Department of Civil Engineering

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Static And Dynamic Analysis Of 2d And 3d Structures Using Python Scripts In Opensees
(Department of Civil Engineering, NITS, 2022) Vishal, Rebba
It is generally accepted that most building structures shall exhibit a nonlinear response when subjected to medium-high intensity earthquakes. It is currently known, however, that this phenomenon is not properly modelled in the majority of cases, especially at the design stage, where only simple linear methods have effectively been used. Recently, as a result of the exponential progress of computational tools, nonlinear modelling and analysis have gradually been brought to a more promising level. A wide range of modelling alternatives developed over the years is hence at the designer’s disposal for the seismic design and assessment of engineering structures. The objective of the study presented herein is to test some of these models in an existing structure, and observe their performance in nonlinear static and dynamic analyses. This evaluation is done by the use of a known range of advanced finite element software opensees. In this study a one bay portal frame and reinforced concrete building is considered for the study and analysed for the static and dynamic loads. To study the behaviour of the structure under earthquake loading five real ground motion data are considered.
Performance Evaluation Of Microsurfacing Mix Containing Reclaimed Asphalt Pavement
(Department of Civil Engineering, NITS, 2022) Kumar, Kallempudi Pavan Mahesh
The current size of the road network, along with a lack of adequate funds for its renovation, has prompted the development of technologies for repairing and maintaining existing pavements. Microsurfacing is one of the most advanced pavement surface treatments available, capable of treating a wide range of pavement distresses while also having a longer shelf life than other options. In this case, RAP materials created during the maintenance and rehabilitation of asphalt pavements can be consumed as part of the required materials in the same process, minimizing material costs and difficulties caused by RAP production. Sustainability, economic benefit, reduced pollution, and the preservation of natural resources are all aspects that encourage the reuse of RAP. We receive largely fine aggregates when we remove the RAP material from the old pavement, which are needed for the microsurfacing mix. The tensile strength of microsurfacing mixtures is one of the most important factors in pavement deterioration and collapse. As a result, the effects of reinforcing microsurfacing mixtures with polypropylene fibres, as well as their engineering performance, were explored in this work. In this investigation, RAP aggregates contained small contaminants, according to FTIR measurements. As a result, these aggregates can be classified as medium-quality aggregates, and the presence of morphological matter in RAP qualifies them for microsurfacing. As a virgin binder, cationic slow setting bitumen emulsion CSS-1 is used. Because a polymer modified emulsion is required for microsurfacing, the emulsion is modified by adding 5% SBS polymer rubber to increase the emulsion's characteristics. The use of fiber reinforcement in microsurfacing improves the performance properties of the material. In the entire investigation, 0.2 % polypropylene fiber by weight of total microsurfacing mix is considered. Various physical property testing for natural and RAP aggregates were conducted, including abrasion value, specific gravity, and water absorption tests. The obtained are in the permissible limit hence we can use directly in the mix. It is carried out penetration test, ductility value, softening point, and specific gravity for bitumen emulsion. The flow value of the mix is increased by adding superplasticizers, and the water content is increased by adding RAP. Increased water content and superplasticizers in the microsurfacing mix alleviate the balling effect problem caused by fibers and fine particles. To determine the performance parameters of microsurfacing mix with various percentages of RAP replacement, prepared specimens are evaluated for marshal stability, ITS, cantabro abrasion loss, and static creep test. The ideal emulsion content for the microsurfacing mix is calculated using an average of the emulsion contents achieved at Marshall stability, 4% air voids, and a bulk density of 13.33 %, which can be used for future testing with RAP aggregates. In comparison to other combinations of mixes with RAP replacement, the results indice 45% as the optimum RAP replacement percentage that can replace conventional aggregates in microsurfacing mixes because it showed the best overall performance in terms of volumetric properties and performance tests. ln comparison to other RAP-replacement mixtures that have been examined So, if a higher percentage of RAP is necessary, we can use up to 45% without compromising the microsurfacing mix's desired performance. Improved RAP material usage could be a critical step in developing long-term pavement infrastructure.
