Earthworks (engineering)

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Caterpillar D10 bulldozer at work CAT-D10N-at-work-01.jpg
Caterpillar D10 bulldozer at work

Earthworks are engineering works created through the processing of parts of the earth's surface involving quantities of soil or unformed rock.

Contents

Shoring structures

An incomplete list of possible temporary or permanent geotechnical shoring structures that may be designed and utilised as part of earthworks:

Excavation

Earth moving equipment (c. 1922) Bell telephone magazine (1922) (14569641579).jpg
Earth moving equipment (c.1922)
Flattened and leveled construction site. Road roller in the background. Construction site near Yass site cleared and bull dozed cleared steam roller in background.JPG
Flattened and leveled construction site. Road roller in the background.

Excavation may be classified by type of material: [1] :13.1

Excavation may be classified by the purpose: [1] :13.1,13.2

Civil engineering use

Typical earthworks include road construction, railway beds, causeways, dams, levees, canals, and berms. Other common earthworks are land grading to reconfigure the topography of a site, or to stabilize slopes.

Geofoam is a new lightweight earthworks technique used to build a bridge overpass on weak soil near Montreal. Geofoam bridge overpass.jpg
Geofoam is a new lightweight earthworks technique used to build a bridge overpass on weak soil near Montreal.

Military use

Earthworks ditch and rampart in Germany - age prehistorical prior to 300 BC Ipf Wall.jpg
Earthworks ditch and rampart in Germany - age prehistorical prior to 300 BC

In military engineering, earthworks are, more specifically, types of fortifications constructed from soil. Although soil is not very strong, it is cheap enough that huge quantities can be used, generating formidable structures. Examples of older earthwork fortifications include moats, sod walls, motte-and-bailey castles, and hill forts. Modern examples include trenches and berms.

Equipment

Heavy construction equipment is usually used due to the amounts of material to be moved — up to millions of cubic metres. Earthwork construction was revolutionized by the development of the (Fresno) scraper and other earth-moving machines such as the loader, the dump truck, the grader, the bulldozer, the backhoe, and the dragline excavator.

Mass haul planning

Excavation of over 76 million cubic metres (23 million cubic metres of which was additional to the planned amount due to landslides) for the Culebra Cut, Panama canal construction photo taken c. 1907 Panama Canal under construction, 1907.jpg
Excavation of over 76 million cubic metres (23 million cubic metres of which was additional to the planned amount due to landslides) for the Culebra Cut, Panama canal construction photo taken c.1907

Engineers need to concern themselves with issues of geotechnical engineering (such as soil density and strength) and with quantity estimation to ensure that soil volumes in the cuts match those of the fills, while minimizing the distance of movement. In the past, these calculations were done by hand using a slide rule and with methods such as Simpson's rule. Earthworks cost is a function of hauled amount x hauled distance. The goal of mass haul planning is to determine these amounts and the goal of mass haul optimization is to minimize either or both. [2]

Now they can be performed with a computer and specialized software, including optimisation on haul cost and not haul distance (as haul cost is not proportional to haul distance).

See also

Calculation software

Earthworks cut and fill map and estimation summary produced by Kubla Cubed EarthworksSoftware CutFillMap.jpg
Earthworks cut and fill map and estimation summary produced by Kubla Cubed

Earthwork software is generally a subset of CAD software, in which case it often an add-on to a more general CAD package such as AutoCAD. [3] In that case, earthwork software is principally used to calculate cut and fill volumes which are then used for producing material and time estimates. Most products offer additional functionality such as the ability to takeoff terrain elevation from plans (using contour lines and spot heights); produce shaded cut and fill maps; produce cross sections and visualize terrain in 3D. [4] The means by which volumes are calculated in software can differ quite considerably leading to potentially different results with the same input data. Many software products use methods based on triangulated irregular networks (TINS) and triangular prism volume algorithms, however other calculation methods are in use based on rationalizing elevations into high density grids or cross-sections. [5] [6] [7]

A few programs are specialised in earthworks transport optimization and planning the construction works.

