scholarly journals Analytical Model for Predicting the UCS from P-Wave Velocity, Density, and Porosity on Saturated Limestone

2019 ◽  
Vol 9 (23) ◽  
pp. 5265 ◽  
Author(s):  
González ◽  
Saldaña ◽  
Arzúa

Rock mechanics and rock engineering projects require determining, among other parameters, the uniaxial compressive strength (UCS) of rock. For such a purpose, it is not uncommon to perform ultrasonic pulse laboratory tests. Many researchers have found experimental relationships between strength and P-wave velocity, but these relationships are based mainly on dry conditions and without considering any other physical or chemical characteristics of the studied rock. Specifically, for limestone, there are 11 correlations reported in the literature, eight of which are simple and the remaining three are multiple, and, among the latter, only two of them consider the saturation. In order to evaluate the combined effect of P-wave velocity, density, and porosity on the UCS of saturated limestone, simple and multiple regression analyses were carried out on the test results of 13 saturated limestone specimens to determine the parameters of both previously mentioned predictive models. The results showed that density is not correlated with strength.

2011 ◽  
Vol 250-253 ◽  
pp. 1025-1030
Author(s):  
Yi Ching Lin ◽  
Yung Chiang Lin ◽  
Yu Feng Lin

This paper investigates the feasibility of using the P-wave velocity measured by the impact-echo technique to estimate the strength of hardened self-consolidating concrete. The relationship between the through-transmission ultrasonic pulse velocity (UPV) and the strength of high performance concrete was established previously by performing experimental studies on water-cured cylinders made of concrete having variations in water-cementitious amterial ratio and aggregate content. However, the through-transmission UPV measurement is not applicable to concrete elements with only one accessible surface. In this paper, two plate-like specimens were made of self-consolidating concrete and they had different curing conditions. One specimen was immersed in water and the other was covered with wet gunny sack for 7 days. The impact-echo technique, one-sided wave velocity measurement technique, is adopted to determine the P-wave velocity of the plate-like concrete specimens at an age of 28 days. The difference between the impact-echo P-wave velocity (IE-PV) and the through-transmission ultrasonic pulse velocity (UPV) is studied. In addition, the measured IE-PV is used to estimate the strength of the plate-like concrete specimen and the estimated strength is verified by taking cores from the specimen.


2021 ◽  
Author(s):  
Dariusz Chlebowski ◽  
Zbigniew Burtan

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.


2021 ◽  
pp. 228973
Author(s):  
Junhao Qu ◽  
Stephen S. Gao ◽  
Changzai Wang ◽  
Kelly H. Liu ◽  
Shaohui Zhou ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document