Experimental Study On The Characteristics And Disposal Measures Of Clay Clogging In Tbm Cutter-head

Clay clogging in cutter-head is a worldwide problem in the engineering field.Clay clogging is a phenomenon that the fine particles and debris cut by the cutter-head is retained between the cutter-head and the working face,then it is re-aggregated by the continuous extrusion and friction of the cutterhead and adhered to the cutterhead or the cutter.Finally the muck is formed to be a semi-consolidated or consolidated massive body.the continuous accumulation of clay clogging will reduce the penetration of the cutter and the cutting ability,which will lead to uneven wear and partial high temperature which further solidifies clay around the cutter-head,it is a vicious cycle.At the same time,clay clogging will cause construction safety problems,seriously reduce the shield tunneling efficiency and even lead to the failure of normal tunneling of shield machine.This thesis mainly studied the disintegration,the interface shedding of the clay cake,chemical dispersion of clay clogging in cutter-head and the influence law of different factors.The study was achieved by literature investigation,theoretical analysis and laboratory test.This thesis also ummarize and analyze the advantages and disadvantages of common engineering treatment methods for clay clogging in cutter-head.Finally suggestions on the application of chemical dispersion in the treatment of clay clogging in cutter-head are gived.The research results can provide theoretical basis and technical support for solving the problem of clay clogging in construction.The main research contents and research results are as follows:(1)This thesis introduced the origin and engineering background of the clay cake studied in this paper,and the basic physical and mechanical properties and microstructure analysis of the original clay cake are carried out.(2)The disintegration test of original clay cake was carried out by an improved disintegration instrument,and the effects of solvent type,solution concentration,clay cake size,initial moisture content of mud cake,drying temperature and dry-wet cycles on the disintegration of mud cake were obtained.(3)The interface clay cake was made by the interface clay cake production equipment and the shedding test was carried out.The effects of solution concentration,initial moisture content of clay cake,drying and drying temperature,dry-wet circulation,and interface geometric structure on the shedding amount and speed of clay cake on the metal interface were obtained.(4)Through the self-made cutterhead clay cake and the self-designed cutterhead clay cake chemical dispersion test,the effects of soaking with a specific concentration of chemical dispersion solution,reducing the moisture content of the cutterhead clay cake,high-temperature drying treatment,dry-wet circulation treatment on the treatment of cutterhead clay cake by chemical dispersion method were verified,and the application suggestions for the treatment of cutterhead clay cake by chemical dispersion method were put forward.