SURVEYING EQUIPMENT AND LEVEL SET-UP

SURVEYING EQUIPMENT AND LEVEL SET-UP The opposite figure shows a LEICA Level packages. Make sure the surveying equipment you will borrow is reliable and in good working order. To ensure this a two peck test must be carried out each time you borrow a level. Surveying instruments that you need to complete your projects,  can be borrowed from the following persons: Equipment For carrying out your project work you need to borrow the following equipment: Level Tripod Staff (5 metre) Staff bubble Measuring tape (50 metre) Wooden pegs (if needed) Additional equipment is needed for some other projects and the lecturer will inform you what you need to do this exercises. The following information is extracted from 'LEICA NA720 User Manual'. Level types There are different types (Leica, Sokkia, Wild) of levels you can borrow. The level opposite is a Leica NA720. Most level instruments have an automatic horizontal adjustment of the line of sight. Levels are supplied in a case in which the instrument can be shock proof stored. All survey levels operate in a similar way. The function and operation of levels is explained using the Leica 720 which is the most available instrument in the storerooms. Endless drive (both sides) Bubble level (to check horizontal plane) Mirror to view bubble level Base plate (sits on tripod) Footscrew (to adjust the horizontal plane) Eyepiece (focus adjustment Knurled ring (for horizontal circle reading) Objective Course aiming devise Focusing knob (turn until staff reading is clearly visible) Window for digital angle reading (see 7) Setting up the tripod Loosen screws of tripod legs, pull out to required length and tighten screws. In order to guarantee a firm foothold sufficiently press the tripod legs into the ground. When pressing the legs into the ground note that the force must be applied along the legs. Check all screws and bolts for correct fit. When setting up the tripod pay attention to a horizontal position of the tripod plate. Minor inclinations of the tripod can be corrected with the footscrews of the tribrach. Place level onto tripod head. Tighten central fixing screw of tripod. Turn footscrews A and B simultaneously in opposite directions until bubble is in the centre (on the imaginary "T"). Turn the instrument 90° and then turn the foot screw C until bubble is centred. If you want to centre an instrument over a ground point:   1. Attach plumb bob and arrange the tripod in such way that the plummet is over the point.   2. For fine adjustment loosen central fixing screw slightly and shift instrument parallel on tripod until the plummet is exactly over the point.   3. Tighten central fixing screw. Focusing telescope Aim telescope against a bright background (e.g. white paper). Turn eyepiece until reticule is sharp-focused and deep black. Now the eyepiece is adapted to your eye. Aim telescope on staff using the coarse aiming device. Turn focusing knob until image of staff is sharply focused. Levelling staffs (rods) and accessories There are many types of staffs, with names that identify the form of the graduations and other characteristics. Staffs can be one piece, but most of them are sectional and adjust the length by telescoping.. The metric staff has major numbered graduations in meters and tenths of meters (there is a tiny decimal point between the numbers). Our staves have an ''E'' shape mark (or its mirror image) with horizontal spaces between them of 10 mm. When viewed through an instrument's telescope, the observer can easily visually interpolate a 10 mm mark to a quarter of its height, giving a reading accuracy of 2.5 mm. On one side of the rod, the colours of the markings alternate between red and black with each meter of length. The Black arrows indicates where to push to extend the staff to its full length.                                                                  Staff readings The figure below shows three different staff readings: It is easy to read (b) and (c) because the cross-hair is exactly on a mark division. The reading for (a) is between 1.630 and 1.640. To assess the mm reading you have to estimate where the position of the cross-hair is. For (a) the reading is 1.636. The millimeter reading is to be estimated and can very between ± 1 mm. reading (a) is 1.636 (b) is exactly 1.500     and (c) is 1.580 Spirit & line levels There are a wide range of spirit levels to meet the varying requirements of specific jobs. The majority of those used on construction work are made of powder coated aluminum or die cast construction. The length varies from 800 mm to 2000 mm. Spirit levels are very handy for short distance levelling (depending on the spirit level up to 2 metres and with straight edge up to approximate 5 metres). The straight edge is used if the the points to be levelled exceed the length of the spirit level. The line level has been designed and made with two small hooks to hold it on a line as shown in the figure above. A line level is a level designed to hang on a string line. The level must hung in the center of the string and each ''leg'' of the string line extends the levels plane. The line level is a simple surveying instrument which can be used to lay out contours and gradients, and also to assist measuring horizontal distances at slope. Plumb bobs   A plumb-bob or a plummet is a weight with a pointed tip on the bottom that is suspended from a string