Types of Surveying
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Surveying has a
broader scope of application. Its importance is felt in the following areas
and/ or services:
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Classification Of Surveying
Surveying is
indispensable to a number of human endeavour, which use surveying principles
and practice to their required areas of application. The types of surveying
and application are identified and explained below:
1.
ALTA, ACSM Survey:
This a surveying
standard jointly proposed by the American Land Title Association and the
American Congress on surveying and mapping that incorporates elements of the
boundary survey, mortgage survey, and topographic survey. ALTA/ACSM Surveys,
frequently shortened to ALTA surveys, are often required for real estate
transactions.
2.
Archaeological survey:
Used to accurately
assess the relationship of archaeological sites in a landscape or to
accurately record findings on an archaeological site.
3.
Agricultural Development Survey:
It is a survey
carried out to assess the production, yield studies, growth, and the
development of agricultural sector taken over a specified period of time
saying 2001-2008.
4.
As–build survey:
Is a survey conducted
several times during a construction project to verify, for local state and
federal boards, that the work authorized was completed to be specifications
set on the plot plan or site plan. This usually entails a complete survey of
the site to confirm that the structures, utilities, and roadways proposed
were built in the proper locations authorized in the plot plan or site plan.
As – built survey is usually done 2-3 times during the building of a house,
once the foundation has been poured, one after the walls are put up, and at
the completion of construction.
5.
Bathymetric survey:
This is a survey
carried out to map the seabed profile.
6.
Boundary survey:
A boundary survey to
establish the boundary of a parcel using its legal description which
typically involves the corners or restoration of monuments or markers at the
corners or along the lines of the parcel, often in the ground, or nails set
in concrete or asphalt in the past, wooden posts, blazes in trees, piled
stone corners or other types of monuments have also been used. A map or plat
is then drafted from the field data to provide a representation of the parcel
surveyed.
7.
Construction Survey:
This is otherwise
described as “Lay-out” or “setting out”. It is the process of establishing or
marking the position and detailed layout of new structures such as roads, or
buildings for subsequent construction. Surveying is regarded as a
sub-discipline of civil engineering all over the world. All degree and
diploma level engineering institutes world wide have detailed items of
surveying in the curriculum for undergraduate courses in the discipline of
civil engineering.
8.
Deformation Survey:
This is a survey
carried out to determine if a structure or object is changing shape or
moving. The three dimensional positions of specific points on an object are
determined. A period of time is allowed to pass and these positions are then
re- measured and calculated, and a comparison between the two sets of
positions is made.
9.
Erosion and sediment control plan:
This is a plan that
is drawn in conjunction with a sub division plan that denotes how up coming
construction activities will affect the movement of storm water and sediments
across the construction site and into abutting properties and how developers
will adjust grading activities to limit the depositing of more storm water
and sediment into abutting properties than was done prior to construction
10.
Foundation survey:
A survey done to
collect the positional data on the foundation that has been poured and is
curved. This is done to ensure that the foundation was constructed in the
location authorized in the plot plan, site plan, or sub division plan. When
the location of the finished foundation is checked and approved, the building
of the remainder of the structure can commence. This should not be confused
with an As-built survey which is not to be done until a particular lend of
work is completed on the required stage.
11.
Geological Survey:
It is a generic term
for a survey conducted for the purpose of recording the geologically
significant features of the area under investigation. In the past in the
remote areas, there was often no base topographic map available, so, the
geologist also needed to be a competent survey or to produce a map to the
terrain, on which the geological information could then be draped. More
recently, satellite imagery or aerial photograph is used as a base, where no
published map exists. Such a survey may also be highly specialist for
instance focusing primarily on hydro-geological, geochemical or geomagnetic
themes.
12.
Hydrographic Survey:
Hydrographic survey
is a survey conducted with the purpose of mapping the coast line and seabed
for navigation, engineering, or resource management purposes. Products of
such surveys are nautical charts.
13.
Mortgage survey or physical survey:
It is a simple survey
that generally determines land boundaries and building locations. Mortgage
surveys are required by title companies and lending institutions when they
provide financing to show that there are no structure encroaching on the
property and that the position of structures is generally within zoning and
building code requirements. Some jurisdictions allow mortgage surveys to be
done to a lesser standard, however most modern Nigerian minimum standards
require the same standard of care for mortgage surveys as any other survey.
The resulting high price of mortgage surveys has led some lending
institutions to accept mortgage inspections not signed or sealed by the
surveyor.
14.
Plot plan or site plan:
It is a proposal plan
for a construction site that include all existing and proposed conditions on
a given site. The existing and propose conditions always, include hydrology,
drainage flows, endangered species habitat, among others.
