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 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 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 Geotechnical factors in seismic design of foundations state-of-the-art report

2000 ◽  
Vol 33 (3) ◽  
pp. 347-370 ◽  
Author(s):  
Miguel P. Romo ◽  
Manuel J. Mendoza ◽  
Silvia R. Garcia
Keyword(s):  
Artificial Intelligence ◽  
Soil Properties ◽  
Seismic Design ◽  
Laboratory Testing ◽  
State Of The Art ◽  
Testing Equipment ◽  
Seismic Stability ◽  
Seismic Load ◽  
Numerical Techniques ◽  
Dynamic Soil Properties

This paper revises the factors that influence the behavior of foundations in seismic environments. It discusses aspects related with seismic load definition, dynamic soil properties, field and laboratory testing equipment, geoseismic instrumentation of prototypes, foundation seismic stability, use of artificial intelligence, among others. It also points out areas where more research is needed to better our knowledge on the physics of the problem and to improve experimental and numerical techniques, with the purpose of making more reliable and less costly foundation systems.

scholarly journals Stress analysis of infinite laminated composite plate with elliptical cutout under different in plane loadings in hygrothermal environment

2021 ◽  
Vol 8 (1) ◽  
pp. 1-12
Author(s):  
Ashok Magar ◽  
Achchhe Lal
Keyword(s):  
Stress Concentration ◽  
Stress Distribution ◽  
Composite Plate ◽  
Volume Fraction ◽  
Elliptical Hole ◽  
Laminated Composite ◽  
Laminated Composite Plate ◽  
Concentration Changes ◽  
Hygrothermal Environment ◽  
Plate Analysis

Abstract This paper presents the solution of stress distribution around elliptical cutout in an infinite laminated composite plate. Analysis is done for in plane loading under hygrothermal environment. The formulation to obtain stresses around elliptical hole is based on Muskhelishvili’s complex variable method. The effect of fibre angle, type of in plane loading, volume fraction of fibre, change in temperature, fibre materials, stacking sequence and environmental conditions on stress distribution around elliptical hole is presented. The study revealed, these factors have significant effect on stress concentration in hygrothermal environment and stress concentration changes are significant with change in temperature.

scholarly journals Dynamic Responses to Acute Heat Stress between 34 °C and 38.5 °C, and Characteristics of Heat Stress Response in Mice

2003 ◽  
Vol 26 (5) ◽  
pp. 701-708 ◽  
Author(s):  
Naoki Harikai ◽  
Kanji Tomogane ◽  
Mitsue Miyamoto ◽  
Keiko Shimada ◽  
Satoshi Onodera ◽  
...  
Keyword(s):  
Heat Stress ◽  
Stress Response ◽  
Dynamic Responses ◽  
Heat Stress Response ◽  
Acute Heat Stress

Earthquake Damage and Design Requirement of Stair in Frame Structure

2013 ◽  
Vol 438-439 ◽  
pp. 1461-1465 ◽  
Author(s):  
Yuan Bing Cheng ◽  
Kang Wang ◽  
Yong Qiang Ren
Keyword(s):  
Seismic Design ◽  
Earthquake Damage ◽  
Frame Structure ◽  
Seismic Load ◽  
Specific Calculation ◽  
Rescue Work ◽  
Design Requirements ◽  
Serious Injury ◽  
Death Investigation ◽  
Current Code

In building structure, staircase is more complex and relatively weak. As an important emergency routes when earthquakes and other emergencies (such as fire, explosion, etc.) take place, stairs subject highly evacuation live or seismic load, destruction of the stair caused delay of evacuation and affected the commencement of rescue work, and produced serious injury or death. Investigation of Wenchuan earthquake damage also finds that many stairs broken before the main structure. In the current code for seismic designof building, seismic design advice of stairs was only given instructionally, and specific calculation methods and construction requirements were lacked. Based on the analysis of earthquake destroy of stairs in frame structure, this paper proposes some design requirements of stair.