and used as a vertical reference line. This instrument has been used since the time of the ancient Egyptians by bricklayers, masons, and carpenters to ensure that their constructions are "plumb", or perfectly upright. It may also be used in surveying to sight a point on the ground that is not readily visible. Small plumb bobs are often included in the kits of various instruments such as levels and theodolites. They are used to set the instrument exactly over a fixed datum marker, prior to taking fresh readings. In conjunction with the line-level the can also be used to assist the horizontal measurement on slopes. Water level An old device but a simple instrument for measuring the level differences of two points. This level, is illustrated in the opposite figure. The two levelling staffs are of the same length with a graduated tape attached to each stave. The tube is filled with water. The ends of the tube are fitted with rubber stoppers to prevent loss of water. The total length of tube defines the range of the instrument. Straight edge A 'straight edge' in conjunction with a spirit level and tape measure can be used to establish a gradient. The straight edge is usually 3 to 5 metres long and set horizontally with the aid of a spirit level. This method should be used for the measurement of gradients which continue only for short distances, e.g. to calculate the horizontal distance shown in plan-views. The figure below shows how a gradient for the ground profile is found. Measurements along a slope Distinguish between a horizontal distance and a slope distance. All distances should be measured 'horizontally'. Do not measure along slopes. Sag (tape are not supported for its length will sag under the influence of gravity) and to a lesser extent temperature may have an effect on the distance measurement also. To reduce the sag break tape measurement into shorter lengths. The sum of horizontal lengths (L1 & L2) equals the horizontal distance of the slope from A to C. Remember the horizontal distance is always shorter than the measurement on the slope. For an accurate measurement, the tape should be held horizontal and straight with a specified tension applied to it. Slopes - Gradient calculations A slope is the steepness, incline, gradient, or grade of a straight line, and it is defined as the ratio of the "rise" divided by the "run" between two points on a line. The gradient of a straight line shows how steep a straight line is. The slope of a line in the plane containing the y (rise) and x (run) axes may be represented as: (a) gradient      (1:50;  1:2) (b) percentage  ( 2%; 50%) (c) decimal fraction  (0.02;      0.5) (d) angle                  (1.146°;  26.565°)  Here are the calculation example of the figures shown in the "Straight edge" section (a) Gradient     200 : 3000 = 1 : x     x = 15     Gradient = 1 :15 (b) Decimal fraction 200/3000 = 0.066666     Fraction = 0.0667 (c) Percentage multiply decimal fraction by 100                      0.06666 × 100 = 0.06666            Percentage = 6.667% (d) Angle in degree inverse tan-function rise over run (tan-1 function on calculator)          tan a = 200/3000 = 0.06666                     a = 3.814° Distance measurement methods For measuring a distance we use steel or fibre glass tapes as shown in the opposite figure. They are available in 30 metre and 50 metre length. A more sophisticated method is to use the Electronic Distance Measuring (EDM). We will not use this method. EDM devices use electromagnetic waves, infrared waves, or lasers to measure distances precisely. Approximate (fairly accurate) distance measurement method is 'pacing' or using the 'stadia lines' on the reticle of the level Pacing Don't try to pace out one metre with every step. Walk casually over 50 or better 100 metre counting the number of steps. Work out the length of a casual step and use this instead. The longer the walking distance the more accurate is the step measurement. Example If it takes you 65 steps to walk 50 metres; then your step is 50/65 = 0.77 metre. If you would waked 39 steps, then the distance is 39 x 0.77 = 30 m. Stadia lines The stadia lines on the reticle can be used for simple distance measurement. The distances intercepted on the vertically-held rod between two stadia hairs seen in the eyepiece gives the distance. Just multiply the difference on the rod between the top and bottom stadia lines by 100* as shown in the figure below. In the example above the distance between the top and bottom stadia hair is 62 mm. Therefore, the distance to the staff is 62 × 100 = 6200 mm or 6,2 metres. * The 100 figure should be checked before beginning any survey by measuring the known distance with a tape. Surveyors usually use total stations for land surveying. A total stations is a combination of an electronic theodolite (transit), and electronic distance measuring device (EDM). Other accessories Optical square Range Pole Opticle Square and Range Poles are used in surveying course No W5939 Change Plate - a small flat metal plate with a raised point in the centre that is used to support the staff on the ground. The plate is firmly embedded into the ground to stop the staff from subsiding. There are various types of staff bubbles available to assist in keeping the staff in an upright position. You will need pegs or stakes and hammer for Project 4 (Grid points for RL's) All can be borrowed from the surveying department.

