DESIGN OFMICROPILESFORLANDSLIDE RISK REDUCTION

Abstract

Slope stabilization is crucial for civil engineering projects to prevent slope failures and landslides. Among the various methods available, micropiles have gained popularity due to their unique advantages. Micropiles are slender, high-capacity, drilled-in-place elements with a diameter of less than 300mm. They offer greater flexibility in design and installation compared to traditional piles, can be installed in limited access areas, and are less prone to damage during installation. This study focuses on the use of micropiles for slope stabilization and delves into the design philosophies associated with them. The arching effect, which involves redistributing soil stresses around micropiles, especially for debris slides, is identified as a critical factor in determining micropile spacing. The literature review conducted in this research highlights the significance of the arching effect and presents various design strategies to determine micropile spacing based on this effect. An experimental program was carried out to investigate the impact of arching on micropile spacing. This program determined the maximum spacing for micropiles while considering the arching effect. Empirical calculations were employed to determine the lateral force acting on the micropiles. Furthermore, charts were developed to simplify the calculation of lateral resistance by establishing a relationship between the lateral resistance and the earth pressure acting on the micropile. A design example for micropiles, following the procedure provided by the FHWA method (2005), is presented in this research. This example encompasses all the necessary calculations for designing micro-piled reinforced slopes. The findings of this research offer valuable insights into the design of micropile-supported slopes. The results from the experimental program and the lateral force calculations can serve as a reference for future slope stabilization projects. The research highlights the importance of the arching effect and provides design strategies that contribute to the stability and safety of slopes. The developed charts for calculating lateral resistance provide an efficient method for designing micropiles, ensuring accuracy and efficiency in the designs of designers and engineers.