New prevention and treatment techniques and their applications to landslides and engineering slopes of expansive soils

Expansive soils are widely distributed in China, especially in the regions with high population density. Characterized by the well-known 'three properties', i.e., swelling-shrinkage, cracking and over-consolidation, the expansive soils are highly susceptible to climate change and engineering activities, and thus can easily cause landslides. Due to the lack of consideration to the interactive 'three properties' of the expansive soils, the traditional techniques can hardly be effective for the treatment of expansive soil landslides and engineering slopes, leaving the latter known as 'cancer' that imperils the safety of engineering projects. During the 13th Five-Year Plan period, the National Key Research and Development Program of China "New prevention and treatment techniques and their applications to landslides and engineering slopes of expansive soils" was approved. With special attention to the interactive 'three properties' of the expansive soils, the program has made series of innovations including the instability mechanism and the key disaster factors of expansive soil landslides, multi-field information monitoring and early warning techniques, 'surface-shallow-deep' integrated and ecological reinforcement technique, health diagnosis and rapid restoration techniques for slope protection structures. These techniques are integrated as a technical system and have been implemented in three engineering demonstrations. The relevant achievements have provided new theories, techniques and construction methods for treating the landslides and engineering slopes of the expansive soils. Meanwhile, they have achieved significant social, economic and environmental benefits, with broad application prospects.