15.
Soil survey:
This is also called
soil mapping. It is the process of determining the soil types or other
properties of the soil covered over a landscape, and mapping them for others
to understand and use.
16.
Subdivision Plan:
It is a plot or map
based on a survey of a parcel of land. Boundaries lines are drawn inside the
larger parcel to indicate the creation of new boundary lines and roads. The
number and location of plats, or the newly created parcels, are usually
discussed back and forth between the developer and the surveyor until they
are agreed upon. At this point, monuments, usually in the form of square
concrete blocks or iron rods or pins are driven in to the ground to mark the
lot corners and curve ends, and the plat is recorded in the cadastre or land
registry. In some jurisdictions, the recording or filling of a subdivision
plat becomes, in effect a contract between the developer and the city or
country, determining what can be built on the property and under what
conditions. Always upon finally completion of a subdivision, an As-built plan
is required by the local government. This is done so that the roadway
constructed therein will pass ownership from the developer to say local
government by way of a contract called a covenant. When this stage is
completed, the roadways will now be maintained, repaved, swept, and plowed
(if necessary) by the local government.
17.
Tape survey:
This type of survey
is the most basic and inexpensive type of land survey. Popular in middle part
of the 20th century, tape surveys while being accurate for distance, lack
substantially in their accuracy of measuring angle and bearing. Considering
that a survey is the documentation of half (1/2) distance and half (1/2)
bearing, this type of survey is no longer accepted among local, state or
federal regulatory committees for any substantial construction work.
18.
Topographic survey:
This is surveys that
measures the elevation of point on a particular piece of land, and present
them as contour lines on a paper.
19.
Wetland Delineation and location survey:
This is a survey that
is completed when construction is to be done on or near a site containing
defined wetlands. Depending on the local state, and federal regulations,
wetlands are usually classified as areas that are completely inundated with
water more than two weeks during growing season. The boundary of the wetlands
is determined by observing the soil color, vegetation, erosion patterns,
scour marks, hydrology and morphology. Typically blue or pink coloured flags
are then placed in key locations to denote the boundary of the wetland. A
survey is done to collect data on location of the placed flags and a plan is
drawn to reference the boundary of the surrounding plots or parcels of land
and the construction work proposed within.
BUILDING
SURVEYING
Building surveying
emerged in the 1970s as a profession in the United Kingdom by a group of
technically minded general practice surveyors. Building surveying is a
recognized profession within Britain and Australia. In Nigeria in particular,
due to risk mitigation/ limitation factors, the employment of surveyors
undertaken in Nigeria are broad but include:
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Land Survey, Setting-Out Engineering, GIS Processing, Structural/Civil Works and General Contracts Call +2347064649087 www.heroizutechng.blogspot.com.ng
Friday, 15 July 2016
Lesson Note on Types of Surveying
Lesson Note On Maintenance of Surveying Equipments
Maintenance
of Surveying Equipment
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Surveying
equipment is being used under most stressful conditions. The equipment is
exposed to extreme weather conditions, used in dusty construction areas and
is subject to bumpy transportation. Proper care in the method by which
equipment is used, stored, transported, and adjusted is a major factor in the
successful completion of the survey. Lack of good maintenance practices not
only causes unjustified replacement costs, but also can serious the
efficiency and accuracy of the entire survey.
General Care and
Maintenance of Surveying Equipment and Tools
Surveying
instruments, which include theodolites, levels, total stations, electronic
measuring devices, and GPS receivers, are designed and constructed to provide
years of reliable use. The shafts, spindles, pendulums, and electronics of
precision instruments, although constructed for rugged field conditions, can
be damaged by one careless act, or continued negation prescribed procedures
for use, care, and adjustment of the instrument.
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Each new instrument is furnished with an operator’s manual. The manual
contains a description of the instrument, specifications of its various
components and capabilities, and applications. The manual also contains basic
instructions for use of the instrument and describes recommended servicing
and adjusting methods. The operator’s manual should be kept with the
instrument at all times. Each operator should thoroughly study the manual
prior to use of he instrument, particularly whenever prescribed field adjustments
are to be made. If the manual is lost, stolen, or damaged beyond use, a
replacement copy should be obtained as soon as practicable.
The
following general principles of care and servicing should be applied as a
routine matter for all survey equipment and supplies.
§ All equipment and tools should be
kept as clean and dry as practicable, particularly if they are to be
transported or stored for any length of time.
§ Wooden surfaces should be wiped
clean of caked mud or moisture prior to returning the equipment to the
vehicle. The original painted or varnished surfaces should be repaired as
often as needed to keep moisture from entering the wood.
