Book Chapters
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Item Strength Behavior of Rammed Earth Stabilized with Metakaolin(Springer, 2020) Thiviya, S.K.; Krishnan, A.G.; Kalathuru, M.; Sharma, A.K.; Kolathayar, S.Rammed earth is an ancient construction technique practiced in India and in other parts of the world. The ancient traditional technique was of the un-stabilized method but incorporating suitable stabilizing materials will improve the strength of rammed earth construction. The main objective of the present study is to assess the behavior of the rammed earth with metakaolin. The suitability of the soil was tested based on sieve analysis and followed by mini compaction tests; optimum moisture content for the rammed earth construction for the selected soil was fixed for different proportions of binders with the soil. From the compaction results, the binder content was fixed for stabilization of rammed earth. The unconfined compressive strength of the sample was found for the samples at 7, 14, 28 days of curing, and microstructural studies of the samples were performed. The compression strength of rammed earth cubes was tested and also the durability of the cubes was determined by the spray erosion test. © 2020, Springer Nature Singapore Pte Ltd.Item Challenges and opportunities for coastal reservoir development in India(Elsevier, 2020) Sitharam, T.G.; Kolathayar, S.In India, presently 320 million people remain in the water-starved parts of the country, and according to the United Nations, 840 million people are expected to be water-starved in India by 2050. Although there has been no significant change in India’s rainfall pattern, the number of areas under drought in India is increasing every year. Increase in population is one of the reasons for water scarcity, but inefficient management of the precipitation received stands as the major cause. Although extreme rainfall events are significantly increasing, there is a spatial nonuniformity in the rainfall events that occur. This makes it difficult to preplan large-scale water storage at different locations. Solution to India’s water problem lies in conserving the abundant monsoon water bounty by storing it in coastal reservoirs for future use. This paper focuses on the challenges and opportunities in India for storing river floodwaters in coastal reservoir. The paper also presents the concept of Sarovar Mala, a chain of coastal reservoirs, an innovative concept that has the potential to ensure water availability to India throughout the year. © 2020 Elsevier Inc.Item Geotechnical considerations for coastal reservoirs(Elsevier, 2020) Sitharam, T.G.; Kolathayar, S.Geotechnology and geotechnical schemes have a significant role to play in conserving the water. This chapter highlights the importance of geotechnology in surface and subsurface water storage and in coastal reservoirs. Groundwater hydrology, soil/rock characteristics and permeability are the major factors governing the efficiency of water storage techniques in the ground. The innovative materials for construction of water storage schemes in the ground and for lining are briefly discussed. The chapter further discusses the concept of the subsurface dike or underground dams and its applicability in storing a large amount of water underground and in check seawater intrusion. The role of geotechnology in construction and maintenance of coastal reservoirs is discussed in detail. Different dike construction methods are discussed considering recent developments on techniques and materials. The major geotechnical components in the design and construction of coastal reservoirs are the stability of sea dike and settlement of the soil below the dike. The geotechnical parameters and the concepts of checking the stability factor of safety and settlement calculations are presented in this chapter. The coastal reservoirs must be safe against earthquakes, and deterministic estimation of seismic hazard is introduced briefly at the end. © 2020 Elsevier Inc.Item RECENT DEVELOPMENTS IN SYNTHESIS OF EARTHQUAKE MOTIONS USING LINEAR JOINT TIME FREQUENCY ANALYSIS TECHNIQUES(International Association for Earthquake Engineering, 2021) Ramkrishnan, R.; Devaraj, D.; Kolathayar, S.; Sitharam, T.G.Temporal distribution of the frequency contents of a multi-component signal like seismic motions are not captured and well-represented in Fourier Transform (FT) techniques. Linear Joint Time-Frequency Analysis (LJTFA) addresses this issue and can transform and represent a signal in not only time domain and frequency domain, but in time-frequency domain simultaneously. Considering the better resolution and less spectral spillage when compared to Short Time Fourier Transform (STFT) and less complexity when compared to Wavelet Transform (WT), Gabor Transform (GT) is adopted in the current study. Actual recorded time-histories from recording stations in Japan had been considered for a LJTFA based synthesis of earthquake motions in this study considering the high seismicity of the area and large number of data available. Recorded time-histories of 23 earthquakes throughout Japan has been collected from K-Net and