Mesh Free Method Numerically Simulates Rock Single Crack Hydraulic Fracturing

Along with the development of scosiety, lost of heavy cnostructions are developing to the underground, underground engineering can't separate with the force of groundwater,all of these promote the development of hydraulic fracturing research. The hydraulic fracturing of rock mass is one embranchment of the fissured rock mass seepage-stress coupling research. Up to now study on this problem is just in its initial stage,losts of basic theoretical problems should be researched more deeply.Firstly, the fundamental theories of Moving Least Squares Method(MLSM) which is the basic theory of EFM are studied. Based on this, the basic equations of EFM are derived, solving equations with Conjugate Gradients Method. Numerical examples show that EFM simplifies pre-processing and post-processing can solve problems with higher accuracy. Then, combining with the theory of facture mechanics and the analysis of hydraulic proerties incracks, the analysis on the stress field, strain field and displacement field in the area of crack tips and the consequent displacement of rock mass, as well as the propagation proposed crack fracturing were studied. The analysis on hydraulic fracturing mechanism.Then, it is assumed that fracture shape is a half eellipse-shaped in hydraulic fracturing of rock material. Base on the mass conservation and momentum principle, the formula of liquid mass conservation and differential equation of water pressure distribution due of hydraulic fracturing are obtained using the finite control volume approach. The theoretical formula at any time of fracture stable propagating is obtained also. The theoretical formula is analyzed and compared with experimental results from two aspects of qualitative and quantitative respectively.At last, in this paper, combining with the theory of facture mechanics, aim at theâ… type crack. the Hillerborg cohensive zone model and the theoretical formula at any time of fracture stable propagating are used. So an element-free program for the simulating of hydraulic fracturing was complied. Numerical examples show that element-free program crack propagation has a good description of the crack propagation.