Evaluating The Efect Of Fly Ash Pellets As A Replacement Of Aggregates In Pavement Quality Concrete
(Department of Civil Engineering, NITS, 2022) Javeed, Mohammed
Concrete is fundamentally a man-made mixture comprising aggregates which are 70 to 80 percent of the volume of concrete that is held together by a cementing phase. Aggregates are one of the largest used materials globally. Due to the extraction of the aggregates from the quarry’s it will create an ecological imbalance and natural resources are depleted as a result. The environmental impact of aggregate extraction from a quarry is one of the most pressing concerns. Aggregate quarries have a number of negative environmental consequences which consist of, effects on climate, water environment, landscape, natural environment. Throughout the last many years, the demand for natural resources has skyrocketed, as it is firmly connected to the urban area's turn of events and its financial development. Therefore, there is a need to develop a substitute for aggregates and artificial aggregates are one of such alternatives, Fly ash pellets are one of such artificial aggregates that can be used in construction to replace traditional aggregates. Thermal power facilities produce fly ash as a byproduct, India is expanding electricity demand necessitates the use of thermal power plants to generate 70% of the country's electricity. Air pollution from particle emissions, water pollution, and a lack of land for disposing fly ash are among environmental concerns from these plants. the production of fly ash pellets is a good way to put a lot of fly ash to good use.The fly-ash pellets are made in this study using a laboratory procedure (manual) followed by cold bonding curing to get the desired strength to the pellets. Fly ash pellets are prepared in different fly ash and cement ratios using manual method. On comparing the strength properties of the pellets with different ratios 3:1 fly ash (FA) and cement(C) ratio gave the better results. Then the pellets are prepared with 3:1 FA:C with varying percentage of basalt fibers for giving more strength to the pellets, after comparing the results, for 3:1 FA:C ratio the optimum percentage of basalt fibers obtained is 0.5 percent. then for decreasing the water absorption of the pellets, it is treated with the water glass, here, the water glass used is sodium silicate. The treatment of the pellets with the water glass results in decreasing the water absorption about 15 percent. The treated pellets which are prepared with 3:1 FA:C ratio and in pavement quality, basalt fibers are utilized to replace aggregates. concrete. The fly ash pellets as a substitute for coarse aggregates in the percentages of 5%, 10%, 15% and 20% for M40 grade concrete. Following the comparison, with the traditional concrete, the maximum replacement obtained is 15 percent.
Durability analysis of chemically stabilized fiber reinforced clayey soil
(Department of Civil, NITS, 2024-07) Acharjee, Abhash
This study aims to investigate the effect of varying percentages of lime, ground granulated blast furnace slag (GGBS), rice husk ash (RHA) and coir fiber on the Atterberg’s limit and durability of the samples. It was observed that addition of chemical stabilizers reduced the plasticity index of the soil samples rendering the soil less plastic. This could potentially reduce the swelling and shrinkage of clay soil. The incorporation of lime, GGBS or RHA reduced the linear shrinkage of the soil but higher dosage of lime made the soil more brittle indicated by multiple cracks on the surface of the soil sample. It was observed that when part of the soil is replaced with lime, GGBS, RHA and coir fiber and were tested for durability after curing of 28 days by subjecting them to alternating wetting and drying cycles the inclusion of lime, RHA, GGBS and coir fiber facilitates pozzolanic reactions, enhancing soil binding and reducing plasticity. The results show significant improvements in the durability of the treated soils compared to untreated clay. The inclusion of 5% lime, 10% GGBS and 1% coir fiber rendered the best performance after being subjected to wetting drying cycles with a UCS of 743.2 kPa after the 10th cycle and cumulative mass loss of 11.52% of its initial mass after 10th cycle.
Seismic Fragility Analysis Of Multi Span Simply Supported Bridge System
(Department of Civil Engineering, NITS, 2022) Chand, Deep
Bridges are essential lifeline infrastructures that constantly enable mobility and support operations for a society; past earthquakes, such as the 1971 San Fernando earthquake, the 1994 Northridge earthquake, the 1995 Great Hanshin earthquake in Japan, and the 1999 Chi Chi earthquake in Taiwan, have demonstrated that bridges are vulnerable to earthquakes. The seismic vulnerability of highway bridges is usually expressed in fragility curves, which display the conditional probability that the structural demand (structural response) caused by various levels of ground shaking exceeds the structural capacity defined by a damaged state. Fragility curves of structures can be generated empirically and analytically. Empirical fragility curves are usually developed based on the damage reports from past earthquakes, while analytical fragility curves are developed from seismic response analysis of structures, and the resulting fragility curves are verified with actual earthquake data, if available. Since earthquake damage data are very scarce, so analytical method is the only feasible approach to develop fragility curves for structures in this region. This report presents an analytical method for the development of fragility curves of highway bridges. In this method, uncertainties in the parameters used in modelling ground motion, site conditions, and bridges are identified and quantified to establish a set of earthquake-site bridge samples. A incremental dynamic analysis is performed for each earthquake-site-bridge sample to establish the probabilistic characteristics of structural demand as a function of a ground shaking parameter, for example, spectral acceleration or peak ground acceleration. Furthermore, bridge damage states are defined, and the probabilistic characteristics of structural capacity corresponding to each damage state are established. Then, the conditional probabilities that structural demand exceeds structural capacity are computed, and the results are displayed as fragility curves. The advantage of this approach is that the assessment of uncertainties in the modelling parameters can be easily verified and refined. To illustrate the proposed method, the method is applied to a continuous T-beam girder bridge.
