scholarly journals Numerical Simulation and Dynamic Analysis of Single-Hole Cliff-Side Loess Cave Dwelling under Seismic Actions

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yane Hao ◽  
Xingwen Liang ◽  
Yongqiang Lan
Keyword(s):  
Seismic Waves ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Time History ◽  
Northwest China ◽  
Building Structures ◽  
Single Hole ◽  
Key Factor ◽  
Prone Area ◽  
Earthquake Load

Loess cave dwellings are the most typical style of regional architecture in northwest China; now, there are still tens of millions of people living in them. The northwest is an earthquake-prone area, and cave dwellings have suffered a lot of damage in previous moderate and strong earthquakes, so their earthquake resistance has attracted people’s attention. At present, the seismic analysis of aboveground building structures is relatively mature, while the seismic analysis of loess cave dwellings is less researched. To study the seismic response of loess cave dwellings, a single-hole cliff-side loess cave dwelling located in Yangjialing revolution former sites of Yan’an City of northwest China was investigated and surveyed; the three-dimensional numerical model was established by MIDAS/GTS NX. Combining the historic earthquake damage investigation, dynamic time-history analysis of the single-hole loess cliff-side cave dwelling subject to four horizontal earthquake actions was conducted to determine the weak positions, failure characteristics, and the corresponding displacement and stress of the loess cave dwelling under earthquake load. The results show that the loess has an amplification effect on the seismic waves, the arch vault is a key factor to the stability of the loess cave dwellings, the cliff-side loess cave dwellings in an 8-degree area cannot be used to continue living, and the entrance to loess cave dwellings is the most dangerous place when the earthquake happens.

Comparison of Interstorey Drift in General RC Buildings in Pounding and No Pounding Case

2020 ◽  
Vol 2 (1) ◽  
pp. 40-47
Author(s):  
Anand Dev Bhatt
Keyword(s):  
Seismic Analysis ◽  
Linear Time ◽  
Time History ◽  
Case Analysis ◽  
Rc Buildings ◽  
Adjacent Buildings ◽  
Sufficient Distance ◽  
Earthquake Load ◽  
Interstorey Drift ◽  
Lower Height

 Inter-storey drift is an important parameter of structural behavior in seismic analysis of buildings. Pounding effect in building simply means collision between adjacent buildings due to earthquake load caused by out of phase vibration of adjacent buildings. There is variation in inter-storey drift of adjacent buildings during pounding case and no pounding case. The main objective of this research was to compare the inter-storey drift of general adjacent RC buildings in pounding and no pounding case. For this study two adjacent RC buildings having same number of stories have been considered. For pounding case analysis there is no gap in between adjacent buildings and for no pounding case analysis there is sufficient distance between adjacent buildings. The model consists of adjacent buildings having 4 and 4 stories but unequal storey height. Both the buildings have same material & sectional properties. Fast non-linear time history analysis was performed by using El-centro earthquake data as ground motion. Adjacent buildings having different overall height were modelled in SAP 2000 v 15 using gap element for pounding case. Finally, analysis was done and inter-storey drift was compared. It was found that in higher building inter-storey drift is greater in no pounding case than in pounding case but in adjacent lower height building the result was reversed. Additionally, it was found that in general residential RC buildings maximum inter-storey drift occurs in 2nd floor.

scholarly journals Evaluasi Kesehatan Struktur Bangunan berdasarkan Respon Dinamik Berbasiskan Data Akselerometer

2017 ◽  
Vol 23 (2) ◽  
pp. 142
Author(s):  
Wan Fikri Darmawan ◽  
Reni Suryanita ◽  
Zulfikar Djauhari
Keyword(s):  
Pushover Analysis ◽  
Damage Index ◽  
Time History ◽  
Frame Structure ◽  
Accelerometer Data ◽  
Building Structures ◽  
Element Analysis ◽  
Earthquake Load ◽  
Damage Condition ◽  
A Minor

