Abstract
Red beds mainly refer to continental clastic rocks formed during the Jurassic, Cretaceous, Paleogene, and Neogene periods, dominated by lacustrine, fluvial-lacustrine alternating, or piedmont alluvial facies, which are exposed worldwide. For red bed slopes with interbedded sandstone and mudstone, the key disaster-causing factor triggering landslides is the damage and deterioration of mudstone layers. Due to the property of red bed mudstone that it deteriorates upon water absorption and disintegrates upon water loss, sampling and specimen preparation are difficult, and few scholars have conducted research on it. Therefore, studying the time-dependent deformation behavior of red bed mudstone under water-rock interaction is of great significance for revealing the creep deformation behavior of slopes. This study takes red bed mudstone from southwestern China as the research object, conducts triaxial creep tests under different water saturation times, and analyzes the creep deformation, creep rate, and long-term strength of red bed mudstone. Based on traditional creep models, a nonlinear viscoplastic element is proposed to establish a one-dimensional creep constitutive model. By introducing the initial damage and process damage of water-rock interaction into this model, a damage creep constitutive model for red bed mudstone is constructed, the model parameters are calibrated, and the model is further derived from one-dimensional to three-dimensional. The new constitutive model can better reflect the creep characteristics of red bed mudstone during the water saturation process.
Full Text
Preamble
Study on Rheological Damage Constitutive Model of Red Bed Mudstone Considering Water Saturation Time
Hongke Zhou¹
(¹ Power China Guiyang Engineering Corporation Limited, Guiyang 550081)
Abstract
Red beds primarily comprise continental clastic rocks formed during the Jurassic, Cretaceous, Paleogene, and Neogene periods, dominated by lacustrine, fluvial-lacustrine alternating, or piedmont alluvial facies, and are extensively exposed worldwide. In red bed slopes characterized by interbedded sandstone and mudstone layers, the critical factor triggering landslides is the damage and deterioration of mudstone strata. However, due to the inherent property of red bed mudstone to weaken upon water absorption and disintegrate upon water loss, sampling and specimen preparation present significant challenges, resulting in limited research attention. Therefore, investigating the time-dependent deformation behavior of red bed mudstone under water-rock interaction is essential for elucidating the creep deformation mechanisms of red bed slopes.
This study examines red bed mudstone from southwestern China through triaxial creep tests conducted under various water saturation durations, systematically analyzing creep deformation characteristics, creep rates, and long-term strength. Building upon traditional creep models, we propose a nonlinear viscoplastic element to establish a one-dimensional creep constitutive model. By incorporating both initial damage and process-induced damage from water-rock interaction, we construct a damage creep constitutive model for red bed mudstone. Model parameters are calibrated, and the formulation is subsequently extended from one-dimensional to three-dimensional. The proposed constitutive model effectively captures the creep characteristics of red bed mudstone during water saturation.
Keywords: red bed; water-rock interaction; constitutive model; creep