Inferring hillslope response under seismic loading and rainfall: A case study from the SE Carpathian, Romania

2021 ◽  
Author(s):  
Vipin Kumar ◽  
Léna Cauchie ◽  
Anne-Sophie Mreyen ◽  
Philippe Cerfontaine ◽  
Mihai Micu ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Slope Stability ◽  
Surface Runoff ◽  
Dynamic Condition ◽  
Seismic Loading ◽  
Seismic Stability ◽  
Seismic Load ◽  
Stability Evaluation ◽  
Rainfall Events ◽  
Year 2000

<p>Seismic stability evaluation plays a crucial role in landslide disaster risk reduction. Related modeling also has to consider the potential influences of the rainfall on the hillslopes. This study aims at understanding the relative influence of the seismic loading and extreme cumulative rainfall on a massive active landslide in the seismically active Vrancea-Buzau region of the Romanian Carpathians (45° 30' 23" N, 26° 25' 05" E). This region has been subjected to more than 700 earthquakes (M>4) events with the highest magnitude of 7.2 (M<sub>w</sub>) during the year 1960-2019. Rainfall data of the year 2000-2019 revealed the occurrence of relatively intense rainfall events, especially during the last ten years. The landslide has an aerial dimension of ~9.1 million m². It hosts the small village of Varlaam at the toe along the Bisca River. The slope (with an average gradient of 15-20°) is covered by shrubs and scattered trees near its borders and is relatively barren in the central part. Shales with some intercalated sandstone layers belonging to the Miocene thrust belt constitute the rocks of the slope.   </p><p>A first survey involving the multi-station array and related Horizontal-to-Vertical noise Spectral Ratio (HVSR) measurements was completed in summer 2019. The findings of the HVSR were processed using the inversion process to infer the shear wave velocity distribution with depth and to detect the sliding surface of the landslide. These velocities were further used to estimate the geotechnical properties of the subsurface using the empirical equations. The HVSR based depth profiles and the Unmanned Air Vehicle based topographic information were used to take four 2D slope sections. These sections were considered for 2D discrete element modeling based stability evaluation under static and dynamic condition along with sensitivity analysis. Static simulation was used to determine the Factor of Safety (FS) using the shear strength reduction approach. Ricker wavelet was used as input seismic load in the dynamic simulation. Potential run-out and flow characteristics of the slope material were explored using the Voellmy rheology based RAMMS software. The relationship between rainfall, surface runoff, and soil moisture was also explored to understand the hydrogeological influence on slope stability.</p><p>Though the slope reveals meta-stability (1.0<FS<2.0) condition under static loading, displacement in the soil reaches up to 1.5 m that further increases to 2.8 m under dynamic loading. According to the topographic characteristics of the slope and to the presence of landslide material or intact bedrock near the surface, acceleration along the slope reaches a Peak Ground Acceleration in the range of 0.6 to 1.3g. Eight extreme rainfall events (>50mm/24 hours) during the year 2000-2019 are noted to temporally coincide with enhanced surface runoff and increased soil moisture in the region. Debris flow runout modeling indicated that the slope material may attain a maximum flow height and flow velocity of 13±0.8 m and 5±0.5 m/sec, respectively, along the river channel.</p><p><strong>Keywords: </strong>Landslide;<strong> </strong>Earthquake; Slope stability; Runout; SE Carpathian</p>

scholarly journals Influence of Structure on the Aseismic Stability and Dynamic Responses of Liquefiable Soil

2021 ◽  
Author(s):  
Pengfei Dou ◽  
Chengshun Xu ◽  
Xiuli Du ◽  
Su Chen
Keyword(s):  
Earthquake Engineering ◽  
Damping Ratio ◽  
Free Field ◽  
Shaking Table ◽  
Dynamic Responses ◽  
Seismic Stability ◽  
Geotechnical Earthquake Engineering ◽  
Liquefiable Soil ◽  
Porewater Pressure ◽  
Lateral Displacements

