Abstract

Structural engineering involves clear understanding of characteristics of ground motion used in the design of structures to identify the critical aspects of their behavior. Peak amplitude of response (a, v, or d), predominant frequency and duration of strong ground motion are the most important parameters of ground motion that are required for this purpose. These parameters are influenced by the source, path and site conditions. However, it is also found that for the same distance these characteristics are highly sensitive to the fault direction and the side on which the site lies ie, hanging wall or foot wall. In this paper, a case study is performed to understand the influence of fault direction and location of site on the characteristics of the ground motion. For this purpose, 371 ground motions recorded during 1999 Chi-Chi, Taiwan earthquake are selected. Initially, these ground motions were arranged in terms of fault parallel and fault normal direction and also according to distance from the fault. Later, ground motion characteristics were obtained using standard procedures. From the above, it was found that, in the near-fault region, PGA and PGV on the hanging wall are higher by at-least 20% than that on the footwall. From this observation, the near-fault region can be defined not by using the distance from the fault, but by observing the ratio of PGA values in fault normal and parallel directions. This method of estimating the near-fault region is reliable because the hanging wall effect is caused only due to the inclined dip-angle of the fault which is inevitable in most of the thrust and normal faults.

Abstract

Development of Force-based seismic design is historical, and every earthquake has thrown new challenges for already existing assumptions and principles, which helped in the evolution of force-based design. Although many of the assumptions were answered but some remained unaltered and unanswered. Hence, this paved way for developing new theories and philosophies and one such theory is Direct Displacement-Based seismic Design (DDBD). Indian Standard codes, IS 1893 and IS 13920, underwent a major revision in the year 2016, considering the latest developments in Force based design principles. Current work is an attempt to understand the performance comparison between latest IS 1893 & IS 13920 with DDBD method. Initially, three buildings ie, 3, 6 and 9 storey buildings were designed using DDBD at inter-storey drift of 4% with a performance objective to achieve “No collapse”. The spectrum developed using IS code equations does not represent ideal displacement spectrum shape and hence PGA, T and CA dependent equations are used for DDBD methodology of design. PGA of 0.36 g is used in the current study which represents the highest seismic zone in India. Later these buildings were subjected to lateral displacement using displacement-based pushover analysis method. The inelastic strength along with drifts achieved by DDBD are compared with the IS code compliant buildings. From the comparison, it was observed that inelastic strength achieved by 6, 9 storey buildings designed according to FBD are greater than the buildings designed according to DDBD at “No Collapse”. For 3 storey structure, the strength …

Abstract

A ground-structure vibration response study was carried out at the Ramappa Temple near Warangal, Telangana, India, shaken by underground blasting undertaken at the neighbouring Devadula Lift Irrigation Project to build water tunnels. The intensities of vibrations were examined–subsurface and ground vibrations were measured using velocity meters, and shaking at the temple using accelerometers. The study concluded that high-frequency vibrations of the ground were filtered by the soft natural clay bed underneath, and vibrations at the temple structure were small and well below the levels that can cause damage to it. Here we present the scientific findings of the vibrations recorded during the blasts and their implications.

Abstract

In building construction, reinforced concrete (RC) Frame structures are frequently used due to ease of construction and rapid progress of work. In this study, two types of infill’s are used ie, unreinforced masonry infill and semi-interlocked masonry infill. For the analysis purpose of infill, a double strut nonlinear cyclic model is used. The main objective of the study is to investigate the importance of interlocked brick infill in the RC frame structure. For understanding the same, nonlinear static pushover analysis is carried out on analytical models using finite element based software, SeismoStruct. The response reduction factor components such as ductility reduction factor and overstrength factors were computed from nonlinear static pushover analysis and finally, the response reduction factor is calculated for all models. The primary focus is given to numerical modeling, nonlinear behavior of brick masonry RC buildings subjected to lateral loads and calculation of the response reduction factor of'RC'infilled frames with different aspect ratios.

