Seasonal Dynamics in Soil Properties Along a Roadway Corridor: A Network Analysis Approach

Area of Science:

• Geotechnical Engineering
• Soil Mechanics
• Civil Engineering

Background:

• Understanding soil property variability is crucial for effective road construction and maintenance.
• Seasonal changes significantly influence soil characteristics, impacting infrastructure stability.
• Optimizing road design requires knowledge of soil behavior under varying moisture conditions.

Purpose of the Study:

• To investigate the seasonal variability of soil properties along a roadway in Maiduguri, Nigeria.
• To analyze the impact of wet and dry seasons on key soil parameters.
• To assess the structural differences in soil networks between seasons using network analysis.

Main Methods:

• Geotechnical testing of nine soil parameters at 25 stations across wet and dry seasons.
• Application of network analysis with z-score standardization and similarity metrics.
• Multi-threshold analysis (θ = 0.05, 0.10, 0.15) to evaluate network structures.

Main Results:

• Significant seasonal differences observed in Atterberg limits, compaction characteristics (MDD, OMC), and California Bearing Ratio (CBR).
• Wet season soils showed higher plasticity and lower CBR (18.9%) compared to dry season soils (27.5%).
• Network analysis revealed structural differences, with wet season networks showing reduced connectivity and density.

Conclusions:

• Seasonal moisture variations critically alter soil properties, influencing road design and performance.
• Adaptive road design is essential, recommending moisture-resistant materials for wet seasons and optimized compaction for dry periods.
• Soil classification shifted from A-4(1)/ML in the wet season to A-2(1)/SM in the dry season due to moisture-induced plasticity changes.