Effects of cooling thermal shock on the P-wave velocity of granite and its microstructure analysis under immersion in water, half immersion in water, and near-water cooling conditions

2021 ◽  
Vol 81 (1) ◽  
Author(s):  
Jingwei Gao ◽  
Lifeng Fan ◽  
Yan Xi ◽  
Xiuli Du
Keyword(s):  
Thermal Shock ◽  
Wave Velocity ◽  
Microstructure Analysis ◽  
P Wave ◽  
Water Cooling ◽  
Cooling Conditions ◽  
P Wave Velocity

Relationships between P-wave velocity and mechanical properties of granite after exposure to different cyclic heating and water cooling treatments

2021 ◽  
Vol 168 ◽  
pp. 375-392
Author(s):  
Zhennan Zhu ◽  
Pathegama Gamage Ranjith ◽  
Hong Tian ◽  
Guosheng Jiang ◽  
Bin Dou ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wave Velocity ◽  
P Wave ◽  
Water Cooling ◽  
Cyclic Heating ◽  
P Wave Velocity

scholarly journals Role of Cyclic Thermal Shocks on the Physical and Mechanical Responses of White Marble

Machines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 58
Author(s):  
Yujie Feng ◽  
Haijian Su ◽  
Yinjiang Nie ◽  
Honghui Zhao
Keyword(s):  
Thermal Shock ◽  
Wave Velocity ◽  
Shear Failure ◽  
P Wave ◽  
Rock Properties ◽  
Compression Tests ◽  
Underground Engineering ◽  
P Wave Velocity ◽  
Thermal Shocks

Marble is a common rock used in many buildings for structural or ornamental purposes and is widely distributed in underground engineering projects. The rocks are exposed to high temperatures when a tunnel fire occurs, and they will be rapidly cooled during the rescue process, which has a great impact on the rock performance and the underground engineering stability. Therefore, the role of cyclic thermal shocks on the physical and mechanical properties of marble specimens was systematically investigated. Different cyclic thermal shock treatments (T = 25, 200, 400, 600, 800 °C; N = 1, 3, 5, 7, 9) were applied to marble specimens and the changes in mass, volume, density and P-wave velocity were recorded in turn. Then, the thermal conductivity, optical microscopy and uniaxial compression tests were carried out. The results showed that both the cyclic thermal shock numbers (N) and the temperature level (T) weaken the rock properties. When the temperature of a thermal shock exceeds 600 °C, the mass loss coefficient and porosity of the marble will increase significantly. The most noticeable change in P-wave velocity occurs between 200 and 400 °C, with a 52.98% attenuation. After three thermal shocks, the cyclic thermal shock numbers have little influence on the uniaxial compressive strength and Young’s modulus of marble specimens. Shear failure is the principal failure mode in marble specimens that have experienced severe thermal damage (high N or T). The optical microscopic pictures are beneficial for illustrating the thermal cracking mechanism of marble specimens after cyclic thermal shocks.

scholarly journals Mechanical Behaviors of Granite after Thermal Shock with Different Cooling Rates

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3721
Author(s):  
Peng Xiao ◽  
Jun Zheng ◽  
Bin Dou ◽  
Hong Tian ◽  
Guodong Cui ◽  
...  
Keyword(s):  
High Temperature ◽  
Thermal Shock ◽  
Wave Velocity ◽  
P Wave ◽  
Air Cooling ◽  
Mechanical Parameters ◽  
Mechanical Behaviors ◽  
Nuclear Waste Storage ◽  
P Wave Velocity ◽  
Splitting Test