Abstract In previous major earthquakes, the damage and collapse of structures located in liquefied field which caused by site failure a common occurrence, and the problem of evaluation and disscusion on site liquefaction and the seismic stability is still a key topic in geotechnical earthquake engineering. To study the influence of the presence of structure on the seismic stability of liquefiable sites, a series of shaking table tests on liquefiable free field and non-free field with the same soil sample was carried out. It can be summarized from experimental results as following. The natural frequency of non-free field is larger and the damping ratio is smaller than that of free field. For the weak seismic loading condition, the dynamic response of sites show similar rules and trend. For the strong ground motion condition, soils in both experiments all liquefied obviously and the depth of liquefaction soil in the free field is significantly greater than that in the non-free field, besides, porewater pressure in the non-free field accumulated relately slow and the dissapited quikly from analysis of porewater pressure ratios(PPRs) in both experiments. The amplitudes of lateral displacements and acceleration of soil in the non-free field is obviously smaller than that in the free field caused by the effect of presence of the structure. In a word, the presence of structures will lead to the increase of site stiffness, site more difficult to liquefy, and the seismic stability of the non-free site is higher than that of the free site due to soil-structure interaction.

Seismic Design for Offshore Wind Farms – Lessons Learnt From the ACE Joint Industry Project

2021 ◽  
Author(s):  
Marcus Klose ◽  
Junkan Wang ◽  
Albert Ku
Keyword(s):  
Seismic Design ◽  
Wind Turbines ◽  
Wind Farms ◽  
The United States ◽  
Offshore Wind ◽  
Seismic Load ◽  
Support Structures ◽  
Offshore Wind Farms ◽  
Asian Pacific Region ◽  
The Impact

Abstract In the past, most of the offshore wind farms have been installed in European countries. In contrast to offshore wind projects in European waters, it became clear that the impact from earthquakes is expected to be one of the major design drivers for the wind turbines and their support structures in other areas of the world. This topic is of high importance in offshore markets in the Asian Pacific region like China, Taiwan, Japan, Korea as well as parts of the United States. So far, seismic design for wind turbines is not described in large details in existing wind energy standards while local as well as international offshore oil & gas standards do not consider the specifics of modern wind turbines. In 2019, DNV GL started a Joint Industry Project (JIP) called “ACE -Alleviating Cyclone and Earthquake challenges for wind farms”. Based on the project results, a Recommended Practice (RP) for seismic design of wind turbines and their support structures will be developed. It will supplement existing standards like DNVGL-ST-0126, DNVGL-ST-0437 and the IEC 61400 series. This paper addresses the area of seismic load calculation and the details of combining earthquake impact with other environmental loads. Different options of analysis, particularly time-domain simulations with integrated models or submodelling techniques using superelements will be presented. Seismic ground motions using a uniform profile or depth-varying input profile are discussed. Finally, the seismic load design return period is addressed.

Stress Distribution in Be Compact Tension Specimen

2007 ◽  
Vol 561-565 ◽  
pp. 2033-2036
Author(s):  
Rui Wen Li ◽  
Ping Dong
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Stress Distribution ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
Tension Specimen ◽  
X Ray ◽  
Measured Stress ◽  
Local Stresses ◽  
Fracture Behaviors

Beryllium (Be) is susceptible to introduce stress because it is a brittle metal with a high elastic modular. The compact tension (CT) specimens of beryllium were designed to determinate stress and fracture behaviors. Stress distribution near notch in CT beryllium was measured by the combination of an X-ray stress analysis and a custom-designed load device. The results show that local stresses near notch tip are much higher than those on other area. Thus, stress concentration lead the CT specimens fracture along the notch direction. Residual stresses due to machining are remained. A finite element ( FE ) calculation on the same loaded geometry was made, and the result is agreement with the measured stress distribution near notch.

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