1. INTRODUCTION
Rock mechanics is a discipline that uses the principles of mechanics to describe the behaviour of rock in different engineering scale level. Usually for engineering projects (slopes, tunnels and foundations), the scale ranges from a few tens to a few hundred meters. At engineering scale, rock is said to be inhomogeneous, discontinuities, anisotropic and non-linearly elastic. Besides that, rock mechanics also deals with the response of rock when the current boundary condition is disturbed; for instance, excavation of a tunnel in the ground, the in-situ stress of the rock is disturbed.
In this advanced rock mechanics module, a few major rock mechanics topics had been discussed; from the basic fundamental knowledge of the natural
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Therefore, in this report, the knowledge gained in this module are summarized and arranged into several sections. Firstly, a brief introduction about the background and the formation of rock will be discussed in Section 2. The formation process of three different categories of rocks is clearly illustrated into a diagram- the rock cycle. Secondly, in different engineering scale, rock can be considered as continuous (intact rock) and discontinuous (rock mass). In general, rock is a discontinuous medium because there is existence of various type of discontinuities. Rock mass and rock discontinuities especially rock joints are studied. The rock behaviors are usually governed by the properties of rock mass and rock joints. Therefore, several classification schemes that are used to estimate the rock mass properties as well as the geometrical, …show more content…
Igneous rock is formed when molten rock (magma) cools and solidifies, with or without crystallization. Igneous rock is then further classified into intrusive and extrusive; this phenomenon will affect the grain texture of the rocks. Intrusive igneous rock is rock that formed below the Earth surface whereas extrusive igneous rock is erupted onto the surface, hence this leads to the formation of coarse-grained and fine-grained rocks respectively. Sedimentary rock is formed from several ways; (i) the deposition of the weathered remains of the other rocks, (ii) the deposition of the results of biogenic activity, and (iii) the precipitation of solution. As for metamorphic rock, it is the formation of new rock from the transformation of an existing rock through metamorphism, i.e. the process in which the rock is subjected high heat and pressure. In comparison between the three types of rocks; igneous, sedimentary and metamorphic rocks, sedimentary rocks have a lower material strength than igneous and metamorphic rocks. This is due to the texture of the rock itself. In another words, the grains of sedimentary rocks are usually clastic which means that the
Riley, C.M. "Lahars." Geological and Mining Engineering Sciences. Michigan Tech. Web. 6 Feb. 2010. .
and Metamorphic rocks can be found. There are also a lot of crusted plates, and violent
Hartman, Howard L., and Jan M. Mutmansky. "Introduction to Mining." Introduction to Mining Engineering. 2nd ed. N.p.: Wiley, 2002. 1-22. Print.
The rock coquina is originally a sedimentary rock. Sedimentary rocks are made up of sediments. The sediments are formed by the mechanical or chemical activities of the natural activities like running water, blowing wind, glaciers etc. this which causes disintegration and decomposition of the pre-existing rocks. The products of decay are transported to some depositional sites by the natural agencies, where they get deposited and with subsequent compaction form sedimentary rocks (Hefferan, O’Brien, 2010). . The sedimentary rocks usually accumulate under a great variety of conditions. This shows the variation in rock, chemical structure as well as in texture. Weathering is the most important process that operates in the formation of sedimentary rocks. Weathering takes place by three methods as: mechanical disintegration, rock decomposition, and biological weathering. Mechanical disintegration is due to frost action, thermal expansion and contraction, aided with gravitational forces. Due to mechanical disintegration, the reduction of size and desegregation of rocks takes place. Chemical weathering is the use of the chemical elements of the atmosphere such as moisture, carbon dioxide, and oxygen (Hefferan, O’Brien, 2010). . This depends on the composition of the rock and the size of the particles that make up them. Biological weathering is a form of weathering caused by growth of roots and burrowing of animals. The environment of a sedimentary rock can show the deposition the quality and quantity of the deposition is affected. Sedi¬mentary rocks differ from environment to environment. These environments include the continental environments such as estuarine, lacustrine (fresh and salt water), deltaic, glacial. Anothe...
This is related to the blending of the fluids and rocks of the reservoir. Skeletal properties of interest to reservoir engineers include porosity, pore size distribution, compressibility, and absolute permeability of the rod. Interaction or dynamic properties of reservoir rocks are affected by the nature and by its interaction with present fluids, as...
...e shaped and given a smooth finish by rubbing rock on rock, an abrasive. For gouging and digging, artists used a drill tipped with extremely hard stone and a mounted by a rod weighted down with bags of small stones and rotated by a handle. This method required immense amounts of dexterity and patience.
