پیوندهای مفید
آمار
| تعداد نشریات | 8 |
| تعداد شماره‌ها | 419 |
| تعداد مقالات | 5,514 |
| تعداد مشاهده مقاله | 6,262,009 |
| تعداد دریافت فایل اصل مقاله | 5,425,571 |
The Effect of the Crack Initiation and Propagation on the P-Wave Velocity of Limestone and Plaster Subjected to Compressive Loading | ||
| AUT Journal of Civil Engineering | ||
| مقاله 5، دوره 4، شماره 1، خرداد 2020، صفحه 55-62 اصل مقاله (1.77 M) | ||
| نوع مقاله: Research Article | ||
| شناسه دیجیتال (DOI): 10.22060/ajce.2019.15984.5558 | ||
| نویسندگان | ||
| Tohid Asheghi Mehmandari* 1؛ ahmad fahimifar2؛ Farhad Asemi3 | ||
| 1Department of Civil & Environmental Engineering, Amirkabir University of Technology, Tehran, Iran | ||
| 2Amirkabir University of Technology | ||
| 3Department of Civil and Environmental Engineering, University of Zanjan, Tehran, Iran | ||
| چکیده | ||
| Since many large-scale projects such as tunnels, boreholes constructed for extracting gas and oil and underground excavations for the disposal of chemical wastes are being produced in high stress rock masses; it is necessary to consider the crack initiation and propagation process in rock. Various methods have been developed for monitoring the material damage and fracture. Among these methods, in recent years, the use of the variation trend of the velocity of ultrasonic waves due to the unique characteristics has attracted the attention of researchers in the field of damage mechanics. In this research, the effectiveness of this method was evaluated in the monitoring of the crack initiation and propagation process in the rock. For this purpose, the effect of crack initiation and propagation on pressure wave velocity was investigated for loading at four stress levels of 30, 50, 70 and 90% of peak strength in limestone (travertine) and six stress levels of 30, 50, 60, 70, 90 and 100% of peak strength in plaster. A microscopic thin-section of limestone sample was prepared and studied in order to clarify the cracking process after compressive loading parallel with the loading direction. The results of the research indicate that, the pressure wave velocity has increased up to a certain stress level as a result of compressive loading and then, with a higher loading, the pressure wave velocity suddenly and severely decreases. Accordingly, in the limestone to the stress level of 50% of the peak strength, the pressure wave velocity increased by about 5% and then decreases by about 50 percent with increasing load. Similarly, in plaster artificial stone up to the loading level of 70%, the wave velocity increased by about 1.6% and then suddenly decreased. In addition, the study of microscopic thin sections showed that when the limestone is subjected to stress, the cracks initiate and propagate approximately parallel with the applied load (0-10֯). It was also observed that under stress around the pores in the texture of the rock, concentration of stress has occurred and, cracks around these pores have grown and penetrated into the grains by breaking the bond between the grains. | ||
| کلیدواژه‌ها | ||
| Crack initiation and propagation؛ Uniaxial compressive strength؛ Pressure wave velocity؛ Limestone and plaster | ||
| مراجع | ||
|
[1] Martin C, Chandler N. The progressive fracture of Lac du Bonnet granite. International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts: Elsevier; 1994. p. 643-59. [2] Brace W, Paulding B, Scholz C. Dilatancy in the fracture of crystalline rocks. Journal of Geophysical Research. 1966;71:3939-53.
[3] Bieniawski ZT. Mechanism of brittle fracture of rock: part II—experimental studies. Int J Rock Mech Min &’i & Geomech Abstr. 1967;4:395-404.
[4] Horii H, Nemat‐Nasser S. Compression‐induced microcrack growth in brittle solids: Axial splitting and shear failure. Journal of Geophysical Research: Solid Earth. 1985;90:3105-25.
[5] Hoek E, Bieniawski Z. Brittle fracture propagation in rock under compression. International Journal of Fracture Mechanics. 1965;1:137- 55.
[6] Dyskin A, Sahouryeh E, Jewell R, Joer H, Ustinov K. Influence of shape and locations of initial 3-D cracks on their growth in uniaxial compression. Engineering Fracture Mechanics. 2003;70:2115-36.
[7] Dyskin A, Germanovich L, Jewell R, Joer H, Krasinski J, Lee K, et al. Some experimental results on three-dimensional crack propagation in compression. Proceedings of the 1995 2nd International Conference on the Mechanics of Jointed and Faulted Rock-MJFR-2 New York:[sn]1995. p. 91-6.
[8] Eberhardt E, Stead D, Stimpson B. Quantifying progressive pre-peak brittle fracture damage in rock during uniaxial compression. International Journal of Rock Mechanics and Mining Sciences. 1999;36:361-80.
[9] Meng Q, Zhang M, Han L, Pu H, Li H. Effects of size and strain rate on the mechanical behaviors of rock specimens under uniaxial compression. Arabian Journal of Geosciences. 2016;9:527.
