## 6 Discussion and Conclusions
Large-scale triaxial creep tests and three-dimensional numerical simulation analysis were conducted here to study (1) the creep characteristics of the Huaipa landslide sliding zone, which consisted of strongly weathered argillaceous sandstone, and (2) the mechanism of the disaster evolution of the slope under excavation and rainfall. The following conclusions were obtained:  
(1) The strongly weathered argillaceous sandstone clearly exhibits creep properties, and the instantaneous strain and creep strain of the specimens can be observed in the tests. With increasing stress levels, the damage process of the specimens follows decay creep \(\rightarrow\) steady creep \(\rightarrow\) accelerated creep. The creep process of the strongly weathered argillaceous sandstone essentially involves the slow adjustment of internal particles and release of stress under the action of an external force, accompanied by complex strength loss and recovery. Via particle sliding, rotation, and fragmentation, the final state of particle adjustment minimizes the contact stress of each particle under a certain stress condition. There is no positional movement or particle fragmentation, and the rheological deformation tends to stabilize. (2) The stress level plays a decisive role in the creep characteristics of the strongly weathered argillaceous sandstone. Higher stress levels are associated with higher instantaneous displacement and creep displacement and longer times required to reach stable deformation. The stress level magnitude also determines the creep stage (decay creep, steady creep, or accelerated creep). When the stress level is low, the adjustment of the internal structure of the specimen is dominated by void compression and particle movement, whereas particle fragmentation occurs mostly at high stress levels when the particle contacts inside the specimen increase and the contact stress is high. (3) Water content also has an important influence on the creep characteristics of the strongly weathered argillaceous sandstone. The creep specimen with 13% moisture content had a high frictional resistance to particle movement. The specimen deforms slowly and shows better stability than saturated specimens. In contrast, internal moisture in the saturated creep specimen had a lubricating effect on particle movement, the particle adjustment process was fast, and the displacement increased sharply with increasing stress levels, thereby resulting in poor stability. (4) The long-term strength of the strongly weathered argillaceous sandstone was approximately 62-66% of its instantaneous strength. The internal friction angle decreased by approximately 8\({}^{\circ}\) during deformation relative to that of the instantaneous strength, and the cohesion decreased by approximately 30%. The creep effect has an important influence on the strength of the strongly weathered argillaceous sandstone. Therefore, long-term rock strength must be fully considered in the stability calculations of all related engineering projects. (5) Excavation of the bauxite mine at the slope front edge destroyed the support at the slope foot of the Huaipa landslide, leading to unloading and large uplift deformation at the slope foot. However, the slope did not experience significant overall sliding at that time, and thereafter underwent creep deformation. Continuous rainfall later saturated the sliding zone, at which point the slope deformation notably accelerated and the slope slid as a whole, leading to the landslide disaster. The simulation results show that the landslide can be divided into a front edge bulging zone, a central sliding zone, and a trailing edge tension zone. These findings are fully consistent with the analysis results of the field geological investigation, thus providing important insight on the creep deformation evolution process and landslide disaster mechanism under the actions of front edge excavation and rainfall. [PERSON] conducted the experiment, processed the data, and revised the article.