This book focuses on the engineering properties of unsaturated widely graded soils and their influence on slope stability. This book characterizes the natural widely graded colluvial soils from macroscale, mesoscale, and microscale viewpoints, introduces the techniques for measuring hydro-mechanical properties for unsaturated widely graded colluvial soils, and clarifies the hydro-mechanical behavior and the failure mechanism of widely graded colluvial soils subjected to environmental loads. This book improves the understanding of rainfall-induced landslides on natural slopes. Researchers and engineers in the field of civil engineering can benefit from the book.

Li Xu is a professor, doctoral supervisor, director of the geotechnical laboratory, and director of the Subgrade Engineering Research Institute of Beijing Jiaotong University. He mainly engaged in traffic geotechnical engineering, special soil mechanics, numerical calculation of geotechnical engineering, and risk assessment. He received the first "Huang Wenxi - Chen Zongji" Geo-mechanics Youth Award and the first prize in natural science from the Ministry of Education. Dr. Li is an author of over 70 international journal papers.