Membrane effect of geosynthetic reinforcement subjected to localized sinkholes

Abstract

A membrane effect often occurs in geosynthetic-reinforced structures, where subsoil may have voids or sinkholes. An analytical model is proposed to estimate membrane effect of a geosynthetic reinforcement subjected to localized sinkholes. The upper interface friction in the subsided area and vertical deformation of supporting soil in the anchorage area are considered simultaneously. The maximum geosynthetic strain and maximum surface settlement, serving as key design points, can be determined. Based on the proposed method verified using a full-scale experiment, a parametric study is conducted. The results show that ignoring upper interface friction results in significant undervaluation of maximum geosynthetic strain, and ignoring vertical deformation of supporting soil leads to obvious undervaluation of maximum surface settlement. A practical design framework is also proposed and it is an applicable tool for preliminary design of geosynthetic-reinforced structures, especially for cases with soft ground.

Evaluation of Geomembrane Effect Based on Mobilized Shear Stress due to Localized Sinking

“…In Figure 11, the strains of the de ected geosynthetic calculated by the present method, the Villard and Briançon [22] method, and the Feng et al's [29] method are all close to the test results. Due to the lack of settlement data on the embankment surface, the calculations are all founded on the vertical slip surface assumption.…”

“…is part compares the results of the present method and a full-scale experiment test, as well as the results of the analytical methods proposed by Villard and Briançon [22] and Feng et al [29]. e test was carried out by a sudden deation of an air balloon to investigate the reinforcing behavior of the basal geosynthetic (see Figure 10).…”

“…Refining from the analytical models proposed by Villard and Briançon [22] and Feng et al [29], a similar evaluation method for the geomembrane effect of reinforcement is also presented in this study. In Figure 4, the geosynthetic layer deflects due to a uniform load q g acting on its upper surface, but generates a maximum tension T c at the edge of the subsided area.…”

“…e Villard and Briançon [22] method does not consider the interface friction of geosynthetic and soil within the subsided area, so the peak tensile strain is the smallest and the length of anchorage is the smallest, too. Feng et al [29] argued that ignoring the upper friction results in undervaluation of maximum geosynthetic strain, and their method obtains a relatively higher geomembrane e ect. However, the overlying vertical load and its distribution signi cantly in uence the geomembrane e ect of the geosynthetic.…”

“…en, improved evaluation methods are strongly recommended, and more factors (such as the interfacial friction between the fill material and reinforcement) have to be considered in the geomembrane effect [25][26][27][28][29].…”