scholarly journals Dynamic response of rock slope with anti-dip weak interlayer and its influencing factors under seismic actions

2021 ◽  
Vol 14 (6) ◽  
Author(s):  
Tong Wang ◽  
Chengliang Gao ◽  
Fei Huang ◽  
Di Peng ◽  
Shuwen Tian ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Residual Deformation ◽  
Soil Mass ◽  
Dynamic Responses ◽  
Seismic Stability ◽  
Seismic Load ◽  
Deformation State ◽  
Weak Interlayer ◽  
Slope Displacement

AbstractThe load features of ground motion are mainly reflected by three factors: amplitude, frequency, and duration. The combination of these factors determines the response of rock-soil mass and the structure safety under seismic load. By finite element method, this paper analyzes the influence of the three factors of ground motion on the dynamic response of a slope. The analysis shows that the slope displacement increased with the elevation from the bottom. The anti-dip fault puts the slope in an unfavorable deformation state. Due to the large residual deformation in the fault zone, a large displacement occurred on the slope top. It was also learned that the adjustment of amplitude only leads to proportional growth in the absolute value of the acceleration of the slope. Under the same conditions, the dynamic responses in different parts of the target slope are not greatly affected by the changing amplitude, but depend more on the material and spectral features of the rock-soil mass. The research results provide a reference for the evaluation and prediction of slope seismic stability and the evolution of slope damage under earthquakes with different frequencies, amplitudes, and durations.

scholarly journals Research on Dynamic Response of Slopes With Weak Interlayers Under Mining Blasting Vibration

2022 ◽  
Vol 9 ◽  
Author(s):  
Xiaochao Zhang ◽  
Qingwen Yang ◽  
Xiangjun Pei ◽  
Ruifeng Du
Keyword(s):  
Dynamic Response ◽  
Internal Structure ◽  
Explosive Charge ◽  
Blast Loading ◽  
Dynamic Responses ◽  
Internal Dynamic ◽  
Explosive Energy ◽  
Wide Range ◽  
Blasting Excavation ◽  
Weak Interlayer

As blasting technology starts to be used in a wide range of areas, blast loading has led to an increasing number of geological disasters such as slope deformation, collapses, and soil slippage. Slopes with weak interlayers are more likely to be deformed and damaged under the influence of blast loading. It is of great importance to study the evolution for the deformation of slopes with weak interlayers during blasting excavation. This study constructed a slope model with a weak interlayer to investigate the influence of different factors of blasting, including explosive charge, blast radius, blast origin, and multi-hole blasting, on the internal dynamic response. The deformation mechanism of slopes with weak interlayers under the influence of blast loading was analyzed. Test results show that each layer of the model had a different displacement response (uncoordinated dynamic response) to blasting with various factors. Explosive energy and the pattern of dynamic response of each layer varied depending on different settings of blasting factors such as explosive charge, blast radius, blast origin, and detonation initiation method. When the explosive energy produced under the influence of various factors was small, the change in the uncoordinated dynamic response between layers was significant, and the change gradually became less significant as the explosive energy increased. Therefore, this study has proposed the concept of critical explosive energy, and it is speculated that when the explosive energy produced with various factors is less than critical explosive energy, the dynamic response is mainly affected by the internal structure of the slope (property difference induced geologic layers). In other words, the uncoordinated motion of material’s particles in each layer is caused by different limitations and the degree of movement of the particles, which leads to the uncoordinated dynamic response and uncoordinated deformation of each layer. If the explosive energy is greater than the critical value, the dynamic response of each layer is mainly affected by the explosive energy. The differences in the internal structure of the slope are negligible, and the incoordination of dynamic responses between layers gradually weakens and tends to synchronize.

Dynamic Responses of Slope under the Effect of Seismic Loads

2013 ◽  
Vol 438-439 ◽  
pp. 1587-1591
Author(s):  
Luo Jian Mao ◽  
Qian Xu ◽  
Zheng Jian ◽  
Ying Zhu
Keyword(s):  
Stress Concentration ◽  
Tensile Strain ◽  
Dynamic Responses ◽  
Seismic Stability ◽  
Seismic Load ◽  
Seismic Loads ◽  
Slope Surface ◽  
Concentration Effects ◽  
Time Stress ◽  
Rare Earthquake

