دانلود رایگان مقاله انگلیسی تاثیر فشار هیدرولیکی و استرس تکتونیکی بر شروع شکستگی در سنگ های معیوب - اشپرینگر 2018

This study examines the effects of hydraulic pressure and tectonic stress on fracture initiation in rock flaws by using the finite element method. A square domain with double flaws is analyzed under vertical load, different horizontal loads (modeling tectonic stresses), and various hydraulic pressures.

Conclusions

This study examined the effects of hydraulic pressure and tectonic stress on fracture initiation in rock flaws by using the elastic FEM in ABAQUS. Numerical results show the following:

1. As the lateral pressure coefficient λ increases without water pressure (k = 0), the initiation location of new tensile fractures moves from the position directly ahead of the flaw tip (0.47) to the upper face of the flaw (0.42), then from the lower face (0.54) to the position directly ahead of the flaw tip (0.53). Simultaneously, the initiation location of new shear fractures moves from the position directly ahead of the flaw tip (0.51) to the upper face (0.48). The positions of tensile and shearing fracture initiations depend on the horizontal load, especially when λ < 1.0 and λ > 3.0.

2. As λ increases with a relatively small water pressure (k = 1.5), the initiation location of new tensile fractures moves from the upper face of the flaw (0.48) to the lower face of the flaw (0.53). Simultaneously, the initiation location of new shear fractures moves from the upper face (0.48) to the lower face (0.52), then from the lower face (0.52) to the upper face (0.48). The positions of tensile and shearing fracture initiations depend on the horizontal load with a relatively small water pressure (k = 1.5).

3. Under a relatively large water pressure (k = 3.0), λ has minimal effect on the positions of tensile and shear fracture initiations but exhibit the same trend, and the positions of tensile and shear fracture initiations are directly ahead of the flaw tip (0.5).

4. Two interesting points exist, specifically at the lower face (0.59) and the upper face (0.10), where the maximum principal (shear) stress remains approximately constant for λ. Notably, the constant only relies on the water pressure. The effects of hydraulic pressure and tectonic stress on propagation and coalescence of fractures warrant further study.