Evaluation of geocell-reinforced backfill for airfield pavement repair

After an airfield has been attacked, temporary airfield pavement repairs should be accomplished quickly to restore flight operations. Often, the repairs are made with inadequate materials and insufficient manpower due to limited available resources. Legacy airfield damage repair (ADR) methods for repairing bomb damage consist of using bomb damage debris to fill the crater, followed by placement of crushed stone or rapid-setting flowable fill backfill with a foreign object debris (FOD) cover. While these backfill methods have provided successful results, they are heavily dependent on specific material and equipment resources that are not always readily available. Under emergency conditions, it is desirable to reduce the logistical burden while providing a suitable repair, especially in areas with weak subgrades. Geocells are cellular confinement systems of interconnected cells that can be used to reinforce geotechnical materials. The primary benefit of geocells is that lower quality backfill materials can be used instead of crushed stone to provide a temporary repair. This report summarizes a series of laboratory and field experiments performed to evaluate different geocell materials and geometries in combinations with a variety of soils to verify their effectiveness at supporting heavy aircraft loads. Results provide specific recommendations for using geocell technology for backfill reinforcement for emergency airfield repairs.

Deformation properties of a subgrade in structures reinforced with full displacement piles

Construction of transport infrastructure facilities on weak subgrades requires special soil improvement measures. One of the advanced methods for deep subgrade soil compaction is known to be Full Displacement Piles (FDP). The purpose of this paper is to establish dependencies of subgrade deformation properties of a soil body reinforced with full displacement piles on reinforcement parameters and soil conditions. Using numerical simulation methods, the authors identified reinforcement parameters and initial soil indicators that have a significant effect on change in the deformation modulus of the reinforced body in the considered boundary conditions. Results of field experimental studies confirmed the reliability of the newly established relationships and regularities.