The aim of the research is to analysis the health of a simple frame structure based on accelerometer data. The research is a preliminary study which used the accelerometer data in the time history analysis of the structure. The parameters has been used in the study are the Story Damage Index (SDI), the ApproximateStory Damage Index (ASDI), the Flexibility Damage Index (MFDI), and the Park Ang Damage Index. The finite element analysis is used to identify the damage of building structures through the pushover analysis. The study has conducted the minor damage index, physical appearance to check the cracked beam andconcrete column. The damage index average is in the range 0-0.08. It can be concluded the building is still able to withstand the earthquake load. However, the building is stated in a minor damage condition after the earthquake occurred.

A simple approach for optimal allocation of dampers in nonsymmetrical 3D multi-storey structures

2014 ◽  
Vol 14 (03) ◽  
pp. 1350074 ◽  
Author(s):  
L. J. Leu ◽  
J. T. Chang
Keyword(s):  
Optimal Allocation ◽  
Seismic Analysis ◽  
Search Algorithm ◽  
Three Dimensional ◽  
Time History ◽  
Simple Approach ◽  
Optimal Placement ◽  
Drift Ratio ◽  
History Analysis ◽  
Stop Criterion

A new simple approach is proposed to search for the optimal placement of dampers in nonsymmetrical three-dimensional (3D) structures. Dampers are placed uniformly and initially at each storey of two selected bays of the bare structures and the time-history seismic analysis is performed. The maximal inter-storey drift ratio is chosen as the performance index. Then the inter-storey drift ratio is checked for the locations where dampers were added. The damper in the location with the minimal inter-storey drift ratio is moved to the location having the maximal inter-storey drift ratio. This process is repeated until the prescribed stop criterion is met. Both linear and nonlinear viscous dampers are used in this study. The damping coefficient of added dampers for the initial damper placement is determined by setting the maximal inter-storey drift ratio of the whole structure equal to a certain value when a ground motion is applied. In the proposed relocation process, the maximal inter-storey drift ratio will be reduced significantly. Three examples, including two 10-storey and one 20-storey 3D nonsymmetrical structures, are used to demonstrate the efficiency and accuracy of the proposed approach. The results are compared with those obtained using the simplified sequential search algorithm (SSSA). It is found that the proposed approach requires fewer number of time-history analysis than that using the SSSA while their accuracy is comparable.

scholarly journals Dynamic Response and Time-Frequency Characteristic of Dangerous Rocks under the Combined Action of Rock Cavity Weathering and Earthquake

2021 ◽  
Vol 2021 ◽  
pp. 1-19
Author(s):  
Qingyang Ren ◽  
Honghua Jin ◽  
Xiaokun Ren ◽  
Xingxing Zhang
Keyword(s):  
Dynamic Response ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Time History ◽  
Steep Slope ◽  
Time Frequency ◽  
Failure Evolution ◽  
Combined Action ◽  
Rock Model ◽  
Matlab Programming

In order to further reveal the failure mode and dynamic response law of dangerous rocks with different degree of weathering in the rock cavity under the action of earthquake and to provide early warning and forecast for steep slope of dangerous rocks in similar earthquake areas, a typical steep slope of dangerous rock in earthquake area of Sichuan, China, was taken as the research object, after detailed geological survey, and according to the chain development law of dangerous rock, the steep slope of dangerous rock before the earthquake was restored. Based on the 3D particle flow software PFC3D, the dangerous rock was divided into 3 modes according to the degree of weathering of the mudstone rock cavity, and the three-dimensional discrete element dangerous rock model under different modes was established. By introducing the horizontal and vertical two-way coupled seismic waves in Wenchuan, Sichuan, in 2008, the failure evolution process of steep slope of dangerous rock under the action of the horizontal and vertical coupled seismic waves was dynamically simulated, which proved the rationality of the simulation. The frequency spectrum of velocity-time history signal of each rock block in the dangerous rock model was analyzed by MATLAB programming, and the time-frequency characteristics of each dangerous rock model under the action of coupled seismic wave were studied. The research results have important scientific guiding significance and practical value for the dynamic stability evaluation and prediction of such steep slope of dangerous rocks under the combined action of rock cavity weathering and earthquake.

