The concept of seismic resilience has received significant attention from academia and industry during the last two decades. Different frameworks have been proposed for seismic resilience assessment ...of engineering systems at different scales (e.g., buildings, bridges, communities, and cities). Testbeds including Centerville virtual community (CVC), Memphis testbed (MTB), and the virtual city of Turin, Italy (VC-TI) have been developed during the last decade. However, the resilience assessment results of Chinese cities still require calibration based on a unified evaluation model. Therefore, a geographic information system (GIS)-based benchmark model of a medium-sized city located in the southeastern coastal region of China was developed. The benchmark city can be used to compare existing assessment frameworks and calibrate the assessment results. The demographics, site conditions, and potential hazard exposure of the benchmark city, as well as land use and building inventory are described in this paper. Data of lifeline systems are provided, including power, transportation, water, drainage, and natural gas distribution networks, as well as the locations of hospitals, emergency shelters, and schools. Data from past earthquakes and the literature were obtained to develop seismic fragility models, consequence models, and recovery models, which can be used as basic data or calibration data in the resilience assessment process. To demonstrate the completeness of the data included in the benchmark city, a case study on the accessibility of emergency rescue after earthquakes was conducted, and the preliminary results were discussed. The ultimate goal of this benchmark city is to provide a platform for calibrating resilience assessment results and to facilitate the development of resilient cities in China.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The objective of this paper is to demonstrate how assessment of seismic vulnerability can be effective in protection against earthquakes. Findings are reported from a case study in a densely ...populated urban area near an active fault, utilizing practical methods and exact engineering data. Vulnerability factors were determined due to technical considerations, and a field campaign was performed to collect the required data. Multi-criteria decision making was carried out by means of an analytical hierarchy process including a fuzzy standardization. Earthquake scenarios were applied through an implicit vulnerability model. GIS was utilized and the results were analyzed by classifying the state of vulnerability in levels as very low, low, moderate, high, and very high. Seismic resilience was evaluated as vulnerabilities below the moderate state, being about 40% in an intensity of 6 Mercalli and less than 10% in 10 Mercalli. It is concluded that seismic resilience in the area studied is not acceptable, the area is vulnerable in the expected scenarios, and due to the high seismicity of the region, proper crisis management planning is required in parallel with attempts toward retrofitting. In this regard, an emergency map was developed with reference to the assessed vulnerabilities.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
This article presents a literature review of modern methods of diagnosis and treatment for urethral strictures. In addition, the own results of a pilot study on the use of synthetic ...tissue-engineering structures as a material for urethroplasty substitution are presented as well.
The natural landscape in China exposes many existing RC buildings to aggressive environments. Such exposure can lead to deterioration in structural performance with regard to resisting events such as ...earthquakes. Corrosion of embedded reinforcement is one of the most common mechanisms by which such structural degradation occurs. There has been increasing attention in recent years toward seismic resilience in communities and their constituent construction; however, to date, studies have neglected the effect of natural aging. This study aims to examine the effect of reinforcement corrosion on the seismic resilience of RC frames that are designed according to Chinese seismic design codes. A total of twenty RC frames are used to represent design and construction that is typical of coastal China, with consideration given to various seismic fortification levels and elevation arrangements. Seismic fragility relationships are developed for case frames under varying levels of reinforcement corrosion, i.e., corrosion rates are increased from 5% to 15%. Subsequently, the seismic resilience levels of uncorroded and corroded RC frames are compared using a normalized loss factor. It was found that the loss of resilience of the corroded frames is greater than that of their uncorroded counterparts. At the Rare Earthquake hazard level, the corrosion-induced increase in loss of resilience can be more than 200%, showing the significant effect of reinforcement corrosion on structural resilience under the influence of earthquakes.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The article discusses the safety requirements specified in pertinent standards and recommendations for designing civil engineering objects, with particular emphasis on earth structures intended for ...vehicle traffic. The focus was on the following issues: the essence of reliability and durability of the structure and ensuring safety at the stage of designing vehicle traffic embankments with a slope supported with the use of a retaining wall and embankments placed on a substrate characterized by insufficient bearing capacity. The procedure for designing traffic embankments on weak ground, reinforcing weak ground and designing retaining structures (on the example of a reinforced soil massif) was carried out in accordance with the calculations pertaining to the field of geo-engineering, applying general analytical dependencies.
