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With the vigorous development of China’s railroad industry, increased railroad construction has extended to complex and dangerous mountainous areas. During the construction and operation of railroads in this area, various geological disasters are inevitable, bringing significant difficulties to railroad construction and significant threats to personal safety. This study focuses on the typical railroad passing through dense and dangerous mountainous areas as the research object. Through on-site investigations, the characteristics of slope disasters along the railroad were analyzed following the laws of disaster distribution and characteristics of disaster development. The study analyzes the causes of slope disasters by investigating internal and external factors. The research results show that the geological disasters along the railroad can be divided into landslides and collapses, of which there are 8 landslide disasters and 15 collapse catastrophes. Landslides are characterized as creeping and fretting stages according to their development characteristics. Collapses can be divided into four types of dangerous rock masses according to the scale of disaster distribution. Many factors influence the development of landslide geological disasters, and the development of geological disasters is the result of the combined action of multiple influencing factors. By analyzing the slope disaster along the railroad, this study provides an effective reference basis for constructing complex mountain railroads in the future.

Landslide is one of the most widely distributed and most severe geological hazards among the types of slope damage. China is among the countries most seriously affected by landslide disasters in the world. The unreasonable landslide anti-slide design will not only miss the best time for landslide treatment but also cause unnecessary engineering waste. Some may even worsen slope deformation and damage. Thus, reasonable slope protection and reinforcement and landslide anti-slide engineering design have become the current research fascination. This paper uses the Chengdu–Lanzhou Railway as the research object. This railway exhibits the typical characteristics of “four poles and three heights” in engineering geology. The main geological hazards and typical geological conditions of the Chengdu–Lanzhou Railway are systematically explained. The reasons for the determination of the principal axis section of the most unfavorable landslide and the basis for the determination of the sliding surface are summarized. Moreover, in this paper, a reasonable anti-slide engineering design is proposed. Finally, the friction coefficient of the main sliding section is calculated using the method of the coefficient of stability of the block, and the landslide thrust is calculated. Then, the stability coefficient of the landslide is verified using the GEO-Slope limit equilibrium method to determine whether the anti-slide engineering design is reasonable. This article provides a more scientific anti-skid engineering design idea and a scientific analysis method for the rationality of anti-skid engineering design.

In order to obtain waterborne two-component polyurethane (WB 2K-PUR) with good mechanical properties as well as excellent corrosion resistance, a series of hydroxyl-based polyurethane (HO-WPU) were synthesized using isophorone diisocyanate (IPDI), dimethylolpropionic acid (DMPA), and different proportions of polyether polyol (PTMEG) and polyester polyol (P1012) in this paper. Then WB 2K-PUR coatings were prepared with water-dispersible isocyanates (WDPI) as curing agent. The influence of the proportion of polyester polyols and polyether polyols in soft segments on coatings properties was studied. The characteristics of the coatings were analyzed by Fourier transform infrared spectroscopy (ATR-IR), contact angle, differential scanning calorimetry (DSC), dynamic mechanical thermal analysis (DMTA) and atomic force microscopy (AFM). The results showed that the mechanical properties and corrosion resistance of polyester and polyether polyols with appropriate proportion are improved significantly. The mechanism tended to be that with the addition of polyester, more hydrogen bonds were formed between the molecules, which increased the compactness of the coating as a physical crosslinking point. However, the ester groups have a strong affinity to water molecules, so the hydrophilicity of the coating was increased by excessive polyester polyols, and the shielding effect on the corrosion medium was reduced. With the inclusion of 40 % (g/g) P1012 in polyols, the coating has satisfied comprehensive properties.

High solid content waterborne polyurethane dispersions (PUDs) were synthesized via to the combination of ionic and nonionic monomers, in which the effect of the molecular mass of poly (ethylene glycol) (PEG) and its connection relationships of those hydrophilic groups in polyurethane with dimethylol propionic acid (DMPA) (through changed the synthetic schemes of PUDs) were researched. It is found that the molecular mass of PEG has obvious effect on combining with DMPA to synthesize PUDs. The incorporation of small molecular mass PEG200 (Mn = 200) had little effect on improving the dispersion and stability properties of anionic PUDs. But as the molecular mass of PEG increasing, they (PEG400, PEG600, PEG1000 and PEG2000) have obvious effect on improving the dispersion and stability properties, and can decrease the required dosage of DMPA to stabilize PUDs, moreover, cam improve the solid content of the latex. However, the effect of PEG2000 is less prominent than that of PEG400, PEG600 and PEG1000. The connection relationships of PEG with DMPA also have a certain effect on the property of the latex. When the small molecular mass one (PEG400) directly connects with DMPA, the synergistic effort is enhanced and the required dosage of DMPA to stabilize latex decreases to 2.0% (using DMPA alone needs 2.4%). As a result, the solid content of PUDs increased from 42% (using DMPA alone) to 52%, and the water resistance of PUDs is also improved. The thermal, dynamic mechanical and tensile-strength properties of derived films of PUDs were also analyzed, and the results show the incorporating PEG into polyurethane decrease the glass transition temperature of soft segments (Tgs), as well decreases the crystallinity and the extent of phase separation, which both cause the decrease of heat resistance. But through the combination, the synthetic formulas of PUDs with better tensile strength and elongation ratio than using DMPA alone were obtained. Besides, it is found that the molecular mass of PEG and the connection relationships of PEG with DMPA also had some influence on the properties of the derived films.