Dynamic Interaction Analysis of PCC Bridge Abutment-Layered Soil System Subjected to Varying Earthquake Ground Motions in Indian Scenario | Chapter 6 | Engineering Research: Perspectives on Recent Advances Vol. 6

The present research investigates the linear static and dynamic structural behaviour of a PCC bridge abutment-layered soil system under varying earthquake ground motions. A numerical analysis of the interaction system is carried out using the latest version of ABAQUS/CAE-2024 considering it as a plane strain problem with different types of soil in the layered soil strata. Three significant earthquake- India-Burma (1988), Chamba (1995) and Bhuj (2001) are selected as ground motions to assess the dynamic structural response of the interaction system in the Indian scenario. Both static and dynamic analyses are performed to evaluate the displacement in the PCC abutment and underneath Layered soil strata. The model is created considering 2D plane strain condition in part module, with realistic soil properties (property module) and appropriate boundary conditions in ABAQUS/CAE-2024 software. The interaction between the abutment and the surrounding soil is modeled with contact-to-contact interaction, and then simulation is performed.

 

The results of analyses are presented for all three types of ground motions (low, medium and high intensities). The comparison of the displacements between static and dynamic analyses highlights the necessity of incorporating soil-structure interaction effects in the abutment-backfill and abutment-underpinning soil system. The India-Burma earthquake exhibited the highest horizontal displacement of 175mm compared to the Bhuj and Chamba earthquakes which developed horizontal displacement of 52mm and 36mm respectively. The static horizontal displacement of top most point of the abutment of 9.5mm remains significantly lower. In contrast, vertical displacement remained relatively consistent across all earthquake events and is found slightly higher than in static conditions (77 mm), indicating minimal impact on foundation settlement. The key objective of the research work is to understand the displacement, stress variations, and stability of the abutment system under earthquake excitations. These findings emphasize the importance of realistic soil modelling in improving the accuracy of seismic performance assessments for PCC bridge abutments.

 

 

Author (s) Details

Rishav Kumar
Department of Civil Engineering, Maulana Azad National Institute of Technology, Bhopal, India.

 

M.S Hora
Department of Civil Engineering, Maulana Azad National Institute of Technology, Bhopal, India.

 

Please see the book here:- https://doi.org/10.9734/bpi/erpra/v6/5067

Application of Quantitative Feedback Theory to the Robust Control of a Coaxial Micro-helicopter | Chapter 4 | Engineering Research: Perspectives on Recent Advances Vol. 1

Unmanned aerial vehicles (UAVs) are aircraft capable of flying and performing a mission without human presence on board. Initially developed as part of military activities, there is now a great potential for civil activities (surveillance, cartography...). This chapter on the dynamic analysis and QFT-based robust control design of a coaxial micro-helicopter is significant for the scientific community as it addresses a critical intersection of aerodynamics and control engineering. The paper presents the dynamic behavior of the micro-helicopter under Quantitative Feedback Theory (QFT) control, highlighting the non-linear and complex flight dynamics of autonomous air vehicles (AAVs) with rotating rings. It emphasizes the necessity of characterizing these non-linearities for each flight configuration to enable effective autonomous flight and navigation capabilities.

To tackle this complexity, the nonlinear model is linearized around an operating point using specific assumptions, followed by the application of a robust QFT control law to meet performance specifications. QFT serves as a powerful design method that leverages frequency domain concepts to manage uncertainties commonly encountered in small aerial vehicle design. The QFT design approach involves conventional frequency response loop shaping, manipulating gain variables in conjunction with the poles and zeros of the nominal transfer function, with the entire process executed using MATLAB software.

This research not only presents innovative methodologies that enhance stability and performance in increasingly complex environments but also lays a foundation for future studies in micro-robotics and autonomous systems, underscoring the importance of interdisciplinary collaboration. Personally, I appreciate the chapter for its clear articulation of theoretical concepts alongside practical applications, making it both accessible and highly relevant to ongoing discussions in the field. Overall, the integration of theory and practice in this work contributes valuable insights to both academia and industry.

 

Author (s) Details

 

Aissa Meksi
Electrical Engineering Department, Faculty of Electrical Engineering, University of Sciences and Technology of Oran, Algeria.

 

Ahmed Hamida Boudinar
Electrical Engineering Department, Faculty of Electrical Engineering, University of Sciences and Technology of Oran, Algeria.

 

Benatman Kouadri
Electrical Engineering Department, Faculty of Electrical Engineering, University of Sciences and Technology of Oran, Algeria.

 

Please see the book here:- https://doi.org/10.9734/bpi/erpra/v1/3330

Rockfill Dam with Reinforced Concrete Watertight Diaphragm: Static and Dynamic Analysis of Stress and Deformations | Chapter 2 | Advances and Challenges in Science and Technology Vol. 3

 This study presents the stress-strain state in the dam physique depending on the type of rockfill that was acted according to the importance of completion of the dam and the first contents with water. Large dams are a very relevant instance for determining seismic risk. On the individual hand, the dams themselves are valuable, accompanying ramifications for the whole economy by way of energy production, water delivery systems for watering, flood protection, thus. On the other side, dam structural decay can create harsh disasters and reveal the people to the results of abrupt floods. The situation in Romania is aforementioned that the future safety of existent dams should be thought-out. The first reason is because these dams were realized and built on the footing of technical averages, the majority of that are no longer in effect; the second reason is the current dramatic humidity changes, which have happened in an accumulation of water in happening slowly huge lagoons. A third sane argument is the length of existent dams. The stress-deformation condition that happens in the Rastolita dam body contingent upon the kind of rockfill is examined in this research. Calculations were ruined two cases, namely the finishing of construction and the first filling of the dam accompanying water. The results show that after finishing of construction, the maximum conclusion is recorded in the principal area of the dam, beneath the middle third; level displacements of the downstream crystal are significantly higher distinguished to deformations of the upstream crystal in the area place the used material has a taller compressibility. Maximum principal normal stress registers few local distortions inside acceptable limits; minimum principal normal stress exhibits meaningful gradients in the first stage contact district downstream of the dam slope accompanying the tuff-pyroclastic embankment tier, as well as the first three tiers of intercalated filling biased near the slope. Stress increases caused by hydrostatic pressure later the initial contents do not result in stress concentrations fantasy thought of when awake different than those written at construction finishing.

Author(s) Details:

Mihaela Toderas,
University of Petrosani, Petrosani, 332006, Romania.

Please see the link here: https://stm.bookpi.org/ACST-V3/article/view/12014

The Cash Flow Concept in Modern Financial Analysis of Internal Sources of Companies’ Investment Financing| Chapter 7 | Current Aspects in Business, Economics and Finance Vol. 7

 In current theories of financial study, a financial approach has been selected which is established the dynamic (modern) coefficients settled from cash flows - cash flow indicators. Some of the fields of their application are capital investments, that largely believe internal sources of funding and the ability of companies to create such sources of expenditure, especially in environments of crisis and insolvency. In this regard, they have distinctive importance for the Republic of Serbia, whose macroeconomic environment is further broken by the current global realm and energy crunch, insolvency, collapse and shutdown of household capacities, and the concentration of capital in the commercial sector. In this study, the focus is on examining the difference 'tween investment capacities established internal sources of outlay established on static and active indicators, in consideration of prove the necessity of requesting dynamic coefficients based on available funds analysis, which are not very accepted in practice in Serbia. The benefits of using the mentioned limits based on the cash flow idea as a modern tool in the research question on the instance of energy all at once of the most important arms of the Serbian economy were examined and resulted.