunan diperoleh sebesar 708.9520 cm/dt2 atau 0.7227 g. Apabila melihat peta gempa SNI 1726-2012 yang menggunakan probabilitas yang sama maka nilai percepatan tanah puncak (PGA) ketika gempa bumi berkisar antara 0.4 g - 0.6 g. Nilai ini mengalami peningkatan yang berarti tingkat resiko terhadap gempa bumi pada wilayah kota Sorong meningkat.

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