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Probability-Based Assessment of Soil Liquefaction Potential using Artificial Neural Network
(National Institute of Technology, Silchar, 2026) Waikhom, Sonali
LOAD-SETTLEMENT BEHAVIOUR OF CLAYEY SOIL REINFORCED WITH FLY-ASH + LIME + CLAY COLUMN
(National Institute of Technology, Silchar, 2026) Baruah , Jubilee
Deep-seated medium-soft cohesive soil possess major difficulties in geotechnical engineering because of weak shear-resistance, low-bearing capacity, high compressibility, and tendency to undergo excessive settlement. This study focuses on the utilization of fly-ash which is a waste byproduct in geotechnical application to improve the clayey soil at a reasonable cost and also to provide environmentally sustainable alternative solution. The present study highlights the utilization of fly-ash along with the combination of lime and clay for the construction of Fly-ash+Lime+Clay (FLC) Columns to improve the load carrying capacities of the cohesive soils. The objectives of this study are to firstly determine the optimum percentage of fly-ash, lime and clay to prepare the FLC column. Secondly, to determine the load-settlement behaviour shallow foundation rested on Fly-ash+Lime+Clay column embedded in clayey soil bed by experimental investigation. Another objective is to study the effect of length, spacing, number and confinement of FLC column through numerical analysis using PLAXIS-3D software. To achieve the medium-soft consistency of clayey soil bed UCS sample were prepared at different water content and observed that at 43% water content clay soil attains the UCS value of 29.42 kPa that falls under the medium soft category. To achieve the desired proportion of FLC mix, clayey soil was blended with varying percentages of fly-ash and lime, UCS samples were prepared and tested after curing of 7, 14, and 28 days. The optimum proportion of the FLC mix was found to be 47% Fly-ash, 3% Lime and 50% Clay (F47L3C50). A test-tank of dimension 1m³ was filled with medium-soft cohesive soil up to a depth of 0.9m, and vertical load test was performed on a shallow-foundation of size 0.3m×0.3m×0.05m to determine its capacity. Two FLC column configurations, single and square group with 3D spacing were constructed in clay soil bed, each with a uniform diameter (D) of 50mm and with varying L/D ratios of 6, 8, and 10. Vertical load tests were performed on shallow-foundation of same size rested over FLC column improved clayey soil to determine its capacity. The ultimate load obtained from load settlement graphs demonstrated improvement of capacity as 33.83%, 48.69%, 78.81%, 123.05%, 149.07% and 182.16% respectively for the L/D ratios of 6, 8 and 10, for both single and group column. The load-improvement factor was evaluated for settlements of 5 to 50 mm and the settlement reduction factor was determined for applied loads of 0.2 to 0.8 kN. Load-sharing behaviour between shallow-foundation and FLC column was also evaluated. PLAXIS-3D software was used to perform the parametric study where the effect of length, spacing and pattern of FLC column rested on medium-soft clay bed was studied. The efficiency of FLC column with varying length and spacing was also evaluated. Finally, after summarizing all the results the optimum L/D ratio was fixed as 10, spacing as 2D, and the pattern as square. The findings from both the experimental load tests and the numerical simulations provide practical insights for designing efficient deep stabilization methods for medium-soft clay foundations, ensuring improved strength and load-bearing capacity.
GROUND RESPONSE ANALYSIS AND LIQUEFACTION POTENTIAL AT TWO BRIDGE SITES IN SILCHAR TOWN
(National Institute of Technology, Silchar, 2026) NATH, SNEHASISH
Silchar, in southern Assam, is the state's second most densely inhabited city, with an economy cantered on agriculture, forestry, and tea cultivation. The current study focuses on ground response analysis and liquefaction potential assessment at two key bridge sites: Itkholaghat and Sadarghat. Subsurface soil conditions were characterized using detailed geotechnical data from eight boreholes across these sites collected from the Public Works Department (PWD) of Assam. Ground response analysis was carried out with the SHAKE2000 software, which included a typical acceleration time history from a Mw 7.2 Indo-Burma region earthquake obtained from the COSMOS Virtual Data Centre. The peak ground acceleration (PGA) values obtained were then used to determine the liquefaction potential of the soil profiles. The analysis shows that most boreholes are highly susceptible to liquefaction, particularly at shallow depths, due to the presence of loose, moist soil layers. Borehole 5 (BH5) at the Sadarghat bridge site, on the other hand, shows significant resistance to liquefaction up to 30 m deep, most likely due to denser or more cohesive soil strata. Furthermore, the study considers the impact of seasonal groundwater table variations, which is an important aspect in liquefaction assessment. It was discovered that as the groundwater table rises closer to the ground surface—particularly during monsoon seasons—the likelihood and severity of liquefaction increase significantly. These findings emphasize the significance of site-specific geotechnical evaluation and groundwater concerns in seismic risk assessment and infrastructure design in the region.
Comparative Fatigue Life Assessment of Beryllium Copper and Stainless-Steel Wave Spring for Automobile Suspension System
(National Institute of Technology, Silchar, 2026) Fayaz, Mohammed
Shock absorber springs are critical for mitigating kinetic energy in suspension systems.While wave springs offer a compact, lightweight alternative to traditional coil springs for space constrained applications, their sharp cross-sectional edges often cause higher stress concentrations. To address this, this study compares the performance of Beryllium Copper(C17200) and Stainless Steel(ASTM A313) wave springs under an ISO 8608 road profile using random vibration analysis. Evaluated the fatigue life through the Steinberg formulation and S-N approach, the Beryllium Copper(C17200) wave spring demonstrates an 15% improvement in fatigue life over the Stainless Steel (ASTM A313). And the BeCu(C17200) wave spring provides approximately 16% lower total life cycle cost than stainless steel(ASTM A313). These findings make an attempt to select the best material for automotive suspension system.