Kik-Net Strong Motion Seismograph Network of Japan and is categorized according to various Magnitude and hypocentral distances. Events of magnitude ranging from 5 to 5.5 and hypocentral distances 0 to 100km is sorted and GT is applied to transform the signals to their time-frequency domain and estimate their Gabor amplitude coefficients. Mean Gabor amplitude coefficients are estimated for different Magnitude (Mx) and Distance (Dy) combinations like M5D0-25, M5D25-50, M5-5.5D0- 25, and M5-5.5D25-50. Using an inverse GT process; Gabor Expansion (GE), the mean transformed Gabor amplitude coefficients are used to reconstruct and synthesize a time-history which doesn’t compromise on the quality of their spectral and frequency contents, thus yielding reliable synthetic seismic motions. Response spectra is developed from the actual and synthesized time-histories and are compared. A statistically good fit in terms of the coefficient of determination factor, R2 is observed between the actual and synthetic response spectrum developed. © 2021, International Association for Earthquake Engineering. All rights reserved.Item Disaster Risk Reduction and Civil Engineering—An Introduction(Springer Science and Business Media Deutschland GmbH, 2022) Kolathayar, S.; Pal, I.; Ganni, S.V.S.A.B.This chapter presents the definitions and concepts of disaster risk reduction and its relation to the discipline of civil engineering. It is important to have the infrastructure resilient to disaster. In addition, civil engineering has the potential to offer solutions that can reduce the risk during a disaster. The disaster risk can be reduced by reducing the exposure and vulnerability. The civil engineers can reduce the disaster risk in several ways such as proper land use planning, integrating efficient codal provisions, appropriate design reducing the vulnerability, quality improvement in construction, provision of sea walls, flood protection structures, drainage systems, and earth retention schemes. This book envisages knowledge dissemination on disaster risk reduction primarily focusing on civil engineering perspectives and cross-cutting issues. Research and innovations in civil engineering have the potential to offer solutions toward disaster resilient infrastructures. The vision of this book is in line with the priorities set by UN-SFDRR and UN-SDGs to promote a global culture of risk-awareness and disaster reduction. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Review on Landslide Early Warning System: A Brief History, Evolution, and Controlling Parameters(Springer Science and Business Media Deutschland GmbH, 2022) Menon, V.; Kolathayar, S.A landslide is a life-threatening event causing large infrastructural damages. The major causes for landslides are rainfall, earthquakes, blasting, and other man-made activities. The landslides can happen even without human interference, and hence, it can be classified as a natural process. The population expansion in landslide-prone areas demands a better sustainable method for slope protection and landslide prediction. The main objective of this chapter is to review the previous research studies conducted in the soil slopes using manual instrumentations and the improved data acquisition systems (DAQ) that are used recently. A landslide early warning system (LEWS) is only as strong as the understanding of the phenomenon. The first objective of the development of an early warning system is to find the triggering mechanism of the impending disaster. The three landslide triggering mechanisms are excess rain, seismic activities, and man-made activities. For rainfall-induced landslides, finding the rainfall threshold parameter is one of the difficult tasks. The methods involved in finding this threshold and using it for the development of the LEWS will be discussed in this chapter. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.Item Deterministic Seismic Hazard Analysis of Grand Ethiopia Renaissance Dam (GERD)(Springer Science and Business Media B.V., 2022) Al-Ajamee, M.; Baboo, A.; Kolathayar, S.This paper presents the Deterministic Seismic Hazard Analysis for Grand Ethiopia Renaissance Dam (GERD) (11.2183ºN, 35.0941ºE). This area is of special importance because GERD is the largest hydroelectric power plant in Africa and the seventh-largest in the world. The Hazard analysis was done using linear sources present near the dam site (Inferred faults and Indicated faults); 713 faults were used for the analysis. Earthquake data was collected for the dam region, and homogenization of data was done to moment magnitude followed by declustering foreshock and aftershock events. 1375 earthquakes of moment magnitude 4–7 were considered and represented on a seismotectonic map. Ground Motion Prediction Equations (GMPEs) were identified for the dam site, and suitability was checked by comparing the Data Support Index (DSI) value of various prediction equations. Considering the selected GMPEs and input data, DSHA was performed by using a MATLAB program developed for this purpose. The dam site was further divided into a grid cell of 100 m × 100 m, and hazard parameters were obtained at the midpoint of the grid cells, bearing in mind all seismic sources within a 500 km radius. Obtained PGA values were compared with USGS developed Instrumental Intensity scale. The hazard map showing the spatial variation of the risk associated with the dam site is presented. