Volume 1, Issue 1 — Year 2024 — Article e100010

Negar Salehi Alamdari¹; Hamid Reza Azizi Pestehbaglo²

1. Department of Civil Engineering, University of Roshdiyeh, Tabriz 5158464918, Iran
2. Department of Civil Engineering, University of Roshdiyeh, Tabriz 5158464918, Iran

Soil behavior can be categorized into two types: on-site soil behavior and reconstituted soil behavior in the lab. The stronger the soil structure, the greater the difference between these two behaviors. This structural strength results in a higher porosity at the same stress levels and divides soil behavior into elastic and plastic parts. To model structured soil behavior, various constitutive models have been developed, with many based on the cam-clay and modified cam-clay models. However, these models differ in integration and lack accuracy under varying stress levels. In this study, a modified cam-clay model is used to simulate structured clays. The model incorporates unstructured soil parameters and introduces modifications to account for hardening-softening behavior using initial yield pressure and other structured soil parameters. Simulations of triaxial tests show that the proposed model provides accurate predictions of structured soil behavior. Since most existing models in commercial software focus on unstructured soils, there has been limited research on practical problems involving structured soils. This paper applies the proposed model to 3D finite element software to study settlement due to tunnel drilling, showing excellent accuracy compared to other analytical methods.

Structured soil, Cam-clay model, Finite element method, Tunnel drilling