Journal of Structural Technology

Study of Causes of Cracks and Their Remedial Measures in Structure

Abhishek Powar, Dev Shetkar, Jayant Dixit, Harshavardhan Patil, M. B. Patil — Tue, 02 Apr 2024 00:00:00 +0000

This project aims to investigate the causes and remediation of cracks in buildings to enhance
structural integrity and safety. Cracks in buildings are a current issue that can arise due to
various factors including structural movement, foundation settlement, material defects,
environmental conditions, and design flaws. The presence of cracks not only affects the aesthetic
appeal of buildings but also poses potential risks to occupants and structural stability. In this
discussion, we will explore the causes, types, and potential consequences of building cracks, as
well as strategies for their prevention and repair. By gaining insight into this topic, architects,
engineers, builders, and property owners can better manage and maintain the integrity of their
structures, ensuring their safety and longevity. Through a comprehensive literature review and
field studies, this project will identify common types of cracks observed in buildings and their
underlying causes.

Enhance Structural Strength and Ductility for Blast Load Mitigation

Chaudhari Ashutosh Vaman, Vinay Kumar Singh Chandrakar — Tue, 20 Feb 2024 00:00:00 +0000

The study focuses on understanding the behaviour of structures under blast stress to enhance their
resilience against explosive events. Explosions, whether caused by bombs or gas-chemical
reactions, can severely damage buildings. This damage includes the destruction of external and
internal structural frameworks, collapsing walls, shattering windows, and disabling life-safety
systems. Occupants face risks such as direct impact from the blast, structure collapse, flying
debris, fire, and smoke. Indirect effects can compound the danger, hindering or preventing rapid
evacuation. Major disasters induced by explosions impose stress conditions beyond the original
design loads of structures. This dynamic aspect makes it challenging to ensure structural integrity
and occupant safety in the event of an explosion. Over the past three decades, efforts have been
made to develop structural analysis and design methods that can withstand blast loads. These
approaches aim to mitigate the impact of explosions and protect structures and occupants. The
study aims to understand how armoured structures behave under blast stress, to design structures
capable of responding effectively to explosions. The study contributes to the development of
strategies for designing blast-resistant structures, which are essential for ensuring the safety and
resilience of buildings in areas prone to security threats or industrial accidents. In this study, we
consider RCC structure and pre-stress structure and find out their behaviour and we got pre-stress
structure is more capable than RCC structure to withstand the blast load. These analyses have
been done in Staad Pro software with different parameters such as bending moment, share force
and displacement.

Developing Regional Seismic Fragility Curves Using ETABS for a Multi-Storey Residential Building

Muhammad Moniruzzaman, Md. Safwan Bin Minhaz, Imran Sarker Siam — Tue, 23 Jan 2024 00:00:00 +0000

Seismic risk assessment is critical for improving the resilience of buildings in earthquake-prone areas. The main goal of this study is to create regional seismic fragility curves for a high-rise residential structure in Dhaka, Bangladesh. Pushover analysis, a complex nonlinear static approach, is used in the analysis, which is carried out using the ETABS structural analysis software. The main goal is to quantify the building's structural performance under various seismic intensities to fully comprehend its susceptibility and develop solutions for risk mitigation. The research begins with the selection of a typical Dhaka residential building typology that serves as a sample case study. Using ETABS, a three-dimensional finite element model of the building is created, taking into account its geometrical characteristics and material composition following regional building standards and codes. Using experimental and empirical data, the model's dependability is verified. A collection of ground motion records that are typical of the local seismic risk is then used as input for the pushover analysis. Insight into potential failure mechanisms, such as column yielding, beam plasticization, and overall structural collapse, is provided by the study, which evaluates how the building performs at various earthquake intensities. The fragility curves are created by comparing structural damage states to the associated seismic intensity measurements. The probability of achieving or exceeding a particular damage state for a given seismic intensity level is quantified using fragility curves, which are fundamental probabilistic techniques. For risk assessment, emergency response planning, and strategy retrofitting, these curves offer useful information. By determining fragility correlations particular to the Dhaka environment and taking into account elements including regional soil characteristics, building design, and earthquake patterns, the study adds to the body of current information.

Advancing Structural Understanding: System Identification of Steel Plate Girder Bridges in Nepal

Gangesh Kumar Joshi, Raghabendra Yadav, Sushma Arayal — Mon, 01 Apr 2024 00:00:00 +0000

Efficient infrastructure management relies on accurate bridge system identification, crucial for
societal well-being and economic prosperity. This research pioneers a method to determine the
fundamental frequency of steel plate girder bridges using smartphone accelerometers and Finite
Element Method (FEM) modelling. Conducted along the East-West Highway in Nepal, this study
focuses on 12 motorable bridges, employing the Android app Phyphox to gather vibration data
induced by highway traffic. By applying operational modal analysis and peak picking techniques,
the natural frequencies of these bridges are pinpointed, while a detailed FEM model in SAP2000
aids in correlating field observations. Notably, the study reveals that a bridge's span significantly
influences its frequency, with longer spans exhibiting lower frequencies and vice versa. Close
alignment between FEM predictions and smartphone-acquired data underscores the method's
reliability, with disparities generally limited to 10%, primarily attributed to simplifications in
modelling assumptions. Moreover, the investigation identifies structural issues like girder cracks
on Pasaha Bridge, elucidating instances where field observations diverge from FEM predictions.
This comprehensive approach not only enhances our understanding of bridge dynamics but also
furnishes invaluable insights for maintenance and infrastructure planning, essential for ensuring
the longevity and safety of critical transportation networks.

Pushover Analysis of Different Shapes of Symmetric and Asymmetric Reinforced Concrete Buildings as per BNBC 2020

S.M. Hedaetullah Bin Siddik, Mst. Nusrat Jahan Disha, Arup Sutrodhar — Thu, 29 Feb 2024 00:00:00 +0000

Bangladesh is situated in an earthquake-active region. It is necessary to identify structures at risk
of damage and implement an effective safety standard. This evaluation requires methods beyond
simplified linear-elastic approaches. As the number of high-rise buildings is increasing daily,
there is an urgent need to design structures considering seismic loading. Although different
procedures are possible, to assess how well a structure performs, the non-linear static analysis,
also referred to as Pushover Analysis (or collapse analysis), is seen as a practical method. In the
present study, four different shapes of multistoried buildings were analyzed according to BNBC
2020. At first, a model was prepared; loading was done and analysis was run using Etabs v16.2.1
(structural analysis and design software). The results show that the effect of lateral loads due to
earthquakes is different in the case of different building shapes and how a building behaves during
earthquakes is mostly influenced by its overall geometry and shape.

Open Soft Floor High-rise Building's Seismic Reaction

Mohd Sulayman Malik, Komal Bedi — Wed, 17 Jan 2024 00:00:00 +0000

In Indian cities, soft first storeys are a typical feature of modern multistory structures. Emerging
economies like India continue to construct a large number of multistory buildings with soft floors
even though these buildings are inherently prone to toppling following an earthquake. The
practical and social requirement of having open stories at different levels of the structure for
workplaces and parking spaces at ground level outweighs the technical community's disapproval
of such constructions. The use of software in civil engineering has significantly decreased the
complexity of numerous sectors in project analysis and design due to the availability of fast
computers. This study examines how several soft-story structure types such as bare frames, infill
frames, bracing frames, and shears wall frames behave seismically when subjected to seismic
stress. When compared to a soft story, it has been shown that offering a range of models enhances
the structure's resistive performance.