Municipal Solid Waste Land fill Site-Hydrological Risk Factors
(National Institute of Technology, Silchar, 2026) Deb, Chandrika
The rapid growth of urban population and waste generation has made the selection of environmentally suitable landfill sites a critical challenge for sustainable solid waste management. This study aims to identify optimal landfill locations in the Silchar Municipal Area using a Geographic Information System (GIS)-based Multi-Criteria Decision Analysis (MCDA) integrated with the Analytic Hierarchy Process (AHP). Multiple environmental, hydrological, and infrastructural parameters—including land use/land cover (LULC), rainfall, groundwater depth, slope, elevation, and proximity to road sand streams—were considered for suitability analysis. Spatial datasets were processed and reclassified into thematic layers, and AHP was employed to assign relative weights to each criterion through pairwise comparison, ensuring a consistent and systematic decision-making framework. The weighted overlay analysis classified the study area into five suitability zones ranging from not suitable to most suitable, leading to the identification of potential landfill sites. To enhance the reliability of the results, a detailed hydrological risk assessment was conducted using stream proximity, rainfall distribution, and ground water depth, highlighting areas prone to contamination risks. Sensitivity analysis was further performed by varying the weights of key criteria, and the results demonstrated minimal variation in site selection, confirming the robustness of the model. Field validation was carried out for the shortlisted sites to verify ground conditions, resulting in the rejection of unsuitable locations and the final selection of the most feasible site. The selected land fill site satisfies both environmental and practical criteria, ensuring minimal impact on surrounding ecosystems. The study presents an integrated and systematic approach that combines spatial analysis, risk assessment, and field verification for reliable landfill site selection. The methodology can serve as a decision-support tool for urban planner sand policy makers in achieving sustainable and environmentally sound solid waste management, particularly in data-limited urban regions
A Two-Stage Method for Damage Detection in Members and Joints of Steel Frames
(National Institute of Technology, Silchar, 2026) Sagar, Sharjid
REAL TIME STRUCTURAL MONITORING BY USING IoT AND ANALYTICAL METHODS
(National Institute of Technology, Silchar, 2026) Bandi, Rohith
Assessing the safety and performance of civil engineering structures requires methods that go beyond periodic visual checks. This study develops a vibration-based structural health monitoring approach that combines IoT-based sensing with analytical evaluation to detect internal changes in structural behavior. ESP32 microcontrollers paired with ADXL345 accelerometers were used to collect real-time vibration data from reinforced concrete slabs. Experiments were conducted on slabs from both an existing and a newly constructed building (Chapter 6). Sensors were fixed at multiple positions, and controlled impacts were applied at different drop heights (50 cm, 100 cm and 150 cm) to generate vibration responses. The recorded data was processed to extract natural frequency and damping ratio using five methods (Chapter 5) Half Power Bandwidth, Logarithmic Decrement, Curve Fit, Phase-Based, and Nyquist Plot. The Half Power Bandwidth method returned the most consistent and accurate results across all test cases. The Logarithmic Decrement and Nyquist Plot methods also performed reliably. Differences in structural condition and material properties between old and new building slabs produced distinct response patterns, which the methods captured clearly (Chapter 7). Contour mapping was used to present frequency and damping values to represent spatially across the floors (Chapter 7). The resulting maps make it straight forward to identify damage locations of changed stiffness or altered energy dissipation through color variations. The results confirm that combining sensor-based data collection, structured analytical methods, and spatial visualization gives a practical framework for monitoring structural behavior and identifying potential issues without depending on visual inspection alone.