Related Research Articles

<span class="mw-page-title-main">Geotechnical engineering</span> Scientific study of earth materials in engineering problems

Geotechnical engineering, also known as geotechnics, is the branch of civil engineering concerned with the engineering behavior of earth materials. It uses the principles of soil mechanics and rock mechanics to solve its engineering problems. It also relies on knowledge of geology, hydrology, geophysics, and other related sciences.

<span class="mw-page-title-main">Trench</span> Excavated channel in ground

A trench is a type of excavation or depression in the ground that is generally deeper than it is wide, and narrow compared with its length.

<span class="mw-page-title-main">Open-pit mining</span> Surface mining technique

Open-pit mining, also known as open-cast or open-cut mining and in larger contexts mega-mining, is a surface mining technique that extracts rock or minerals from the earth using a pit, sometimes known as a borrow pit.

<span class="mw-page-title-main">Slurry wall</span> Civil engineering technique

A slurry wall is a civil engineering technique used to build reinforced concrete walls in areas of soft earth close to open water, or with a high groundwater table. This technique is typically used to build diaphragm (water-blocking) walls surrounding tunnels and open cuts, and to lay foundations. Slurry walls are used at Superfund sites to contain the waste or contamination and reduce potential future migration of waste constituents, often with other waste treatment methods. Slurry walls are a "well-established" technology but the decision to use slurry walls for a certain project requires geophysical and other engineering studies to develop a plan appropriate for the needs of that specific location. Slurry walls may need to be used in conjunction with other methods to meet project objectives.

<span class="mw-page-title-main">Retaining wall</span> Artificial wall used for supporting soil between two different elevations

Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to. They are used to bound soils between two different elevations often in areas of inconveniently steep terrain in areas where the landscape needs to be shaped severely and engineered for more specific purposes like hillside farming or roadway overpasses. A retaining wall that retains soil on the backside and water on the frontside is called a seawall or a bulkhead.

<span class="mw-page-title-main">Berm</span> Raised bank of land or barrier

A berm is a level space, shelf, or raised barrier separating areas in a vertical way, especially partway up a long slope. It can serve as a terrace road, track, path, a fortification line, a border/separation barrier for navigation, good drainage, industry, or other purposes.

<span class="mw-page-title-main">Foundation (engineering)</span> Lowest and supporting layer of a structure

In engineering, a foundation is the element of a structure which connects it to the ground or more rarely, water, transferring loads from the structure to the ground. Foundations are generally considered either shallow or deep. Foundation engineering is the application of soil mechanics and rock mechanics in the design of foundation elements of structures.

<span class="mw-page-title-main">Engineering geology</span> Application of geology to engineering practice

Engineering geology is the application of geology to engineering study for the purpose of assuring that the geological factors regarding the location, design, construction, operation and maintenance of engineering works are recognized and accounted for. Engineering geologists provide geological and geotechnical recommendations, analysis, and design associated with human development and various types of structures. The realm of the engineering geologist is essentially in the area of earth-structure interactions, or investigation of how the earth or earth processes impact human made structures and human activities.

<span class="mw-page-title-main">Caisson (engineering)</span> Rigid structure to provide workers with a dry working environment below water level

In geotechnical engineering, a caisson is a watertight retaining structure used, for example, to work on the foundations of a bridge pier, for the construction of a concrete dam, or for the repair of ships.

<span class="mw-page-title-main">Cut and fill</span> Earthmoving technique to minimize labor

In earthmoving, cut and fill is the process of constructing a railway, road or canal whereby the amount of material from cuts roughly matches the amount of fill needed to make nearby embankments to minimize the amount of construction labor.

<span class="mw-page-title-main">Gabion</span> Cage full of rock

A gabion is a cage, cylinder or box filled with rocks, concrete, or sometimes sand and soil for use in civil engineering, road building, military applications and landscaping.

<span class="mw-page-title-main">Earth structure</span> Building or other structure made largely from soil

An earth structure is a building or other structure made largely from soil. Since soil is a widely available material, it has been used in construction since prehistoric times. It may be combined with other materials, compressed and/or baked to add strength.

<span class="mw-page-title-main">Deep foundation</span> Type of foundation

A deep foundation is a type of foundation that transfers building loads to the earth farther down from the surface than a shallow foundation does to a subsurface layer or a range of depths. A pile or piling is a vertical structural element of a deep foundation, driven or drilled deep into the ground at the building site.

