Experimental Research On New Chemical Grouting Material To Reinforce Broken Coal

Because of the soft coal and cracked roof of fully mechanized caved face, in the process of mining, large area of roof falling in front of the hydraulic support easily appeared which makes bracket impossible and has a seriously impact on safety of fully mechanized working face. Therefore, chemical grouting reinforcement to soft coal wall and broken roof has being used usually. A new kind of grouting reinforcement material is needed relative to current materials like Marithan, Solid State, Cpmpany etc. which construction technology is complex and more expensive. The physical and mechanical properties of new chemical grouting material were studied due to the research achievement of Anhui University. The grouting technology of new material to reinforcement soft coal was studied through large scale physical model test.The common test of physical-mechanical properties shows that consolidated sand using Gubangte has higher strength than other four double liquid grouting material which strength value is5.56MPa,8.85MPa and12.40Mpa with the serum dosage of6:1,5:1and4:1respectively. When coal gangue and grouting quality ratio is5:1, Gubangte still has the highest consolidation strength in waste rock consolidation with4.15Mpa of compressive strength and0.47Mpa of tensile strength. So Solid State is the prior selection when using chemical grouting technology. The properies experiment shows that the sand consolidation strength reaches35.3MPa,39.62MPa and43.48Mpa when serum dosage is6:1,5.5:1and5:1respectively. Under the condition of confined pressure, consolidation strength is up to63.64Mpa with slurry with standard sand quality ratio of1:3.4. Brifly, in the condition of confined compression consolidation or no-pressure consolidation, the new chaemical grouting material is superior to commonly used double liquid grouting material.A grouting test apparatus was made to reinforce soft coal with new type of chemical grouting material. Through the Through new chemical grouting material large-scale physical model experiment, the grouting process in coal body pressure variation law with time was revealed, which could be divided into three stages:rise, fall and flatten. Slurry splits into the model by the distance of700mm and spreads to the whole steel tube by infiltration model. This show that fracturing grouting is the priority way to grouting and osmotic grouting is complementary way. The large difference of coal strength grouting consolidation after grouting which up to the maximum of11.77MPa and minimum of2.04MPa shows that grout diffusion within the model is not uniform.The paper could provide a basis for subsequent grouting process design of new chemical grouting materials, grouting parameters, etc.