Thickness And Strength Of Compression Arch Of Prestressing Anchors (Ropes) Of Different Lithologies

With the gradual increase of coal mining depth,reasonable support selection is crucial to maintain the stability of the surrounding rock of the roadway.High-strength anchor（cable）exerts high preload force to extrude the surrounding rock,and with the help of anchor net and steel belt to form a certain thickness compression arch inside the surrounding rock,the compression arch makes full use of the self-bearing capacity of the surrounding rock,assists metal support,grouting and other loading,thereby significantly improving the stability of the surrounding rock has been widely used in engineering,and the analysis of the thickness and strength of compression arch of different lithological prestressed bolts（cable）is of great significance in engineering practice.Combined with the actual situation of the deep roadway project of Zhuxianzhuang Coal Mine,this paper uses FLAC^3D software to analyze the additional stress distribution of prestressed compression arches formed by different lithology in different bolt（cable）pretension,different bolt spacing and different bolt（cable）lengths,and studies the thickness and strength of four different lithological prestressed anchor（cable）compression arches,and concludes as follows:（1）With the same lithology,the influence of bolt support parameters on the thickness and strength of the prestressed compression arch is:the preload of the bolt has no obvious effect on the thickness of the compression arch,and has a significant effect on the internal strength of the compression arch;The length of the bolt has no obvious effect on the strength of the compression arch,and the influence on the thickness of the compression arch is obvious.The spacing between bolts has no obvious effect on the thickness of the compression arch,and has a significant effect on the strength of the compression arch.（2）With the same lithology,the influence of anchor cable support parameters on the thickness and strength of the prestressed compression arch was as follows:the influence of anchor cable length and preload force on the thickness of the compression arch was not obvious,and the influence on the strength of the compression arch was obvious.（3）With the same support,the influence of lithology on the thickness and strength of the prestressed compression arch is:the influence of lithology on the thickness of the prestressed compression arch is not obvious;Lithology will affect the strength of the prestressed compression arch,the better the lithology,the smaller the increase in the strength of the compression arch,and the smaller the increase in the adhesion force in the prestressed compression arch.（4）The influence of compression arch thickness and strength at different positions of the roadway gang with the same support is:the thickness of the prestressed compression arch does not change significantly at different positions;The closer the distance from the baseline position of the roadway arch,the more obvious the increase in compression arch strength.（5）The thickness of the compression arch of the typical roadway of Zhuxianzhuang Coal Mine was measured on site by using a multi-point displacement meter,and the results obtained were similar to the numerical simulation results,which verified the accuracy of the numerical simulation results.Figure[49]table[28]reference[68]...