Reinforcement of sandy soil performance to supporting shallow footing under eccentrically-inclined load: A review

• Main Authors: Ali, Jumana Y. M., Al-Saidi, A’amal A. H.
• Format: Conference Proceeding
• Language: English
• Subjects: Carrying capacity; Columns (structural); Earth reinforcement; Eccentric loads; Eccentricity; Failure modes; Footings; Frame structures; Inclination; Machine foundations; Optimization; Reinforcement; Retaining walls; Sandy soils
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0186177

In various structures, such as retaining walls, columns, portal framed buildings, property line footings, and machine foundations, footings may be subjected to inclined loads, eccentric loads, or both. Its impact on footing carrying capacity is concerning. So, understanding the performance of the soil is crucial whenever the footing is exposed to eccentric and inclined loads. The inclined load raises the horizontal displacement of the footing, which causes slip failure. In contrast, the eccentric load causes non-uniform pressure under the footing and increases with increasing eccentricity leading to decreasing the carrying capacity of the footing. This increases the size of the footing and makes the design uneconomical. The issue is compounded if the soil is poor; thus, a mechanism to enhance it and prevent footing failure must be provided. This study examines the performance and behavior of several shallow footings that withstand inclined and eccentric loads and rest on weak sandy soils, and are reinforced to enhance their characteristics and carrying capacity. In addition to assessing the concept of reinforced earth and its mechanism, interaction with soil, and failure modes, a literature study reveals that under eccentric-inclined loads, the optimal number of geogrid reinforcement layers is N=3-5, and the optimum depth ratio for the first reinforcement layer is u/B=0.20-0.35. The inclination and eccentricity of the load severely minimize the foundation’s carrying capacity, while the reinforcement minimizes the horizontal displacement and footing tilt. Also, There have been few restricted investigations on the combined impacts of eccentricity and inclination loads on ring footing.