In order to study the seismic response of slope under the effect of seismic load, a numerical model was established by ANSYS program. It was mainly analyzed the dynamic responses of slope under the effect of both general earthquake and rare one. The results indicate that under general earthquake, slope deforms a little, there is small stress within slope, and small tensile stress on the top of slope; under rare earthquake, slope deforms greatly, slope surface has large displacement, and there is larger tensile strain on the slope top. At the same time, stress concentration effects expand further within slope and slope toe. Consequently, with regard to slopes in higher fortification intensity area, some steps should be taken to strengthen slope in order to improve slope seismic stability.

scholarly journals Dynamic Response and Failure Characteristics of Slope with Weak Interlayer under Action of Near-Fault Ground Motion

2021 ◽  
Vol 2021 ◽  
pp. 1-18
Author(s):  
Bing Yang ◽  
Jiangrong Hou ◽  
Yifei Liu ◽  
Zihong Zhou
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Large Scale ◽  
Failure Modes ◽  
Beam Theory ◽  
Amplification Effect ◽  
Near Fault ◽  
Weak Interlayer ◽  
Horizontal Ground Motion ◽  
Near Fault Ground Motion

Investigations into the Wenchuan earthquake (2008, China) demonstrated that landslides were concentrated in the near-fault areas, and numerous large-scale landslides occurred in slopes with weak interlayers. A mathematical model was established based on the shear beam theory, while a numerical model was developed based on the discrete element method which perfectly matched layer boundary theory. Through a theoretical analysis and numerical simulation, the dynamic response and failure modes of the slope with a weak interlayer under the near-fault ground motion were studied. It was found that a combined effect took place between the near-fault ground motion and the weak interlayer, causing the slope near a fault to be destroyed more easily. The coupling between the near-fault ground motion and the weak interlayer leads to a maximum amplification effect of the slope. The existence of a weak interlayer induces nonconforming vibration between the upper and the lower rock masses of the interlayer. The variation in the amplification effect along the slope elevation is related to the ratio of the input seismic period to the natural slope period. Under horizontal ground motion, weak interlayers will be subjected to impacting and shearing action. The failure mode of the slope with a weak interlayer under near-fault ground motion can be expressed as a trailing edge tension crack, as well as weak interlayer impacting and shearing failure.

scholarly journals Dynamic Response Spectrum of Multi-Story Shear Frame Subjected to Moderate Ground Motion

2021 ◽  
Vol 14 (2) ◽  
pp. 71-79
Author(s):  
Assal Hussein
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Response Spectrum ◽  
Response Spectra ◽  
Mode Shapes ◽  
Seismic Load ◽  
Seismic Zone ◽  
Maximum Displacement ◽  
Shear Frame ◽  
The Impact

Design structures to resist natural hazards is a vital issue to mitigate the impact of such threats. Earthquakes could lead to numerous injuries and infrastructure destruction. Specifically, when structures are not designed to resist seismic load.  This article presents dynamic analysis of four-story shear frame under moderate ground motion to determine the dynamic response. The proposed location of the considered frame is near Iraq-Iran border due to increase of seismic activities in last years. Structures in the considered seismic zone are essentially either residential or commercial buildings and not designed to resist seismic load, therefore structural system failure is probable. Simplified model is considered to determine response spectrum according to the International Building Code requirements. The algorithm of the analysis is developed using MATLAB® code to get mode shapes, response spectrum acceleration, maximum displacement, maximum shear forces, and modal participation mass at each story. The article develops design response spectra curve of Erbil city. Furthermore, the analysis results showed that first mode shape has more contribution than the other modes because higher percentage of the mass of the shear frame responds to the ground motion, and 88.53% of shear-frame mass is participating responds to the ground motion in the same mode

Seismic Performance Analysis of Fill Slope with Pre-Stressed Anchors

2013 ◽  
Vol 353-356 ◽  
pp. 2052-2056 ◽  
Author(s):  
Qi Wen Jin ◽  
Qian Xu ◽  
Tong Ning Wang ◽  
Fei Geng
Keyword(s):  
Stress Response ◽  
Stress Concentration ◽  
Performance Analysis ◽  
Stress Distribution ◽  
Seismic Design ◽  
Dynamic Responses ◽  
Seismic Stability ◽  
Seismic Load ◽  
Stability Of Slope ◽  
Fill Slope

Pre-stressed anchors were widely used to strengthen slopes, in this passage the dynamic responses of fill slope with pre-stressed anchors under the effect of seismic load were simulated by ANSYS program. And it was mainly analyzed the effect of pre-stress anchors on seismic performances of slope under general earthquake. The results indicate that changing the value of pre-stress has little effect on slope deformation, but has larger effect on stress distribution in slope. And with the increases of pre-stress value, stress response on the top of slope is small, the stress concentration in slope is alleviated, while the stress on slope toe increases a little, the seismic stability of slope is improved to some extent. And these conclusions may provide some theory basis for slope seismic design and study.

