scholarly journals Influence of Ground Motion Parameters on the Seismic Response of an Anchored Rock Slope

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ningbo Peng ◽  
Yun Dong ◽  
Ye Zhu ◽  
Jie Hong
Keyword(s):  
Seismic Response ◽  
Axial Force ◽  
Seismic Waves ◽  
Rock Slope ◽  
Dominant Role ◽  
Dynamic Responses ◽  
Seismic Action ◽  
Rock Slopes ◽  
Permanent Displacement ◽  
Structural Plane

The seismic response of rock slopes is closely related to the dynamic characteristics of earthquakes. In this study, based on a numerical model of rock slopes with bolt support, the seismic responses of both anchored and unanchored rock slopes under different seismic waves are calculated. The results show that a “cumulative effect” of the relative permanent displacement of the slope is generated during seismic action, and it is found that the permanent displacement of the slope is caused by larger earthquake accelerations. The dynamic responses of an anchored slope are analyzed in terms of the wave type, frequency, amplitude, and duration and are compared with those of an unanchored rock slope. This comparison suggests that the nominal shear strain increases with the amplitude and duration, which decreases as frequency increases. The axial force is directly related to the surrounding rock strain. The maximum axial force of the bolt is near the rock interface, which shows that the structural plane of the slope plays a dominant role in the seismic response. The seismic waves are random, whereas the structural plane of the rock slope is certain. The seismic response characteristics of the slope under different earthquake conditions are similar, and the dynamic stability of the slope can be attributed to the structural analysis of the rock slope.

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.

General Laws of Dynamic Responses of the High Slope Construction under Earthquake

2014 ◽  
Vol 1065-1069 ◽  
pp. 1412-1417
Author(s):  
Yong Li ◽  
Ren He Jin
Keyword(s):  
Dynamic Response ◽  
Seismic Response ◽  
Seismic Design ◽  
Seismic Waves ◽  
Time History ◽  
Internal Force ◽  
Dynamic Responses ◽  
Response Analysis ◽  
High Slope ◽  
Stochastic Seismic Response

Based on stochastic seismic response and time-history seismic response analysis，Dynamic response laws of the high slope constructions by three real seismic waves and a synthetic seismic wave were studied using finite - element method, discussing the differentiation and relation between the high slope constructions and ground constructions. The results show that the dynamic response on high slope constructions are less intensive than ground constructions due to delaying effect of high slope soil acts on the structure, but its internal force stronger than ground constructions as the pile in high slope constructions are anti-sliding and bearing. Results are conducive to the seismic design of high slope constructions.

scholarly journals Near-Fault Seismic Response Analysis of Bridges Considering Girder Impact and Pier Size

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 704
Author(s):  
Wenjun An ◽  
Guquan Song ◽  
Shutong Chen
Keyword(s):  
Seismic Response ◽  
Bending Moment ◽  
Expansion Method ◽  
Response Analysis ◽  
Seismic Action ◽  
Transient Wave ◽  
Cross Sectional ◽  
Displacement Response ◽  
Near Fault ◽  
Continuous Girder Bridge

Given the influence of near-fault vertical seismic action, we established a girder-spring-damping-rod model of a double-span continuous girder bridge and used the transient wave function expansion method and indirect modal function method to calculate the seismic response of the bridge. We deduced the theoretical solution for the vertical and longitudinal contact force and displacement response of the bridge structure under the action of the near-fault vertical seismic excitation, and we analyzed the influence of the vertical separation of the bridge on the bending failure of the pier. Our results show that under the action of a near-fault vertical earthquake, pier-girder separation will significantly alter the bridge’s longitudinal displacement response, and that neglecting this separation may lead to the underestimation of the pier’s bending damage. Calculations of the bending moment at the bottom of the pier under different pier heights and cross-sectional diameters showed that the separation of the pier and the girder increases the bending moment at the pier’s base. Therefore, the reasonable design of the pier size and tensile support bearing in near-fault areas may help to reduce longitudinal damage to bridges.

