Digging, also referred to as excavation, is the process of using some implement such as , , manual or heavy equipment, to remove material from a solid surface, usually soil, sand or rock on the surface of Earth. Digging is actually the combination of two processes, the first being the breaking or cutting of the surface, and the second being the removal and relocation of the material found there.Carl Dreher, " The Right Way to Dig", Popular Science (March 1957), p. 179. In a simple digging situation, this may be accomplished in a single motion, with the digging implement being used to break the surface and immediately fling the material away from the hole or other structure being dug.
Many kinds of animals engage in digging, either as part of burrowing behavior or to search for food or water under the surface of the ground.Zen Faulkes, " Morphological Adaptations for Digging and Burrowing" (2013), p. 276-295. Historically, humans have engaged in digging for both of these reasons, and for a variety of additional reasons, such as engaging in agriculture and gardening, searching for minerals, metals, and other raw materials such as during mining and quarrying, preparing for construction, making fortifications and irrigation, and also excavations in archaeology, searching for and rocks in palaeontology and geology and burial of the dead.
Like other animals, humans dig in the ground to find food and water. Wood-lined are known from the early Neolithic Linear Pottery culture, for example in Kückhoven (an outlying centre of Erkelenz), dated 5090 BC and Eythra, dated 5200 BC in Schletz (an outlying centre of Asparn an der Zaya) in Austria. Humans are unique among animals in the practice of burial of the dead. Intentional burial, particularly with grave goods, may be one of the earliest detectable forms of religious practice since, as Philip Lieberman suggests, it may signify a "concern for the dead that transcends daily life". Evidence suggests that the Neanderthals were the first Homo to practice burial behavior and intentionally bury their dead, doing so in shallow graves along with stone tools and animal bones.Chris Scarre, The Human Past Exemplary sites include Shanidar in Iraq, Kebara Cave in Israel and Krapina in Croatia. Some scholars, however, argue that these bodies may have been disposed of for secular reasons. Notably, burial of the dead prevents diseases associated with the presence of corpses, and prevents and other predators from being attracted.
The earliest undisputed homo sapiens burial discovered so far dates back 100,000 years. Human skeletal remains stained with red ochre were discovered in the Skhul cave at Qafzeh, Israel. A variety of grave goods were present at the site, including the mandible of a wild boar in the arms of one of the skeletons.
As human technology advanced, digging began to be used for agriculture, mining, and in earthworks, and new techniques and technologies were developed to suit these purposes.
In some cases, the borrow pits may become filled with ground water, forming areas or sustainable wildlife habitats (one such example is the Merton Borrow Pit, near Oxford in central England, excavated to provide materials for the nearby M40 motorway). In other cases, borrow pits may be used for landfill and waste disposal.
Borrow pits are common archaeological features in Waikato, where sand and gravel were dug to mix with clay topsoils to improve their drainage and friability, to suit growth of kūmara and taro, brought by Māori from tropical islands.
A regional variation of this is termed " barrow pit" in the western United States (especially the Rocky Mountains). The localism—sometimes pronounced "borrer pit"—describes the ditch along a roadway. These ditches were excavated to provide the fill to level and crown the roadway and subsequently provided drainage for the road.Cassidy, Frederic Gomes, and Joan Houston Hall (eds). (2002) Dictionary of American Regional English. Cambridge, Massachusetts: Harvard University Press.
An excavation lake (also a flooded gravel pit) is an artificial lake, which usually has its origins in the excavation of gravel or sand for construction materials or in some other kind of surface mining. In many cases, the excavation holes are landscaped according to the land restoration required by law. Because the excavation reached a point below the water table, lakes form naturally. Less frequently, excavation lakes are intentionally made, especially as .
In Germany and Austria the lakes are almost always used for fishing, since a fishery is created by law with every surface water. At some excavation lakes, beaches are added for swimming or other water sports, in particular boating, water skiing or windsurfing. To support these uses, large parking lots, changing areas, and eating areas are also set up. In some cases, the excavation lake serves as a nature reserve, as in the case of the lakes in the Attenborough Nature Reserve.
Historically, manual shoveling (often in combination with pickaxe) was the chief means of excavation in construction, mining, and , and digging projects employed large numbers of people. After the Industrial Revolution, mechanization via and later hydraulics equipment ( such as and loaders) gradually replaced most manual shoveling; however, individual homeowners still often find reasons to engage in manual digging during smaller-scale projects around the home. Different methods of digging can also result in different excavation depth and force, potentially risking exposure or damage to subsurface pipelines and wiring. In the United States and Canada, homeowners and contractors are required to notify a utility-run call center before digging to ensure they do not strike buried utilities and infrastructure.
The rippability of an earth (rock) material is a measure of its ability to be excavated with conventional excavation equipment.(accessed 17-Sep-2009) A material may be classified as rippable, marginally rippable or non-rippable. The rippability of a material is often evaluated by an engineering geologist and/or geophysicist utilizing the seismic refraction equipment (see refraction). Rippability studies can involve the performance of seismic refraction traverses, the drilling of borings with an air percussion drill rig, the excavation of test trenches with a bulldozer with rippers or backhoe, and by geologic mapping.
|
|