EXPERIMENTAL STUDY OF THE BEHAVIOUR OF THE TREATED LOAD TRANSFER PLATFORM ON RIGID INCLUSIONS

Rigid inclusion (RI) is a ground improvement technique that has been significantly developed in recent years. Granular load transfer platforms (LTP) are commonly used in this technique leading to an increase in the use of natural resources. In this context, soil treatment can be considered as an alternative solution to use the in-situ soil, improve its characteristics and limit the pressure on the granular material resources. As part of the national ASIRI+ project, two full-scale tests were carried out to test the behaviour of treated LTP (with and without a working platform) on rigid inclusions. An experimental program was conducted to fully characterize the soil and find the best treatment for the LTP with consideration for the environmental and economic effects. Then, the tests were carried out in an 8m x 8m pit with 16 rigid inclusions of 30 cm diameter and 1 m height. Settlement and stress sensors were installed to monitor the load transfer mechanisms within the treated platform. The instrumentation allowed us to highlight the load transfer mechanisms within the treated LTP and the negative friction along the RI. It showed that the load transfer was immediate in the case of a treated LTP unlike in the case of a granular LTP where the load transfer mechanisms were slightly more gradual. The results indicated that the treated LTP behaved like a rigid slab with two failure mechanisms observed: punching shear (test 1: without a working platform) and bending failure (test 2: including a working platform).