Introduction Of Surveying

Surveying

Surveying is the art of making suitable measurements in horizontal or vertical planes. This is one of the important subjects of civil engineering. Without taking a survey of the plot where the construction is to be carried out, the work cannot begin.

Surveying Chart

Levelling

Levelling is the art of representing relative positions in the vertical plane of different points on the earth’s surface.

It helps in determining the areas that are to be levelled to achieve a certain slope.

Principles of Surveying

All the surveys that are conducted are based on two fundamental principles. They are as follows:

1. Working from whole to part
2. Fixing a point with reference to two fixed points

Working from whole to part

In order to localize errors and prevent their accumulation, a set of control points is always established with great precision first for the whole area to be surveyed.

Later on, details or filled in between these control points to a relatively smaller precision.

This fundamental work principle is known as “Working from whole to part”.

Fixing a point with reference to two fixed points

Survey stations are fixed by atleast two measurements, either both linear or angular measurements or linear and angular measurements from two control points.

Let A and B be two control points. Another point C can be located by any of the following methods:

By two distances AC and BC

The point C is plotted by intersection of arc taking AC and BC as radius and with centres A and B.

Two Distances Method

By perpendicular distance CD and distance AD

Perpendicular distances Method

By angle <CAB and distance AC

Angle Method

By the angles BAC and ABC

Two Angles Method

By the <ABC and distance AC

Arc and Angle Method

Types of Bearings

Types of Bearings 

It is an angle made by the survey line with reference to some fixed meridian.

Bearings are classified into three types:

1. True bearing
2. Magnetic bearing
3. Arbitrary Bearing

True bearing

The angle made by a survey line with reference to the meridian is known as true bearing. It always remains constant.

Magnetic bearing

The angle made by a survey line with respect to magnetic meridian is known as magnetic bearing. It changes from place to place.

Arbitrary Bearing

The angle made by the survey line with reference to arbitrary meridian is known as Arbitrary Bearing.

Designation of Bearings

1. Whole circle bearing
2. Reduced Bearing (RB) or quadrantal bearing (QB)
3. Fore Bearing (FB) or forward bearing (FB)
4. Back bearing or Backward bearing (BB)
5. Calculated bearing

Designation of Bearings | Guide to Compass Surveying

In my previous article, I discussed different types of Bearings in Compass Surveying. In this article, we will discuss in brief different designations given to the bearings depending on measurement of angles.

Designation of Bearings

1. Whole circle bearing
2. Reduced Bearing (RB) or quadrantal bearing (QB)
3. Fore Bearing (FB) or forward bearing (FB)
4. Back bearing or Backward bearing (BB)
5. Calculated bearing

Whole Circle bearing

Bearings measured from north in a clockwise direction is termed as whole circle bearing.

The value varies from 0 degrees to 360 degrees.

Reduced bearing/Quadrantal bearing

The bearings measured either from the north or from the south towards east or west whichever is nearer is known as reduced bearing.

The values vary from 0 degrees to 90 degrees for a particular quadrant.

It is also known as quadrantal bearing (QB).

Fore Bearing (FB)

The bearings measured in the progress of surveying i.e. in the forward direction of survey lines is known as forebearing or forward bearing.

Back Bearing (BB)

The bearings measured in opposite to the progress of surveying i.e. in backward direction of survey line is known as Backward Bearing.

Observed Bearing

The bearings taken in a field with an instrument is known as Observed Bearing.

Calculated Bearing

The bearings calculated from the field observation is known as calculated bearing.

10 TIPS FOR SUCCESS FOR ENGINEERING STUDENTS

origanlly published in usnews.com

"Where According to a recent survey by the Higher Education Research Institute at UCLA, one third of college freshmen plan to major in science and engineering, while about 8 percent of all first-year students intend to concentrate in engineering proper. Some of these engineering students are destined to land major leadership roles in the United States and worldwide, while others are . . . well, every field has its "lesser lights."

We were interested in finding out what current engineering students could do to put themselves on the fast track to career success. We invited visiting blogger Edward Crawley, professor of engineering and director of the Bernard M. Gordon Engineering Leadership Program at MIT, to share with us the advice he gives his own undergraduate engineering students. Here are his best tips, most of which would work for any career-aspiring college student:

1. Identify the people who inspire you, and find out what makes them tick. If you love Apple products, Steve Jobs may be your idol, or perhaps you love the Segway and its creator, Dean Kamen. You can easily find out a lot of information about Jobs and Kamen—or just about any other prominent person in technology—so use it to look into what's helped these people and their companies become so successful. Then emulate their good traits in your personal, scholastic, and professional life.

2. Develop a portfolio of projects. Participate in every hands-on, experiential learning opportunity that a balanced schedule allows. This way, you'll have something unique to show a prospective employer (or venture capitalist) when you graduate, while other students will only be able to list their courses. In addition, you'll be far more likely to retain the knowledge you've gained in classes because you'll be applying it and, in the process, boosting your communication and interpersonal skills.

3. Learn the value of networking. When it comes to being a leader, whom you know is almost as important as what you know. Attend lectures on your campus and introduce yourself to the speakers. Check with your school's alumni association to get a list of alumni from your program who want to connect with undergraduates.