Dynamic Characteristics of Base-Isolated Steel Frame under Seismic Ground Motion

2011 ◽  
Vol 255-260 ◽  
pp. 2341-2344
Author(s):  
Mohammad Saeed Masoomi ◽  
Siti Aminah Osman ◽  
Ali Jahanshahi
Keyword(s):  
Ground Motion ◽  
Base Isolation ◽  
Time History ◽  
Steel Structure ◽  
Steel Structures ◽  
Steel Frame ◽  
Nonlinear Time History Analysis ◽  
Seismic Load ◽  
Vector Method ◽  
Seismic Ground Motion

This paper presents the performance of base-isolated steel structures under the seismic load. The main goals of this study are to evaluate the effectiveness of base isolation systems for steel structures against earthquake loads; to verify the modal analysis of steel frame compared with the hand calculation results; and development of a simulating method for base-isolated structure’s responses. Two models were considered in this study, one a steel structure with base-isolated and the other without base-isolated system. The nonlinear time-history analysis of both structures under El Centro 1940 seismic ground motion was used based on finite element method through SAP2000. The mentioned frames were analyzed by Eigenvalue method for linear analysis and Ritz-vector method for nonlinear analysis. Simulation results were presented as time-acceleration graphs for each story, period and frequency of both structures for the first three modes.

3-D elastic coupling vibration and acoustical radiation characteristics of cracked gear under elastic support condition

2015 ◽  
Vol 23 (9) ◽  
pp. 1548-1568 ◽  
Author(s):  
Shao Renping ◽  
Purong Jia ◽  
Xiankun Qi
Keyword(s):  
Dynamic Response ◽  
Support System ◽  
Three Dimensional ◽  
Elastic Support ◽  
Dynamic Responses ◽  
Tooth Root ◽  
Support Condition ◽  
Elastic Boundary ◽  
Root Crack ◽  
Elastic Disc

According to the actual working condition of the gear, the supporting gear shaft is treated as an elastic support. Its impact on the gear body vibration is considered and investigated and the dynamic response of elastic teeth and gear body is analyzed. On this basis, the gear body is considered as a three-dimensional elastic disc and the gear teeth are treated as an elastic cantilever beam. Under the conditions of the elastic boundary (support shaft), combining to the elastic disk and elastic teeth, the influence of three-dimensional elastic discs on the meshing tooth response under an elastic boundary condition is also included. A dynamic model of the gear support system and calculated model of the gear tooth response are then established. The inherent characteristics of the gear support system and dynamics response of the meshing tooth are presented and simulated. It was shown by the results that it is correct to use the elastic support condition to analyze the gear support system. Based on the above three-dimensional elastic dynamics analysis, this paper set up a dynamics coupling model of a cracked gear structure support system that considered the influence of a three-dimensional elastic disc on a cracked meshing tooth under elastic conditions. It discusses the dynamic characteristic of the cracked gear structure system and coupling dynamic response of the meshing tooth, offering a three-dimensional elastic body model of the tooth root crack and pitch circle crack with different sizes, conducting the three-dimensional elastic dynamic analysis to the faulty crack. ANSYS was employed to carry out dynamic responses, as well as to simulate the acoustic field radiation orientation of a three-dimensional elastic crack body at the tooth root crack and pitch circle with different sizes.

Dynamic Response of Frame Structure with Different Stiffness in Two Horizontal Directions under Oblique Seismic Action

2013 ◽  
Vol 368-370 ◽  
pp. 1644-1647
Author(s):  
Zhen Bao Li ◽  
Hai Teng Wang ◽  
Li Fei Liu ◽  
Wen Jing Wang
Keyword(s):  
Dynamic Response ◽  
Ground Motion ◽  
Structure Design ◽  
Frame Structure ◽  
Maximum Response ◽  
Seismic Action

The ground motion is multidimensional, random and uncertain in directions when earthquakes occur, so dynamic response under oblique seismic action needs to be considered in the structure design. A frame structure with different stiffness in two horizontal directions was analyzed under seismic action with different input angles. The maximum response of beams and columns was obtained. The seismic mechanism of structures under oblique seismic action was discussed.

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