Vieillissement d’une mousse à base de tensioactif dans un sol sableux-argileux modèle

Abstract

Lubricants are used in the excavation procedure by earth pressure tunneling machines (EPBs). They help to fluidize the soil structure and thus prevent the clay from sticking to the cutting head. Excavated soil is classified as waste and stored in the disposal area. Reuse of this type of soil depends on their state after excavation and their evolution over time. To identify and understand the physical and mechanical evolu tion of excavated soil, a first step is to analyze physi cal evolution of foam on the soil. The foaming agents are characterized by aging which results in a physical modification of the foam. The aim of this study is to analyze the aging of CLB F5TM surfactant based li quid foam mixed with clayey sandy soil. The evolution of the volume of the foam over time shows a rapid degradation of the bubbles that constitute it. The phy sical degradation of the foam in the soil takes more time compared to the foam in the open cell thanks to the protection of bubbles by porous media. A column drainage test was performed to identify the evolution of the foam in the mixture through its effect on inters titial pressure. These tests show that the presence of the foam in the mixture promotes the drainage phe nomenon compared to the case of unconditioned soil.