§ Metal surfaces should be cleaned
and wiped as dry as practicable. A coat of light oil should be applied to
tapes and the metal parts of tools to prevent rusting during storage. Excess
oil should be wiped off.
Routine Care
of Surveying Instruments.
§ Before making the first set up of
the day, visually inspect the instrument for cracks, bumps, and dents. Check
the machined surfaces and the polished faces of the lenses and mirrors. Try
the clamps and motions for smooth operation (absence of binding or gritty
sound).
§ Frequently clean the instrument
externally. Any accumulation of dirt and dust can scratch the machined or polished
surface and cause friction or sticking in the motions.
§ Dirt and dust should be removed
only with a clean soft cloth or with a camel hair brush.
§ Non-optical parts may be cleaned
with a soft cloth or clean chamois.
§ Clean the external surfaces of
lenses with a fine lens brush and , if necessary, use a dry lens tissue. Do
not use silicon treated tissues, as they can damage the coated optics. It is
permissible to breath on the lens before wiping it, but liquids, such as oil,
benzene, water, etc., should never be used for cleaning purposes. DO NOT loosens or attempt to clean the
internal surface of any lens.
§ Cover an instrument whenever it
is uncased and not being used for any length of time, particularly if there
is dust or moisture in the air. After an instrument has been used in damp or
extremely cold situation, special precautions must be taken to prevent condensation
of moisture inside of the instrument. When working with the instrument in
cold weather, it should be left in the carrying case in the vehicle
overnight. If stored in a heated room overnight, the instrument must be
removed from the carrying case. If the instrument is wet or frost covered it
should be remove it from its case, and leave it at room temperature to dry
out.
3. Care in Transporting Surveying Equipment.
Vehicular
Transport
§ The major damage to equipment and
tools occurs when they are being placed into or taken out of the survey
vehicle. Other damage occurs during transport, when equipments is jostled
against other tools or equipment. Compartments (lined with carpeting, when possible)
should be provided to keep equipment and supplies separated. This not only
keeps the equipment from being damaged, it facilitates finding such items
more rapidly. Heavier items should be carried in the lower parts of vehicles
and they should never be in direct contact with other tools or equipment
below them.
§ The care, organization, and
general housekeeping of a vehicle are good indications of the attitude of the
entire survey crew. Keep passenger compartments free of unnecessary clutter
and equipment. Any equipment or material carried in the passenger compartment
should be firmly secured.
§ Transport and store instrument in
positions that are consistent with the carrying case design. Many instrument
cases indicate the position in which they should be transported. Treat
optical targets, prisms, and staffs with the same consideration.
§ Transport the instruments in
their carrying cases placed in a compartment cushioned with firm poly foam or
similar material to protect them from jolting or excessive vibrations.
§ Remember, loose equipment, out of
place tools, and general clutter not only contributes to damage of the items,
they also waste crew time in locating them and are a safety hazard.
Casing
and Uncasing
Before
removing an instrument, study the way it is placed and secured in the case.
The instrument must be replaced in the same position when returned to the
case. In removing the instrument from the case, carefully grip it with both
hands, but do not grip the vertical circle standard or where pressure will be
exerted on tubular or circular level vials.
Field
Transport of Surveying Instrument
Do
not “shoulder” or carry a tripod mounted theodolite or electronic
distance measuring equipment (EDM). These instruments should always be
removed from the tripod and secured in their carrying cases when moved.
These
precautions are necessary because the center spindle (center spigot or
standing axis) of a theodolite is hollow and relatively short. When carried
horizontally while on the tripod, the alidade’s weight is an excessive load
for the hollow centerpiece to bear. Instrument damage can result if the above
precautions are ignored. Also, the instrument fastener can break, causing the
theodolite to fall.
4. Care During
Instrument Setups
5. Adjustments
of Surveying Instruments.
Field
Adjustments
The
crew leader should develop a set of test procedure to be used frequently for
elimination of gross errors. Such tests should include a check of items such
as the level, optical plummet, and tripod. In the field, adjustments should
only be made when the instrument results are poor or require excessive
manipulation.
Normally,
each instrument should be periodically checked at a facility where the best
conditions for testing are possible. Only the adjustments described in the
manual for the instrument should be made in the field or shop. Do not “field
strip” (dismantle) instruments.
Major
Adjustments
When
an instrument has been damaged or otherwise requires major adjustments, it
will need to be sent to an authorized repair shop. The instrument should be
accompanied by a written statement indicating the types of repairs needed. In
the case of electronic devices, the request should describe conditions under
which the instrument does not function properly, i.e. coldness, dampness,
etc. if a “loaner” is needed, this should also be indicated.