Analysis for the 3-Dimensional Time History Response of a Base-Isolated Building Structure

2011 ◽  
Vol 368-373 ◽  
pp. 1961-1964
Author(s):  
Jin Xia Kang
Keyword(s):  
Composite Structures ◽  
Seismic Waves ◽  
Three Dimensional ◽  
Time History ◽  
Economic Benefits ◽  
Seismic Structure ◽  
Finite Element Program ◽  
Concrete Frame ◽  
Element Program ◽  
Lateral Displacements

In this paper, the models of traditional anti-seismic and base-isolated masonry and concrete frame composite structures were created by the three-dimensional finite element program and their time history responses were analyzed under the actions of different seismic waves. The results show that whether they were under the action of frequently occurred earthquake or rarely occurred earthquake, the story shears of base-isolated structure are far less than those of traditional anti-seismic structure; the lateral displacements of the former are nearly translational, while those of the latter are approximately parabolic; and the fundamental period of the former is much longer than the counterpart. In conclusion, the seismic fortification intensity of base-isolated structure is one or two degree less than that of traditional anti-seismic structure, and adopting the base-isolated structure will protect the life-safety and property of people and achieve good economic benefits as well.

Seismic Analysis of a Water Release Integrated Structure Part I: Response Spectrum Analysis of Intake Tower

2013 ◽  
Vol 470 ◽  
pp. 938-941
Author(s):  
Yong Wang ◽  
Zhen Ting Lin ◽  
Chao Song ◽  
Bo Ya Dong
Keyword(s):  
Spectrum Analysis ◽  
Seismic Analysis ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Safety Evaluation ◽  
Response Spectrum Analysis ◽  
Water Release ◽  
Dimensional Finite Element ◽  
Earthquake Load ◽  
Three Dimensional Finite Element

The stress, deformation and stability for the intake tower of a water release integrated structure under the normal storage water level and operational basis earthquake load case are investigated using the three dimensional finite element method. The response spectrum analysis is adopted to study the seismic response of the intake tower. Special attention is paid to the weak zones of the structure and foundation. The safety evaluation of the intake tower is performed based on the computational results.

scholarly journals Blasting Vibration Generated by Breaking-Blasting Large Barriers with EBBLB

2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Wang Zhen-xiong ◽  
Gu Wen-bin ◽  
Liang Ting ◽  
Liu Jian-qing ◽  
Xu Jing-lin ◽  
...  
Keyword(s):  
Seismic Waves ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Time History ◽  
Ground Vibration ◽  
Blasting Vibration ◽  
Human Beings ◽  
Hilbert Huang Transform ◽  
Energy Information ◽  
Center Time

Equipment for breaking and blasting large barriers (EBBLB) is new break-blast equipment, which inevitably induces ground vibration and may cause substantial damage to rock mass and nearby structures as well as human beings. The ground vibration induced by break-blast is one of the inevitable outcomes. By monitoring vibration at measuring points at different distances from blasting center, time history curve of vibrating velocity can be obtained; it can be drawn that blasting seismic waves are generated mainly from the explosion of the precharge. Furthermore, different approaches have been adopted to fit relationship between particle peak velocity (PPV) and distance from blasting center, comparative analysis of which provides the most appropriate relation expression to predict attenuation of PPV of vibration with distance from blasting center. The relation between vibration frequency and distance from blasting center is obtained by Fourier transform. And the research decomposes vibrating signals in vertical direction of different distances from blasting center with Hilbert-Huang Transform (HHT), extracting information of empirical mode components of blasting vibration signals; thus vibrating signals are contracted by spectrum information and energy information, three-dimensional energy, and energy attenuation of vibration with different distances from blasting center. The study can predict ground vibration generated by EBBLB and assess its damaging effects of blasting vibration for security and protection.

