Modular precast concrete facing for soil-nailed retaining walls: laboratory study and in situ validation

Abstract

A new concept for constructing the facing of soil nailed walls is proposed and validated through experimental and numerical approaches. This new process uses precast concrete panels. For each excavation step, the soil reinforcements are first connected to the panels. A slightly cemented 4-6 mm crushed stone is then injected, through the weep holes, between the panels and the excavation vertical cut, applying a confining pressure to the ground and providing continuous high capacity drainage behind the facing. The structural design of the precast reinforced concrete panel, based on full scale loading tests in the laboratory and nonlinear numerical simulations, are presented in detail. Crack initiation and failure modes are properly predicted by the model. A full-scale experimental soil nailed wall 7.5 m high was also built to evaluate the environmental, economic and mechanical performances of the new construction technique compared to the conventional shotcrete technique. The new construction technique greatly improves worker's safety, significantly reduces construction duration and cost and improves the mechanical behavior of the soil nailing technique and drainage of the facing. Compared to the conventional shotcrete technique, the new technique reduces concrete consumption by 64% and greenhouse gases emission by 56%.

Donatılı Zeminler için Alternatif Hafif Kompozit Panel Elemanları

“…Although the maximum lateral earth pressure is higher in a flexible facing, its collapse zone is located at a deeper level than a rigid model. Bui et al (2020) propose a shotcrete as an effective method due to the results of experimental and numerical studies related to the behavior of anchored modular precast concrete in a special geometry. While it is stated that attention should be paid to appropriate material selection and sizing in scaled facing models, the importance of bending rigidity is also emphasized by Ren et al (2020).…”

Application of the Nailing Technique to Stabilize a Slope in a Section of the Twinning of Road and Rail Infrastructure

“…Soil reinforcement by nailing is one of the practical techniques for improving the mechanical characteristics of inplace soils. This stabilization method is currently undergoing a very significant and widely employed development [1]- [5] due to its many advantages, namely its ease and speed of implementation [6]- [10], but also it preserves the geometry of the treated site. Soil nailing is a versatile and cost-effective technique for stabilizing slopes and retaining structures [11]- [13].…”