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Civil Engineering
Civil Engineering is a profession of designing and executing structural works that serve the general public, like houses, buildings, roads, etc. A Civil Engineer is an engineer trained in the design and construction of public works, such as bridges or dams, and other large facilities.
4,921 Questions
Gravel is an inorganic material typically made up of small, rock fragments. It is not considered organic because it does not contain living organisms or come from once-living materials.
What is the spring constant of a slinky?
The spring constant of a slinky can vary depending on factors such as the material it is made of, its design, and manufacturing process. Typically, the spring constant of a slinky is around 1-2 N/m.
What is porosity in relation to groundwater?
Porosity is a measurement of the ratio of pore space to solids in a given volume of material.
The pore spaces form in soils and rocks due to the gaps between the individual clasts or grains that aggregate to form them. Compaction and consolidation (where the soil or rock is compressed) can force the grains closer together and so reduce the size of the pore spaces and so decrease the porosity.
Below the phreatic surface or water table, these pore spaces are normally filled with water (there are exceptions however for simplicities sake it is a reasonable assumption). The larger the porosity of a rock or soil, the more space per unit volume there is to store groundwater. Also the larger the interconnections between the pore spaces and the greater the number of interconnections, the more permeable the material will be to the movement of groundwater.
Porosity is a dimensionless quantity which is calculated by dividing the volume of void space by the total volume of the material in question. There are a number of methods of determining the value of the porosity of a material and for more information please see the related link.
What produces cross-sectional views?
Cross-sectional views are typically produced by slicing an object along a plane perpendicular to its axis. This allows for a detailed examination of the internal structure and features of the object. Technologies such as computerized tomography (CT) scans, magnetic resonance imaging (MRI), and engineering drawings are commonly used to create cross-sectional views.
What remedial measures could be adopted to overcome an imminent mass movement?
That depends on the exact nature of the mass movement!
Rock masses:Areas that may be prone to rock falls or rock slides are commonly assessed by an engineering geologist. They will attempt to identify regions where the rock mass forming the slope or cliff face is at risk of failure.These regions are likely to be those where there is weak material (for example a band of shale in other higher strength sedimentary rocks) or areas where the structure of the rock mass makes a failure more likely to occur. An example might be where the bedding planes or joints within the rock mass dip steeply towards the slope face.
When they identify areas where failure is a potential risk, they will then suggest a solution depending on the exact nature of the potential problem. Solutions may include rock bolts which are used where discrete blocks in a rock mass might fall from the face of a cliff and the bolt or anchor essentially acts to secure the block to the stable rock mass behind. Rock anchors perform a similar role to rock bolts but are used where greater restraining forces are required.
Other solutions include the scaling of the face. This involves removing loose material and small loose blocks that have the potential to fall. The engineer may also recommend that retaining structures are built in front of certain portions of the weak rock mass to act to support weakened material. Rock catch netting may also be attached to the face of a potentially unstable slope to catch small blocks which may fall from the face. Larger collapse may be halted by rock catch fences which are high strength steel posts secures firmly into the ground and which are connected by rows of high tensile strength steel cable. These are placed at the base of slopes or cliffs to halt any larger blocks which may fall from the cliff face.
Another solution which is commonly used before the application of rock bolts is "shotcreteing". This is when a reinforcing steel mesh is bolted to the rock face and then high viscosity concrete is sprayed onto the face. This sets and acts to support the rock face. An extreme solution may be to actually trim the rock face back to an angle that is stable however this is commonly not possible / economic.
Soils / Soil slopes:If the mass movement is acting in soil slopes there are a number of potential solutions which commonly involve either increasing the strength of the soil mass or reducing the stress acting upon it.Soil nailing is a process whereby steel bars are grouted into holes drilled into the unstable soil slope face. These are places in a regular array and act to reinforce the soil by increasing it's tensile and shear strength.
Mini piling is similar in concept to soil nailing however the piles are commonly of higher strength and larger dimensions than a soil nail and so would be used in situations where a greater restraining force is required to support the soil mass but also require more extensive and expensive works to place.
Other solutions include lime stabilisation which involves boring columnar holes into the soil and mixing a lime or other grouting material into the soil which acts to increase the soil strength, inhibiting the formation of shear planes and halting soil movement.
Another solution may be de-watering which is a process where the groundwater table is lowered. This acts to reduce the pore water pressure in the soil mass in turn increasing the in-situ stress and hence the shear strength of the soil which can halt movement.
