The impact of long-fiber geotextiles on the granular stability of riverbanks is often concurrent in such situations. Long-fiber geotextiles offer superior properties such as permeability, filtration, soil retention, acting as separators, drainage filters, and protective barriers. They are cost-effective, priced competitively, easy to install, and convenient to use. The effect of water flow on riverbanks can be categorized into two scenarios: one where water directly impacts the riverbank, agitates the sediment particles, and carries them away; and another where water erodes the slope foot, increasing the height or angle of the bank, causing the upper wall to collapse due to gravity. The sediment composing riverbanks generally falls into two categories: non-plastic soil and cohesive soil.

Geotextile Long Filaments for Non-Cohesive Soils: The stability of the surface particles of riverbanks can be determined by the ratio of the force acting on the particles to the resistance that prevents their movement. For cohesive particles, their erosive resistance is not solely determined by the characteristics of individual particles. These particles typically form aggregates, usually ranging in size from 1.10M. Besides clay, these aggregates often contain sand and silt. The cohesive force between particles within an aggregate is much greater than the force between aggregates, making them akin to cohesive soil aggregates. The erosive resistance of geotextile long filaments is significantly greater than that of single particles. The reduction in bulk strength due to external influences is directly related to the moisture content of the soil mass, which depends on climatic conditions and soil properties (fineness, structure, morphology, and texture).

The collapse of riverbanks, resulting from the aforementioned process, is closely related to the dimensions (height, slope, etc.), shape, soil layer conditions, and soil properties. Riverbanks can be categorized into three types based on soil characteristics: primary, secondary, and composite, with each type experiencing different degrees of collapse. For riverbanks composed of non-plastic soil, two scenarios need to be distinguished: one with good water drainage, where the soil body strength may decrease and the friction angle may decrease below the bank slope, leading to collapse; or one where the upper riverbank slides due to the erosion at the foot of the slope. In cases with poor drainage, the collapse situation is similar to that with good drainage, but with the added effect of void water pressure. When the soil is saturated, void water pressure is positive and can limit the slope angle to be less than the angle of repose; if the soil is unsaturated and the void water pressure is negative, the void water pressure can cause the non-plastic soil to exhibit apparent plasticity, which is beneficial for the stability of the bank slope.