4-Star Tip. In addition to E-mail, you can use LinkedIn or other social media tools to connect online. But remember: There's no substitute for a traditional, face-to-face meeting, so if you can find a way to meet in person, that's always the best.

4. Work in teams as much as you can. Whether it's creating a solar-powered car, participating in a sport, or writing for the school paper, get involved with an organization that requires a team effort to produce great results. Throughout your career, you can be sure you'll work in teams, and the skills you develop in school will help prepare you to lead teams when you graduate.

5. Seek informal leadership roles. You're always a leader, whether you're officially in charge of a team or not. Sounds counterintuitive, but you can lead from any position in an organization by influencing how people work together and how they make decisions. Usually people think that the leader is the president or the manager, but if you learn how to recognize and deal with various leadership styles from any position in a team, you'll be seen as a leader when you take on your first job or internship.

6. Find your flaws—and fix them. As with any skill, leadership needs constant improvement. When you are part of a team, try to create a way to get feedback from team members, group leaders, and professors. When you have concrete feedback on how people view you, you can work to improve your skills, including communication and leadership. Plus, you'll learn how to accept—and give—constructive criticism. That's absolutely necessary for your future career.

7. Take a business class. As an engineer, it's not enough for you to be technically proficient; you need to have business savvy. If you're going to be a leader, you need to understand what a P&L is (also known as an income statement), read organization charts, know how to negotiate contracts, and be familiar with the myriad other functions that every top engineer needs to know. Otherwise, you won't understand what to do when an accountant, lawyer, or middle manager gets in the way. A business course or two can take you a long way, and these classes are often easier to pass than your calculus course!

8. Take design and other humanities classes. There's a wide world out there beyond problem sets, laboratories, and theory. Take a visual design course so you'll learn to represent ideas graphically. Take a cognitive science course to learn how people interpret the world and understand it. Take a literature course to develop your knowledge and appreciation of the classic books, which will help you write and communicate more effectively.

5-Star Tip. Tomorrow's leaders will have to communicate effectively across international borders and be familiar with other cultures, so develop some proficiency in another language, travel abroad, or meet students from other cultures. Start "globalizing" right at college.

9. Make your summers productive. Employers place tremendous value on practical experience. Seek out internship opportunities actively and early in your academic career. Try to demonstrate through your internships a series of evolving leadership experiences, and use the internships to build your portfolio of actual projects/products. New graduates who can show a commitment to using their summer to continue to learn are always viewed more seriously by a prospective employer.

10. Recruit and develop your personal b oard of d irectors. As an undergraduate, you might feel alone when confronted with hard decisions about the courses to take, jobs to apply for, or even balancing school work and your personal life. You won't feel alone if you develop a personal board of directors just for you. Just as a company has a board that guides the organization, you can stock your board with professionals from organizations and companies, as well as former teachers and knowledgeable family friends.

Extra Pointer. Be sure to "nurture" your board of directors: Keep in touch with them, provide them regular updates, ask them for guidance, and be sure to thank them for any help they provide. And don't be afraid of conflicting advice. If members offer different suggestions, you'll have the occasion to balance off one idea against another and make your own decision—just like at a real company

Chaining On Sloping Ground

Direct Method of Chain Surveying

This method is also known as “Stepping Method”.

The horizontal distances are directly measured by the process of stepping.

Procedure

A path of chain or tape is stretched out from ‘P’.

The path length of chain or tape depends on the steepness of the ground.

The follower holds the zero end of the chain at ‘P’ and directs the leader at P1 to be in the line of PQ and stretch the chain or tape above the ground in horizontal line.

Direct Method | Chain Surveying

The leader then transfers the point ‘P1’ to P2 on the ground by means of plumb bob or dropping a pebble or an arrow,

Now the followers take the new position ‘P2’ and directs the leader to move forward and stretch the tape or chain in a line of PQ.

Now the followers take the new position ‘P2’ and directs the leader to move forward and stretch the tape or chain in a line of PQ and the new position is P3.

Again the leader transfers the point P3 to P4 on the ground as done earlier.

This process is repeated till the point Q is reached.

Horizontal distance PQ = S1 + S2 + S3 + S4 + S5

Optical Square

Optical Square It is more accurate than the cross staff and it can be used for locating objects situated at larger distances. It is small and compact hand instrument (Fig.8) and works on the principle of reflection. Generally it is a round brass box about 5 cm in diameter and 1.25 cm deep. There is also a metal cover to protect it from dust, moisture etc. As shown in fig. 8, it consists of horizontal mirror (H) and index mirror (1) placed at an angle of 450 to each other. The mirror H is half silvered and the upper half is plain while the mirror I is fully silvered. There are three openings a, b and c on the sides. Let AB is the chain line and it is required to locate an object O during the process of surveying. The optical square is held in such a manner that a ray of light from object O passes through slot c, strikes the mirror, gets reflected and strikes the silvered portion of the mirror H. After being reflected from H, the ray passes through the pin hole and becomes visible to the eye. The observer looking through the hole a can directly see the ranging rod at B through the un-silvered portion of the mirror H and he image of the ranging rod placed at O. Thus when both the ranging rods coincide, the line OD becomes perpendicular to the chain line. If they do not coincide, the optical square has to move back and forth to get the correct position of D.