Analysis of the Elastic‐Plastic Theoretical Model of the Pull‐Out Interface between Geosynthetics and Tailings

Abstract

Aiming at the strain-hardening and strain-softening phenomena between geosynthetics and tailings during pull-out tests, bilinear and trilinear shear stress-displacement softening models were proposed. The pull-out process of the hardening reinforcement was divided into the elastic stage, elastic-hardening transition stage, and pure hardening stage. The pull-out process of the softened reinforcement was divided into the elastic stage, elastic-softening transition stage, pure softening stage, softening-residual transition stage, and pure residual stage. The expressions of the interface tension, shear stress, and displacement at the different stages under a pull-out load were derived through the interface basic control equation. At the same time, the evolution law of the interface shear stress at different pull-out stages was analysed, and the predicted results of the two elastic-plastic models were compared with the experimental results. The results show that the predicted results are in good agreement with the experimental data, which verifies the validity of the proposed two elastic-plastic models for the progressive failure analysis of reinforcement at the pull-out interface. During the process of pull-out, the transition stage is not obvious. When the reinforcement is in the elastic stage, the nonlinearity and maximum value of the interface shear stress increase with an increase in the elastic shear stiffness, while the tensile stiffness shows the opposite trend. When the reinforcement is in the hardening or softening stage, the larger the hardening (softening) shear stiffness is, the larger the change range of shear stress is and the more obvious the hardening (softening) characteristics of the reinforcement are. The results comprehensively reflect the progressive failure of reinforcement-tailing interfaces with different strain types and provide theoretical support for the study of the interface characteristics of geosynthetic-reinforced tailings.

Analysis of interface mechanical properties between geotextiles and tailings during pull-out tests

“…k s1 L is the relative displacement; and Z ¼ k s2 k s1 is the relative interface shear stiffness. In general, |k s1 |>|k s2 | [20], so the value range of the relative interface shear stiffness is −1<η<0.…”

“…Eq (20) presents an estimate of the value of α based on the tensile force-displacement test results. The values of α and k s1 under different test conditions can be estimated by drawing the Origin image of function f(α).…”

“…The values of α and k s1 under different test conditions can be estimated by drawing the Origin image of function f(α). The relationship between f(α) and α in Eq (20) is shown in Fig…”

“…To validate the proposed model, the author [20] selected the pull-out test results of a one-way geogrid and cohesive soil under a normal stress of 100 kPa and compaction degree of 0.85 in Reference [21] to perform a simulation. Two classical reinforced-soil interface models, namely, the ideal elastic-plastic [22] and elastic-exponential softening [5] models, were used for comparison (see Fig 14).…”

Effects of Geosynthetic Reinforcement on Tailings Accumulation Dams

“…It is well known that new geosynthetic materials can improve soil structure and strength, as they have been widely used for strengthening in subgrade and slope engineering [6][7][8][9]. Given that the reinforcement of a tailings dam is similar to that of subgrade and slope engineering, geosynthetics have been considered for this application [10][11][12][13][14]. Model testing, an important means of engineering and scientific research, can be employed to obtain regular or qualitative conclusions regarding the research object and has been widely used in many fields [15].…”