Mechanism And Application Of Grouting Reinforcement Technology In Goaf Under Expressway

With the development of the times and the rapid progress of the socio-economic level,people are paying more and more attention to their own security issues.As road safety is an important issue to maintain people’s personal safety,it is necessary to establish a sound and more complete facility structure and protection standards in this regard.The construction of facilities in the mined-out area under the expressway is an important part of ensuring the effective improvement of road safety,and one of the primary problems to promote the successful construction of expressway projects is to solve the problem of the go-out area under the expressway.Grouting reinforcement is currently one of the most commonly used engineering methods in the treatment of the goaf underneath the expressway.This paper takes the treatment of the goaf section K2+800-K6+000 in the coal mine goaf section of the new project A1 of the Pingxiang-Lianhua Expressway as an example to study the grouting reinforcement technology and its application in the low-speed goaf area.On the basis of theoretical analysis,the author conducted field tests on the different proportions of cement and fly ash slurry under anhydrous and water-free anaerobic conditions,and obtained the change of the compressive strength of the slurry stone body with age in the two external environments.At the same time,the trend chart compares and analyzes the change curve of the compressive strength of the grout stone body under different water-solid ratios under natural conditions,and gives the recommended value of the "best mix ratio area" of cement-fly ash grout.Based on the existing goaf data,this paper establishes a simplified model of the goaf,and uses finite element numerical software to gradually simulate the process of full filling and grouting.The results show that the reserved coal pillar has an important influence on the deformation of the goaf,but the influence of the uniform load on the upper subgrade is relatively small.On this basis,a twodimensional geological model was established for the center line section of the mined-out area under the A1 bid section of the new Pingxiang-Lianhua Expressway project,and the software was used to simulate it.The results show that the deformation of the mined-out area after the grouting is fully filled The obvious decrease,even close to zero,shows that the grouting effect is obvious,and the conclusion that the grouting method is reasonable,feasible and effective is drawn.According to the above theoretical analysis,test results and numerical simulation conclusions,combined with the grouting project of section K2+800-K6+000 in the coal mine goaf of section A1 of the new Pingxiang-Lianhua Expressway project,the whole process of grouting is analyzed and explained.Including the optimization of grouting technology,the selection of grouting parameters,and the detection and monitoring of grouting effects,so that theoretical analysis,experimental research and practical testing form a complete system,which has certain theoretical significance for future goaf grouting projects And practical guidance value.