6. Care of
Tools
7. Care of Theodolites and Total Stations
§ Although the instruments are
ruggedly built, careless or rough use and unnecessary exposure to the
elements can seriously damage them. If handled reasonably, they will provide
consistently good result with a minimum of downtime for repair or adjustment.
Some general guidelines for the care of instruments are:
§ Lifting – instruments should be removed
from the case with both hands, gripping the micrometer knob standard and base
on the older instruments. Newer instruments are equipped with a carrying
handle; the other hand should support the base. One hand should continually
support the instrument until the tribrach lock is engaged and the tripod
fixing screw secured.
§ Carrying Tripod - In most cases, the instrument
should be removed and re-cased for transportation to a new point. If the
point is nearby, the instrument should be carried in the vertical position
(tripod legs pointing straight down). An instrument should never be
“shouldered” or carried horizontally.
§ Adjusting collimation – The collimation error of
theodolites and total stations is determined by following the procedure
outlined in the users’ manual. If the collimation error is found to be
consistently in excess of ten seconds on the horizontal and twenty seconds on
the vertical, the instrument should be adjusted. The collimation adjustment
should be made in the field only by a specially trained individual. Otherwise,
the instrument should be returned to an authorized repair shop.
8. Care of EDM
Devices
§ EDMs are designed, contracted and
tested to withstand normal field conditions. They are however, precision
instruments and should be handled with the same degree of care required for
other types of precision survey equipment.
§ Secure EDM in vehicles in padded
compartments with substantial the downs so movement and jarring are
minimized. Cushion with firm polyfoam or similar material. Do not use soft
foam rubber. The instruments should be stored and transported in the position
indicated on the case.
§ Required maintenance of most EDMs
is minimal. However, protection from the elements and routine external
cleaning is necessary.
§ NEVER point an EDM directly at the sun.
The focused rays of the sun can damage sensitive internal parts.
§ Protect EDMs from excessive heat.
Heat can cause erratic readings and deterioration of components. Do not leave
instruments in closed vehicles that are parked in the sun. Avoid rapid
changing temperature, particularly from extreme cold to warm, which can cause
condensation in the internal parts of the instruments. Condensation can
normally be avoided by leaving the instrument in its carrying case for at
least 10 minutes and then opening the case to allow any trapped moisture to
evaporate. An instrument taken from a warm office or vehicle to an extremely
cold operating environment may require some time to adjust itself. The same
type of precautions should be taken to let the instrument cool off slowly.
§ Although EDM instruments are
water resistant and well shielded, keep them as dry as practicable. The case
should be opened and the instrument allowed to dry in a warm dry room when
not in sue.
§ Frequent partial discharge and
charge of batteries could cause the battery to lose its ability to hold
power. Periodically, batteries should be discharged completely and then
recharged overnight, or for the specified charge time. Effective usage of
batteries will also decrease at low temperatures. An EDM in the tracking mode
position will discharge the battery will also decrease at low temperatures.
An EDM in the tracking mode position will discharge the battery quite
rapidly, so it is important to be able to charge batteries to their maximum
capacity. In general, one should follow the user’s manual instructions on how
to maintain the batteries for top performance. If the batteries still fail to
hold power, they should be re-celled or replaced.
9. Care of
Tapes
§ Routine care extends tape life.
The following are basic guidelines for the care of tapes.
§ Do not place a tape where it can
be stepped on or run over, unless the tape is flat, taut, and fully supported
on a smooth surface. Keep the tape straight when is used. When pulling a
slack tape, a loop can develop into a kink and easily break the tape. Avoid
pulling a tape around poles or other object, as a hard pull can stretch or
break the tape.
§ Do not wind tapes overly tight on
their reels, as it can cause unwanted stresses and lead to stretching of the
tape.
§ After the day’s work, clean tapes
that are soiled. In wet weather, dry before storing. Clean rusty tapes with
fine steel wool and cleaning solvent or kerosene. Use soap and water when
tape is dirty or muddy. To prevent rust after cleaning, oil lightly and then
dry the tape.
§ Avoid storing in damp places.
10. Care of Tribrachs
Tribrachs
are an integral part of the precision equipment and should be handled
according. They should be transported in separate compartments or other
containers to prevent damage to the base surface, bulls eye level, and optical
plummet eye piece. Over tightening of the tripod fastener screw can put undue
pressure on the leveling plate.
11. Care of
Tripods
A
stable tripod is required for precision in measuring angles. A tripod should
not have any loose joints or parts which might cause instability. Some
suggestions for proper tripod care are:
12. Care of
Levels
Review
the previously stated guidelines for the care of instruments. These
guidelines are also generally true for the proper care of pendulum levels. Additional
guidelines are.