Effect of High Temperature on Mode I Intralaminar Fracture Toughness
(National Institute of Technology, Silchar, 2026) Kumar, Pinisetti Praveen
This study explored fracture behaviour of two types of glass-fiber-reinforced polymer (GFRP) – a pultruded I-beam and a hand-layup sheet – behave under high temperature. The pultruded profile contained about 73% glass fiber by weight with three different fiber layers (random mat, combined mat, and unidirectional 0° mat), while the hand-layup laminate had roughly 40% fiber with a 0° core and random outer skins. Mechanical tests showed that both materials are much stronger along the fiber direction than across it. Fracture toughness was measured using single-edge notch bending (SENB) tests at room temperature and after heating to 60 °C, 100 °C, 200 °C, and 300 °C. At room temperature, the critical stress intensity factor (K1c) was 26.5 MPa·mm1/2 for the profile and 22.6 MPa·mm1/2 for the laminate. After heating, the peak load rose slightly at 100 °C (possibly from extra curing) but fell sharply at 200 °C and 300 °C due to matrix breakdown; at 400 °C the resin melted completely. A 2D Abaqus model using CPS4R elements for the bulk GFRP and COH2D4 cohesive elements for the crack path, with Hashin damage, successfully reproduced the experimental trend – simulated peak loads dropped from 2.89 kN at room temperature to 0.78 kN at 400 °C. Damage patterns shifted from brittle at low temperatures to more ductile at high temperatures. Overall, GFRP works well up to about 200 °C, and the numerical model provides a useful way to predict its fracture behaviour under heat.
Development of CMIP6 Based Data-driven Rainfall Models Using Machine Learning and Deep Learningfor Early Detection of Future Extreme Events
(National Institute of Technology, Silchar, 2026) Phukan, Annwesha
Computational Modelling of Fluid Flow through Non-Isothermal Discrete Fracture Network in Enhanced Geothermal Systems
(National Institute of Technology, Silchar, 2026) Hazarika, Rishabh
TRENCH ISOLATION SYSTEM FOR SCREENING OF VIBRATION COMING FROM TRAIN LOAD TO A BUILDING
(National Institute of Technology, Silchar, 2026) HUSSAIN, GULZAR
Railway induced ground vibration has become an important issue due to the increasing movement of trains near residential and commercial structures. Vibrations generated from train movement propagate through the soil and may affect nearby buildings, foundations, and occupants. Continuous exposure to vibration can lead to discomfort, reduction in serviceability, and possible structural problems. The present study investigates the effectiveness of trench isolation systems for reducing railway induced ground vibration using finite element modelling in ABAQUS. Field investigation and laboratory testing were carried out to determine the engineering properties of the soil. Soil parameters required for numerical analysis were obtained from Standard Penetration Test (SPT), laboratory tests, and empirical correlations. Field vibration measurements were also conducted using a geophone during train passage to study the actual vibration response near the railway track. These measurements were used to understand the vibration characteristics and compare them with the numerical response obtained from the finite element model. Dynamic implicit analysis was performed in ABAQUS to study the propagation of vibration through soil under train induced loading. Infinite boundary elements were used to minimize artificial reflection of stress waves at the model boundaries. Different trench configurations including single open trench, double open trench, and infilled trench systems with varying trench depths and widths were analyzed. The effectiveness of the trench systems was evaluated in terms of displacement, velocity, acceleration, and Amplitude Reduction Factor (ARF). The results indicate that trench geometry has a significant influence on vibration attenuation behavior. Increase in trench depth and width generally improved vibration reduction performance. Double trench systems showed comparatively better vibration isolation than single trench systems, while infilled trenches also demonstrated noticeable reduction in vibration response under certain conditions.
