ABSTRACT
The construction of jet-grouting plugs is a common practice to carry out underground works, such as underground lines, underpasses, shafts, etc. Many times, these constructions are developed in clayey soils with low resistance capacity, where the open excavations are carried out below the water table. This situation makes necessary to carry out very deep walls to avoid uplift of the bottom slab. To shorten the length of the walls and guarantee the stability of the bottom slab, it is possible to execute jet-grouting column plugs, improving the stiffness of the wall embedment level and the waterproofing of the excavation, as well as ensuring that the bottom uplift does not occur due to water pressure. This article presents a new method to analyse the uplift of the jet-grouting plugs, based on an analytical calculation of the wall-plug system, assimilating the behaviour of the jet-grouting plug to a thick beam subjected to uniformly distributed pressure. Also, a study of the same problem has been carried out using numerical modelling through the finite element method, that confirms that both numerical and analytical models result in similar stress fields at the wall/ jet-grouting plug interface.