Another potential solution is the planting of vegetation on the soil slope whereby the roots will act to bind the soil mass increasing it's strength and acting to inhibit the formation of shear surfaces which are commonly necessary for slope failures / movements to occur in soils. Vegetation will also act to reduce the infiltration rate of water into the soil which can reduce the fluctuations in pore water pressure which will act to increase the stability of the soil.
The above is a brief summary into methods that may be used to halt mass movements.
How can you prepare for a sinkhole?
In areas where sinkholes are common there are a number of engineering solutions that can make structures more resistant to the potential effects of sinkholes.
Foundation improvement:
A new building will likely be constructed on a reinforced concrete raft foundation which would be able to span any sinkhole likely to develop below it. Larger structure may also used piled foundations (piles are long thin foundation elements that extend into the ground and allow the building load to be spread onto deeper stronger layers) designed to bear on strata below the surface that are known to be competent (i.e. not likely to fail) based on data from a site investigation.
Existing building may undergo "underpinning" which is a process where the existing building is retrofitted with pile foundations to improve stability in the event that sinkhole subsidence may occur.
Ground improvement:
Where sinkholes form as the result of the collapse of subsurface voids (for example old abandoned mine workings) then a process known as "grouting" may be used. Depending on the exact nature of the underground voids, holes will be drilled and a mixture of cement grout and gravel will be emplaced in the voids. This material is viscous and the engineers are able to create cones within the void space that once set, act to support the roof of the void, stabilising it and so stopping the roof collapse from occurring in the first place. Smaller voids may be totally filled with the gravel / grout mix to stabilise them.
Signs that sinkhole or other subsidence may be occurring:
As a ordinary member of the public, there are some signs that you may wish to look out for that might warn you that a sinkhole is developing or that you are living in an area that they may occur:
Ponding of water in an area where this previously did not happen - this suggests that the ground surface is sinking and may indicate that a sinkhole is forming below this spot.
Other changes in drainage patterns - a spring drying up or the sudden loss of water from a stream or river, may also indicate subsurface movement.
A local history of mining - if mining has occurred in your local area (maybe consult local maps or historical maps for signs of old shafts, or the locations of collieries or other mines) then there is the potential for instability.
Cracking or changes in alignment - masonry structures are very sensitive to changes in ground level, especially if this occurs to different degrees along the length of a structure (known as differential settlement) and which causes tilting. This in turn can lead to the formation of cracks. If you notice cracks in your house and they appear to be getting larger, it would be sensible to consult a chartered surveyor / structural engineer to undertake an inspection. However most masonry structures undergo some degree of slight cracking and this is not necessarily a cause for alarm!
What to do as a member of the public:
It is important to realise that sinkhole subsidence can be a very sudden occurrence with very little prior warning, the best way to prepare for a sinkhole is to employ a qualified engineer to remediate (fix) the problem before it reaches the surface! If in doubt consult the authorities / a professional engineer or geologist!
What are physical properties of bitumen?
Bitumen is a black or dark-colored solid or semi-solid material that is sticky, water-resistant, and highly viscous. It is insoluble in water but soluble in carbon disulfide and carbon tetrachloride. Bitumen has a high melting point and can soften when heated.
What happens to water that does not percolate?
Water that does not percolate (move down through the soil) either is retained above the impermeable layer or becomes surface runoff.
What is the difference between Sandy Clay and Clayey Sand?
Their both the same, really, just two different names for sand with clay in it, however one might have more clay in one (sandy clay) than the other (clayey sand), but only by miniscule amounts.
What is the specific gravity of magnetite?
There is no such thing as a specific gravity for any element.
Would you think that percolation rate be greater in loamy sand thin in silt clay?
Yes, the percolation rate would generally be greater in loamy sand compared to silt clay. This is because loamy sand has larger particles with higher porosity and permeability, allowing water to move more freely through the soil compared to the fine particles in silt clay which can lead to slower percolation rates.
What is the specific weight of brc 3315 weldmesh?
Hi, In common the wire diameter is 1.2mm. And the weight of 30m is 13.2 kg. If the length is 20m, the total weight is 11kg.
Hope above all is useful for you.
Best Regards
Ailsa
Does a tall building have a longer natural period than a short one?
Yes, a tall building typically has a longer natural period of vibration compared to a shorter building. This is because the taller building has a greater mass and stiffness, which results in a slower oscillation frequency.
What is compression zone and tension zone?