STABILIZATION OF PEAT USING CALCIUM LIGNOSULFONATE AND RICE HUSK ASH
(National Institute of Technology, Silchar, 2026) Deori, Teenamoni
Peat is viewed as one of the most troublesome geomaterials for use in construction because it is highly organic, highly compressible, and possesses extremely low shear strength, resulting in poor engineering performance and excessive settlement. This study aims to utilize lignin based biopolymer calcium lignosulfonate (CLS) and rice husk ash (RHA) to overcome these challenges. CLS concentrations of 0, 3, 5, and 7% by dry weight of peat were used, while RHA was used as an additional filler at concentrations of 10, 20, and 30%. Laboratory investigations were conducted to evaluate the compaction characteristics, unconfined compressive strength (UCS), pH, electrical conductivity (EC), and durability through wetting-drying (W-D) cycles. Test results indicated that the maximum dry density (MDD) increased due to improved particle aggregation and better packing of the treated peat matrix, along with a slight reduction in optimum moisture content (OMC). A significant improvement in UCS of about 497.02 kPa and 300.5 kPa was achieved at an optimum CLS content of 5% and 20% RHA, respectively, whereas a UCS of 506.28 kPa was achieved by combining both stabilizers at an optimum CLS content of 5% and 20% RHA. Compared to natural untreated peat, which showed a strength of only 7.59 kPa, the addition of CLS and RHA resulted in strength gains of 66-fold and 40-fold, respectively. Meanwhile, the combined effect increased the strength by about 68-fold. This study also demonstrates the variation in elastic modulus (E50) with respect to UCS for both stabilizers. Durability experiments, however, indicated a progressive loss of strength with an increasing number of wetting-drying cycles as a result of mass loss and destabilization of calcium silicate hydrate (CSH) gel. The tests revealed that, after three cycles, visible deterioration and breakage occurred. Furthermore, microstructural analyses using X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), and Energy Dispersive X-ray Spectroscopy (EDX) confirmed peat aggregation and particle densification, which were responsible for the observed strength gain in peat.
Study of Dynamic Parameters for an Existing RC Building including Fluid Viscous Damper
(National Institute of Technology, Silchar, 2026) Barbhuiya, Shah Nawaj
This work examines how well a current six-level concrete structure in Karimganj, Assam withstands shaking during quakes; the area falls into Zone V on India's hazard map (IS 1893 Part 1:2016). Shaped like a long thin rectangle - measuring 46.37 meters by 6.75 meters - it risks large sideways movement when ground motion strikes. Computer simulations ran in ETABS version 18.1.1 produced five versions: one without added supports, another fitted with one type of shock absorber layout, then two setups splitting dampers across different floor groups, finally a model concentrating devices just on lower levels. Each design underwent spectral assessment along the primary horizontal axis, tracking shifts in vibration period, floor-by-floor shift amounts, changes between adjacent level gaps, total base force resistance, plus how rigidity spreads through height. Results highlight variations tied directly to placement strategy. Among the tested setups, the greatest interstorey drift consistently appears at the bottom level across every model. At peak performance, the dual FVD setup slashes drift by 80.0% - dropping values from 0.00762 to 0.00152 - and cuts roof movement by 73.6%, shifting it from 94.5 mm down to 25.0 mm. With noticeably fewer units installed, the lower-floor damper layout still manages a 66.7% drop in drift, reaching 0.00254, along with a 60.5% shrink in displacement, ending at 37.3 mm - a strong balance between savings and impact. Meanwhile, placing dampers higher up barely changes outcomes: drift slips just 9.2% to 0.00692, while base force eases only 8.7%, stepping from 18,926 kN to 17,286 kN, which underscores its weak contribution. Roughly half of the total lateral resistance vanishes when dampers anchor low, regardless of exact arrangement, suggesting minimal added benefit once a strategic minimum is met. Most effective results come when dampers go where movement is greatest - lower levels matter more than quantity. Placing them higher tends to reduce benefit, so upper floors see little advantage. Evidence clearly supports focusing on low-level installation for better performance during quakes. This approach works well for concrete structures of moderate height in active quake regions like northeast India.
