In the rock engineering fields dealing with the excavation of rock masses such as quarrying, surface mining, the term" discontinuity" is a widely used collectively term. A discontinuity is a plane that marks a change in physical or chemical characteristics in a soil or rock mass and has the zero or low tensile strength. It can be in the form of geological structures such as joints, bedding planes, faults, fractures, fissures, crack etc. The ISRM (1978) refers to the use of ten parameters for the characterization of discontinuities and these include three geometric parameters: spacing, persistence, and orientation. Each of these ten parameters has a significant influence on the rock properties. However, three geometric parameters in particular, …show more content…
The mapping methods developed can be grouped into two types. One is by direct methods and another is by indirect methods. In the indirect method, initially, measurement of physical properties of the rock mass such as the seismic velocity and the discontinuity parameters are estimated from the physical parameters (Grainger et al., 1973). The direct method uses the visual measurement of each discontinuity. Such measurements of lengths and angles are made directly on rock outcrops, bench faces, boreholes (Piteau, 1970; ISRM, 1978) as well as from photographs of rock exposures (Franklin & Maerz, 1988; Farmer et al., 1991). The direct measurement of rock exposures can be carried out using line mapping techniques. Line mapping often referred to as the Scanline technique is widely used …show more content…
In the modeling of discontinuity geometry, delineation of discontinuity sets is a first step in creating discontinuity geometry patterns (Dershowitz & Einstein, 1988). Discontinuities in rock masses are not uniformly distributed in all directions but are often formed in sets (Piteau, 1970; Pollard & Yaddin, 1988). There are several analytical functions available to describe the discontinuity orientation distribution, such as the Fisher and the Bingham distributions (Baecher, 1983; Dershowitz & Einstein, 1988; Priest,
Marshak, S. (2009) Essentials of Geology, 3rd ed. New York: W.W. Norton & Company, ch. 11, p. 298-320.
The Long Point Fault is located in Harris County, which covers 83,450 square miles located with in Houston, Teaxas City Limits. Research specifies that there are three sections of the Long Point fault that appear to be active; some sections of the Long Point fault have averaged more than 2 cm per year of vertical offset over the last 20 years. Evidence of the faults concludes it is a natural fault. The reason for activity is not caused by man, even though man’s activities are not helping the issues, but clearly humans are not the initial cause, biological activity can be in fact an adiitional cause for its movement. A brief description of the type of fault and its relationship with the strata and the faults beneath the Houston area, are at depths of 1,000 to 4,000 m. They have been well-defined through the study of well logs and seismic lines. Studies have resuted in assumuptions that some of these subsurface faults penetrate younger sediments at shallower depths, and contain faults that have of set the present land surface to produce recognizable scarps. (Gabrysh)
Tarbuck E., Lutgens F., Tasa D., 2014, An Introduction to Physical Geology, 5th Ed, Pearson Education, Upper Saddle River, New Jersey.
Since California had previously been mentioned, it is a great place to begin explaining the complex geological impacts starting with the San Andreas Fault. The San Andreas is what geologists know as a strike-slip fault, meaning that when two pl...
These estimation are done with the aid of the useful data form the field such as the depth, thickness, strike and dip data and the discontinuities angles and orientations and estimated values from the Lss Software. Basically, the extraction technique will take note of the thickness of overburden, the quarry slopes and dimensions, the stripping ratio and the discontinuities orientation and angles. For the purpose of simplicity, the extraction will be carried out in stages. As shown
If the cone is made up entirely of rock debris, we found very high gradient for the space occupied by the base. Here we find the gradient of 30 degrees and sometimes up to 40 degrees Celsius and these forms usually arise as a result of volcanic eruptions and represented in the islands in Indonesia.
...ierra Nevada on west and Mojave Desert on east (Fig.X). The topography of the province is largely characterized by “abrupt changes in elevation,” causing a wide range of elevation values. These include the province’s highest point which lies east of Owens valley, at an elevation of 4,341 meters above sea level, and the lowest point in the United States located in the famous Death Valley basin, 86 meters below sea level (Harden, 130). Throughout the province, many range-front faults are found. Range-front faults are young faults that are formed along the edge of an uplifting mountain range. The fact that most of the range-front faults, found in the basin, are normal faults has led geologists to believe that the repeated vertical motion along the normal fault systems is the major cause of the characteristic basin’s topography. Some of these faults are active faults.
The definition of the term thin bed involves the concept of the resolving power (Widess, 1973) thus seismics is impacted by resolution. Most geological structures have a smaller vertical dimension than a horizontal one (Chang et al, 1996), thus, the ratio of the vertical dimensions plays a very important role in seismic resolution. As the dimension ratio decreases, the difficulty in identifying geological events increases and become more challenging (Chang et al, 1916). Sheriff, (1991) defines Seismic resolution as the ability to separate two features that are very close together; the minimum separation of the bodies before their identifies are lost. It is seen as the minimum distance between two events that can be seen
These technologies are found in nearly every aspect of mineral development activity - from exploration methods, through production, mineral processing and even marketing. Computers and related equipment now have a lot of different applications in geophysical logging, geochemistry, geological mapping and surface contouring5. At the mine planning stage, the job of designing a mine is now greatly simplified by automation. Through the use of advanced software, geological models can be produced from drill hole data. Computers are also being used to develop plans for mine expansion, develop mining schedules for yearly, quarterly and in some cases, weekly operations. At the operating stage, this new technology is everywhere6.
This Inverted topography is the result of gravitative flow process (a tectonic diapirism) due to the differential loading or unloading caused by the excavation of valleys. As for as faulting is concerned,... ... middle of paper ... ... f plastic rocks.
The 6.7 magnitude earthquake was felt throughout most of southern California and as far away as Utah and Mexico with a max acceleration of 1.0g in several different areas and the highest at Tarzana with a recorded value of 1.8g. The earthquake also deformed over 1500 square miles of the Earth’s crust, forcing the surface upward in a dome shape. The Susana Mountains sustained the most soil deformation with an uplift of around 15cm causing numerous rockslides, blocking many roadways. Soil liquefaction was observed in the Simi Valley area and other parts of the Los Angeles Basin. After all the term oil ended the preliminary cost estimate of damage was between 15 and 20 billion U.S. dollars. Today, Geologists remain to search for thrust faults throughout the southern California area by using a 3 dimensional modeling system to view folds and upli...
The field of geology has many different branches. Some of these areas have hardly anything in common. The one thing that they all include, though, is that each one concentrates on some part of the Earth, its makeup, or that of other planets. Mineralogy, the study of minerals above the Earth and in its crust, is different from Petrology, the st...
Most people don’t know the difference from a hanging wall and footwall. A footwall is the underlying block of a fault having an inclined fault plane. And a hanging wall is the mass of rock overlying a mineral deposit in a mine. (add citation from the book)
Waltham, Tony. "Sinking cities." Geology Today 18.3 (2002): 95+. Academic OneFile. Web. 08 Feb. 2014.
Earthquakes belong to the class of most disastrous natural hazards. They result in unexpected and tremendous earth movements. These movements results from dissemination of an enormous amount of intense energy in form of seismic waves which are detected by use of seismograms. The impact of earthquakes leaves behind several landmarks including: destruction of property, extensive disruption of services like sewer and water lines, loss of life, and causes instability in both economic and social components of the affected nation (Webcache 2).