What are the Roles and Responsibilities of a Civil Engineer?

What are the Roles and Responsibilities of a Civil Engineer?

What is a civil engineer do?

Civil engineers design, build, supervise, operate, and maintain construction projects and systems in the public and private sector, including roads, buildings, airports, tunnels, dams, bridges, and systems for water supply and sewage treatment. Many civil engineers work in design, construction, research, and education.

Civil Engineering incorporates a broad range of different job roles. From the construction of highways and buildings to dams, tunnels, bridges and other smaller facilities the role and responsibility of civil engineers is vast.
The two crucial aspects within this field are consulting engineering and contracting engineering. Consulting engineers design a specific project whereas contracting engineers manage the physical construction and play a significant role in transforming the proposed development into architecture.
Civil engineering further encompasses a number of other specialisations, each of which is essential for successful completion of the structure. The key roles and responsibilities of the civil engineer are as listed below.
The first, and most important, responsibility is to analyse the site location and the surrounding area. This includes a search and investigation, verifying its feasibility for construction purposes.
The second is to design a plan, outlining the key variables and what needs to be changed prior to the construction.

The third role and responsibility of civil engineer is to develop a detailed design layout, keeping the requirements of the client in mind. The design and any subsequent reports need to be reviewed and approved, and any potential risks and challenges of the project identified.
Following the completion of this tender the proposal will need to be submitted to those officials that supervise the tendering process, ensuring that all rules, regulations and guidelines are fulfilled. It’s paramount that all safety measures are met whilst the project is being undertaken.
Whilst the project is underway it is the responsibility of the civil engineer to monitor the staff onsite. They must keep an open dialogue with architects, consultants and subcontractors. Should any issues arise, they have the responsibility of resolving them.
Wherever possible all construction work should be completed within budget and to the agreed timescale. The responsibility of scheduling the work, ensuring that sound organisational skills are employed and that all the raw materials are present also lies with a civil engineer.
A civil engineer plays a pivotal role in the effective execution of all manner of engineering projects. Their input, and leadership where necessary is essential to secure the smooth execution of a vast selection of projects.

History of Civil Engineering

History of Civil Engineering:

It is difficult to determine the history of emergence and beginning of civil engineering, however, that the history of civil engineering is a mirror of the history of human beings on this earth. Man used the old shelter caves to protect themselves of weather and harsh environment, and used a tree trunk to cross the river, which being the demonstration of ancient age civil engineering.
Civil Engineering has been an aspect of life since the beginnings of human existence. The earliest practices of Civil engg may have commenced between 4000 and 2000 BC in Ancient Egypt and Mesopotamia (Ancient Iraq) when humans started to abandon a nomadic existence, thus causing a need for the construction of shelter. During this time, transportation became increasingly important leading to the development of the wheel and sailing.
Until modern times there was no clear distinction between civil engg and architecture, and the term engineer and architect were mainly geographical variations referring to the same person, often used interchangeably. The construction of Pyramids in Egypt (circa 2700-2500 BC) might be considered the first instances of large structure constructions.
Around 2550 BC, Imhotep, the first documented engineer, built a famous stepped pyramid for King Djoser located at Saqqara Necropolis. With simple tools and mathematics he created a monument that stands to this day. His greatest contribution to engineering was his discovery of the art of building with shaped stones. Those who followed him carried engineering to remarkable heights using skill and imagination.
Ancient historic civil engineering constructions include the Qanat water management system (the oldest older than 3000 years and longer than 71 km,) the Parthenon by Iktinos in Ancient Greece (447-438 BC), the Appian Way by Roman engineers (c. 312 BC), the Great Wall of China by General Meng T’ien under orders from Ch’in Emperor Shih Huang Ti (c. 220 BC) and the stupas constructed in ancient Sri Lanka like the Jetavanaramaya and the extensive irrigation works in Anuradhapura. The Romans developed civil structures throughout their empire, including especially aqueducts, insulae, harbours, bridges, dams and roads.
Other remarkable historical structures are Sennacherib's Aqueduct at Jerwan built in 691 BC; Li Ping's irrigation projects in China (around 220 BC); Julius Caesar's Bridge over the Rhine River built in 55 BC, numerous bridges built by other Romans in and around Rome(e.g. the pons Fabricius); Pont du Gard (Roman Aqueduct, Nimes, France) built in 19 BC; the extensive system of highways the Romans built to facilitate trading and (more importantly) fast manoeuvring of legions; extensive irrigation system constructed by the Hohokam Indians, Salt River, AZ around 600 AD; first dykes defending against high water in Friesland, The Netherlands around 1000 AD; El Camino Real - The Royal Road, Eastern Branch, TX and Western Branch, NM (1500s AD).
Machu Picchu, Peru, built at around 1450, at the height of the Inca Empire is considered an engineering marvel. It was built in the Andes Mountains assisted by some of history’s most ingenious water resource engineers. The people of Machu Picchu built a mountain top city with running water, drainage systems, food production and stone structures so advanced that they endured for over 500years.
A treatise on Architecture, Book called Vitruvius' De Archiectura, was published at 1AD in Rome and survived to give us a look at engineering education in ancient times. It was probably written around 15 BC by the Roman architect Vitruvius and dedicated to his patron, the emperor Caesar Augustus, as a guide for building projects.
Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stonemasons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and seldom supplanted by advances. Structures, roads and infrastructure that existed were repetitive, and increases in scale were incremental.
One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering is the work of Archimedes in the 3rd century BC, including Archimedes Principle, which underpins our understanding of buoyancy, and practical solutions such as Archimedes’ screw. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation (volume) computations.