VIBRATION CONTROL IN PRESTRESSED CONCRETE (PSC) BOX-GIRDER BRIDGE USING DIFFERENT TYPES OF DAMPER
(National Institute of Technology, Silchar, 2026) HAZARIKA, PRIYANSHU KASHYAP
PERFORMANCE EVALUATION OF GEOPOLYMER CONCRETE INCORPORATING SUGARCANE BAGASSE ASH
(National Institute of Technology, Silchar, 2026) R, Hemachandran
The increasing environmental impact associated with Ordinary Portland Cement (OPC) production has created a need for sustainable alternative construction materials. Geopolymer concrete has emerged as an eco-friendly material due to its lower carbon emissions and effective utilization of industrial and agricultural waste materials. In this study, Sugarcane Bagasse Ash (SCBA), an agricultural waste obtained from sugar industries, was used as a partial replacement for fly ash in geopolymer concrete to evaluate its mechanical and flexural behaviour under ambient curing conditions. Initially, geopolymer mortar cubes with different SCBA replacement levels were prepared to determine the optimum binder composition based on compressive strength. From the mortar optimization study, 20% SCBA replacement in the total binder content was identified as the optimum level. Based on the optimized mix, geopolymer concrete specimens and reinforced concrete beams were prepared using 20% SCBA, 30% fly ash and 50% GGBS. A geopolymer control mix containing 50% fly ash and 50% GGBS, along with conventional M30 grade concrete, was also prepared for comparison. The mechanical properties of concrete were evaluated through compressive strength, split tensile strength and flexural strength tests at 28 days. The geopolymer control mix achieved a compressive strength of 42.8 MPa, while the SCBA-based geopolymer concrete attained 39.1 MPa, which was higher than the conventional concrete strength of 37.6 MPa. Geopolymer concrete specimens also exhibited improved tensile and flexural strengths compared to conventional concrete. The flexural behaviour of reinforced concrete beams was studied under four-point static loading conditions. The geopolymer concrete beams exhibited improved flexural performance, delayed crack initiation, stable crack propagation and good ductile behaviour compared to the conventional RCC beam. Analytical modelling carried out using ANSYS Workbench showed behaviour similar to the experimental investigation with acceptable variation in results. The study demonstrates that SCBA can be effectively utilized as a sustainable supplementary geopolymer binder material for reinforced concrete applications without significant reduction in structural performance
Modelling and Predicting Local Weather Condition Using UAV-Based Sensors Networks
(National Institute of Technology, Silchar, 2026) Mangte, Haoneihling Jarvis
ASSESSMENT OF ROAD CONNECTIVITY USING GIS: A CASE STUDY OF HAILAKANDI DISTRICT
(National Institute of Technology, Silchar, 2026) Chauhan, Rohit
In most districts in India, the existing road network is unable to meet the increasing travel demand. Effective utilisation is required due to the transportation system's high development costs, and this can only be achieved with proper connectivity. In this study, an attempt was made to analyse and evaluate the road network structure of Hailakandi District in terms of its connectivity and coverage. The District was analysed three times, considering different types of analytical units, i.e., District, Blocks and Grids of 10 sq. Km, and a comparison was made among the results obtained using different analytical units. This comparison highlighted errors that occurred when using a smaller area size as analytical units in connectivity analysis. Hence, this research suggested that the analytical area should be kept as large as operationally feasible. Also, this research sought to improve the existing methodology for connectivity analysis by introducing a new index, the c-index that accounts for the effect of road category. Based on the findings, a set of recommendations was also proposed.
STRUCTURAL DAMAGE IDENTIFICATION USING OPTIMIZATION TECHNIQUES
(National Institute of Technology, Silchar, 2026) HUSSAIN, ALTHAF
The present study investigates model-based vibration damage identification through an inverse finite element (FE) updating framework. Structural damage is characterized as a reduction in elemental stiffness parameters and identified by minimizing discrepancies between measured and numerically simulated dynamic responses. The inverse problem is formulated by updating stiffness-related properties to match modal and frequency-domain characteristics of the structure. A progressive modeling strategy was used to assess the performance and robustness of the inverse algorithms as the structural fidelity increases: initially using an Euler–Bernoulli beam model to assess optimization performance for bending-dominated behavior, extending the formulation to Timoshenko beam theory to account for shear deformation and rotary inertia effects for improved dynamic accuracy, and finally generalizing the methodology to a two-dimensional frame model to capture axial–bending interaction and geometric transformation effects for assessing damage localization in redundant structural systems. The damage identification problem was generated as a nonlinear optimization problem and solved using global metaheuristic algorithms, namely Particle Swarm Optimization (PSO), Genetic Algorithm (GA), Simulated Annealing (SA), Teaching–Learning Based Optimization (TLBO), and Differential Evolution (DE). Three objective functions based on the frequency residual, Modal Assurance Criterion (MAC), and Frequency Response Function (FRF) have been considered to study the sensitivity of various vibration measures. Damage characterization was considered at both the elemental and zonal levels, where a two-step zonal analysis was proposed to improve localization and prevent false positives. Noise perturbation was also considered for frequencies, MAC, and FRFs to test the effectiveness under practical uncertainties. To alleviate the high computational load posed by the repetitive FE analysis during each iteration of the optimization process, a surrogate model was incorporated within the methodology. A non-parametric mapping between the damage parameters and the structure’s response was established through structured sampling of damage configurations and GP-based regression modeling. The surrogate model substitutes the FE model in the evaluation of the objective function, thus providing fast predictions of modal properties with accuracy
LOAD-SETTLEMENT STUDY OF SKIRTED FOOTING RESTED ON STONE COLUMN IMPROVED CLAYEY SOIL
(National Institute of Technology, Silchar, 2026) Das, Nisha

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