Great Wenchuan Earthquake Research Articles

Impact of the 2008 MW\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M_W$$\\end{document} 7.9 Great Wenchuan earthquake on South China microplate motion

Tectonic plate motions drive the earthquake cycle, as they result in the slow accrual and sudden release of energy along plate boundaries. Steadiness of plate motions over the earthquake cycle is a central tenet of the plate tectonics theory and has long been a main pillar in models of earthquake genesis, or of plate-margins seismic potential inferred from slip-deficit estimates. The advent of geodesy in the geosciences and the availability of multi-year-long series of position measurements permit tracking the motions of tectonic plates from before to after the time of significant seismic events that occur along their margins. Here, we present evidence that large earthquakes are capable of modifying the motions of entire microplates. We use high precision Global Navigation Satellite System (GNSS) position time-series covering the periods 2001–2004 and 2014–2017 to demonstrate that, contrary to the tenet above, the South China microplate motion changed after the 2008 MW\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$M_W$$\\end{document} 7.9 Great Wenchuan earthquake. The GNSS data and associated uncertainties indicate a plate motion slowdown of up to 20% that is beyond the possible impact of data noise and is thus tectonically meaningful. We use quantitative models of torque balance to show that generating this kinematic change requires a force upon the South China microplate compatible with that imparted by the Great Wenchuan earthquake of 2008. The existence of a kinematic signal linked to the earthquake cycle that impacts an entire microplate might offer an additional, novel perspective to assessing the hazards of earthquake-prone tectonic regions.

Sensitivity Study of Seismic Amplification Effect of Large-Scale Sichuan Basin on Key Parameters During the Great Wenchuan Earthquake

The effect of soil parameters on basin amplification effect has been widely investigated, especially for the small and medium-sized basins under plane wave incidence or point source ruptures. However, the sensitivities of seismic amplification effect of large-scale basins with respect to soil parameters during great earthquakes with tremendous rupture faults have obtained relatively less attention. In this paper, based on the established three-dimensional Sichuan basin model, the effects of four material parameters of the basin sediments, including the shear wave velocity, Poisson’s ratio, and the shear quality factor of the Quaternary sediment, as well as the velocity of the rock above the basin crystalline basement (which will be referred as SVQS, PRQS, QFQS, and VCBR, respectively), on the long-period wave amplification patterns of the Sichuan basin during the great Wenchuan earthquake are investigated by using the spectral element method and parallel computing technique. The results show the following: (1) SVQS has the greatest influence on the basin horizontal component ground motions, while the vertical component is comparably insensitive to it. (2) PRQS demonstrates comparable effects on the horizontal and vertical basin ground motions. With the increase of PRQS, the amplitudes and regions of the strong shakings both become smaller. However, the influence of PRQS is less significant compared with SVQS and VCBR. (3) QFQS mainly affects the relatively high-frequency motions inside the basin, and the low-frequency motions are generally insensitive to it. With the reduction of QFQS, the amplitudes and regions of the basin strong ground motions turn a little smaller, but the distribution features are generally unchanged. (4) Effects of VCBR on the horizontal and vertical component basin ground motions are opposite. With the growth of VCBR, the amplitudes and areas of strong horizontal motions increase consequently, but they decrease for the vertical component.

Fractal Patterns in Groundwater Radon Disturbances Prior to the Great 7.9 Mw Wenchuan Earthquake, China

This study reports a fractal analysis of one-year radon in groundwater disturbances from five stations in China amidst the catastrophic Wenchuan (Mw = 7.9) earthquake of 12 May 2008 (day 133). Five techniques are used (DFA, fractal dimensions with Higuchi, Katz, Sevcik methods, power-law analysis) in segmented portions glided throughout each signal. Noteworthy fractal areas are outlined in the KDS, GS, MSS data, whilst the portions were non-significant for PZHS and SPS. Up to day 133, critical epoch DFA-exponents are 1.5≤α<2.0, with several above 1.8. The fractal dimensions exhibit Katz’s D around 1.0–1.2, Higuchi’s D between 1.5 and 2.0, and Sevcik’s D between 1.0 and 1.5. Several power-law exponents are above 1.7, and numerous are above 2.0. All fractal results of the KDS-GS-MSS are further analysed using a novel computerised methodology that locates the exact out-of-threshold fractal areas and combines the outcomes of different methods per five, four, three, and two (maximum 13 combinations) versus nineteen Mw≥ 5.5 earthquakes of the greater area. Most coincidences using different techniques are before the great Wenchuan earthquake and after the earthquake. This is not only with one method but with 13 different methods. Other interpretations are also discussed.

