Nuevo mortero compresible para excavaciones ejecutadas con tuneladoras de escudo (TBM)

Abstract

This paper describes a new compressible mortar for excavations executed using Tunnel Boring Machine (TBM). Previous studies by different researchers establish the importance of considering pre-existing deformations and efforts history in the analysis of excavations, which requires a numerical model. Therefore, the objective of this article is to develop a new compressible mortar for filling between land and supporting that minimizes solicitations and makes displacements compatible. For this, the materials were characterized and the dosages to be tested were considered, estimating the ranges with Taguchi. A new test of the confined material was designed, for then manufactured and tested it. On the other hand, a numerical model was developed considering: land, mortar, invert precast concrete, water table, hydrostatic overpressures and progress of the TBM. Subsequently, different scenarios were simulated for short and long term, varying types of rock and disintegration rates, among others. Finally, similarities were found between the results for both terms, obtaining a good response from practically all mixtures (especially M7 and M8), which achieved a lower transmission of tensions. For all these reasons, the conclusion is that the new mortar makes it possible to combine displacements in the system, reducing deadlines, increasing security, and optimizing material volumes.