CASE REPORT | Feb. 17, 2021
Forensic Engineering Investigation on a Collapsed School Building Involved Multiple Deaths: A Real Case Report
T. Nataraja Moorthy
Page no 17-19
Forensic crime scene investigators need to have the basic knowledge of science, engineering and medicine fitted for legal or public argumentation. Only an experienced forensic crime scene investigator can handle such cases and to arrive a conclusion for the presentation in the legal system. Forensic engineering investigation is multi-disciplinary process for investigating and reporting the cause of engineering problems which may have legal ramifications. Building collapse becomes a major threat to the society and people lost the confident on constructors and government. The professionals involved in the construction, viz. engineers, builders and contractors are under severe scrutiny about their role and responsibilities in the collapses. The municipal and corporation authorities have been approving for building constructions such as apartments, schools, colleges and many others. Irrespective of town or villages, construction industry, sometimes has been operating in a chaotic manner due to inadequate legislative building codes or violating building codes. The causes of building collapse ranges from substandard building materials to corruption. The present crime scene case study investigated a collapsed school building forensically the causes of elementary school building collapse, led to the death of 5 children and many sustained injuries, the incident occurred in India, as investigated by the author and identified the cause. The author presented his testimony in the court of law and Honourable Judge accepted the forensic findings and the case ended with conviction.
ORIGINAL RESEARCH ARTICLE | Feb. 17, 2021
Study of the Effect of Connection Stiffness on Structural Systems and Theire Structural Integrity
Page no 20-31
Structural systems consist of sub-systems and elements. Connection elements are needed for the subsystems and assembly and integration of these systems to the main system. Because the main system can fulfill its functional tasks when its assembly and integration with the subsystem is completed. Systematic static strength and dynamic behavior of structures, load bearing material and static cross-sectional properties as well as the strength and stiffness properties of the connections have a significant effect. The effect of the stiffness of the connection elements is higher in thin structural systems where the cross-sectional dimensions are much lower than the system dimensions. Assembly and integration are provided by using connection elements also in thin structural systems such as steel structure, scaffolding and rack structures. Therefore, the strength and stabilization of corner connections and fixing elements affect the entire system. However, while making systematic calculations, the structures, staying on the safe side, are modeled with rigid or rotatory hinged approach. When the connections are modeled as rotatory hinges, larger cross sections are required and support elements are added to prevent the system from becoming kinematic and collapse. With this approach, in buildings that require a lot of connection elements, the weight of the building increases too much and thus the cost increases. On the other hand, when the system is modeled with rigid approach, since the joints are unnecessarily excessively safe and the system's elasticity is very low, sudden overloads may result in collapse accidents and cause loss of life. For this reason, connection elements, especially in thin structures, must be modeled with real stiffness values and verified by tests under the prescribed loads. The purpose of this research is to examine the structural system design approach by modeling thin structure connection elements realistically and to create sensitivity in this regard. With this modeling method, it is aimed both to reduce costs and to prevent possible accidents caused by wrong modeling.
REVIEW ARTICLE | Feb. 23, 2021
Damage Localization Test of Civil GFRP Material Based on Acoustic Emission
Yanhua She, Gaojie Cai
Page no 32-36
To detect the damage location, the acoustic emission sensor is fixed on the surface of civil GFRP tube by the external bonding method. And damage position of the GFRP Tube under static loading is studied. The acoustic emission sensor is used to receive the signal of the GFRP tube rupture under static loading, and the data is processed by using the acoustic emission damage location principle to realize the real-time display of the specific location of the damage point on the specimen. It is found that the position shown by the test data is approximately the same as the actual damage position of the GFRP tube. The test indicates that the damage position of GFRP tube under static force can be displayed in real time in three dimensions through acoustic emission technology.