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2022.Item Applications of civil engineering in disaster risk reduction(CRC Press, 2024) Menon, N.V.C.; Kolathayar, S.; Sreekeshava, K.S.The United Nations Office for Disaster Risk Reduction (UNDRR) observes that "disaster risk reduction (DRR) is aimed at preventing new and reducing existing disaster risk and managing residual risk, all of which contribute to strengthening resilience and therefore to the achievement of sustainable development". It further clarifies that "DRR is the policy objective of disaster risk management, and its goals and objectives are defined in disaster risk reduction strategies and plans". The compliance with multi-hazard resilient building codes, town planning bylaws, regulations against construction of buildings and structures in flood-prone areas and unstable slopes, etc. by practitioners of civil engineering, structural engineering and geo-technical engineering is essential for the structural integrity of the building stock to withstand disasters such as earthquakes, tsunamis, floods, hurricanes, landslides, etc. The multi-hazard resilient construction of critical infrastructure such as dams, airports, flyovers, highways, power supply, water supply, telecommunications, etc. will strengthen the resilience of local communities which depend on uninterrupted service delivery of these facilities even when disasters strike neighbourhoods. Hospitals, schools, government offices, malls, etc. must function effectively to continue to deliver their services even during disasters without facing damage, destruction or collapse. The good practices of civil engineering as demonstrated by disaster-resilient structures in recent earthquakes must be studied to disseminate such lessons widely. Disaster risk reduction must also be introduced in the curriculum of institutions imparting education in civil engineering, structural engineering, geo-technical engineering, architecture, urban planning, etc. We need to ensure compliance with the National Building Code (NBC) and other codes for all new construction and critical infrastructure being built. We must also identify weak structures which are life threatening and carry out seismic strengthening and retrofitting to save lives in high-risk zones. The vulnerability of weak structures which collapse in earthquakes, landslides and cyclones make it necessary to undertake a structural safety audit of weak structures and socio-economic assessment as a follow-up to changes in a multi-hazard risk map. The implications need to be communicated to urban administrators rather than just mere incorporation into standard codes of practice. © 2025 selection and editorial matter, Sreevalsa Kolathayar, N Vinod Chandra Menon and Sreekeshava K S. All rights reserved.Item Sustainable communities with net zero targets: An introduction(CRC Press, 2024) Kolathayar, S.; Menon, N.V.C.; Sreekeshava, K.S.In the contemporary world, the resilience building of communities to make them sustainable necessarily can be ensured only through development pathways which conserves, preserves and regenerates scarce resources. The four global frameworks promoted by the United Nations agencies and being operationalised during the period 2015 to 2030 - the Sendai Framework for Disaster Risk Reduction (SFDRR), Sustainable Development Goals (SDGs), the Paris Agreement on Climate Change and the New Urban Agenda - are all targeted at strengthening the resilience of communities by reducing their risk, vulnerability and exposure to shocks, disasters, extreme events, conflicts and climate change. There has been a growing realisation in recent years that sustainable and resilient communities must necessarily reduce their consumption of fossil fuels and strive for energy transition by promoting new and renewable sources of energy. The reduction in greenhouse gas emissions, global warming, sea level rise and melting of glaciers is necessary to reduce the economic damages caused by the increasing frequency of heatwaves and climate change-induced hydro-meteorological disasters. Innovative disaster risk financing instruments must be designed and promoted to ensure multi-hazard resilience and disaster risk reduction in fragile ecosystems prone to disasters, extreme events and climate change. Ecosystem restoration by nature-based solutions must be promoted by centre staging communities and other stakeholder groups in fragile ecosystems. Risk governance must be prioritised in development planning to ensure sustainable development without loss of lives and disruption of livelihoods. Critical infrastructure protection must be ensured so that critical infrastructure service delivery is not disrupted due to disasters, extreme events and climate change. © 2025 selection and editorial matter, Sreevalsa Kolathayar, N Vinod Chandra Menon and Sreekeshava K S. All rights reserved.