Abstract

Catchment scale conceptual hydrological models apply calibration parameters entirely based on observed historical data in the climate change impact assessment. The study used the most advanced machine learning algorithms based on Ensemble Regression and Random Forest models to develop dynamically calibrated factors which can form as a basis for the analysis of hydrological responses under climate change. The Random Forest algorithm was identified as a robust method to model the calibration factors with limited data for training and testing with precipitation, evapotranspiration and uncalibrated runoff based on various performance measures. The developed model was further used to study the runoff response under climate change variability of precipitation and temperatures. A statistical downscaling model based on K-means clustering, Classification and Regression Trees and Support Vector …

Abstract

In the present study, it was attempted to investigate the cyclic resistance of equi-proportionate silt–sand range pond ash (with 50% fines) at relatively high shear strains using the strain-controlled cyclic triaxial test. The cyclic triaxial tests have been performed considering the effect of relative compaction (97–99%), cyclic shear strain (0.6–1.35%), frequency of loading (0.3–1 Hz) and effective confining pressure (50–100 kPa) on cyclic resistance of pond ash. Dynamic characteristics such as dynamic shear modulus and damping ratio of equi-proportionate silt–sand range pond ash was evaluated for all the parameters considered at high shear strain. The maximum value of the dynamic shear modulus and damping ratio of pond ash observed in this study was 6534.8 kPa and 23.64%, respectively. The dynamic shear modulus and damping ratio of pond ash was decreased from 6534.8 to 5023.87 kPa and 23.64 to 14.17 …

Abstract

We thank the respected discussers for appreciating the relevance of the present work, critically analyzing it, and bringing forth the possible constraints in its applicability. This discussion provides us an opportunity to elaborate the point related to the scope and applicability of original work, especially with focus on the hydrological community that otherwise would possibly remain unclarified. Because there are two discussions of our paper, we have addressed them in two different sections.

Abstract

High resolution Digital Elevation Models (DEMs) are an important requirement for many applications like modelling water flow, landslides, avalanches etc. Yet publicly available DEMs have low resolution for most parts of the world. Despite tremendous success in image super resolution task using deep learning solutions, there are very few works that have used these powerful systems on DEMs to generate HRDEMs. Motivated from feedback neural networks, we propose a novel neural network architecture that learns to add high frequency details iteratively to low resolution DEM, turning it into a high resolution DEM without compromising its fidelity. Our experiments confirm that without any additional modality such as aerial images (RGB), our network DSRFB achieves RMSEs of 0.59 to 1.27 across 4 different datasets.

Abstract

This paper proposes a system for monitoring of condition and surface of roads in developing countries like India. This system will be used by government agencies to monitor municipal activities like road laying and planning. The system utilizes a database created by geo-citizens or government workers as an input. The heavy machinery in existing systems is not an optimized solution to this problem. Some existing systems use GPS and accelerometer data for determining such artifacts. So, it is evident that there is a need for a system that generates robust, frequent and accountable geo-tagged data. We propose a new collaborative model for such a purpose by fusion of data from multiple sensors hosted on smart-phones of several active geo-citizens. The system focuses mainly on volunteered geographic information, in which users can use their respective smart-phones to collect the data required and upload it for …

Abstract

Radio Frequency (RF) based sensors have shown great potential for the qualitative and quantitative analysis of different chemical and biological entities. In this work, the feasibility of performing RF based sensing by using gold particles has been explored with the help of the computational tool, HFSS (High Frequency Structure Simulator). The analysis is performed for an Interdigitated Capacitor based sensor. Various physical parameters of cylindrical gold particles such as radius and thickness have been varied, and the electrical parameters of the sensor systems have been studied. In particular, the reflection coefficients have been determined for various cases. In addition to the physical parameters, different configurations of the gold particles such as their linear and non-linear arrangements have been analyzed. The analyses offer promising results for the development of efficient sensing platforms.