Do managers hedge disaster risk? Extreme earthquake shock and firm innovations

In this paper, we investigate how extreme earthquake events affect energy firms' innovations to hedge disaster risk. On May 12, 2008, a magnitude-8 earthquake hit Sichuan province. It was the most damaging earthquake since the foundation of the People's Republic of China. Using the Great Wenchuan earthquake as a shock, we find the following: 1) the extreme disaster shock spurs innovations of firms with similar strong earthquake experiences. 2) The effect is pronounced for shock-proximate firms, firms with a negative previous experience, and firms with financial constraint. 3) We also find that labor protections and political pressure also drive firms to improve innovation activities after the extreme event. Overall, this study sheds light on determinants of energy firms' innovations from the perspective of extreme natural disasters.

The Community Velocity Model V.1.0 of Southwest China, Constructed from Joint Body- and Surface-Wave Travel-Time Tomography

Abstract Southwest China, located at the southeastern margin of the Tibetan plateau, plays an important role for the plateau growth and its material extrusion. It has complicated tectonic environment and strong seismic activities including the 2008 Wenchuan great earthquake. Numerous geophysical studies have been conducted in southwest China. However, a community velocity model (CVM) in this region is still not available, which makes it difficult to have a consistent catalog of earthquake locations and focal mechanisms and a consistent velocity model for simulating strong ground motions and evaluating earthquake hazards. In this study, we aim at building a high-resolution CVM (both VP and VS) of the crust and uppermost mantle in southwest China along with earthquake locations by joint inversion of body- and surface-wave travel-time data. In total, we have assembled 386,958 P- and 372,662 S-wave first arrival times and nearly 8100 Rayleigh-wave dispersion curves in the period band of 5–50 s. A multigrid strategy is adopted in the joint inversion. A coarser horizontal grid interval of 0.5° is first used and then a finer grid interval of 0.25° is used with initial models interpolated from the coarser-grid inverted velocity models. The spatial resolution of both VP and VS models can reach up to 0.5° horizontally and 10 km vertically according to the checkerboard tests. The comparisons of our inverted VP and VS models with those from other studies show general consistency in large-scale features. The inverted models are further validated by P-wave arrival times from active sources and Rayleigh-wave data. In general, our velocity models show two low-velocity zones in the middle-lower crust and a prominent high-velocity region in between them. Our new models have been served as the first version of the CVM in southwest China (SWChinaCVM-1.0) for future studies.

Assessing indirect economic losses of landslides along highways

Landslides along highways not only induce direct losses related to cost of replacement, repair or maintenance due to physical damage, but also induce indirect losses due to reduction in production in different sectors in an economic system. In this study, a method is suggested to assess the indirect losses of landslides along highways, where the impact of landslides on the transportation network is evaluated through the gravity model, and the output losses of different sectors are computed based on the dynamic input–output model. The suggested method is used to assess the indirect losses of landslides that occur along highways related to Yingxiu Town, Sichuan Province, China, which is the epicenter of the 2008 great Wenchuan earthquake. It is found that the impact of a landslide hazard on different sectors is not the same depending on their dependence relationship with the transportation sector. The indirect losses of a landslide increase as the repair time increases and decrease as the transportation network becomes more robust. Also, the location of a landslide will affect the caused indirect losses, and the indirect losses will increase as the transportation network is attacked by more landslides. The suggested method provides a useful instrument for estimating the indirect losses of landslides along highways, which were seldom addressed in previous studies.

