http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/4 Tue, 02 Jun 2026 00:23:02 GMT 2026-06-02T00:23:02Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7324 Development of standard design methodology for slopes reinforced with plastic pins and Vetiver Grass Shariful Islam, Dr. Mohammad; Kaysaru Zaman Kawshiq, A S M.; 0421042201; 624.162095492/KAY/2025 Slope stability is a critical concern in geotechnical engineering, particularly in regions prone to erosion, shallow failures, and infrastructure instability. This research presents the development of a design methodology for slope stabilization using Vetiver grass and Recycled Plastic Pins (RPP) as a sustainable, cost-effective, and environmentally friendly alternative to conventional stabilization techniques. The study integrates laboratory testing, field monitoring, numerical modeling, and predictive modeling to evaluate the effectiveness of Vetiver and RPP in improving slope stability. The research begins with soil characterization through laboratory testing, assessing index properties, engineering properties, and chemical characteristics of different soil samples. Three soil types were analyzed: Tahirpur soil, classified as clayey silt with high plasticity, consisting of 84% silt and 16% clay, requiring pH adjustment for optimal vegetation growth. Dacope soil, categorized as lean clay with moderate plasticity, contained 73% silt and 27% clay but exhibited high salinity (ECe = 9 dS/m), making it challenging for plant survival. Chilmari soil, identified as silty sand with 60% sand, 35% silt, and 5% clay. Field monitoring of Vetiver growth at two sites, Dacope (Khulna) and Chilmari (Kurigram), demonstrated Vetiver’s ability to thrive in saline and nutrient-deficient soils. Survival rates exceeded 75% in high-salinity conditions and reached 95% in sandy soil. Growth data indicated shoot lengths of up to 213 cm and root penetration extending to 70 cm, confirming Vetiver’s strong anchorage and effectiveness in erosion control. To enhance real-time assessment of soil movement, moisture content, and reinforcement performance, an IoT-based monitoring framework was conceptually introduced. Numerical analysis using PLAXIS 2D was performed to assess the effectiveness of Vetiver and RPP reinforcement. The results were validated against conventional method of slices. A parametric study was conducted to evaluate the influence of slope geometry, soil strength, reinforcement depth, plant age, and spacing on stability. The findings revealed that increasing the slope angle from 20° to 60° led to a 61% decrease in FS, indicating the vulnerability of steeper slopes to failure. Soil cohesion played a crucial role in stability, as an increase from 0 to 20 kPa resulted in a 126% improvement in FS, confirming that cohesive soils provide better stability. The effectiveness of Vetiver reinforcement was strongly correlated with plant age, with a 62% increase in stability observed after two years due to deeper root penetration. Denser Vetiver and RPP spacing configurations contributed to higher FS values, while wider spacing reduced reinforcement effectiveness. The optimal RPP length was determined to be up to 2.0 meters for RPP alone, beyond which additional length yielded diminishing returns, but with vetiver deeper RPP lengths provided additional 16% improvement of FS when length was increased from 2 to 3 meters. To develop a practical design tool, Multi-Linear Regression (MLR) and Artificial Neural Network (ANN) models were formulated for FS prediction. A cost analysis demonstrated that Vetiver and RPP reinforcement was significantly more economical than conventional concrete-based stabilization methods, reducing costs by up to 56%. The Vetiver and RPP hybrid system had more cost-to-performance ratio, making it a viable solution for large-scale slope protection projects. Sat, 15 Mar 2025 00:00:00 GMT http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7324 2025-03-15T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7323 An automated walking guide to assist way-finding and situation awareness for the visually impaired Liakot Ali, Dr. Md.; Sheezanul Hassan; 1018312010; 006.424/SHE/2024 Safe and independent mobility is one of the major daily challenges faced by the visually impaired. To navigate a new area safely, they need to know the location of obstacles and other things in their path. They struggle with object detection and obstacle avoidance, making it challenging to navigate new or unfamiliar situations and be aware of obstacles and their relative positions. However, establishing secure and safe mobility and pathfinding for the visually impaired is a critical issue in their life that must be solved accurately and efficiently. Recognizing currency is another severe problem for them because different notes in our country have similar colors, surfaces and sizes causing major problems for the visually impaired. Object recognition alone may not be sufficient to assist visually impaired individuals effectively. Incorporating lateral position identification can provide users with a sense of spatial orientation within their environment, enabling them to navigate paths toward recognized objects more accurately. In this thesis, a system is proposed to assist visually impaired individuals by identifying both navigation objects and their corresponding lateral positions, and recognizing Bangladeshi currency. This system aims to serve as a comprehensive walking guide, offering benefits for both indoor and outdoor navigation. By enhancing spatial awareness and providing critical information about their surroundings, this system will enable visually impaired users to make informed decisions regarding their movements and actions; thereby, improving their independence and quality of life. The system utilizes EfficientNet, a Convolutional Neural Network architecture for Machine Learning to design