Research On The Theory Of Grouting Diffusion And Reinforcement In Loose Medium

With the development of national economy, the pace of transportation infrastructure construction is accelerating, the exploitation and consumption of mineral resources is increasing, large number of traffic tunnels, mines, roadway and other underground projects have been put on the agenda. In the construction of underground engineering, frequent geological disasters seriously imperil the safety of personnel and engineering, among them, Water-bursting and Mud-bursting which occur most frequently and have the greatest danger. According to the statistics, Water-bursting and Mud-bursting hazards accounted for more than half of the total number of the underground engineering accident. The main factors of Water-bursting and Mud-bursting disasters including natural factors and artificial factors. Natural factors include the presence of unfavorable geologic bodies such as weathered broken rock mass, weak interlayer, karst fissures etc, which is the root cause of the Water-bursting and Mud-bursting disasters; The artificial factor is mainly produced by construction disturbance, which is the direct induction factor.Grouting is the most common governance means of inrush clay and water, yet complex geological conditions caused great trouble for effective disasters governance. Mainly reflected on:(l)To choose a suitable grouting process for specific geological conditions, it is necessary to grasp a variety of construction methods and the ability of grouting process; (2) Complex formation is difficult to reinforcement, resulting in a lot of labor and material consumption. Currently, a large study are concentrate on grouting at single medium conditions, while research on grouting theoretical and grouting technological at complex media condition is rarely carried out.This paper focus on researching the proliferation and reinforcement mechanism of cement single slurry at multi-media condition, combining single cement slurry characteristic of separating water, using the combination of theoretical and experimental method. The main contents and conclusions include the following:(1)The ordinary cement slurry has the characteristic of separating water rapidly. It is confirmed by laboratory test that whether under gravity or grouting pressure, the excess free water in cement single slurry will separate out rapidly, resulting in great increase of slurry concentration and viscosity.(2)To the non-uniformity of geological conditions, put forward the concept of the advantages of the diffusion region including Permeable advantage diffusion region and the advantages of compression type diffusion region.Designed and carried out the grouting test under the condition of the advantages of the diffusion region.(3)Design and carry out single-reinforced cement slurry test which is also under the condition of the advantages of the diffusion region. Using the model test method, the medium containing the advantages of the diffusion region grouting, slurry diffusion analysis and determination of grouting plus solid strength, demonstrated the advantages of the diffusion zone plus solid help improve strength, to ensure the stability of the reinforcement effect.(4) In the analysis and research of grouting plus solid uniaxial compression and dried failure characteristics, based on the concept of "analysis of water-saturated layer" that the analysis of water-saturated layer is weak structural surface grouting process of the formation.