Abstract:The hydraulic fracturing in fields of water conservancy,hydropower and mining engineering is produced by natural hydraulic power. Its boundary conditions are different from those in artificial hydraulic fracturing applied in fields of petroleum and natural gas engineering. Considering hydraulic fracturing characteristics of natural hydraulic power in the fields of water conservancy and hydropower engineering,a numerical simulation model of hydraulic fracturing of rock with a single fracture initially filled by saturation water is built. It is assumed that the flow in the fracture is the Newtonian fluid without compressibility. It is in accordance with lubrication theory. The flow pattern is one-dimensional laminar flow. The fracture flow is meshed as one-dimensional element. The differential equation of water pressure gradient of fracture inner surface and opening width is induced using semi-analytical and semi-numerical methods. This method simplifies coupling analysis iteration and improves analysis precision. The fracture propagation model employs Hillerborg cohesive zone one model COD criterion modified by damage factor. The interface elements with zero thickness are arranged in possible fracturing zone. Through adding or deducing the number of interface element,the dynamic motions of fracture and procedure iteration process are carried out. Finally,the hydraulic fracturing process of rock sample with a single fracture is simulated. The simulation results are compared with other experimental ones. The inner water pressure distribution law is consistent with experimental one. The rationality of the model and reliability of the calculation results are confirmed.