Semiempirical Method for Estimation of Pullout Capacity of Grouted Soil Nails in Saturated and Unsaturated Soil Environments

Abstract

The design of soil nail systems used in engineering practice is either based on conventional soil mechanics or empirical procedures, and generally ignores the influence of matric suction. An experimental program was conducted to investigate the influence of matric suction on the pullout capacity of soil nails installed in compacted sand under both saturated and unsaturated conditions. Pullout tests were performed on soil nails installed vertically, horizontally, and at an inclination of 15° to the vertical in a specially designed test box. A strong relationship was observed between the pullout capacity and matric suction. A semiempirical method is proposed for the estimation of the pullout capacity of soil nails by using the average matric suction value and the saturated soil strength parameters,