Soil nailing as a ground reinforcement method of a storey building constructed on weathered siltstone: Analytical and numerical evaluation

Tóm tắt

The stability and load-bearing capability of an existing building/structure are primarily dependent upon its foundation. Current research and design standards require the foundation of any building must be able to withstand both passive and active loads, as well as dynamic ones. Yet, due to the changes in the ground conditions beneath the structure or additional loads applied, unexpected alterations could occur. Consequently, the foundation itself is unable to resist additional stresses. In some cases, the building could be subsided due to ground instability, especially in the case that the structure is situated on the weathered ground. Thus, the foundations require reinforcements. The paper presents a case study on the use of in-situ reinforcement technique, namely soil nail, to stabilize a shallow foundation of an existing building constructed on weathered siltstone. The two-dimensional limit equilibrium method was employed to evaluate the stability of the existing foundation with/without incorporating soil nail elements. The analytical results show that the stability of the foundation, presented in terms of the factor of safety, increases with the case of placing the soil nail elements underneath the shallow foundation. Moreover, the angle of the design cut-slope also affects the global stability of the foundation. Lastly, the single-wedge failure mechanism with the planar sliding surface is applicable to aid geotechnical engineers in quickly assessing and choosing the reinforcing method for the ground of footing due to its simplicity of calculation procedure and ease of interpretation of results.