The Seismic Analysis of Kiewitt Shell Based on the SMA Three-Dimensional Isolator

2010 ◽  
Vol 163-167 ◽  
pp. 4570-4574
Author(s):  
Jin Li Wang ◽  
Hai Qing Liu
Keyword(s):  
Seismic Analysis ◽  
Three Dimensional ◽  
Outer Part ◽  
Time History ◽  
Internal Force ◽  
Rubber Bearing ◽  
Base Isolator ◽  
Laminated Rubber Bearing ◽  
Lattice Damage ◽  
Acceleration Analysis

The SMA 3D isolator is based on a new intelligent material: shape memory alloy, which compensate the weakness in stiffness of the laminated rubber bearing. Through the seismic analysis of the kettlewell double layer shell, the truss horizontal and vertical internal force dropped obviously with the SMA 3D base isolator, especially the outer part which easily happened deformed damage and the structure internal force distribution is more reasonable, the deformation in harmonies, the lattice damage of weakness part is limited and offer efficient protection. Either the acceleration analysis, the peak acceleration reduced significantly and time history tends to slow, the isolating effect of the SMA 3D base isolator is prior to the laminated rubber bearing.

Seismic Analysis of the Entrance Section of a Nuclear Power Intake Tunnel

2014 ◽  
Vol 1065-1069 ◽  
pp. 426-432
Author(s):  
Shi Kui Huang ◽  
Jie Zhao
Keyword(s):  
Nuclear Power ◽  
Large Scale ◽  
Seismic Waves ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Nonlinear Dynamic Analysis ◽  
Analysis Method ◽  
Response Characteristics ◽  
Entrance Section ◽  
Tunnel Entrance

For a nuclear power intake tunnel project, large-scale three-dimensional finite difference model is established by Flac3D to simulate the seismic response regularity of the entrance section of tunnel under the action of seismic waves schedule with the nonlinear dynamic analysis method. Through the input of the site seismic wave, the structure response characteristics of the tunnel entrance and slope are explored and duration curve of tunnel hole lining force under seismic waves action and tunnel lining figure can be obtained. The analysis results show that the anti-seismic weak parts of the tunnel entrance is at the location of tunnel spandrel and the sidewall. The analysis method and conclusions can be for reference in the seismic design of similar nuclear power intake tunnel project.

scholarly journals Optimal Design of Earthquake-Resistant Buildings Based on Neural Network Inversion

2021 ◽  
Vol 11 (10) ◽  
pp. 4654
Author(s):  
Carlo Calledda ◽  
Augusto Montisci ◽  
Maria Cristina Porcu
Keyword(s):  
Neural Network ◽  
Optimal Design ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Structural Response ◽  
Time History ◽  
Optimal Choice ◽  
Design Parameters ◽  
Earthquake Resistant ◽  
Non Linear

An effective seismic design entails many issues related to the capacity-based assessment of the non-linear structural response under strong earthquakes. While very powerful structural calculation programs are available to assist the designer in the code-based seismic analysis, an optimal choice of the design parameters leading to the best performance at the lowest cost is not always assured. The present paper proposes a procedure to cost-effectively design earthquake-resistant buildings, which is based on the inversion of an artificial neural network and on an optimization algorithm for the minimum total cost under building code constraints. An exemplificative application of the method to a reinforced-concrete multi-story building, with seismic demands corresponding to a medium-seismicity Italian zone, is shown. Three design-governing parameters are assumed to build the input matrix, while eight capacity-design target requirements are assigned for the output dataset. A non-linear three-dimensional concentrated plasticity model of the structure is implemented, and time-history dynamic analyses are carried out with spectrum-consistent ground motions. The results show the promising ability of the proposed approach for the optimal design of earthquake-resistant structures.

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