Rapid Visual Screening Procedure Research Articles

Seismic Vulnerability Assessment of Buildings for Seismic Retrofitting Strategies: Rapid Visual Screening Method

The objective of this study is to provide the assessment of the seismic vulnerability of R.C.C. and Load bearing structures by the Rapid Visual Screening Method. As Rapid Visual Screening is a preliminary stage to conducting a Simplified Vulnerability Assessment of the building.The rapid visual screening procedure requires only a visual evaluation and a few additional details. These procedures are recommended for all buildings. Rapid Visual Screening score has been evaluated for the various building which suggests further assessment for Seismic Vulnerability. India is expected to be the most populous country in the world by 2025. India has a huge volume of building stocks at present, and most of them are significantly vulnerable to earthquake hazards. In order to overcome this issue, firstly it is required to conduct the seismic vulnerability assessment at a massive scale of building stocks and buildings with a high probability of damage further evaluated with the simplified vulnerability assessment method procedures. After a detailed evaluation, it recommends a suitable retrofitting strategy. In this paper, we have studied various parameters of the Rapid Visual Screening method and the procedure to conduct it. Keywords: Seismic vulnerability, Existing Building, Simplified Vulnerability Assessment, Method, Rapid Visual Screening, Detailed vulnerability assessment.

A Proposed Rapid Visual Screening Procedure for Developing Countries

Many earthquakes in the past had shown that major damage to structures took place in the absence of proper design, construction, and quality control. Based on the extent of damages caused by earlier earthquakes and the building vulnerability parameters that has caused the damages, a statistical analysis was carried out to develop a vulnerability score sheet. In this score sheet, a vulnerability score is computed considering building attributes such as soft storey, substantial overhang, re-entrant corners, the age of buildings, apparent material and construction quality, eccentric staircase location with respect to building plan, maintenance, soil type and a number of storeys. This score sheet will be a very helpful technique for assessing huge building stocks.

Rapid visual screening procedure of existing building based on statistical analysis

A statistical regression method was used to model the relationship between the outcome variable, e.g. different damage grade of existing building during an earthquake, and the explanatory variables concerning the building attributes that enhance the vulnerability of building during an earthquake. The analysis was performed by employing a building database of 396 damaged buildings surveyed after the 4th January Manipur earthquake of 2016. It is observed that the type of soil, apparent construction quality, maintenance condition, age of the buildings, substantial overhang and number of storey of the existing buildings are highly significant parameters in analyzing the vulnerability of the building during an earthquake. From the statistical analysis, a rapid visual screening procedure is proposed which can used as preliminary assessment technique for identifying vulnerable buildings in disaster risk reduction programme.

Rapid visual screening of earthquake-susceptible buildings

Many people in the Indian subcontinent can only afford non-engineered shelters. Unfortunately, such buildings are easy victims of earthquakes and they need to be assessed and graded to see how susceptible they are to damage during the frequent, moderate tremors of the region. The large number of these buildings warrants a wide screening programme but a dearth of technical personnel requires a simple methodology that can be carried out by non-technical people. This paper discusses the strategies for evolving a rapid visual screening procedure for non-engineered and semi-engineered buildings as a means of seismic vulnerability assessment. It is based on damage surveys of three moderate earthquakes and from shake-table experiments. The proposed methodology can be applied to traditional and semi-engineered buildings using a number of visually identifiable parameters.

An inventory of buildings in the city of Tunis and an assessment of their vulnerability

Tunis is a densely populated city. Its building stock was constructed without any seismic design code and mostly over soft soils. These facts make a seismic risk assessment of the city necessary. To prepare a large-scale vulnerability assessment of the buildings of Tunis, the following methodology was employed: (1) a collection of data based on a rapid visual screening procedure was gathered using an inventory form. These data were composed of files and information placed at the disposal of the authors by the municipality of Tunis. The data also contained information gathered by surveys carried out by engineering departments and information gathered from building owners. (2) A classification of building typologies was carried out considering construction material, structural system, age, height, function and state of maintenance. A measure of seismic vulnerability was assigned to each typology considering the first two parameters. (3) A large-scale vulnerability assessment using two methods was conducted for buildings for which few data were available. Vulnerability methods inspired by the EMS98 concepts and the Italian GNDT concepts were modified and applied to pilot-scale buildings located in the downtown zone (Habib Bourguiba Avenue) and in the old zone (Medina). The data analysis, through the application of the two methods, suggests that the vulnerability of buildings surveyed in Tunis is significant and risk mitigation efforts are necessary.

