Fragility Curves for Slope Stability of Geogrid Reinforced River Levees

Abstract

When constructing flood protection structures such as river levees, oftentimes due to various factors engineers must design composite structures, i.e., reinforced earthen structures which comply with all the stability criteria. The most common way of reinforcing such structures is the usage of geosynthetics, or mostly geogrids when talking about stability. Since geosynthetics are man-made materials produced in a controlled environment and go through quality control measures, their characteristics contain a negligible amount of uncertainty compared to natural soils. However, geosynthetic handling, their installation in the levee, and their long-term degradation can all have significant effects of variable magnitude on geosynthetic characteristics. These effects and their variability can be considered as random variables, which can then be used in probabilistic analyses together with soil properties. To investigate the effects of the geogrid’s resistance variability on slope stability compared to soil properties variability, probabilistic analyses are conducted on a river levee in northern Croatia. It is found that the geogrid’s variability generally has very little effect on the total uncertainty compared to the friction angle’s variability, but out of the three geogrid layers used the top grid has the most influence.

Importance of PET geogrid in the enhancement of hill slope's safety factor: a finite element approach

“…Geogrid also used in reinforced backfill with gabion faced retaining wall for stabilization of slope (Wang et al 2021). Another important application of geogrid to stabilize the slope on a river levee in northen Croatia (Rossi et al 2021). To increase the stability of land fill slope, geogrid plays crucial role (Cortellazzo et al 2022).…”

Methodology for Identification of the Key Levee Parameters for Limit-State Analyses Based on Sequential Bifurcation

“…A combination of only the observed extreme values often leads to unrealistic levee section and material parameters, and if numerical analyses are used to obtain results, this leads to numerical problems and thus results are impossible to acquire. Additionally, the relationships of deformations and other responses to all the input parameters are highly non-linear, similar to the function of safety factors shown in Rossi et al [17]. Since the SB is based on a linear metamodel, this would cause the model to be unfit for the data and as a result give incorrect factor importances.…”

Dam Safety-Overtopping and Geostructural Risks

“…Three papers are directly related to the development of fragility curves that are necessary for the risk assessment [9][10][11]. The fragility curves represent the probability of failure, or a certain level of damage, depending on a parameter that defines the intensity of the main action that might cause the failure.…”

“…Fragility curves for river levees reinforced with geogrid, related to slope stability, were developed by Rossi et al [10]. They concluded that the global uncertainty is much more conditioned by the uncertainty of the friction angle value of the dam material than that associated with the geogrid material.…”