a model for currency and navigation objects that can recognize fifteen classes of objects for assisting the visually impaired. The architecture also applies computational logic to the model to identify lateral positions of the navigation objects; and thus conceptualizing a system that can act as a walking guide for visually impaired people aiding navigation and awareness. The model proposed in the system has been evaluated with real-world objects to assess the performance of the proposed method. The experimental analysis demonstrates that the system achieves notable Accuracy, Precision, Recall, and F1 scores, highlighting its prospective relevance and effectiveness in the field. Sat, 19 Oct 2024 00:00:00 GMT http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7323 2024-10-19T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7322 Experimental study on rheological properties of water based drilling fluid and its impact on drilling operations Mahbubur Rahman, Dr. Mohammed; Sumon Chowdhury, Md.; 1018132012; 622.3381/SUM/2024 Most encountered problems like fluid loss, wellbore stability, well control, poor capacity of cuttings transport, poor torque performance, increased drag, and stuck pipe can occur during drilling due to the improper design of the drilling mud, which can increase the cost of drilling. This study looks into the rheological properties of ten water-based drilling mud and their impact on drilling operations. A viscometer is used to conduct the analysis in the laboratory. The density of the prepared mud ranges from 8.7 ppg to 10.01 ppg. This experimental study focuses on determining the viscosity, gel strength, and yield point of ten water-based drilling mud which are formulated under different barite concentrations. The plastic viscosity of the ten mud samples ranges from 10 cp to 18 cp, yield point ranges from 5 lb/100ft2 to 12.75 lb/100ft2 and gel strength ranges from 2 lb/100ft2 to 9 lb/100ft2. The effect of density on viscosity, gel strength, and yield point is also observed in this study. Key findings indicate that the viscosity, gel strength, and yield point of the drilling fluid are significantly influenced by the density of mud at constant pressure and temperature. Five drilling mud rheological models such as Newtonian, Bingham plastic, Power law, API, and Herschel-Bulkley are analyzed to select the most suitable fluid model and measure the total frictional pressure drop in the wellbore, considering the suitable model. The error analysis of experimental/measured shear stress and theoretical/modeled shear stress is done to choose the most perfect fluid model. The minimum error indicates the best fitted rheological fluid model. This study found the error between experimental/measured shear stress and theoretical/modeled shear stress maximum for Newtonian model (7% to 18%) and minimum for API model (up to 0.16%). The mud samples are preferable for the API model to calculate the standpipe or pump pressure. Data matching is done to compare the experimental and real pressure loss data, SBHP and FBHP. There is good scope in the future to study the effect of some chemical additives on the rheological properties of water based drilling mud in different pressure and temperature. Tue, 28 May 2024 00:00:00 GMT http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7322 2024-05-28T00:00:00Z http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7321 Reservoir performance analysis of the gas fields of Bangladesh Mahbubur Rahman, Dr. Mohammed; Nazmul Islam, Md.; 1015132031; 665.773095492/NAZ/2024 Reservoir performance prediction is an iterative process that incorporates various data points, such as production rates, pressure, fluid properties, and geological characteristics. Techniques like decline curve analysis, material balance, and reservoir simulation are commonly used for evaluating a reservoir. The Reserve Performance Indicator (RPI) analyzes parameters such as production rates, pressure data, and fluid properties to evaluate the performance of a reservoir over time. Till now 29 gas fields was discovered in Bangladesh. There isn't any literature or publication that addresses a consistent approach of ranking these reservoirs based on their performance. In this study, an approach is taken to rank the reservoirs according to various indicators used for analyzing the reservoir performance and to identify more prolific and problematic reservoirs. After collecting all the available reports from the public domain (Annual Reports, MIS Reports), reservoirs are ranked by initial reserves, cumulative production (Gas, Condensate), Gas Recovery. The Jalalabad gas field has retrieved more gas than its initial reserve which suggests the necessity of reserve re-estimation. For the majority of discovered fields, the last reserve estimation was completed 14 years ago. Although there is a noticeable reserve in the Kailashtila and Rashidpur fields, just 22.21% and 19.24% of the gas has been recovered, respectively, suggesting that their field development approach is inadequate. Potential gas recovery is possible from these fields. In addition to displaying inadequate development strategies for such fields, only 1 well was drilled in Meghna field during its 26-year production life, while 2 wells were drilled in Narsingdi field over its 27-year production life. Suspended wells of Titas, Habiganj, Bakhrabad, and Kailashtila fields are examined further and the wells of Titas, Bakhrabad, and Kailashtila fields having the potential for workover operation on a priority basis are also identified. Finally, the top 4 fields that are performing well are categorized as Category-I fields, and the 4 fields whose performance was poor and need to change the field development tactics are categorized as Category-II fields. Tue, 28 May 2024 00:00:00 GMT http://lib.buet.ac.bd;localhosthttp://:8080/xmlui/handle/123456789/7321 2024-05-28T00:00:00Z