A Proposed Rapid Visual Screening Procedure for Seismic Evaluation of RC-Frame Buildings in India

Poor performance of reinforced concrete (RC) frame buildings in India during past earthquakes has been a matter of serious concern. Hence, it becomes important to identify and strengthen the deficient buildings. When dealing with a large building stock, one needs evaluation methods for quick assessment of the seismic safety of existing buildings so that corrective retrofitting measures may be undertaken on the deficient buildings. This paper presents a review of some of the available methods for rapid visual screening (RVS) of RC-frame buildings and proposes a RVS method for RC-frame buildings in India based on systematic studies on damage data of the 2001 Bhuj earthquake.

Development of an index assignment procedure compatible with the regional seismicity in the province of Quebec for the rapid visual screening of existing buildings

In the context of the seismic vulnerability evaluation of buildings, the score assignment method can be used as the first step of a multiphase procedure aimed at identifying hazardous buildings that must then be analysed in greater detail. Because the existing Canadian rapid visual screening procedure has not been updated since 1992, a new procedure is proposed based on a set of vulnerability indices for different cities in the province of Quebec. A seismicity level (low, moderate, or high) is attributed to each city using the spectral acceleration response values included in the 2005 edition of National building code of Canada (NBCC) and the criteria proposed in FEMA 310 Handbook for the seismic evaluation of buildings - a prestandard. The structural vulnerability indices (SVIs) are calculated using the recently improved nonlinear static analysis procedure in FEMA 440, Improvement of nonlinear static seismic analysis procedures for each seismicity level. The NBCC 2005 reference soil class C is considered in the calculation of the SVIs, and index modifiers for the building height, irregularities, and design and construction year. The application of these indices to the estimation of the probable damage distribution in building inventories is discussed at the end.

Pre-earthquake fuzzy logic and neural network based rapid visual screening of buildings

When assessing buildings that may collapse during a large earthquake, conventional rapid visual screening procedures generally provide good results when identifying buildings for further investigation. Unfortunately, their accuracy at identify buildings at risk is not so good. In addition, there appears to be little room for improvement. This paper investigates an alternative screening procedure based on fuzzy logic and artificial neural networks. Two databases of buildings damaged during the Athens earthquake of 1999 are used for training purposes. Extremely good results are obtained from one database and not so good results are obtained from the second database. This finding illustrates the importance of specifically collecting data tailored to the requirements of the fuzzy logic based rapid visual screening procedure. In general, results demonstrate that the trained fuzzy logic based rapid visual screening procedure represents a marked improvement when identifying buildings at risk. In particular, when smaller percentages of the buildings with high damage scores are extracted for further investigation, the proposed fuzzy screening procedure becomes more efficient. This paper shows that the proposed procedure has a significant optimisation potential, is worth pursuing and, to this end, a strategy that outlines the future development of the fuzzy logic based rapid visual screening procedure is proposed.

First-Level Pre-earthquake Assessment of Buildings Using Fuzzy Logic

This paper discusses the performance of a fuzzy logic–based rapid visual screening procedure that results in the categorization of buildings into five different types of possible damage with respect to the potential occurrence of a major seismic event. In order to provide results representing expected damage, adaptive neural networks were used to train the method according to information obtained from the vulnerability of 102 buildings stricken by the Athens earthquake of 1999. The precision of the method was thereby enhanced, implying an improvement in efficiency and presenting remarkable advantages when compared to probabilistic approaches to rapid visual screening. Due to the small size of the database used for the training procedure, however, the prospects of the method remain to be discussed. Nonetheless, by using information from larger databases, the method has the potential for self-improvement, a fact that underlines a good prospect for the formation of reliable and robust pre-earthquake assessment methods.