Simulation Study On Strata Movement Regular In P-CRIP UCG Without Shaft Style

Through a series of thermochemical reactions,the underground coal resources are converted into clean oil and gas resources and chemical raw materials by P-CRIP UCG without shaft style.It reduces the discharge of solid waste such as ash and slag,and realizes the efficient cleaning and low carbonization of coal resources,which is in line with green mining.Based on the geological and mining conditions of a mine in Wulanchabu as the prototype,the movement and deformation law of strata and surface after completion of P-CRIP UCG without shaft style is analyzed by means of theoretical analysis,numerical simulation and similar material simulation experiment.The main research results are as follows:1)Through consulting the literature and theoretical analysis,it is revealed that the form of combustion cavity is approximately "trapezoid",and the formation of isolated coal pillars is approximately "inverted trapezoid" in the near ideal state after completion of P-CRIP UCG without shaft style.2)After the completion of P-CRIP UCG without shaft style,numerical simulation experiments were carried out to study the movement and deformation rules of the roof and the distribution characteristics of isolated coal pillar plastic zone under different dimensional effect;Through the comparative analysis on the differences betweeb P-CRIP UCG without shaft style and “strip mining-regional mining” CRIP UCG with single channel,it is shown that the maximum vertical stress of isolated coal pillar and the roof and surface movement deformation of the former is smaller,and proves the feasibility of P-CRIP UCG without shaft style from the side.3)Similar material experiments were carried out to study the law of strata movement and deformation in P-CRIP UCG without shaft style.It reveals the dynamic change rule of the roof rock stress field and the isolated coal pillar stress field,and lays a theoretical foundation for the design of isolated coal pillar.4)We study the "inverted trapezoid" isolated coal pillar bearing mechanism through theoretical analysis,and after the completion of P-CRIP UCG without shaft style,numerical simulation experiments were carried out to revealed the isolated coal pillar stress distribution law under different dimensional effect,and proposes a simplified evaluation method of "inverted trapezoid" isolation coal pillar stability.5)After the completion of P-CRIP UCG without shaft style,studying the surface subsidence law under different dimensional effect through the numerical simulation,and compared with the prediction model parameters under the probability integration method of conventional strip mining,the surface subsidence prediction method of P-CRIP UCG without shaft style is established based on "actual mining thickness".