Pile foundations are essential to transmit structural loads to the underlying soils and rocks. Piles may functionally or accidently be subjected to lateral soil movements, most often due to the slope's failing nature, deep excavation, soil liquefaction and seismic activities, which significantly affect its stability and safety. This study uses PLAXIS 3D software to predict the response of pile foundations subjected to lateral soil movements. Two case studies were analysed to validate the predictive ability of the software, to test the sensitivity of the input parameters, and to serve as a practical guide for the selection of the parameters in case of lack of availability of complete in-situ information. The behaviour of soil-pile interaction in different types of soils, particularly clay soils, was also considered. The results underline the importance of advanced modelling and accurate parameter selection for the stability and reliability of pile foundations under passive loading and lateral soil movement conditions.
This study investigates the application of Ordinary Stone Columns (OSCs) and Geogrid-Encased Stone Columns (GESCs) in enhancing the properties of soft clay soils through numerical analysis using PLAXIS 3D (version 2024). The study contrasts numerical findings with two well-researched field case studies: one in Korea and one in Iraq. The analyses were calibrated using the Mohr-Coulomb and Hardening Soil models, and settlement responses were assessed for different reinforcement scenarios, including untreated soil, OSCs, and GESCs. The results show a strong match between PLAXIS 3D simulations and field measurements, confirming the method's reliability. In the floating case (in Iraq), OSCs increased load-bearing capacity by about 21%, while GESCs improved it by around 30% compared to untreated soft clay. For the end-bearing case (in Korea), even greater enhancements were recorded, with OSCs increasing the bearing capacity by nearly doubling it and GESCs by almost 2.5 times compared to untreated soil. Geogrid encasement is presented as significantly improving settlement control and bearing capacity, with PLAXIS 3D proving to be an important design aid in geoground improvement systems.
As infrastructure development accelerates, ensuring the quality of the subbase layer in roadworks has become increasingly vital. Among various evaluation tools, the Dynamic Cone Penetration (DCP) test is widely recognized for its practical advantages—namely its ease of use, affordability, and ability to deliver real-time, continuous assessments of soil strength directly on-site without disturbing the ground. The research involved conducting both DCP and SRM tests on subbase materials classified as types B, C, and D, which are frequently utilized in Basra’s Road construction. The investigation measured parameters such as the Dynamic Cone Penetration Index (DCPI), moisture content, and dry density under three distinct moisture conditions, all assessed within a controlled laboratory setting. Results were analyzed using SPSS (version 27), revealing a strong inverse relationship between dry density and DCPI, A direct correlation between DCPI and moisture content and between moisture content and dry density. Three predictive equations were developed for each subbase type. The approach has proven to streamline testing processes by minimizing time and resource demands, making it a credible and efficient alternative to conventional subgrade resistance methods for field-based soil assessment.