Wyniki wyszukiwania - BazTech

1

The study of elastic properties and chemical composition of selected rocks

Herber S., Stan-Kłeczek I.

Contemporary Trends in Geoscience

|

2018

|

Vol. 7, iss. 1

104--109

EN

The aim of the investigation was to study the elastic properties and chemical composition of rock samples based on laboratory measurements. Three cuboid samples of diabase, granite and quartz were tested under laboratory conditions. The shape of samples is a cuboid with dimensions 0.1 x 0.05 x 0.05 m and the measurements were made in three directions. The Pundit Lab+ equipment was used for tests. The signal frequency value was 250 kHz. The propagation times of P- and S-waves were designated that allows to determine the elastic dynamic moduli values. The Japanese JEOL USA Scanning Electron Microscope was also used for tests. The chemical composition of rocks were determined by characteristic X-rays analysis. Obtained results show that the ultrasonic measurements and SEM are useful tools to assign properties of rocks. This knowledge makes easier recognition in preliminary stages during engineering study.

2

Zastosowanie MASW i sejsmiki refrakcyjnej do badania anizotropii prędkości w masywie skalnym

Stan-Kłeczek I., Marciniak A.

Zeszyty Naukowe Instytutu Gospodarki Surowcami Mineralnymi i Energią PAN

|

2016

|

nr 93

123--131

PL

Jedną z najbardziej charakterystycznych cech skał jest występowanie w nich spękań o różnym kształcie i wypełnieniu. Te nieciągłości powierzchni mają istotny wpływ na właściwości fizyczne skał. Efektem uprzywilejowania określonych kierunków jest anizotropia właściwości sprężystych masywu, w szczególności zaś anizotropia prędkości fal sejsmicznych, charakteryzująca się tym, że prędkość fal w kierunku prostopadłym do biegu spękań jest mniejsza niż w kierunku równoległym. Prezentowane badania prowadzone były w kopalni dolomitu Podleśna. W celu określenia związku pomiędzy szczelinowatością a prędkością fal sejsmicznych wykorzystano metodę sejsmiki refrakcyjnej (RFR) oraz wielokanałową analizę fal powierzchniowych (MASW). Otrzymane wartości prędkości fal sejsmicznych dla azymutów 0, 30, 60, 90, 120 i 150° porównano z kierunkami systemów spękań pomierzonych kompasem geologicznym. Do opisu kierunkowych rozkładów prędkości wykorzystano również rachunek tensorowy, który pozwala na odwzorowanie anizotropii sejsmicznej. Uzyskane maksima prędkości dla fali P pomierzonej za pomocą sejsmiki refrakcyjnej, jak i wartości prędkości fali S uzyskanej metodą MASW pokazują korelację z kierunkami głównych systemów spękań pomierzonych kompasem geologicznym, co pozwala na wykorzystanie wymienionych technik do badania szczelinowatości masywów skalnych.

EN

One of the most characteristic features of rocks is occurrence different kinds and sizes of cracks. These surface discontinuities have an important influence on the physical properties of rocks, especially on seismic wave velocity. The preferred orientation of crack systems involves the anisotropy of seismic wave velocity. It is characterized by a wave velocity that is smaller in the direction perpendicular to the crack plane than in the parallel direction. The presented study was carried out in the Triassic dolomite quarry “Podleśna” located in the South of Poland. The seismic anisotropy of rock mass was measured using the seismic refraction method (RFR) and Multichannel Analysis of Surface Wave (MASW). The research was conducted along oriented seismic profiles (0°, 30°, 60°,90°,120° i 150°) and compared with main crack systems measured on a geological compass. Tensor calculus was also applied to describe the directional distribution of seismic wave velocity. The obtained maximal value of seismic P-wave velocity (RFR) and S-wave velocity (MASW) show very good agreement with the directions of the main crack systems which allow these methods to be used to study of fracturing.

3

Application of Multichannel Analysis of Surface Waves to S-Phase Wave Anisotropy Estimation

Stan-Kłeczek I., Mendecki M. J.

Acta Geophysica

|

2016

|

Vol. 64, no. 5

1593--1604

EN

The Multichannel Analysis of Surface Waves (MASW) is an increasingly used technique for recognition of a shallow geological structure and estimation of geotechnical parameters, e.g., S-wave velocity, layer density, layer thickness, shear modulus, estimated P-wave velocity, and estimated Poisson ratio. MASW surveys were carried out in two limestone quarries in the southern part of Poland. The experimental areas are characterised by a simple geological structure: consolidated Triassic limestone. Measurement profiles were arranged as a shapely six-pointed star. For each survey line, 12 geophones with 2-meter (Deposit 1) and 3-meter (Deposit 2) spacing were applied. The research allowed to compare P- and S-wave velocity changes with the main crack systems in the studied rock masses.

4

Comparison of seismic sources for shallow seismic: sledgehammer and pyrotechnics

Brom A., Stan-Kłeczek I.

Contemporary Trends in Geoscience

|

2015

|

Vol. 4, iss. 1

39--45

EN

The pyrotechnic materials are one of the types of the explosives materials which produce thermal, luminous or sound effects, gas, smoke and their combination as a result of a self-sustaining chemical reaction. Therefore, pyrotechnics can be used as a seismic source that is designed to release accumulated energy in a form of seismic wave recorded by tremor sensors (geophones) after its passage through the rock mass. The aim of this paper was to determine the utility of pyrotechnics for shallow seismic engineering. The work presented comparing the conventional method of seismic wave excitation for seismic refraction method like plate and hammer and activating of firecrackers on the surface. The energy released by various sources and frequency spectra was compared for the two types of sources. The obtained results did not determine which sources gave the better results but showed very interesting aspects of using pyrotechnics in seismic measurements for example the use of pyrotechnic materials in MASW.

5

The role of seismic methods in investigation of rock mass

Stan-Kłeczek I.

Acta Geophysica

|

2008

|

Vol. 56, no. 4

1065-1073

EN

The existence of cracks in a rock mass causes the reduction of seismic wave velocity and the anisotropy of seismic wave velocity, which is characteristic for rocks with preferred orientation of cracks. The present study concerns sedimentary rocks (sandstone, limestone) and igneous rocks (basalt, granite). Studying the relationship between seismic anisotropy and cracks anisotropy in rocks I was only interested in fractures perpendicular to the layering. This allowed me to calculate two-dimensional crack tensors and velocity tensors in planes parallel to the layer surface. An application of tensor calculus enables to take into account both geometry and orientation of cracks. The obtained results confirm that the directions of major axes of second-rank velocity tensor prove the relationship consistent with predictions of theoretical models. Owing to these dependences, seismic methods can be used to study the cracks anisotropy in rocks inaccessible for direct observations.