International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 13 Issue: 05 | May 2026
p-ISSN: 2395-0072
www.irjet.net
LOAD–DEFORMATION BEHAVIOUR OF HYBRID GROUND-IMPROVED CLAY STRATA SUPPORTING SHALLOW FOOTING SYSTEMS Punit Chaurasiya1, Mr. Ushendra Kumar2 1Master of Technology, Civil Engineering, Lucknow Institute of Technology, Lucknow, India
2Head of Department, Department of Civil Engineering, Lucknow Institute of Technology, Lucknow, India
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Abstract -The performance of shallow foundations on soft
foundation performance can lead to structural distress, differential settlement, tilting, or even catastrophic failure. Therefore, understanding the interaction between soil and foundation systems is essential for designing efficient and economical structures. Parameters such as bearing capacity, settlement, and stiffness play a vital role in evaluating foundation performance, particularly in weak soil conditions.
clay is often limited by low bearing capacity and excessive settlement, necessitating effective ground improvement techniques. This study investigates the load–deformation behaviour of hybrid ground-improved clay strata supporting shallow footing systems through a series of controlled laboratory model tests. The research evaluates and compares the performance of untreated clay, soil improved with stone columns, geosynthetic reinforcement, and hybrid systems combining multiple techniques. Plate load tests were conducted to obtain load–settlement responses, from which key parameters such as bearing capacity, stiffness, and settlement characteristics were derived. The results indicate that untreated clay exhibits high compressibility and low loadcarrying capacity, leading to significant deformation under loading. Individual improvement techniques provide moderate enhancement; however, hybrid systems demonstrate substantial improvement due to synergistic effects. The hybrid ground improvement approach resulted in an increase in bearing capacity by approximately 2.5 to 4 times and a reduction in settlement of up to 50–60% compared to untreated soil. Additionally, the stiffness of the soil increased significantly, and the failure mechanism shifted from brittle punching shear to controlled and ductile deformation. The findings highlight the effectiveness of hybrid techniques in improving foundation performance and provide practical insights for the design of shallow foundations on weak clayey soils.
1.1.2 Challenges Posed by Soft Clay Soft clay soils present significant challenges in foundation engineering due to their inherently low shear strength and high compressibility. These soils are unable to support heavy loads without undergoing large deformations, leading to excessive settlement and long-term consolidation issues. Additionally, soft clays are highly sensitive to changes in moisture content, which can further reduce their strength and stiffness. The presence of high pore water pressure and slow drainage characteristics makes their behaviour timedependent, complicating design and analysis. These factors make soft clay deposits unsuitable for supporting shallow foundations without appropriate ground improvement measures.
1.1.3 Limitations of Shallow Foundations on Untreated Clay Shallow foundations constructed on untreated clayey soils often suffer from poor performance due to inadequate bearing capacity and excessive settlement. The applied structural loads tend to induce large vertical deformations, which may exceed permissible limits and affect structural integrity. Furthermore, failure mechanisms such as local shear or punching shear are commonly observed in soft clay, leading to unsafe conditions. The lack of stiffness in untreated clay results in a gradual and uncontrolled deformation pattern, making it difficult to predict failure accurately. These limitations highlight the necessity of improving the engineering properties of clay before the construction of shallow foundations.
Key Words: Hybrid ground improvement; Clay soil; Stone columns; Geosynthetic reinforcement; Load– settlement behaviour; Bearing capacity; Settlement reduction; Shallow foundations
1. INTRODUCTION 1.1 Background 1.1.1 Importance of Foundation Performance in Geotechnical Engineering Foundation performance is a critical aspect of geotechnical engineering, as it governs the safety, stability, and serviceability of civil engineering structures. Foundations act as the primary interface between the superstructure and the supporting soil, ensuring that structural loads are safely transmitted to the ground without exceeding the soil’s bearing capacity or causing excessive settlement. Inadequate
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1.2 Ground Improvement Techniques 1.2.1 Overview of Conventional Techniques Ground improvement techniques are widely employed to enhance the engineering properties of weak soils, particularly soft clay, to make them suitable for construction.
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