The Saldania mobile belt comprises of structural features that are characterised by the occurrence of ductile and dextral strike-slip shearing that preceded the orogenic event which occurred approximately 600 Ma (Scheepers, 2000). This led to the first phase of magmatism about 560-540 Ma (Scheepers & Nortje, 2000). This phase involved the syn- to post tectonic S- type granites intruding the Tygerberg terrane (Scheepers & Nortje, 2000). The second phase involved the intrusion of the I-type granites. Like the S-type granites, the strike-slip movement affected the intrusion of the I- type granitoids which occurred along the Colenso fault in the Swartland and Boland terranes about 540- 520 Ma (Scheepers, 1995; Scheepers & Nortje, 2000). The intrusion of the post-orogenic to anorogenic A- type granites occurred at approximately 520- 500 Ma, representing the third phase of magmatism (Scheepers & Nortje, 2000). They are intrusive in the Tygerberg and Swartland terranes (Scheepers & Nortje, 2000). The final phase of magmatism is often negle...
In Colorado you can find both intrusive and extrusive igneous rocks that date all the way back to the Precambrian era. According to Colorado’s Geological Survey's website “at one time, about 2/3 of Colorado was covered by [extrusive] rocks but much has eroded” (“Volcanic rocks,” 2013). Today, Colorado is home to many different types of intrusive igneous rocks, such as: alkalic complexes, batholiths, dikes, kimberlite diatremes, plugs, sills, and stocks.
This particular sample of granite is phaneritic in texture as described by its visible crystals. The rate at which the rocks cool determines the size of the crystals, in this case, a steady cooling rate produces larger crystals (“Characteristics of Igneous Rocks” n.d). The rate at which rocks cool is also related to the temperature of cooling which determines a rocks mineral composition (“Characteristics of Igneous Rocks” n.d). A low cooling temperature yields rocks with higher amounts of potassium, aluminum, and silicon (“Characteristics of Igneous Rocks” n.d). This is evident by the abundance of potassium feldspar, which also makes granite a felsic
The velocity of the rock at any given point can be determined by adding it's translational velocity at the center of mass (the orange arrow) with it's rotational velocity.
There are a number of technical challenges that must be overcome to advance the concept of in-situ borehole extraction of non-soluble tabular resources to a commercially viable stage. One of the most important challenges is a technical understanding between cavity formation and stability for a given set of operating characteristics and geomechanical rock properties. The first step is to find a numerical code that is more user friendly and also can yield dependable results. Itasca Flac2D code was selected for this ongoing research. The main objective of this research was to verify if a widely employed 2-dimensional modeling software package (ItascaFlac2D) had sufficient accuracy to perform a stress analysis within a borehole mining system as part of a predictive design protocol. To achieve this objective, data derived from an empiric field study was modeled using Flac2D, and the results were compared to those obtained from a case study that used a three dimensional model (Flac3D). The case study data used in this chapter was obtained from a subsidence study prepared by Barr Engineering Company for Cooperative Mineral Resources (CMR) [1]. CMR sought to collect samples from two enriched manganese zones within an oxidized iron-formation at a site located near Emily, Minnesota. Through bulk sampling, CMR intended to evaluate the potential of using a small scale Borehole Mining (BHM) system that employed waterjet technology. CMR believed that the enriched manganese zones in the resource were suitable to BHM excavation methods and as part of the technical feasibility of the project, a subsidence study was performed by Barr Engineering. One of the primary goals of this study was to determine if subsidence would occur under specific operating conditions and, if so, to develop a range of potential depth and the radial extents of the surface damage at the Project Area.
The natural rock gardening ideas are given by the nature. The rocky yards are covered with greenery in order to beautify the area. In the rock gardens the stones, stumps, logs are not removed like the other garden types but are the vital elements of these gardens. Isolated boulders work as the miniature rock gardens which serve as ornament and containers. The natural rock gardens include various elements such as wood steps, path lined with rocks, boulders, variety of plants and rest atop pebbles which give the garden practical and vivid look. The rock garden plants are ferns, spruce evergreen and fir. The functional uses are less important than the aesthetic beauty of the rock gardens. The balance of textures and colors of the plants make the rock gardens visual...
Due to the fact that rocks are composed of high intensity of elastic and brittle material, they therefore store considerable amount of strain energy that results from elasticity, during the action of plate tectonic. The brittleness leads to development of concurrent cracks on the rocks as a result of plate’s action.
Igneous rocks are formed from the ejection of earth’s volcanoes. Deep down inside earth’s mantle there lies hot magma. Magma is molten rock that is kept below the surface. This mixture is usually made up of four parts: a hot liquid substance which is called the melt; minerals that have been crystallized by the melt; solid rocks that have made themselves tangled in the melt because of loose materials, and finally gases that have become liquid. Magma is created by an increase in temperatures, pressure change, and a alter in composition. When this magma is ejected from earth’s crust it earns a new name called lava. The lava hardens and becomes an Igneous rock.
Engineering Mechanics deals with the rigorous study of mechanics, applied mathematics and related fields. This leads to an understanding of advanced analysis and leads to study in structural engineering, hydraulics, mechanics of solids and fluids, or properties of materials.