During the construction of nuclear waste storage facilities, deep drilling, and geothermal energy development, high-temperature rocks are inevitably subjected to thermal shock. The physical and mechanical behaviors of granite treated with different thermal shocks were analyzed by non-destructive (P-wave velocity test) and destructive tests (uniaxial compression test and Brazil splitting test). The results show that the P-wave velocity (VP), uniaxial compressive strength (UCS), elastic modulus (E), and tensile strength (st) of specimens all decrease with the treatment temperature. Compared with air cooling, water cooling causes greater damage to the mechanical properties of granite. Thermal shock induces thermal stress inside the rock due to inhomogeneous expansion of mineral particles and further causes the initiation and propagation of microcracks which alter the mechanical behaviors of granite. Rapid cooling aggravates the damage degree of specimens. The failure pattern gradually transforms from longitudinal fracture to shear failure with temperature. In addition, there is a good fitting relationship between P-wave velocity and mechanical parameters of granite after different temperature treatments, which indicates P-wave velocity can be used to evaluate rock damage and predict rock mechanical parameters. The research results can provide guidance for high-temperature rock engineering.

Empirical Equations of P-Wave Velocity in the Shallow and Semi-Deep Sea Sediments from the South China Sea

2021 ◽  
Vol 20 (3) ◽  
pp. 532-538
Author(s):  
Guanbao Li ◽  
Zhengyu Hou ◽  
Jingqiang Wang ◽  
Guangming Kan ◽  
Baohua Liu
Keyword(s):  
South China Sea ◽  
Wave Velocity ◽  
South China ◽  
Deep Sea ◽  
The South China Sea ◽  
P Wave ◽  
Empirical Equations ◽  
China Sea ◽  
P Wave Velocity ◽  
Deep Sea Sediments

scholarly journals Geophysical and analytical determination of overstressed zones in exploited coal seam: a case study

2021 ◽  
Author(s):  
Dariusz Chlebowski ◽  
Zbigniew Burtan
Keyword(s):  
Coal Seam ◽  
Wave Velocity ◽  
Seismic Tomography ◽  
Analytical Modeling ◽  
Coal Mines ◽  
Vertical Stress ◽  
P Wave ◽  
Rockburst Hazard ◽  
State Of Stress ◽  
P Wave Velocity

AbstractA variety of geophysical methods and analytical modeling are applied to determine the rockburst hazard in Polish coal mines. In particularly unfavorable local conditions, seismic profiling, active/passive seismic tomography, as well as analytical state of stress calculating methods are recommended. They are helpful in verifying the reliability of rockburst hazard forecasts. In the article, the combined analysis of the state of stress determined by active seismic tomography and analytical modeling was conducted taking into account the relationship between the location of stress concentration zones and the level of rockburst hazard. A longwall panel in the coal seam 501 at a depth of ca.700 m in one of the hard coal mines operating in the Upper Silesian Coal Basin was a subject of the analysis. The seismic tomography was applied for the reconstruction of P-wave velocity fields. The analytical modeling was used to calculate the vertical stress states basing on classical solutions offered by rock mechanics. The variability of the P-wave velocity field and location of seismic anomaly in the coal seam in relation to the calculated vertical stress field arising in the mined coal seam served to assess of rockburst hazard. The applied methods partially proved their adequacy in practical applications, providing valuable information on the design and performance of mining operations.

The correlations between the saturated and dry P-wave velocity of rocks

Ultrasonics ◽  
2007 ◽  
Vol 46 (4) ◽  
pp. 341-348 ◽  
Author(s):  
S. Kahraman
Keyword(s):  
Wave Velocity ◽  
P Wave ◽  
P Wave Velocity

Crustal P-wave velocity structure and earthquake distribution in the Jiaodong Peninsula, China

2021 ◽  
pp. 228973
Author(s):  
Junhao Qu ◽  
Stephen S. Gao ◽  
Changzai Wang ◽  
Kelly H. Liu ◽  
Shaohui Zhou ◽  
...  
Keyword(s):  
Wave Velocity ◽  
Velocity Structure ◽  
P Wave ◽  
Jiaodong Peninsula ◽  
P Wave Velocity ◽  
Earthquake Distribution ◽  
P Wave Velocity Structure
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