Seismic Damage Prediction Method for Lining Structures Based on the SEDR Principle

The safety and stability of lining structures are core concerns of tunnel and underground engineering. It is crucial to determine whether a lining structure would crack and which direction the crack would expand with seismic excitation. In previous literature, the principle based on stress and strain has been widely used to predict the seismic damage of lining structures, whereas it cannot specify the cracking modes. Taking account of that deficiency, this paper introduces the strain energy density ratio (SEDR) principle and proposes a seismic damage prediction method for lining structures, which can precisely predict the crack positions and expansion directions. Moreover, numerical simulations of the typical seismic damage sections of two tunnels in the Great Wenchuan Earthquake and a calculating example of the theoretical equations are conducted to verify the proposed method. In summary, the numerical simulation results show that the arch springing cracks first, and the invert cracks next; then the cracks expand to the spandrel, and finally, they form oblique cracks, annular cracks, and longitudinal cracks, whose positions and patterns are in accordance with the field investigation results. In terms of the calculating example results, the obtained two-fold SEDR and cracking angle θ are 1.87 and −6.28°, respectively, which are consistent with the numerical simulation results. Therefore, one can see that the proposed seismic damage prediction method based on the SEDR principle is quite accurate. This method can be used to predict the seismic damage of lining structures and provide a reference for the research of the damage mechanism of tunnels.

Describe the Process of Retrofitting Existing Buildings and Evaluate the Effectiveness of it in Improving the Seismic Performance of Structures in Earthquake-prone Regions

At present, earthquakes are a serious problem for building. Severe damages and collapses of buildings were caused by earthquakes in different degrees. It is reported that there are more than 68,858 deaths and hundreds of billions RMB losses in the May 12, 2008 Great Wenchuan Earthquake [16]. So, more attention should be paid to seismic technology. In order to face the challenges of earthquake on building, the seismic retrofitting was put forward, which “is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes”

Health-Related Rehabilitation after the 2008 Great Wenchuan Earthquake in China:A Ten Year Retrospective Systematic Review.

Being one of the world’s seismically hazard-prone countries, the People’s Republic of China (PRC) witnessed an 8.0-magnitude earthquake on May 12th 2008—which was reported as one of the most destructive disasters since its founding. Following this earthquake, rehabilitation was greatly required for survivors to enable them to achieve and maintain optimal independence; functioning; full physical, mental and social ability; inclusion; and participation in all aspects of life and environments. We conducted a systematic review based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines to retrospectively identify, in five English databases/sources, the existing evidence about the Health-Related Rehabilitation (HRR) that was rendered to the survivors of the 2008 Wenchuan earthquake between 2008 and 2018. Only 11 studies out of 828 initial studies retrieved were included in our study and reported the survivors of the 2008 Wenchuan earthquake to have been aged between 10.5 and 55.7, and predominantly diagnosed with posttraumatic stress disorders. Their HRR was mainly premised on physical and physiological therapies, as well as traditional Chinese medicine and digital technologies. Although all HRR interventions used were reported to be effective, none was identified as much more effective than the others in the post-earthquake era —which calls for more robust research to build upon our systematic review.

Preliminary seismic vulnerability matrix related with fortification intensity for Sichuan region

The significance to develop fortification intensity related vulnerability matrix for earthquake prevention and mitigation is emphasized in this paper. The way to acquire the fortification intensity data of buildings damaged in the great Wenchuan earthquake, from their construction years with the seismic zoning maps in three time periods, is reported. Preliminary statistical results of vulnerability matrices related with fortification intensity VI, VII and VIII, are presented for brick-concrete structure and frame structure buildings in Sichuan region. The results show clearly the decrease of vulnerability with increase of the fortification level.

Empirical Seismic Vulnerability and Damage of Bottom Frame Seismic Wall Masonry Structure: A Case Study in Dujiangyan (China) Region

In order to understand the seismic performance and mechanism of bottom frame seismic wall masonry structure (BFSWMS) and its vulnerability in empirical seismic damage, based on the statistical and numerical analysis of the field seismic damage observation data of 2178 Dujiangyan structures in the Wenchuan great earthquake urban of China on May 12, 2008, a non-linear function model between the seismic grade and the number of field damage samples is established, and the regression curve is given. The empirical seismic vulnerability matrices in multiple intensity regions are established, and the regression model functions of each intensity region and the vulnerability curves based on seismic damage grade and exceeding probability are obtained, respectively. A vulnerability matrix model with mean damage index (MDI) as its parameter is proposed, and the empirical vulnerability matrix is embedded in it. The vulnerability matrix based on this parameter and the regression curve of MDI in Dujiangyan city are derived. The above research results can provide the necessary practical reference for the vulnerability study of BFSWMS and the seismic code of China.

