On the determination of the at-rest lateral earth pressure coefficient and the state parameter using pushed-in high-resolution Pressuremeters

1. Home
2. Publications
3. Online Library
4. On the determination of the at-rest lateral earth pressure coefficient and the state parameter using pushed-in high-resolution Pressuremeters

The state parameter and the at-rest lateral earth pressure coefficient (K₀) are fundamental and critical soil parameters for evaluating liquefaction, deformations and stresses around geotechnical structures such as dams, tunnels and retaining walls. Despite their importance, their in-situ determination remains one of the most challenging aspects of geotechnical characterisation. This study presents a methodology that integrates pushed-in, high-resolution pressuremeters, finite element modelling and artificial intelligence for determining these two parameters, in spite of the disturbance produced during installation. A cylindrical steel chamber was utilised to accurately control the soil and testing conditions. Initially, the pressuremeter was installed prior to soil placement to create an ideal installation conditions, allowing undisturbed measurement of the at rest lateral earth pressure. Subsequently, the instrument was removed and re-installed by pushing it into the same prepared soil sample. A loose soil condition was achieved through dry pluviation using a controlled clean sand. Additionally, three well documented literature case studies were also analysed, including a self-boring pressuremeter and other two cone pressuremeters (pushed-in pressuremeters).  For every case, the pressuremeter curves were interpreted using the Clay and Sand Constitutive model. The interpreted K₀ and state parameter values showed good agreement with the measured values, demonstrating the method validity. Hence, the present study lays a foundation for enhancing the precision of soil characterisation and improvement for analysis and design of geotechnical structures.

8th International Symposium on Pressuremeters (ISP2025)

Data Interpretation and Analysis