Educational & Institutional history of civil engineering

In the 18th century, the term civil engineering was coined to incorporate all things civilian as opposed to military engineering. The first engineering school, The National School of Bridges and Highways, France, was opened in 1747. The first self-proclaimed civil engineer was John Smeaton who constructed the Eddystone Lighthouse. In 1771, Smeaton and some of his colleagues formed the Smeatonian Society of Civil Engineers, a group of leaders of the profession who met informally over dinner. Though there was evidence of some technical meetings, it was little more than a social society.
In 1818, world’s first engineering society, the Institution of Civil Engineers was founded in London, and in 1820 the eminent engineer Thomas Telford became its first president. The institution received a Royal Charter in 1828, formally recognizing civil engineering as a profession. Its charter defined civil engineering as: “Civil engineering is the application of physical and scientific principles, and its history is intricately linked to advances in understanding of physics and mathematics throughout history. Because civil engineering is a wide ranging profession, including several separate specialized sub-disciplines, its history is linked to knowledge of structures, material science, geography, geology, soil, hydrology, environment, mechanics and other fields.”

The first private college to teach Civil Engineering in the United States was Norwich University founded in 1819 by Captain Alden Partridge. The first degree in Civil Engineering in the United States was awarded by Rensselaer Polytechnic Institute in 1835. The first such degree to be awarded to a woman was granted by Cornell University to Nora Stanton Blatch in 1905.

LESSON NOTE ON DEFINITIONS OF TERMS IN SURVEY

DEFINITIONS OF TERMS

 

levelling is the term applied to any method of measuring directly with a graduated staff the difference in elevation between two or more points.

Precise levelling is a particularly accurate method of differential levelling which uses highly accurate levels and with a more rigorous observing procedure than general engineering levelling. It aims to achieve high orders of accuracy such as 1 mm per 1 km traverse.

A level surface is a surface which is everywhere perpendicular to the direction of the force of gravity. An example is the surface of a completely still lake. For ordinary levelling, level surfaces at different elevations can be considered to be parallel.

A level datum is an arbitrary level surface to which elevations are referred. The most common surveying datum is mean sea-level (MSL), but as hydrological work is usually just concerned with levels in a local area, we often use:

An assumed datum, which is established by giving a benchmark an assumed value (e.g. 100.000 m) to which all levels in the local area will be reduced. It is not good practice to assume a level which is close to the actual MSL value, as it creates potential for confusion.

A reduced level is the vertical distance between a survey point and the adopted level datum.

A bench mark (BM) is the term given to a definite, permanent accessible point of known height above a datum to which the height of other points can be referred.

It is usually a stainless steel pin embedded in a substantial concrete block cast into the ground. At hydrological stations rock bolts driven into bedrock or concrete structures can be used, but structures should be used warily as they themselves are subject to settlement. The locations of benchmarks shall be marked with BM marker posts and/or paint, and recorded on the Station History Form.

A set-up refers the position of a level or other instrument at the time in which a number of observations are made without mooring the instrument. The first observation is made to the known point and is termed a backsight; the last observation is to the final point or the next to be measured on the run, and all other points are intermediates.

A run is the levelling between two or more points measured in one direction only. The outward run is from known to unknown points and the return run is the check levelling in the opposite direction.

A close is the difference between the starting level of the initial point for the outward run and that determined at the end of the return run. If the levels have been reduced correctly this value should be the same as the difference between the sum of the rises and falls and also the difference between the sum of the backsights and foresights.

Height of Collimation is the elevation of the optical axis of the telescope at the time of the setup. The line of collimation is the imaginary line at the elevation.

Orders of levelling refer to the quality of the levelling, usually being defined by the expected maximum closing error. These are given in Table 1

 Order                   Purpose                                              Maximum close (m)

Precision order      Deformation surveys                        0.001 x km 

First order              Major levelling control                    0.003 x km

Second order          Minor levelling control                   0.007 x km

Third order            Levelling for construction                0.012 x km 

Table 1 Levelling 

The accuracy requirements for water-level stations relate to the standards; for further information refer to section 1.

Change points are points of measurement which are used to carry the measurements forward in a run. Each one will be read first as a foresight, the instrument position is changed, and then it will be read as a backsight.