Seismic Stability Evaluation of Folsom Dam and Reservoir Project. Report 6. Right and Left Wing Dams

1989 ◽  
Author(s):  
Ronald E. Wahl ◽  
Mary E. Hynes ◽  
Donald E. Yule ◽  
David J. Elton
1988 ◽  
Author(s):  
Jr Leeman ◽  
Hynes Harold J. ◽  
Vanadit-Ellis Mary E. ◽  
Tsuchida Wipawi ◽  
Takashi

2021 ◽  
Author(s):  
Vipin Kumar ◽  
Léna Cauchie ◽  
Anne-Sophie Mreyen ◽  
Philippe Cerfontaine ◽  
Mihai Micu ◽  
...  

<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>


2018 ◽  
Vol 13 (3) ◽  
pp. 171-181
Author(s):  
Kiyonobu KASAMA ◽  
Shiro YAMAGATA ◽  
Hiroki TANAKA ◽  
Zentaro FURUKAWA ◽  
Noriyuki YASUFUKU

1989 ◽  
Author(s):  
Richard S. Olsen ◽  
Paul F. Bluhm ◽  
M. E. Hynes ◽  
Donald E. Yule ◽  
III Marcuson ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Zhaopeng Zhang ◽  
Chaoyu Chang ◽  
Zhiyi Zhao

The slope shape is one of the most intuitive factors affecting the seismic stability of a slope. However, current research on this subject is mainly focused on statistical analysis and seismic response law, and the influence on seismic stability evaluation of the slope is rarely discussed. Furthermore, slope shapes are often simplified for easy numerical model building. In view of this, five slope models with different slope shapes are considered, and the time-history analysis method and Newmark method are chosen to evaluate the seismic stability of these slope models under different amplitudes. The purpose of this paper is to compare the seismic stability of slopes with different slope shapes and to study the feasibility of simplifying the slope shape when evaluating the seismic stability of a slope.


2019 ◽  
pp. 518-524
Author(s):  
H. Kobayakawa ◽  
M. Ishimaru ◽  
K. Hidaka ◽  
A. Sekiguchi ◽  
T. Okada ◽  
...  

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pu Xiaowu ◽  
Wang Lanmin ◽  
Wang Ping ◽  
Chai Shaofeng ◽  
Xu Shiyang

The large-scale shaking table model test, which can directly reproduce the process of slope instability and failure, is an important technical means for the prediction and evaluation of slope seismic stability. However, up to now, the systematic slope stability evaluation method based on the shaking table slope model test has not been established, which limits the application of the expensive shaking table model test in slope seismic design. Therefore, the slope stability evaluation method based on the model test needs to be developed and innovated. In this research, through three loess slope model tests with different rainfall, according to the change law of the peak value of transfer function spectrum, combined with the macrodestructive characteristics of the slope model, an accurate calculation method of the critical instability acceleration of the slope is proposed. Based on the behavior similarity theory, for the shaking table model test of slope whose soil cohesion cannot meet the similarity ratio, the reduction method of applying the critical instability acceleration obtained from the model test to prototype slope is proposed. Based on first-order natural frequency and damping ratio extracted from the TF spectrum curve, a calculation method for the stability factor Fs of loess slope based on the shaking table model test is proposed, and the stability factors of loess slope under the action of different seismic ground motion would be quantitatively calculated. The above methods provide another effective way for qualitative prediction and evaluation of seismic stability of loess slope.


2014 ◽  
Vol 505-506 ◽  
pp. 64-67
Author(s):  
Qian Su ◽  
Jian Zhang ◽  
Bao Liu ◽  
Li Cai Zhang

Three problems remained to be solved in the analysis of the seismic stability of high-fill embankment: the pseudo-static method was defective, the embankment damage model was not clear, and the stability evaluation index was still to be discussed. It analyzed the dynamic response of a typical transect of high embankment with FEM to find out its instability mechanism. Then it chose the most dangerous sliding surface and analyzed its stability. The selection of the evaluation index of the seismic stability of high-fill embankment was discussed at last. The results show that the upper embankment, especially the shoulder is easily to be damaged. It is too conservative to use the safety factor as the involution index of the seismic stability of high-fill embankment, and the permanent displacement is a better choice.


Sign in / Sign up

Export Citation Format

Share Document