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The Xigeda clay-rock strata exhibit typical characteristics of long-term creep deterioration and saturation softening, which is typical slide-prone stratum. Landslides are easily formed in Xigeda strata cut slope due to the continuous deterioration and stability reduction during the operation period, which poses great threats to operational safety. The reduction coefficients for the c and φ values due to long-term creep deterioration of Xigeda clay-rock are determined as 0.87 and 0.84 respectively. These values are derived from shear strength parameters of slope excavation and sliding obtained through geological analysis, discrete element numerical simulation, and mutual verification involving the K2378 + 900 right-side landslide on the Xichang-Panzhihua Expressway. By conducting critical slip surface searches and stability calculations for 17 distinct Xigeda clay-rock slopes representing 5 different types, the average decrease of stability coefficient is found to be 0.184 when shear parameters are reduced in accordance with creep deterioration within the range of 0.87～0.84. Consequently, targeted recommendations are proposed for key factors influencing the long-term stability of Xigeda clay-rock slopes, encomPassing safety coefficients, slope ratios, and reinforcement measures. It is demonstrated that employing a construction approach characterized by a gentler slope, wider platforms, and less intensive reinforcement is proved to be more conducive to the slope long-term stability. The research results provide important guidance and reference for highway construction and slope protection treatment within the Xigeda stratum area.

BackgroundSilicosis poses a threat to workers’ health due to the irreversible lung lesions.DesignA retrospective cohort study.MethodsA total of 259 patients [80 worked with artificial stone (AS), 179 with non-artificial stone (non-AS)] with confirmed silicosis were included in this study. Forty-one of AS and 91 of non-AS had approximately 2 years’ follow-up records [lung function tests and high-resolution computer tomography (HRCT)]. Compared with the first records, increased, densified, or newly emerging lesions in lung HRCT images were judged as progression of the disease. Cox proportional hazards models were used to determine the risk factors. Kaplan–Meier survival curve and log-rank test were used to compare prognostic factors for cumulative risk of progression.ResultsIn 132 patients with median follow-up of 24.0 months (IQR, 13.8, 24.9), 66 patients showed progression, in them, 36 (87.8%) were from AS group and 30 (32.9%) from non-AS group. Working experience of AS processing (hazard ratio, 5.671; 95% CI, 3.048–10.550) and complicated silicosis in CT images (hazard ratio, 2.373; 95% CI, 1.379–4.082) were the main risk factors associated with progression. Forced vital capacity decreased after 1-year (241.5 vs. 55.2 mL) and 2-year (328.1 vs. 68.8 mL) follow-up in the two groups (AS vs. non-AS). History of anti-tuberculosis medication, chest oppression and pain, ground-glass opacity, pleural abnormalities, and restrictive pulmonary dysfunction were more frequently found on HRCT images in the AS group than non-AS group. Lung functions (DLCO, %) were lower in the current/former smokers than the non-smokers (P < 0.05) in AS patients.ConclusionPrevention and protection rules are needed to be enforced in the occupation involving AS processing; smoking may be associated with declined lung function in AS patients.