La presente monograf?a busc? mejorar la resistencia de un suelo Limoso, esto se logr? mediante la adici?n de fibras rectangulares de PET (Polietileno Tereftalato) con dimensiones aproximadas de 2 por 3,5 mm. Se prepararon en total 45 probetas 3 para cada caso y 3 ensayos para los diferentes porcentajes de fibras a adicionar (0.5%, 1%, 1.5%, 2% del peso del suelo) con las cuales se realiz? el ensayo de compresi?n inconfinada. Al realizar los ensayos de compresi?n inconfinada con suelo natural y a las que se les adiciono fibras de PET, se pudo observar que la implementaci?n de las fibras a un suelo fino efectivamente mejora las propiedades mec?nicas de dicho suelo.The present monograph sought to improve the resistance of a muddy soil, this was achieved by adding rectangular PET (Polyethylene Terephthalate) fibers with approximate dimensions of 2 by 3.5 mm. A total of 45 specimens 3 were prepared for each case and 3 tests for the different percentages of fibers to be added (0.5%, 1%, 1.5%, 2% of the soil weight) with which the unconfined compression test was performed. When carrying out the unconfined compression tests with natural soil and to which PET fibers were added, it was observed that the implementation of the fibers to a fine soil effectively improves the mechanical properties of said soil.