Mixing alkali-resistant glass fiber (ARGF) into grouting slurry can prevent the development of cracks; thus, understanding the properties of ARGF grouting material is important for applications in engineering. Two types of ARGFs (Cem-FIL®60 and Anti-Crak®HD) were selected as mixing materials, and their performance was tested in four areas, namely, compressive strength, tensile strength, flexural strength, and impervious performance, under four different mixing amounts of fiber (0%, 0.25%, 0.5%, and 1.0%). Results demonstrate that the addition of ARGF increased the compressive strength and tensile strength of the grouting slurry, and the best performance was at 0.5%. The effect on the flexural strength and impervious performance was related to the mixing amount, and the fiber may have induced a counter-effect for certain amounts of added ARGF. Mixing ARGF could increase the early strength ratio of grout; however, a high early strength ratio did not necessarily result in high strength, as the flexural strength did not change synchronously with the early strength ratio; a similar pattern was found for the impermeability. Cem-FIL®60 had a better effect on the properties of grouting materials than Anti-Crak®HD. These results were successfully applied in the water-plugging and reinforcement engineering of a karst tunnel.

The influence of different vertical position of steel support on the retaining structure of deep foundation pit is studied, and the deformation and deformation of retaining pile under multi-supported support conditions are revealed, which provides support design and excavation optimization design for deep foundation pit engineering. in accordance with. Through the calculation of the rational deep foundation pit calculation software and FLAC3D numerical simulation software, the deformation law of the retaining structure under different vertical position of steel support is studied. The research results are as follows: (1) Different vertical positions of the steel support to the retaining pile the deep horizontal displacement of the pile has a great influence. Appropriate encryption of the lower steel support is conducive to the stability of the retaining structure. (2) The influence of the vertical position change of the steel support on the horizontal displacement of the pile top is limited, but the first two supports are vertical. When the position is unchanged, the third steel support is moved down by 1m, which can effectively limit the horizontal displacement of the pile top, which is beneficial to the stability of the retaining structure.

In order to solve problems raised tunnel ventilation and dust removal, grew up in this paper, the tunnel blasting dust migration rule, through theoretical analysis, experiment on site and numerical simulation of the synthetic study method, study of phase grew up in the tunnel blasting dust migration rule, the conclusion is as follows: (1) Based on fluid mechanics, mechanics of elasticity theory, and combining the fick’s second law, in the initial conditions and boundary conditions, that along the longitudinal tunnel dust unsteady diffusion distribution; (2) The experiment found that the dust concentration decreased gradually with the increase of ventilation time, and the dust accumulated with the increase of distance from the palm surface. The dust in the same section was mainly distributed in the arch waist and below, with obvious stratification. (3) By comparing the numerical simulation with the field monitoring data in FLUENT, the accuracy of the numerical simulation results was verified, which provided theoretical guidance for tunnel construction and dust removal design.