Broad learning for nonparametric spatial modeling with application to seismic attenuation

AbstractSpatial modeling is a core element in geographical information science. It incorporates geographic information to construct the relationship for interpreting the behavior of spatial phenomena. In this paper, a broad learning framework for nonparametric spatial modeling is presented. Broad learning overcomes the obstacle of expensive computational consumption in deep learning and provides a powerful computationally efficient alternative. In contrast to the deep learning architecture that is configured with stacks of hierarchical layers, broad learning networks are established in a flat manner that can be flexibly reconfigured with the inherited information from the trained network. To develop the broad learning network, a simple prototype network is established as the initial trial and it is modified incrementally to enhance its data fitting capacity. Consequently, complex relationship of unstructured spatial data can be modeled efficiently. To demonstrate the efficacy and applicability of the broad learning framework, we will present a simulated example and a real application using the strong ground motion records on the 2008 great Wenchuan earthquake.

Seismic damage mechanism of bedrock and overburden layer slope reinforced by sheet pile wall

Abstract Sheet pile walls, widely used in landslide control projects, have demonstrated excellent seismic performance during the great Wenchuan earthquake, as indicated by an investigation of retaining walls following earthquake damage. To further understand the mechanism of seismic damage based on the Hilbert–Huang transform method and marginal spectrum identification theory, a large-scale shaking table test of bedrock and overburden layer slope reinforced by sheet pile wall was carried out, and the mechanism of seismic damage was analysed. The results show that the change in marginal spectrum amplitude and characteristic frequency can clearly indicate the degree of seismic damage to the slope soil. First, the dynamic response of the slope soil near sheet pile wall is smaller than the response observed in soil farther from the wall, and the degree of seismic damage near the wall is relatively weaker than that farther away from the wall. Second, the energy of the seismic wave cannot be completely transferred behind the wall, and the strip cracks of soil behind the wall can be determined. Finally, the slope soil slides along a slip surface so that the front edge of the slope is squeezed due to the vertical tensile cracks at the rear edge. In addition, the results confirm the feasibility of the Hilbert–Huang transform method for studying the mechanism of the seismic damage to the structure-soil coupling system.

Location-Routing Problem for Relief Distribution in the Early Post-Earthquake Stage from the Perspective of Fairness

To address the shortage of relief in disaster areas during the early stages after an earthquake, a location-routing problem (LRP) was studied from the perspective of fairness. A multi-objective model for the fair LRP was developed by lexicographic order object optimal method in consideration of the urgent window constraints, partial road damage, multimodal relief delivery, disaster severity, and vulnerability of each demand node when its demand is not satisfied. The goals of this model are to minimize (1) the maximum loss of demand node, (2) the total loss of demand node, and (3) the maximum time required for the demand node to receive relief. A hybrid heuristic algorithm was proposed to solve the model. Finally, the utility and fairness of the model and algorithm were demonstrated by a case study during the first day after the great Wenchuan earthquake in China.

The Impact of Earthquake on Poverty: Learning from the 12 May 2008 Wenchuan Earthquake

How to combine disaster prevention and mitigation, post-disaster reconstruction and poverty alleviation has become a new hot issue. On 12 May 2008, a major earthquake devastated the Wenchuan area in Sichuan Province in the heartland of China. After ten-years have passed, it is a good time to review what we learned from the Great Wenchuan earthquake. The impact of Wenchuan earthquake on poverty-stricken counties, poverty-stricken villages, and poverty-stricken households was analyzed. Suggestions for improving the method of combining disaster prevention, post-disaster reconstruction, and poverty alleviation were proposed. The results from this research could serve as an important reference for formulation of the poverty alleviation and development program after a major earthquake.

A robust model predictive control approach for post-disaster relief distribution

Emergency distribution is an important aspect of disaster response. However, when planning such activities, decision makers should consider not only uncertain and dynamic input data such as supply and demand, but also the real-time adjustment requirements of the existing distribution plans that account for the deviation between the predicted and actual (or observed) values of the input data. Consequently, we present a multi-commodity, multi-period distribution model that considers both relief commodities and injured people to minimize the total weighted unmet demand throughout the planning horizon. Furthermore, we propose a rolling horizon-based framework, based on the robust model predictive control (RMPC) approach, to obtain robust relief distribution plans and adjust them in accordance with updated real-time information. We then use a numerical example based on the Great Wenchuan Earthquake that occurred on May 12, 2008, in Sichuan Province, China, to investigate the application of our proposed model and framework, and we perform a detailed analysis of the influence of the settings of robust optimization parameters.