Landslide mitigation refers to several human-made activities on slopes with the goal of lessening the effect of landslides. Landslides can be triggered by many, sometimes concomitant causes. In addition to shallow erosion or reduction of shear strength caused by seasonal rainfall, landslides may be triggered by anthropic activities, such as adding excessive weight above the slope, digging at mid-slope or at the foot of the slope. Often, individual phenomena join to generate instability over time, which often does not allow a reconstruction of the evolution of a particular landslide. Therefore, landslide hazard mitigation measures are not generally classified according to the phenomenon that might cause a landslide. Instead, they are classified by the sort of slope stabilization method used:

Grading in civil engineering and landscape architectural construction is the work of ensuring a level base, or one with a specified slope, for a construction work such as a foundation, the base course for a road or a railway, or landscape and garden improvements, or surface drainage. The earthworks created for such a purpose are often called the sub-grade or finished contouring.

<span class="mw-page-title-main">Cellular confinement</span> Confinement system used in construction and geotechnical engineering

Cellular confinement systems (CCS)—also known as geocells—are widely used in construction for erosion control, soil stabilization on flat ground and steep slopes, channel protection, and structural reinforcement for load support and earth retention. Typical cellular confinement systems are geosynthetics made with ultrasonically welded high-density polyethylene (HDPE) strips or novel polymeric alloy (NPA)—and expanded on-site to form a honeycomb-like structure—and filled with sand, soil, rock, gravel or concrete.

<span class="mw-page-title-main">Pressure grouting</span>

Pressure grouting or jet grouting involves injecting a grout material into otherwise inaccessible but interconnected pore or void space of which neither the configuration or volume are known, and is often referred to simply as grouting.

Geoprofessions is a term coined by the Geoprofessional Business Association to connote various technical disciplines that involve engineering, earth and environmental services applied to below-ground ("subsurface"), ground-surface, and ground-surface-connected conditions, structures, or formations. The principal disciplines include, as major categories:

<span class="mw-page-title-main">Digging</span> Removal of material from a solid surface

Digging, also referred to as excavation, is the process of using some implement such as claws, hands, manual tools 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. 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.

The Neoloy Geocell is a Cellular Confinement System (geocell) developed and manufactured by PRS Geo-Technologies Ltd. Geocells are extruded in ultrasonically welded strips. The folded strips are opened on-site to form a 3D honeycomb matrix, which is then filled with granular material. The 3D confinement system is used to stabilize soft subgrade soil and reinforce the subbase and base layers in flexible pavements. Cellular confinement is also used for soil protection and erosion control for slopes, including channels, retention walls, reservoirs and landfills.

References

  1. 1 2 Frederick S. Merritt, M. Kent Loftin, Jonathan T. Ricketts, Standard Handbook for Civil Engineers, Fourth Edition, McGraw-Hill Book Company, 1995.
  2. "Earthworks cost optimization through mass haul planning". www.topconplanning.com. Archived from the original on 2 April 2015. Retrieved 7 June 2015.
  3. "Taking the Measure of Methods for Estimating Earthwork Volumes - Forester Network". Forester Network. Retrieved 2016-02-09.
  4. "Vertigraph, Inc. -- Automating the Takeoff & Estimating Process". www.vertigraph.com. Archived from the original on 2015-12-15. Retrieved 2016-02-09.
  5. "How to Estimate Cut and Fill Volumes for Earthworks Projects | Grid Method, Cross Section Method, Earthworks Software". www.kublasoftware.com. Retrieved 2016-02-09.
  6. "Vertigraph, Inc. -- Calculating Cut and Fill Quantities : Modern Techniques and Best Practices". vertigraph.com. Archived from the original on 2016-01-31. Retrieved 2016-02-10.
  7. Cheng, Jian-chuan; Jiang, Long-jian (2013-11-06). "Accuracy Comparison of Roadway Earthwork Computation between 3D and 2D Methods". Procedia - Social and Behavioral Sciences. Intelligent and Integrated Sustainable Multimodal Transportation Systems Proceedings from the 13th COTA International Conference of Transportation Professionals (CICTP2013). 96: 1277–1285. doi: 10.1016/j.sbspro.2013.08.145 .