Study On Grouting Reinforcement Technique And Engineering Application Of Loess

Grouting as a very important technical means is widely used in tunnel reinforcement,foundation treatment,building rectification and other projects.With the widely used of grouting technology,the research on grouting technology is also deepened.The selection of grouting parameters is always the most important part of the application process of grouting technology.It determines the quality of the final grouting.Because of the diversity of the properties of the rock filled soil mass,there is no specific method to satisfy all the grouting parameters of rock and soil mass.Therefore,it is necessary to determine the grouting parameters for certain geotechnical bodies through a certain method.This paper takes the Xi'an Metro Line 4 train station to pass through the national railway station field area as the engineering background.Through the indoor split grouting model test and theoretical model calculation.It provides the basis and theoretical guidance for determining the parameters of full section grouting in the field.The main research results are as follows:(1)Through indoor model tests,the diffusion process of the slurry in the old consolidated loess and its influencing factors were studied.Firstly,a grouting test of the same pressure gradient was carried out to determine the splitting pressure of the old consolidated loess.Then the influence of different water content and different grouting pressure on the diffusion was studied under the condition of the same water-cement ratio.Finally,the influence of grouting pressure and water cement ratio on the diffusion is studied under the condition of the certain water-cement ratio.(2)On the basis of previous research.Considering the change of splitting crack height,a wedge-shaped fracture grouting theoretical model was established,and the relationship among the spread radius of the slurry,the grouting pressure difference and the thickness of the open end of the plasma pulse was deduced.Comparing the data obtained by theoretical calculation with the data obtained from laboratory tests,the applicability of the theoretical model in the old consolidated loess was verified.(3)The conclusions from the indoor test and the theoretical model were applied to guide the first cycle of the small section grouting test.The grouting parameters of the site were initially obtained,and then through the optimization of the second-cycle grouting parameters,the grouting parameters that met the on-site construction were obtained and applied to the large-section grouting to achieve a good grouting effect.