[10] Keller A. High resolution, non-destructive measurement and characterization of fracture apertures. International Journal of Rock Mechanics and Mining Sciences. 1998;35:1037-50.
[11] Zang A, Christian Wagner F, Stanchits S, Dresen G, Andresen R, Haidekker MA. Source analysis of acoustic emissions in Aue granite cores under symmetric and asymmetric compressive loads. Geophysical Journal International. 1998;135:1113-30.
[12] Klobes P, Riesemeier H, Meyer K, Goebbels J, Hellmuth K-H. Rock porosity determination by combination of X-ray computerized tomography with mercury porosimetry. Fresenius’ journal of analytical chemistry. 1997;357:543-7.
[13] Martínez-Martínez J, Fusi N, Galiana-Merino JJ, Benavente D, Crosta GB. Ultrasonic and X-ray computed tomography characterization of progressive fracture damage in low-porous carbonate rocks. Engineering Geology. 2016;200:47-57.
[14] Crosta G, Agliardi F, Fusi N, Zanchetta S, Barberini V, Laini M, et al. Rock fabric controls on the failure mode of strongly deformed gneisses. Rock Mechanics in Civil and Environmental Engineering: Taylor & Francis Leiden; 2010. p. 107-10.
[15] Ketcham RA. Three-dimensional grain fabric measurements using high- resolution X-ray computed tomography. Journal of Structural Geology. 2005;27:1217-28.
[16] Hirono T, Takahashi M, Nakashima S. In situ visualization of fluid flow image within deformed rock by X-ray CT. Engineering Geology. 2003;70:37-46.
[17] Vervoort A, Wevers M, Swennen R, Roels S, Van Geet M, Sellers E. Recent advances of X-ray CT and its applications for rock material. X-ray CT for Geomaterials Soils, Concrete, Rocks Balkema Publ. 2004:79-91.
[18] Ohtani T, Nakano T, Nakashima Y, Muraoka H. Three-dimensional shape analysis of miarolitic cavities and enclaves in the Kakkonda granite by X-ray computed tomography. Journal of Structural Geology. 2001;23:1741-51.
[19] Tziallas G, Tsiambaos G, Saroglou H. Determination of rock strength and deformability of intact rocks. Electronic Journal of Geotechnical Engineering. 2009;14:e12.
[20] Zhao J, Cai J, Zhao X, Li H. Experimental study of ultrasonic wave attenuation across parallel fractures. Geomechanics and Geoengineering: An International Journal. 2006;1:87-103.
[21] Nasseri M, Schubnel A, Young R. Coupled evolutions of fracture toughness and elastic wave velocities at high crack density in thermally treated Westerly granite. International Journal of Rock Mechanics and Mining Sciences. 2007;44:601-16.
[22] El Azhari H, El Hassani I-EEA. Effect of the number and orientation of fractures on the P-wave velocity diminution: application on the building stones of the Rabat Area (Morocco). Geomaterials. 2013;3:71.
[23] ISRM. Suggested method for determining Water Content, Porosity, Density, Absorption and Related Properties and Swelling and Slake- durability Index Properties. 1979. p. 141-56.
[24] ISRM. Suggested methods for determining the uniaxial compressive strength and deformability of rock materials. Rock characterization, testing and monitoring—ISRM suggested methods. 1981. p. 113-6.
[25] ISRM. Upgraded ISRM suggested method for determining sound velocity by ultrasonic pulse transmission technique. 2014. p. 255-9.
[26] Akesson U, Hansson J, Stigh J. Characterisation of microcracks in the Bohus granite, western Sweden, caused by uniaxial cyclic loading. Engineering Geology. 2004;72:131-42.
[27] Hadley K. Comparison of calculated and observed crack densities and seismic velocities in Westerly granite. Journal of Geophysical Research. 1976;81:3484-94.
[28] Rigopoulos I, Tsikouras B, Pomonis P, Hatzipanagiotou K. Microcracks in ultrabasic rocks under uniaxial compressive stress. Engineering Geology. 2011;117:104-13.
[29] Rigopoulos I, Tsikouras B, Pomonis P, Hatzipanagiotou K. Petrographic investigation of microcrack initiation in mafic ophiolitic rocks under uniaxial compression. Rock mechanics and rock engineering. 2013;46:1061-72.
[30] Heap M, Faulkner D, Meredith P, Vinciguerra S. Elastic moduli evolution and accompanying stress changes with increasing crack damage: implications for stress changes around fault zones and volcanoes during deformation. Geophysical Journal International. 2010;183:225-36.
[31] Kranz RL. Microcracks in rocks: a review. Tectonophysics. 1983;100:449- 80. | ||
|
آمار تعداد مشاهده مقاله: 633 تعداد دریافت فایل اصل مقاله: 460 |
||