Study on the Calculation Method of the Diffusion Range of Grouting Slurry for a High-speed Railway Ballastless Track Subgrade

Grouting engineering is the most convenient and quick way to deal with postconstruction settlement. Based on the investigation of the Beijing Shenyang high-speed railway in the early stage, the microdestructive force of grout on the soil mass in the process of grouting with the method of fluid solid coupling theory was analyzed. The numerical simulation results show that, in the grouting process, the greater the grouting pressure, the wider the diffusion range of the slurry and the greater the damage to the microscopic contact force of the slurry to the soil; in addition, when the grouting pressure is below 0.15 MPa, the diffusion form of the slurry in the soil is osmotic grouting; when the pressure is about 0.3 MPa, the diffusion form of the slurry in the soil is compacted grouting; on the basis of the simulation results, a deeper research is carried out, and the calculation formula of the slurry diffusion curve is obtained. It fills in the blank of the theoretical study of the slurry diffusion curve. In this paper, the diffusion formula of grouting slurry can be used in the theoretical study of clay grouting, and it can be used as a reference for practical engineering.

Development of Model Test System for Grouting Simulation in Flowing Water and Study of the Diffusion Form of Anti-Dispersion Grout

In order to simulate the diffusion form of anti-dispersion grout, the first visual large-proportion plane fissure test system for the physical model of fracture-grouting in flowing water is developed in China. The plane fissure test system is made up of plane fissure test-bed, monitoring system, water supply and drainage system, grouting system, control system and data acquisition system. The fiber Bragg grating (FBG) sensors for pressure, velocity and temperature monitoring are employed because of its small size and high sensitivity. The U-shaped diffusion form of anti-dispersion grout is found by the plane fissure grouting test in the flowing water.

High-temperature radiation gas dynamics equations in quasi-diffusion form

Nonrelativistic equations of radiation gas dynamics are obtained, adapted for calculations on computers without assumptions about the distribution of photons. These equations are suitable for problems in which the processes of scattering do not prevail over the processes of emission and absorption of photons.