Failure Probability
George Uwadiegwu Alaneme; Gregory C. Ezeokpube; Elvis M. Mbadike
Abstract
Building-failure usually results to collapse if not discovered and properly addressed. Building-collapse/failure most times cause loss of properties and lives. A case study of a partially-collapsed one-story building is presented for emphasis with technical-assessment of the actual collapse cause so ...
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Building-failure usually results to collapse if not discovered and properly addressed. Building-collapse/failure most times cause loss of properties and lives. A case study of a partially-collapsed one-story building is presented for emphasis with technical-assessment of the actual collapse cause so as to proffer remedy of the structure. This is achieved through detailed engineering-analysis of the building’s structural-elements and identification of remedial-options. Field-inspection through excavation of the soil to assess the foundation condition, taking soil-samples from the collapsed-building for laboratory study and non-destructive test. From inspection, it was observed that the building construction was not properly supervised and as a result were under-reinforced, which led to excessive cracks and deflection. The soil is classified by AASHTO as A-2-4; maximum-dry-density of 2.15mg/m3 and optimum-moisture-content of 9%. The compressive-strength of the structural elements were measured using the rebound-hammer and a mean compressive-strength of 13N/mm2 was obtained which indicates a low-compressive-strength concrete. Analytical-hierarchical-process is utilized as the multi-criteria decision making method to derive the actual cause of the collapse and from the priority vector 6%, 56%, 26% and 12% was obtained for soil/foundation, under-reinforcement, low-compressive-strength and overloading alternatives respectively. The consistency-ratio was obtained to be 0.065 this showed that the decision-maker’s subjective assessment is consistent. The summary of the failure investigation underscored the importance of ensuring proper supervision and quality control in the construction of framed structures. The remediation measures outlined are engagement of experts to re-design the structure using relevant-codes; then cracking, chiseling, and excavation to re-build the structure with thorough supervision.
Risk Assessment
K.K. Kiran; Jagadish G Kori
Abstract
Blast load is an impulse, unpredictable load occurs on the structure. It causes not only damage to the structure but also takes the life of the people. Here an attempt is studied is carried out for a high-rise structure exposed to blast load. The response is calculated by using Adaptative based modal ...
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Blast load is an impulse, unpredictable load occurs on the structure. It causes not only damage to the structure but also takes the life of the people. Here an attempt is studied is carried out for a high-rise structure exposed to blast load. The response is calculated by using Adaptative based modal push over analysis. The responses are storey drift, displacement, velocity, accelerations, pressure, impulse, base shear, interstorey displacement, storey drift ratio and normalized pressure impulse. The three-dimensional analysis is carried out. The response is controlled by using M R damper and cladding material. The different algorithm is used for the analysis of MR damper are Bang Bang, Clipped Optimal, Lyapunov and LQR control algorithm.