Soil nailing is a prevalent and cost-effective technique employed to reinforce and enhance the stability of precarious natural or cut slopes; however, its application as a primary support system to prevent collapses or cave-ins during foundation excavation could be more frequent. To better understand the behavior of such a support system, this study simulated a full-scale nail-supported excavation for the foundation pit of a 20-story building to examine the effect of placing a strip footing with various combinations of configurations on the crest of the excavation pit. The results are discussed in terms of the nail axial force, wall horizontal deflection, basal heave, and safety factor against sliding. The results show that the footing width and setback distance are the two most significant factors dominating the wall horizontal deflection. This study also reveals that the maximum axial force is closely related to the apparent active earth pressure, which accounts for the presence of a tension crack, at nail depth. Such a finding allows engineers to assess and mitigate the risks of structural failure more effectively and optimize the design of nail-retaining structures.

Soil-nailing is a simple and economical method of stabilizing cut slopes and retaining excavation. Most of the soil-nailing related studies, in particular the experimental work, were conducted in idealized or homogeneous ground, but such a result might not necessarily be representative. Thus, for a more representative study, instead of treating the ground as homogeneous it should be treated as a system of horizontal layers. This study assessed the performance of a full-scale nailed retaining structure for a foundation pit of a 20-storey building through a series of numerical analyses. The influence of full-face facing thickness, nail head geometrical configuration (size and thickness) and surcharge loading on the response of the structural components of the soil-nailing system adopted is the main concern. The results were evaluated in terms of axial force, shear force and bending moment of the structural facing element and the horizontal displacement of the soil retained behind the facing element. In both cases, the distribution of nail axial (tensile) force in each nail reinforcement was also compared and evaluated. It was found that the thickness of full-face facing affected the facing shear force and bending moment, while the surcharge loading influenced the facing axial force and the horizontal displacement of the retained soil and that the magnitude of the axial force registered at the fixed end was governed by the size of the discrete nail head.

Landslide is a geological process on the surface of the earth, the downward movement of soil mass or rock on the slope region is called a landslide. Natural disaster has always been an important topic of discussion, currently India and many other countries are facing this sort of problem. Through the past study it’s seen that there were thousands of landslides occurred in India due to typhoon and heavy rainfall; Kethikal landslide near to Mangalore in India is one of the hazard occurred in 1998 due to heavy rainfall. The total height of the slope is 67 meter and its length is 140.5 meter. Due to this disaster, traffic has been diverted for few days and some houses in the top of the mountain were damaged. The analysis of this slope failure has been done in Plaxis 2D program and found that the cause of failure of the slope is due to the rise of high porefluid pressure and by the field observation found the same cause. In Plaxis 2D, a number of numerical analyses has been done with soil nailing solution and found that the factor of safety of this solution is satisfactory. Soil nailing has been found to be one of the solutions for the treatment of the unstable slope.

This study conducted a series of model tests on geosynthetic encased columns (GECs) stabilized slopes subjected to seepage to assess the effectiveness of GECs in enhancing slope stability. The model tests simulated a prototype slope with a height (H) of 10 m and a maximum groundwater level (hw) of 8 m. The influence of the infill material within the GECs and the drainage condition at the tip of the GECs on the performance of the stabilized slopes was thoroughly examined. Digital image analysis techniques were employed to determine the displacement profile of the slope surface and to analyze the development of the failure surface at various groundwater levels. The phreatic surface within the slope was also carefully monitored and analyzed during the model tests. For the unreinforced slope, the test results indicated that as the groundwater level rose, the slope began to deform, and tension cracks developed at the top. A complete failure surface developed rapidly at maximum groundwater level (hw = 80% H), leading to sudden collapse. The inclusion of GECs significantly reduced slope deformation and improved slope stability. GECs with drainage ability lowered pore water pressure, resulting in a lower phreatic surface. This performance was due to their superior mechanical and hydraulic properties.