The paper is concerned with the possibilities of long-term monitoring of constructions using modern wireless sensors and systems. There are currently many constructions under long-term monitoring ...performed by modern sensors. The monitoring enables an assessment of the current health of the construction or it can be used to recalculate and adjust the BMI models and subsequently evaluate the static and dynamic resistance of the construction. The sensors and systems installed enable the detection of hidden defects or newly emerging failures and damage. Using the results obtained from the monitoring of the construction, it is possible to predict and carry out a timely repair or maintenance of the construction, which will ultimately decrease the financial and time-related costs, ensure greater safety and prolong its lifetime and resistance.
This study aims to explore the site-specific impact of coastal structures on the stability of the shoreline. For this study, the shoreline data were collected with higher-order accuracy along a few ...vulnerable stretches of the coast in the vicinity of hard structures such as Seawalls, Groyne, Breakwater, and Training walls along the southeast and southwest coasts of India. All the field collected shoreline data were analysed with statistical measures using DSAS (Digital Shoreline Analysis System) tool of ArcGIS software. The presence of shore connected coastal structures dictates the sedimentation process in its purlieu. The observed average rate of erosion and accretion in the adjoining coastlines are −5.7 m/yr and +4.92 m/yr, respectively. The field measurements from the present study would provide an effective base for the planning and implementation of coastal structures near the studied area, as well as to adopt a better methodology for coastal impact assessment. Most of the well-planned and executed hard engineering structures have yielded desirable results and benefit for the local coastal communities.
Full text
Available for:
BFBNIB, GIS, IJS, KISLJ, NUK, PNG, UL, UM, UPUK
As civil engineering structures are growing in dimension and longevity, there is an associated increase in concern regarding the maintenance of such structures. Bridges, in particular, are critical ...links in today’s transportation networks and hence fundamental for the development of society. In this context, the demand for novel damage detection techniques and reliable structural health monitoring systems is currently high. This paper presents a model-free damage detection approach based on machine learning techniques. The method is applied to data on the structural condition of a fictitious railway bridge gathered in a numerical experiment using a three-dimensional finite element model. Data are collected from the dynamic response of the structure, which is simulated in the course of the passage of a train, considering the bridge in healthy and two different damaged scenarios. In the first stage of the proposed method, artificial neural networks are trained with an unsupervised learning approach with input data composed of accelerations gathered on the healthy bridge. Based on the acceleration values at previous instants in time, the networks are able to predict future accelerations. In the second stage, the prediction errors of each network are statistically characterized by a Gaussian process that supports the choice of a damage detection threshold. Subsequent to this, by comparing damage indices with said threshold, it is possible to discriminate between different structural conditions, namely between healthy and damaged. From here and for each damage case scenario, receiver operating characteristic curves that illustrate the trade-off between true and false positives can be obtained. Lastly, based on the Bayes’ Theorem, a simplified method for the calculation of the expected total cost of the proposed strategy, as a function of the chosen threshold, is suggested.
Full text
Available for:
EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Since phase field fracture model is computationally demanding, its application is mostly limited to relatively simple and small-scale specimens or structural components. The main objective of this ...paper is to extend the application of the phase field fracture model to practical engineering structures with strong global–local properties. A computationally and operationally feasible coupling-type global–local phase field method is proposed, in which the phase field model is resolved by fine mesh on a local scale, while a far coarser mesh is adopted to discretize the global region. The numerical solution by the s-version method is formulated to couple the partly overlapping global and local regions with different finite element discretization. The accuracy and efficiency of the s-version method-based phase field fracture model are investigated through several representative numerical examples. The application of the proposed method to a large structure is demonstrated by an example, where the fire-induced spalling process taking place in a shallow-buried box culvert is resolved by the s-version method-based phase field model.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this research, failure mechanisms of carbon fiber reinforced polymer (CFRP) wrapped protective arches under static and blast loadings were investigated through experiments. Adopting bonding and ...partially-wrapping scheme, the plain concrete (PLC) arch is strengthened and its load carrying ability achieves the level of steel bar reinforced concrete (RC) arch in the static loading experiment. Adopting bonding and fully-wrapping scheme, it’s akin to apply hollow CFRP tubular arch to reinforce plain PLC arches. Load carrying capacity of the CFRP composite arch achieves twice as much as that of the RC arch and the composite arch fails in a shear mode. Subjected to explosive loading, anti-blast ability of the CFRP tubular concrete arch is much better than the PLC arch. Critical scaled distance to prevent the arch from dynamic broken is considerably reduced. According to the research, it is confirmed that using the composite technique an efficient composite protective arch structure can be constructed and steel reinforcements can be entirely replaced by CFRP in some cases, such as coastal engineering and anti-blast structures.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
PDF
