| The cementation between rock blocks has a significant influence on the pore structure and seepage properties of the broken rocks,and the cemented broken rocks show a certain degree of water-resisting ability.Under the action of water flow,the seepage parameters of cemented broken rocks show different characteristics from the broken rocks without cementation.Investigating the seepage properties of cemented rock broken rocks is significant to protect the underground water resources in mining engineering.In this paper,clay,gypsum and cement are used as cementing agent to make the tested samples.Laboratory test,theoretical analysis,numerical calculation and response analysis were carried out on the non-Darcy flow seepage properties of cemented broken rocks,and the main results are as follows.(1)A seepage testing system for cemented broken rocks was developed,which could provide stable water pressure and collect water flow rate precisely.The seepage testing system has a double action hydraulic cylinder with large capacity.The water pressure could be controlled indirectly by controlling the hydraulic pressure,and the seepage pressure could be stabilized for a long time.The Coriolis force flowmeter was used to improve the testing precision and ensure the accuracy the of the water flow rate.(2)Based on the time series of pressure gradient and seepage velocity,the calculation method and program of the seepage parameters of cemented broken rocks were established.Using the method,the time varying curves of permeability,non-Darcy β factor and acceleration coefficient were obtained.(3)Through the single factor experiment,the shape parameters(peak value,stable value and attenuation exponent)of permeability for the broken rocks cemented by caly,gypsum and cement were obtainded,respectively.The relationship between shape parameters and influence factors(Talbot exponent,initial porosity and cementing agent mass)were analyzed.Based on the analysis,a permeability model with 33 parameters for cemented broken rocks was carried out.(4)Through the seepage testing of cemented broken rocks with salt,we analyzed the influence of salt mass,Talbot exponent and cement mass on the steady-state value of permeability.The relationship between the steady-state value of permeability and the influence factors was established.The sensitivity of permeability to each factor was carried out.(5)Taking into account the non uniformity of pore distribution of the Karst collapse column,the dynamic model of seepage system for cemented broken rocks was constructed,the algorithm of the response to seepage system was designed,and the caculation program of the response was composed.Based on the algorithm of the response to seepage system of broken rocks cemented by clay,the influence of clay mass,initial porosity and Talbot exponent on the seepage velocity of the rock mass was analyzed. |
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