In snow avalanches, when friction or other mechanical stops are not enough to hold it in place, and the angle is prime, it is held in place by tension and compression. The tension zones, are convex parts near the top and sides of the slide path; and compression zones, are the concave parts near the bottom and sides of the path. Snow is weak in tension and stronger in compression. If the load of snow on the slope has a lubricating layer, underneath it, and a good running surface, at sliding angle (38 degrees is prime), then the only thing hold the snow from sliding is the tension at the top, and the compression at the bottom. Upset this balance by either skiing through (cutting) one zone or the other, or use explosive in one of the zones, and you will have created a slab avalanche. In avalanche control they are often referred to as the "sweet spot"
Yes, a concrete slab is man-made. It is constructed by pouring and leveling concrete to create a flat and durable surface for building structures or pathways.
ABC gravel stands for Aggregate Base Course gravel, which is a mixture of finely crushed aggregate and sand used as a base for paving and construction projects. It is commonly compacted and graded before the application of asphalt or concrete surfaces.
What is the rising of cold water from deeper layers to replace warmer surface water called?
This process is called upwelling. Upwelling occurs when winds push surface water away, allowing cold, nutrient-rich water from deeper levels to rise up to the surface. This phenomenon is important for supporting marine ecosystems by bringing nutrients to the surface and supporting the growth of phytoplankton.
Can you convert cubic meter of concrete with density of 2400 kgm3 to metric tons of concrete?
To convert cubic meters to metric tons, you need to multiply by the density.
Cubic meters to metric tons: 1 m^3 of concrete * 2400 kg/m^3 = 2400 kg or 2.4 metric tons.
Therefore, 1 cubic meter of concrete with a density of 2400 kg/m^3 is equal to 2.4 metric tons of concrete.
What is the difference between a rock and a boulder?
rock is natural while stone is artificial.the rock found under the earths surface while the stone found anywhere on our earth's surface.
How is an orthophoto map different from a topographic map?
An orthophoto map is a true-to-scale aerial image that has been corrected for distortions caused by topography, whereas a topographic map represents the Earth's surface with contour lines to show elevation changes. Orthophoto maps are useful for visual interpretation, while topographic maps provide detailed information on terrain features and elevation.
What earthquake magnitude can a brick building withstand?
it all depends on the material that they build there building. In this case a brick building can resist if it has a good foundation of ground if not it could collapse. My best guess is less than 7.o or 6.6.
To glue wood to wood, apply a thin, even layer of wood glue to the surfaces you want to bond. Press the pieces together firmly and then clamp them in place until the glue dries, following the instructions on the glue bottle. Allow the glued wood to cure for the recommended time before handling it to ensure a strong bond.
13200 metric tons is how many cubic meters?
To convert metric tons to cubic meters, you need to know the density of the material. The relationship between metric tons and cubic meters depends on the density of the substance being measured. For example, for water, 1 metric ton is equal to 1 cubic meter.
Is there a geological phenomenon that swallows up people?
Sink holes are surface subsidence structures that form due to the collapse of underground voids. These voids may form naturally (e.g. due to the dissolution of rocks such as limestone or gypsum by groundwater) or be man made (e.g. mine workings). The surface subsidence pit can vary greatly in depth and diameter from less than a metre wide and 1/2 a metre deep to tens of metres in diameter. They don't swallow people up, however it would be possible for a person to fall into one of these features. There have also been occurrences where they have formed under or close to buildings causing instability and even collapse and which have caused fatalities.
Some further explanation of the sink hole phenomenon along with pictures of sink holes and the damage they can cause can be seen by viewing the related links.
How does one neutralize methane in a lift station?
It all depends on what you mean by neutralize. Methane is a gas given off when organic material decays with little of no oxygen present. It is an odorless flamable gas. Usually there are other gases formed at the same time (such as hydrogen sulfide) that has a bad smell. There is not much that can be done about it except vent it to the atomosphere to prevent explosions. In large treatment plants, it is collected and burned as a fuel but this is not practical in a lift station.
Anaerobic decay can be stopped by adding an oxidident such as chlorine. This kills the bacteria and stops decay until the chlorine combines into stable compounds. Then the decay will resume.
One way to prevent or minimize methane in the design process, is to dispatch the wastewater as quickly as possible. The longer it sits, in the tank, the more the decay and the more methane is produced. This can be accomplished by pumping more often. States usually regulate the storage and pumping requirements which may interfere with a good solution. They are less concerned with odor than they are making the station big enough to handle large periodic loads... which may increase the time the wastwater sits during times of low flows.
One simple improvement might be to pump the tank down at night (when the flow drops off) whether it has reached the "pumps on " level or not.. so it doesn't sit all night while the population is sleeping.