scholarly journals Seismic rocking effects on a mine tower under induced and natural earthquakes

2021 ◽  
Vol 21 (2) ◽  
Author(s):  
Piotr Adam Bońkowski ◽  
Juliusz Kuś ◽  
Zbigniew Zembaty
Keyword(s):  
Seismic Response ◽  
Ground Motion ◽  
Ground Surface ◽  
Tall Buildings ◽  
Earthquake Ground Motion ◽  
Seismic Action ◽  
Seismic Effects ◽  
Copper Ore ◽  
Rotational Components ◽  
Natural Earthquakes

AbstractRecent research in engineering seismology demonstrated that in addition to three translational seismic excitations along x, y and z axes, one should also consider rotational components about these axes when calculating design seismic loads for structures. The objective of this paper is to present the results of a seismic response numerical analysis of a mine tower (also called in the literature a headframe or a pit frame). These structures are used in deep mining on the ground surface to hoist output (e.g. copper ore or coal). The mine towers belong to the tall, slender structures, for which rocking excitations may be important. In the numerical example, a typical steel headframe 64 m high is analysed under two records of simultaneous rocking and horizontal seismic action of an induced mine shock and a natural earthquake. As a result, a complicated interaction of rocking seismic effects with horizontal excitations is observed. The contribution of the rocking component may sometimes reduce the overall seismic response, but in most cases, it substantially increases the seismic response of the analysed headframe. It is concluded that in the analysed case of the 64 m mining tower, the seismic response, including the rocking ground motion effects, may increase up to 31% (for natural earthquake ground motion) or even up to 135% (for mining-induced, rockburst seismic effects). This means that not only in the case of the design of very tall buildings or industrial chimneys but also for specific yet very common structures like mine towers, including the rotational seismic effects may play an important role.

scholarly journals Viscoelastic Boundary Conditions for Multiple Excitation Sources in the Time Domain

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Chen Xia ◽  
Chengzhi Qi ◽  
Xiaozhao Li
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Time Domain ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Seismic Loads ◽  
Element Analysis ◽  
Artificial Boundaries ◽  
The Time Domain ◽  
Transmitting Boundaries

Transmitting boundaries are important for modeling the wave propagation in the finite element analysis of dynamic foundation problems. In this study, viscoelastic boundaries for multiple seismic waves or excitations sources were derived for two-dimensional and three-dimensional conditions in the time domain, which were proved to be solid by finite element models. Then, the method for equivalent forces’ input of seismic waves was also described when the proposed artificial boundaries were applied. Comparisons between numerical calculations and analytical results validate this seismic excitation input method. The seismic response of subway station under different seismic loads input methods indicates that asymmetric input seismic loads would cause different deformations from the symmetric input seismic loads, and whether it would increase or decrease the seismic response depends on the parameters of the specific structure and surrounding soil.

scholarly journals Assessment of Slope Instability and Risk Analysis of Road Cut Slopes in Lashotor Pass, Iran

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Mohammad Hossein Taherynia ◽  
Mojtaba Mohammadi ◽  
Rasoul Ajalloeian
Keyword(s):  
Rock Mass ◽  
Risk Analysis ◽  
Rock Slope ◽  
Classification Systems ◽  
Slope Instability ◽  
Rock Slope Stability ◽  
Rock Slopes ◽  
The Stability ◽  
Cut Slopes ◽  
Road Cut Slopes

Assessment of the stability of natural and artificial rock slopes is an important topic in the rock mechanics sciences. One of the most widely used methods for this purpose is the classification of the slope rock mass. In the recent decades, several rock slope classification systems are presented by many researchers. Each one of these rock mass classification systems uses different parameters and rating systems. These differences are due to the diversity of affecting parameters and the degree of influence on the rock slope stability. Another important point in rock slope stability is appraisal hazard and risk analysis. In the risk analysis, the degree of danger of rock slope instability is determined. The Lashotor pass is located in the Shiraz-Isfahan highway in Iran. Field surveys indicate that there are high potentialities of instability in the road cut slopes of the Lashotor pass. In the current paper, the stability of the rock slopes in the Lashotor pass is studied comprehensively with different classification methods. For risk analyses, we estimated dangerous area by use of the RocFall software. Furthermore, the dangers of falling rocks for the vehicles passing the Lashotor pass are estimated according to rockfall hazard rating system.