13. Care of
Leveling Rods.
Leveling
rods should be maintained and checked as any other precision equipment.
Accurate leveling is as dependent on the condition of the rods as on the
condition of the levels. Reserve an old rod for rough work, such as measuring
sewer inverts, mud levels, etc. The care requirements common to all types of
rods are:-
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Steps in carrying out Triangulation work - How to do triangulation
Steps in carrying out Triangulation
work - How to do triangulation
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Triangulation work is carried out in following step.
1.
Reconaissance:
In geodetic Surveying, reconaissance consists of: (See also: Reconaissance in
Transportation & Highway Engineering )
2.
Selection of Station:
The selection of station is based upon the following
consideration.
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3.
Intervisibility and Hights of Stations:
For indivisibility of two stations they should be fixed on
highest available ground. Such as mountain peaks rides or top of hills when
the distance b/t the two stations is great and the difference in elevation
b/t them is small then it is necessary to raise both the instrument and
signal to overcome the curvature of the earth and to clear all the
intervening obstruction.
The height of both the instrument and signal above the ground
depends upon.
3. 1. Distance between
stations:
If the intervening ground is free any obstruction, the distance
of a visible horizon form a station of known elves above datum as well as the
elves of the signal while may be just visible at a given distance can be
determine from the formula.
Where
H = ht.
of station above a datum
D = Dist from the station to point of tangent R = mean radius of earth M = co-efficient of refraction (0.07 for sight over land and 0.08 for sights over water)
D1 and R being expressed in same units. Alternatively, if ‘h’ is
in meter and D1 is in kilometer then
H (m) = 0.0673 D12 (km) ==> (A)
Or
H (ft) = 0.574 D1 (miles) ==> (B)
D1 and D2 can be determined and dist b/t two stations will be
(D1+ D2)
3. 2. Relative elevations of
stations:
A and B are the two stations
D = dist b/t A and B in km
Ha = known elev of ‘A’ above a datum H = required elev of ‘B’ above a datum D1 = distance (km) of ‘A’ from pt of tangency (p) D2 = distance (km) of ‘B’
Dist D1 can be calculated. Hence the required elev, h = 0.0673
D2
Ha = 0.0673 D12 or
h = 0.0574 D22 (miles)
 Or 
Now D2 = D - D1
Height or signal / Tower/ scaffold a B = Elev of datum + h - R.L
of st B elev of line sight
NOTE:
The line of sight should not be near the surface of ground at pt
of tangency on account of strata of disturbed air and should be kept at least
2m (61) above the ground permeably 3m (1D) and this allowance (clearance)
should be made in deterring the heights of stations.
3. 3. Profile of intervening ground:
If the peaks in the intervening ground are likely to obstruct,
the line of sight, their elevations and locations must be determined.
Procedure:
The elevation of line of sights at the respective points can be
computed and the results compared with the ground elevation at those points
to determine weather the line of sight clears all the intervening
obstruction.
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stationLesson Note On Hydrographic Surveying
Hydrographic Surveying
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Definition:
It is the branch of surveying which deals
with any body of still or running water such as a lake, harbor, stream or
river. Hydrographic surveys are used to define shore line and under water
features.
Objects
of Hydrographic Surveying:
Hydrographic surveying are carried out for
one or more of the following activities.
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Why
we need Hydrographic Surveys - Uses & Applications of Hydrographic Survey
Establishing Horizontal and Vertical Controls (Click Here)
The first step in making a hydrographic survey is to control both horizontal and
vertical.
Horizontal Controls:
In an extensive survey, the primary
horizontal control is established primarily by running theodolite and tape
traverse before the triangulation station. Tthe traverse lines being run to
following the shore lines approximately. In survey of less extent the primary
horizontal control only is required and is established by running a
theodolite and tape traverse sufficiently close to shore line. For rough
work, the control may be established by running a theodolite and staid
traverse or plane table trader.
Vertical Controls:
These are based upon a series of bench
marks established near the shore line by spirit leveling and these serve for
setting and checking tide gages etc to which the sounding are referred.
River Surveying
The survey of the shore line of a river is
made by running a theologize and tape traverse on a shore at a convenient
distance form the edge of the water. If the river is narrow, a single
theologize and tape traverse is on one bank and both banks. Located by staid
or plane table methods.
Sounding Surveying
The measurements of depths below the water
surface is called Sounding. The object of making soundings is to determine
the configuration of the bottom of the body of water. This is done by
measuring form the boat, the depth of water at various points
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