Solidity and Earthquake Risk Level of Lahor Dam by means of Peak Ground Acceleration (PGA) Data

Sunaryo, Adi Susilo and Arief Andy Soebroto

Research entitled solidity and earthquake risk level of Lahor dam by means of peak ground acceleration (PGA) data have been conducted to obtain an overview of the distribution of solidity and the level of risk caused by an earthquake. To obtain PGA values, data from the acquisition of microseismic and seismicity data from USGS are used. Based on the results of processing and interpretation, Lahor dam location has the lowest PGA value of 0.01 Gal which is located at the measuring points MZL04, MZL05, MZL07, MZL08 and MZL26.

The highest PGA value is 0.07 Gal which is located at the measuring point MZL28 and MZL33 while the average PGA value is 0.03 Gal. The very low-risk groups with PGA values in the range of 0.01 - <0.03 Gal are distributed at points MZL01-09, MZL13, MZL15-17, MZL21-23 and MZL32. The low-risk groups with PGA values in the range 0.03 - <0.06 Gal are distributed at points MZL10, MZL14, MZL18-20, MZL24, MZL25, MZL29-31 and MZL35 whereas for the moderate risk 1 group with PGA values in the range 0.06 - 0.07 Gal are distributed at the points of MZL27-28, MZL33-34. This data corresponds that the very low-risk group is found in solid lithology located on the body of the dam and the dam wall on the exhaust side. The low-risk group in the form of lapilli-tuff and surface sediment layer is located relatively in the middle of the exhaust section. The moderate risk 1 group is located in the exhaust section which is dominated by the soft rock in the form of sediment layers without any pavement.

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Statistical analysis of trend and change point in climate series for a semi-arid basin, Tamil Nadu, India

Shimola K. and Krishnaveni M.

This research study aims to carry out the trend test and change point analysis on temperature series including maximum, minimum and mean annual temperature at Kavalur climate station during the period 1965-2010. These tests have been also carried out on rainfall series at 10 raingauge stations during the period 1935-2010 in Vaippar basin, Tamil Nadu, India. The results of Mann-Kendall trend test showed that maximum, minimum and mean annual temperatures exhibited a sign of increasing trend at α=0.05 significance level. An increasing trend in annual rainfall is observed in Aruppukottai, Kovilpatti and Sivagiri but it is statistically insignificant.

Their magnitudes of change over time are determined by Sen’s slope estimator indicating that the overall temperature has been increased by 0.4°C /10 years. The cumulative sum charts (CUSUM) are used for the detection of statistically significant change points. The CUSUM charts show that a major change point has occurred in the late 1970s and 1990s for maximum and minimum temperatures and continued till this decade for temperatures. The CUSUM charts also reveal that there is no major change point in rainfall series as rainfall is erratic and it shows inter-annual variability. This change point detection is a clear indication of climate change.

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Progressive collapse study of 220 KV transmission line tower with different bracing patterns

Madisetti Pavan Kumar, Duba Vishalakshi, Ponnada Markandeya Raju and Dadi Rambabu

India has0huge population0spread all over the country. Electricity is vital for0Residential, Commercial0and Industrial areas. After power generation, power is transmitted through transmission line0towers to distribution systems. Due to increase in0power generation, there is an increase in0transmission line0systems. Progressive collapse is one of the most devastating types of structural failures, most often leading to expensive damages, multiple injuries and possible loss of life. Factors such as unexpected accidental loads, construction errors, miscommunication, poor inspections, or design flaws contribute to these progressive collapses that have led to many changes in building codes throughout the nation. To study the local failure, progressive collapse behavior of the structure is to be analyzed. Progressive collapse is a continuous spread and magnification of localized failure in structures, caused by an accidental load, resulting in a cascade of failure affecting a large portion of the structure.

The main aim is to study the progressive collapse behavior of transmission line tower with different bracing patterns namely K-bracing, X-bracing, (K-X) bracings. All the considered towers are analyzed for gravity and wind loads [IS: 875(Part-III)-2015]. The tower is analyzed as space truss for different load combinations as per IS: 875(Part-V) and IS:456-2000. Based on the analysis of obtained results, a comparison between towers with different bracing patterns namely K-bracing, X-bracing, (K-X) bracings with different Progressive collapse conditions is made.

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A study of seismic resilience and construction techniques of Srinagar city, Jammu and Kashmir, India

Bukhari Kaiser, Yousuf Maqbool and Dar Ayaz Mohmood

Srinagar city is one of the most densely populated regions in the state of Jammu and Kashmir, India and is a major urban, industrial and commercial hub of the Kashmir Valley. Located at the fringe of seismic zones IV and V as per the seismic zoning map of India (BIS, 2002), it is vulnerable to both far and near source seismic sources. Resting on a sedimentary basin of 1.3 km thickness above the basement, highly vulnerable to earthquake, disasters are evidenced by numerous historical earthquakes. Multiple vulnerability components like plan irregularity, age of residential buildings, height/number of storey of residential buildings, construction material, soil condition and slope and ground condition were analysed for the estimation of structural risk of the buildings in the city.

Our results indicate that the lack of present earthquake resistant measures in all these building has survived the odds of time. Although with age, the strength of these buildings has decreased because of the decaying of construction material, the need of the hour is to renovate these heritage buildings as soon as possible.

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Research Issues in Experimenting Tsunami Resistant Structures: A State-of-the Art Report

Palaniappan Meyyappan, Chandrasekar Sivapragasam and Thimmayan Sekar

The recent earthquake and subsequent tsunami that devastated Japan in March 2011, along with the December 2004 Indian Ocean Tsunami that caused severe damage and loss of life to numerous coastal communities, underscores the need for a better understanding of tsunami resisting structures. In the recent past, many researchers are involved in active research in understanding various aspect of the nature of the Tsunami. A brief State-of-the Art of tsunami resistant structures is categorized in to following factors like modeling of tsunami waves, creation of tsunami wave, load calculations, similarity between model and prototype, specifications of models and experimental setup and design guidelines.

The brief research issues of experimenting tsunami resistant structures will make an attention towards the research community to focus more research in this field to formulate appropriate guidelines for the design and construction of tsunami resistant structures.

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