Seismic Response of Embankment Dams Based on Recorded Strong-Motion Data in Japan

2019 ◽  
Vol 35 (2) ◽  
pp. 955-976 ◽  
Author(s):  
DongSoon Park ◽  
Tadahiro Kishida
Keyword(s):  
Time Series ◽  
Seismic Response ◽  
Prediction Models ◽  
Strong Motion ◽  
Dynamic Responses ◽  
Design Stage ◽  
Ground Acceleration ◽  
Motion Data ◽  
Embankment Dams ◽  
Strong Motion Database

It is important to investigate strong-motion time series recorded at dams to understand their complex seismic responses. This paper develops a strong-motion database recorded at existing embankment dams and analyzes correlations between dam dynamic responses and ground-motion parameters. The Japan Commission on Large Dams database used here includes 190 recordings at the crests and foundations of 60 dams during 54 earthquakes from 1978 to 2012. Seismic amplifications and fundamental periods from recorded time series were computed and examined by correlation with shaking intensities and dam geometries. The peak ground acceleration (PGA) at the dam crest increases as the PGA at the foundation bedrock increases, but their ratio gradually decreases. The fundamental period broadly increases with the dam height and PGA at the foundation bedrock. The nonlinear dam response becomes more apparent as the PGA at the foundation bedrock becomes >0.2 g. The prediction models of these correlations are proposed for estimating the seismic response of embankment dams, which can inform the preliminary design stage.

scholarly journals Numerical Analysis of the Seismic Response of Tunnel Composite Lining Structures across an Active Fault

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zude Ding ◽  
Mingrong Liao ◽  
Nanrun Xiao ◽  
Xiaoqin Li
Keyword(s):  
Seismic Response ◽  
Fault Zone ◽  
Composite Structure ◽  
Composite Structures ◽  
Seismic Waves ◽  
Distribution Area ◽  
Damage Degree ◽  
Acceleration Amplification ◽  
Lining Structure ◽  
Composite Lining

The mechanical properties of high-toughness engineering cementitious composites (ECC) were tested, and a damage constitutive model of the materials was constructed. A new aseismic composite structure was then built on the basis of this model by combining aseismic joints, damping layers, traditional reinforced concrete linings, and ECC linings. A series of 3D dynamic-response numerical models considering the composite structure-surrounding rock-fault interaction were established to explore the seismic response characteristics and aseismic performance of the composite structures. The adaptability of the structures to the seismic intensity and direction was also discussed. Results showed that the ECC material displays excellent tensile and compressive toughness, with respective peak tensile and compressive strains of approximately 300- and 3-fold greater than those of ordinary concrete at the same strength grade. The seismic response law of the new composite lining structure was similar to that of the conventional composite structure. The lining in the fault zone and adjacent area showed obvious acceleration amplification responses, and the stress and displacement responses were fairly large. The lining in the fault zone was the weak part of the composite structures. Compared with the conventional aseismic composite structure, the new composite lining structure effectively reduced the acceleration amplification and displacement responses in the fault area. The damage degree of the new composite structure was notably reduced and the damage area was smaller compared with those of the conventional composite structure; these findings demonstrate that the former shows better aseismic effects than the latter. The intensity and direction of seismic waves influenced the damage of the composite structures to some extent, and the applicability of the new composite structure to lateral seismic waves is significantly better than that to axial waves. More importantly, under the action of different seismic intensities and directions, the damage degree and distribution area of the new composite structure were significantly smaller than those of the conventional composite lining structure.

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