EFFICIENT REMOVAL OF CATIONIC SURFACTANT FROM AQUEOUS SOLUTIONS USING ALGINATE MORINGA COMPOSITE BEAD IN HYDROGEL AND DRY CONDITION.
(National Institute of Technology, Silchar, 2026) SAHU, VIDHAN CHANDRA
VALORIZATION OF INDUSTRIAL WASTES INTO GEOPOLYMER ARTIFICIAL AGGREGATES
(National Institute of Technology, Silchar, 2026) Santhosh, Chaluvadi
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
ENZYME INDUCED CARBONATE PRECIPITATION (EICP) TECHNIQUE USED FOR STABILIZATION OF PEAT
(National Institute of Technology,Silchar, 2026) MAZUMDAR, PUSPAM
Peat poses severe geotechnical challenges due to its high organic content, excessive compressibility, and extremely low shear strength. To overcome these geotechnical challenges a sustainable bio-mediated stabilization techniques is used i.e. Enzyme-Induced Carbonate Precipitation (EICP). This study aims to evaluate the effectiveness of EICP for stabilizing peat and examining its strength improvement, durability behaviour and microstructural modifications. EICP utilizes free urease enzyme extracted from soybean and urea–calcium chloride cementation solutions at different concentrations of 0.75 M, 1.0 M, and 1.5 M leading to precipitation of calcium carbonate (CaCO3) within peat. Laboratory investigations were carried out to assess urease activity, compaction characteristics, unconfined compressive strength (UCS), calcium carbonate content by Tube test and acid leaching test, pH, electrical conductivity, microstructural analysis and durability test. EICP treatment enhanced the UCS strength to a maximum value of 323 kPa, which is approximately 45 times higher than untreated -peat at an optimum cementation concentration of 1.0 M after 28 days curing, corresponding to a calcium carbonate content of approximately 29%. The maximum calcium carbonate content (CCC%) of 32-33% was observed at 0.75M and 1M concentration. EICP improved stiffness and durability, with microstructural observations of X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) confirming calcite bridging in EICP-treated samples and enhanced particle aggregation.
RESPONSE OF VERTICAL AND BATTER PILE-SUPPORTED MACHINE FOUNDATIONS AGAINST VERTICAL VIBRATIONS: A PROTOTYPE PREDICTION.
(National Institute of Technology, Silchar., 2026) Gifty, Alluri Bunny.
Machine foundations supported on pile systems are subjected to continuous dynamic loads, making vibration control a critical design requirement. This study investigates the dynamic response of vertical and batter pile-supported machine foundations under vertical vibrations using an integrated analytical, experimental, probabilistic, and numerical approach. Analytical formulations based on IS 2974 (Part 3) were developed and calibrated using experimental data from literature. To account for soil variability, Monte Carlo simulation was performed considering randomness in shear modulus, damping, and weak-zone parameters. Numerical validation was carried out using PLAXIS 3D through a pseudo dynamic frequency sweep approach. Results indicate that resonant amplitude increases nonlinearly with excitation intensity, while resonant frequency remains relatively constant for a given configuration. Batter piles exhibit higher amplitudes and lower frequencies compared to vertical piles due to reduced stiffness. Probabilistic analysis reveals that soil variability can increase the predicted amplitude by up to 35%. Among the methods, PLAXIS 3D provided the closest agreement with experimental results. The study also presents design charts for practical estimation of vibration response.
Bearing Capacity Enhancement of Poor Soils Using Floating Stone-Filled Bamboo
(National Institute of Technology,Silchar, 2026) Kumar, Aditya
In this study we have try to investigate Bearing Capacity Enhancement of Poor Soils Using Floating Stone-Filled Bamboo is based on my project work where I tried to understand how soft soil (Clay soil) can be improved in simple and economical way. In starting our main aim to see how bamboo and stone combination behave when placed in soft soil conditions. After completion of several experiments we have to analysis, numerical modelling was carried out and different cases were analysed step by step. During the all process we have to seen, it was observed that some cases shows better load carrying capacity while others not giving that much improvement load bearing capacity. The comparison of results helped to find which arrangement is performing more efficiently. One important thing I noticed is that small change in spacing and depth can affect the overall response in significant way. The results obtained are quite useful for practical ground improvement techniques. In the end, this work gives a better idea about how sustainable materials like bamboo can be used to improve foundation performance in real field conditions.
LOAD-SETTLEMENT STUDY OF SKIRTED FOOTING RESTED ON STONE COLUMN IMPROVED CLAYEY SOIL
(National Institute of Technology, Silchar, 2026) Das, Nisha
Accurate Dynamic Line Rating Forecasting using Quantum Models
(National Institute of Technology,Silchar, 2026) Panmei, Jaojenlung
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.
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.
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
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.
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.
VIBRATION CONTROL IN PRESTRESSED CONCRETE (PSC) BOX-GIRDER BRIDGE USING DIFFERENT TYPES OF DAMPER
(National Institute of Technology, Silchar, 2026) HAZARIKA, PRIYANSHU KASHYAP
Modelling and Predicting Local Weather Condition Using UAV-Based Sensors Networks
(National Institute of Technology, Silchar, 2026) Mangte, Haoneihling Jarvis
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.

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