Contested Narratives at the Hanwang Earthquake Memorial Park: Where Ghost Industrial Town and Seismic Memorial Meet

This exploratory study investigates contested narratives of dark tourists by focusing on their travel motivations and multi-dimensional visitor experiences in the context of the Hanwang Earthquake Memorial Park, the intersections of a ghost industrial town and seismic memorials arising from the great Wenchuan earthquake of 2008. The study employed participant observation and semi-structured interview in a progressive and sequential manner to collect qualitative data from Chinese visitors on the site. Using NVivo 10, the analysis revealed that it was both the death and suffering of people and destruction and reconstruction of place—the abandoned industrial town and the seismic memorials—that attract visitors to come, distinguishing itself from other dark tourism settings that may be valued for leisure activity or special historical interest. The obligation of commemoration was mixed with curiosity, together with social needs, perceived prestigious, family, and education that motivate people to visit. The site offered visitors an authentic arena for critical thoughts, the recall of tragedy, and self-reflection; help reconcile the imagined landscapes with reality; and allowed the self to express scares and sympathy as well as gratification and satisfaction so as to construct contemporary ontological meanings of mortality as reflected in either cognitive or affective experience.

Resident attitudes towards dark tourism, a perspective of place-based identity motives

Place-based identity theories prove to be valid in better understanding resident attitudes towards support for tourism. Yet, its effectiveness is not verified in the context of dark tourism and resident attitudes towards dark tourism remains unknown. Based on a survey of 526 local residents in China’s Yingxiu, the epicentre of the Great Wenchuan Earthquake, the authors examined the relationships between the local residents’ place-based identity motives and their attitudes towards support for dark tourism development. Results show that the motive of ‘belonging/meaning’ is one of the most important determinants; residents’ involvement in dark tourism and bereavement affect their identity motives and attitudes towards support for dark tourism. The theoretical contributions and managerial implications are discussed.

Dynamic response of anchored sheet pile wall under ground motion: Analytical model with experimental validation

Anchored stabilizing pile is a typical earthquake-resistant structure in reinforced slope with advantages of safety, reliability and low cost. It demonstrated excellent seismic performance during the 2008 Great Wenchuan earthquake. However, due to the complexity of the structural system, the coupling relationship between soil, pile, and anchor cable is not well understood at present. This paper developed an analytical model in modeling the dynamic responses of the pile, anchor cable and soil slope system based on Winkler elastic foundation beam theory. The seismic design of the anchored sheet pile wall can then be carried out. An experimental shake-table test was conducted to validate the proposed analytical model. Through the test, the displacements of the pile, axial force of the anchor cable, and earth pressure along the pile derived from the analytical model were validated by the test results. It shows that the proposed analytical model is suitable for the practical application and can provide theoretical basis for dynamic response analysis and seismic design of anchored sheet pile wall.

Influence factor and posttraumatic growth analysis about nurses after 6years of Wenchuan earthquake

Objective To understand the levels of posttraumatic growth in rescue nurses 6 years after the great Wenchuan earthquake, and analyze the reasons and influence factors. Methods The general information of the nurses and the post-traumatic growth inventory (PTGI) were used to carry out the cross-sectional study in 736 nurses who took part in the rescue works of the great Wenchuan earthquake. Results The average score of PTGI in rescue nurses was (45.39±23.47) points.Rescue nurses had different posttraumatic growth who had different educational level (F=7.180, P=0.000), household income monthly per capita, the type of rescue work, financial loss, health status, residential satisfaction, satisfaction with social support, satisfaction with family members, satisfaction with leaders and colleagues, satisfaction with friends and relatives(F=3.000-17.484, P<0.050). There was also a statistically significant difference between the score of nurses who had received psychological support and who had received no psychological support (t=-3.657, P<0.05). Multiple linear regression analysis showed that satisfaction with friends and relatives, psychological support, household income monthly per capita and satisfaction with leaders and colleagues could affect the total score of PTGI. All the variables could explain 7.5% variance of posttraumatic growth. Conclusions Rescue nurses have relatively low posttraumatic growth. Satisfaction with friends and relatives, psychological support, household income monthly per capita and satisfaction with leaders and colleagues are related to the posttraumatic growth of rescue nurses. Key words: Nurses; Earthquake; Posttraumatic growth